===================================================================
@@ -140,6 +140,7 @@ only one of these two forms, whichever o
* Warning Options:: How picky should the compiler be?
* Debugging Options:: Symbol tables, measurements, and debugging dumps.
* Optimize Options:: How much optimization?
+* Instrumentation Options:: Enabling profiling and extra run-time error checking.
* Preprocessor Options:: Controlling header files and macro definitions.
Also, getting dependency information for Make.
* Assembler Options:: Passing options to the assembler.
@@ -203,8 +204,6 @@ in the following sections.
-fno-threadsafe-statics -fuse-cxa-atexit @gol
-fno-weak -nostdinc++ @gol
-fvisibility-inlines-hidden @gol
--fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]} @gol
--fvtv-counts -fvtv-debug @gol
-fvisibility-ms-compat @gol
-fext-numeric-literals @gol
-Wabi=@var{n} -Wabi-tag -Wconversion-null -Wctor-dtor-privacy @gol
@@ -316,18 +315,6 @@ Objective-C and Objective-C++ Dialects}.
@item Debugging Options
@xref{Debugging Options,,Options for Debugging Your Program or GCC}.
@gccoptlist{-d@var{letters} -dumpspecs -dumpmachine -dumpversion @gol
--fsanitize=@var{style} -fsanitize-recover -fsanitize-recover=@var{style} @gol
--fasan-shadow-offset=@var{number} -fsanitize-sections=@var{s1},@var{s2},... @gol
--fsanitize-undefined-trap-on-error @gol
--fcheck-pointer-bounds -fchecking -fchkp-check-incomplete-type @gol
--fchkp-first-field-has-own-bounds -fchkp-narrow-bounds @gol
--fchkp-narrow-to-innermost-array -fchkp-optimize @gol
--fchkp-use-fast-string-functions -fchkp-use-nochk-string-functions @gol
--fchkp-use-static-bounds -fchkp-use-static-const-bounds @gol
--fchkp-treat-zero-dynamic-size-as-infinite -fchkp-check-read @gol
--fchkp-check-read -fchkp-check-write -fchkp-store-bounds @gol
--fchkp-instrument-calls -fchkp-instrument-marked-only @gol
--fchkp-use-wrappers @gol
-fdbg-cnt-list -fdbg-cnt=@var{counter-value-list} @gol
-fdisable-ipa-@var{pass_name} @gol
-fdisable-rtl-@var{pass_name} @gol
@@ -370,12 +357,13 @@ Objective-C and Objective-C++ Dialects}.
-fenable-@var{kind}-@var{pass} @gol
-fenable-@var{kind}-@var{pass}=@var{range-list} @gol
-fdebug-types-section -fmem-report-wpa @gol
--fmem-report -fpre-ipa-mem-report -fpost-ipa-mem-report -fprofile-arcs @gol
+-fmem-report -fpre-ipa-mem-report -fpost-ipa-mem-report @gol
-fopt-info @gol
-fopt-info-@var{options}@r{[}=@var{file}@r{]} @gol
+-fprofile-report @gol
-frandom-seed=@var{string} -fsched-verbose=@var{n} @gol
-fsel-sched-verbose -fsel-sched-dump-cfg -fsel-sched-pipelining-verbose @gol
--fstack-usage -ftest-coverage -ftime-report -fvar-tracking @gol
+-fstack-usage -ftime-report -fvar-tracking @gol
-fvar-tracking-assignments -fvar-tracking-assignments-toggle @gol
-g -g@var{level} -gtoggle -gcoff -gdwarf-@var{version} @gol
-ggdb -grecord-gcc-switches -gno-record-gcc-switches @gol
@@ -385,7 +373,7 @@ Objective-C and Objective-C++ Dialects}.
-fdebug-prefix-map=@var{old}=@var{new} @gol
-femit-struct-debug-baseonly -femit-struct-debug-reduced @gol
-femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} @gol
--p -pg -print-file-name=@var{library} -print-libgcc-file-name @gol
+-print-file-name=@var{library} -print-libgcc-file-name @gol
-print-multi-directory -print-multi-lib -print-multi-os-directory @gol
-print-prog-name=@var{program} -print-search-dirs -Q @gol
-print-sysroot -print-sysroot-headers-suffix @gol
@@ -435,9 +423,8 @@ Objective-C and Objective-C++ Dialects}.
-fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss @gol
-fomit-frame-pointer -foptimize-sibling-calls @gol
-fpartial-inlining -fpeel-loops -fpredictive-commoning @gol
--fprefetch-loop-arrays -fprofile-report @gol
--fprofile-correction -fprofile-dir=@var{path} -fprofile-generate @gol
--fprofile-generate=@var{path} @gol
+-fprefetch-loop-arrays @gol
+-fprofile-correction @gol
-fprofile-use -fprofile-use=@var{path} -fprofile-values @gol
-fprofile-reorder-functions @gol
-freciprocal-math -free -frename-registers -freorder-blocks @gol
@@ -458,8 +445,7 @@ Objective-C and Objective-C++ Dialects}.
-fsingle-precision-constant -fsplit-ivs-in-unroller @gol
-fsplit-paths @gol
-fsplit-wide-types -fssa-backprop -fssa-phiopt @gol
--fstack-protector -fstack-protector-all -fstack-protector-strong @gol
--fstack-protector-explicit -fstdarg-opt -fstrict-aliasing @gol
+-fstdarg-opt -fstrict-aliasing @gol
-fstrict-overflow -fthread-jumps -ftracer -ftree-bit-ccp @gol
-ftree-builtin-call-dce -ftree-ccp -ftree-ch @gol
-ftree-coalesce-vars -ftree-copy-prop -ftree-dce -ftree-dominator-opts @gol
@@ -479,6 +465,32 @@ Objective-C and Objective-C++ Dialects}.
--param @var{name}=@var{value}
-O -O0 -O1 -O2 -O3 -Os -Ofast -Og}
+@item Program Instrumentation Options
+@xref{Instrumentation Options,,Program Instrumentation Options}.
+@gccoptlist{-p -pg -fprofile-arcs --coverage -ftest-coverage @gol
+-fprofile-dir=@var{path} -fprofile-generate -fprofile-generate=@var{path} @gol
+-fsanitize=@var{style} -fsanitize-recover -fsanitize-recover=@var{style} @gol
+-fasan-shadow-offset=@var{number} -fsanitize-sections=@var{s1},@var{s2},... @gol
+-fsanitize-undefined-trap-on-error -fbounds-check @gol
+-fcheck-pointer-bounds -fchecking -fchkp-check-incomplete-type @gol
+-fchkp-first-field-has-own-bounds -fchkp-narrow-bounds @gol
+-fchkp-narrow-to-innermost-array -fchkp-optimize @gol
+-fchkp-use-fast-string-functions -fchkp-use-nochk-string-functions @gol
+-fchkp-use-static-bounds -fchkp-use-static-const-bounds @gol
+-fchkp-treat-zero-dynamic-size-as-infinite -fchkp-check-read @gol
+-fchkp-check-read -fchkp-check-write -fchkp-store-bounds @gol
+-fchkp-instrument-calls -fchkp-instrument-marked-only @gol
+-fchkp-use-wrappers @gol
+-fstack-protector -fstack-protector-all -fstack-protector-strong @gol
+-fstack-protector-explicit fstack-check @gol
+-fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol
+-fno-stack-limit -fsplit-stack @gol
+-fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]} @gol
+-fvtv-counts -fvtv-debug @gol
+-finstrument-functions @gol
+-finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} @gol
+-finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{}}
+
@item Preprocessor Options
@xref{Preprocessor Options,,Options Controlling the Preprocessor}.
@gccoptlist{-A@var{question}=@var{answer} @gol
@@ -523,21 +535,16 @@ Objective-C and Objective-C++ Dialects}.
-fnon-call-exceptions -fdelete-dead-exceptions -funwind-tables @gol
-fasynchronous-unwind-tables @gol
-fno-gnu-unique @gol
--finhibit-size-directive -finstrument-functions @gol
--finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} @gol
--finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{} @gol
--fno-common -fno-ident @gol
+-finhibit-size-directive -fno-common -fno-ident @gol
-fpcc-struct-return -fpic -fPIC -fpie -fPIE -fno-plt @gol
-fno-jump-tables @gol
-frecord-gcc-switches @gol
-freg-struct-return -fshort-enums @gol
-fshort-double -fshort-wchar @gol
--fverbose-asm -fpack-struct[=@var{n}] -fstack-check @gol
--fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol
--fno-stack-limit -fsplit-stack @gol
+-fverbose-asm -fpack-struct[=@var{n}] @gol
-fleading-underscore -ftls-model=@var{model} @gol
-fstack-reuse=@var{reuse_level} @gol
--ftrapv -fwrapv -fbounds-check @gol
+-ftrapv -fwrapv @gol
-fvisibility=@r{[}default@r{|}internal@r{|}hidden@r{|}protected@r{]} @gol
-fstrict-volatile-bitfields -fsync-libcalls}
@@ -2537,61 +2544,6 @@ and that pointers to function members de
objects may not compare equal. When this flag is given, it is a
violation of the ODR to define types with the same name differently.
-@item -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]}
-@opindex fvtable-verify
-Turn on (or off, if using @option{-fvtable-verify=none}) the security
-feature that verifies at run time, for every virtual call, that
-the vtable pointer through which the call is made is valid for the type of
-the object, and has not been corrupted or overwritten. If an invalid vtable
-pointer is detected at run time, an error is reported and execution of the
-program is immediately halted.
-
-This option causes run-time data structures to be built at program startup,
-which are used for verifying the vtable pointers.
-The options @samp{std} and @samp{preinit}
-control the timing of when these data structures are built. In both cases the
-data structures are built before execution reaches @code{main}. Using
-@option{-fvtable-verify=std} causes the data structures to be built after
-shared libraries have been loaded and initialized.
-@option{-fvtable-verify=preinit} causes them to be built before shared
-libraries have been loaded and initialized.
-
-If this option appears multiple times in the command line with different
-values specified, @samp{none} takes highest priority over both @samp{std} and
-@samp{preinit}; @samp{preinit} takes priority over @samp{std}.
-
-@item -fvtv-debug
-@opindex fvtv-debug
-When used in conjunction with @option{-fvtable-verify=std} or
-@option{-fvtable-verify=preinit}, causes debug versions of the
-runtime functions for the vtable verification feature to be called.
-This flag also causes the compiler to log information about which
-vtable pointers it finds for each class.
-This information is written to a file named @file{vtv_set_ptr_data.log}
-in the directory named by the environment variable @env{VTV_LOGS_DIR}
-if that is defined or the current working directory otherwise.
-
-Note: This feature @emph{appends} data to the log file. If you want a fresh log
-file, be sure to delete any existing one.
-
-@item -fvtv-counts
-@opindex fvtv-counts
-This is a debugging flag. When used in conjunction with
-@option{-fvtable-verify=std} or @option{-fvtable-verify=preinit}, this
-causes the compiler to keep track of the total number of virtual calls
-it encounters and the number of verifications it inserts. It also
-counts the number of calls to certain run-time library functions
-that it inserts and logs this information for each compilation unit.
-The compiler writes this information to a file named
-@file{vtv_count_data.log} in the directory named by the environment
-variable @env{VTV_LOGS_DIR} if that is defined or the current working
-directory otherwise. It also counts the size of the vtable pointer sets
-for each class, and writes this information to @file{vtv_class_set_sizes.log}
-in the same directory.
-
-Note: This feature @emph{appends} data to the log files. To get fresh log
-files, be sure to delete any existing ones.
-
@item -fno-weak
@opindex fno-weak
Do not use weak symbol support, even if it is provided by the linker.
@@ -5954,403 +5906,6 @@ other options are processed, and it does
many times it is given. This is mainly intended to be used with
@option{-fcompare-debug}.
-@item -fsanitize=address
-@opindex fsanitize=address
-Enable AddressSanitizer, a fast memory error detector.
-Memory access instructions are instrumented to detect
-out-of-bounds and use-after-free bugs.
-See @uref{https://github.com/google/sanitizers/wiki/AddressSanitizer} for
-more details. The run-time behavior can be influenced using the
-@env{ASAN_OPTIONS} environment variable. When set to @code{help=1},
-the available options are shown at startup of the instrumended program. See
-@url{https://github.com/google/sanitizers/wiki/AddressSanitizerFlags#run-time-flags}
-for a list of supported options.
-
-@item -fsanitize=kernel-address
-@opindex fsanitize=kernel-address
-Enable AddressSanitizer for Linux kernel.
-See @uref{https://github.com/google/kasan/wiki} for more details.
-
-@item -fsanitize=thread
-@opindex fsanitize=thread
-Enable ThreadSanitizer, a fast data race detector.
-Memory access instructions are instrumented to detect
-data race bugs. See @uref{https://github.com/google/sanitizers/wiki#threadsanitizer} for more
-details. The run-time behavior can be influenced using the @env{TSAN_OPTIONS}
-environment variable; see
-@url{https://github.com/google/sanitizers/wiki/ThreadSanitizerFlags} for a list of
-supported options.
-
-@item -fsanitize=leak
-@opindex fsanitize=leak
-Enable LeakSanitizer, a memory leak detector.
-This option only matters for linking of executables and if neither
-@option{-fsanitize=address} nor @option{-fsanitize=thread} is used. In that
-case the executable is linked against a library that overrides @code{malloc}
-and other allocator functions. See
-@uref{https://github.com/google/sanitizers/wiki/AddressSanitizerLeakSanitizer} for more
-details. The run-time behavior can be influenced using the
-@env{LSAN_OPTIONS} environment variable.
-
-@item -fsanitize=undefined
-@opindex fsanitize=undefined
-Enable UndefinedBehaviorSanitizer, a fast undefined behavior detector.
-Various computations are instrumented to detect undefined behavior
-at runtime. Current suboptions are:
-
-@table @gcctabopt
-
-@item -fsanitize=shift
-@opindex fsanitize=shift
-This option enables checking that the result of a shift operation is
-not undefined. Note that what exactly is considered undefined differs
-slightly between C and C++, as well as between ISO C90 and C99, etc.
-
-@item -fsanitize=integer-divide-by-zero
-@opindex fsanitize=integer-divide-by-zero
-Detect integer division by zero as well as @code{INT_MIN / -1} division.
-
-@item -fsanitize=unreachable
-@opindex fsanitize=unreachable
-With this option, the compiler turns the @code{__builtin_unreachable}
-call into a diagnostics message call instead. When reaching the
-@code{__builtin_unreachable} call, the behavior is undefined.
-
-@item -fsanitize=vla-bound
-@opindex fsanitize=vla-bound
-This option instructs the compiler to check that the size of a variable
-length array is positive.
-
-@item -fsanitize=null
-@opindex fsanitize=null
-This option enables pointer checking. Particularly, the application
-built with this option turned on will issue an error message when it
-tries to dereference a NULL pointer, or if a reference (possibly an
-rvalue reference) is bound to a NULL pointer, or if a method is invoked
-on an object pointed by a NULL pointer.
-
-@item -fsanitize=return
-@opindex fsanitize=return
-This option enables return statement checking. Programs
-built with this option turned on will issue an error message
-when the end of a non-void function is reached without actually
-returning a value. This option works in C++ only.
-
-@item -fsanitize=signed-integer-overflow
-@opindex fsanitize=signed-integer-overflow
-This option enables signed integer overflow checking. We check that
-the result of @code{+}, @code{*}, and both unary and binary @code{-}
-does not overflow in the signed arithmetics. Note, integer promotion
-rules must be taken into account. That is, the following is not an
-overflow:
-@smallexample
-signed char a = SCHAR_MAX;
-a++;
-@end smallexample
-
-@item -fsanitize=bounds
-@opindex fsanitize=bounds
-This option enables instrumentation of array bounds. Various out of bounds
-accesses are detected. Flexible array members, flexible array member-like
-arrays, and initializers of variables with static storage are not instrumented.
-
-@item -fsanitize=bounds-strict
-@opindex fsanitize=bounds-strict
-This option enables strict instrumentation of array bounds. Most out of bounds
-accesses are detected, including flexible array members and flexible array
-member-like arrays. Initializers of variables with static storage are not
-instrumented.
-
-@item -fsanitize=alignment
-@opindex fsanitize=alignment
-
-This option enables checking of alignment of pointers when they are
-dereferenced, or when a reference is bound to insufficiently aligned target,
-or when a method or constructor is invoked on insufficiently aligned object.
-
-@item -fsanitize=object-size
-@opindex fsanitize=object-size
-This option enables instrumentation of memory references using the
-@code{__builtin_object_size} function. Various out of bounds pointer
-accesses are detected.
-
-@item -fsanitize=float-divide-by-zero
-@opindex fsanitize=float-divide-by-zero
-Detect floating-point division by zero. Unlike other similar options,
-@option{-fsanitize=float-divide-by-zero} is not enabled by
-@option{-fsanitize=undefined}, since floating-point division by zero can
-be a legitimate way of obtaining infinities and NaNs.
-
-@item -fsanitize=float-cast-overflow
-@opindex fsanitize=float-cast-overflow
-This option enables floating-point type to integer conversion checking.
-We check that the result of the conversion does not overflow.
-Unlike other similar options, @option{-fsanitize=float-cast-overflow} is
-not enabled by @option{-fsanitize=undefined}.
-This option does not work well with @code{FE_INVALID} exceptions enabled.
-
-@item -fsanitize=nonnull-attribute
-@opindex fsanitize=nonnull-attribute
-
-This option enables instrumentation of calls, checking whether null values
-are not passed to arguments marked as requiring a non-null value by the
-@code{nonnull} function attribute.
-
-@item -fsanitize=returns-nonnull-attribute
-@opindex fsanitize=returns-nonnull-attribute
-
-This option enables instrumentation of return statements in functions
-marked with @code{returns_nonnull} function attribute, to detect returning
-of null values from such functions.
-
-@item -fsanitize=bool
-@opindex fsanitize=bool
-
-This option enables instrumentation of loads from bool. If a value other
-than 0/1 is loaded, a run-time error is issued.
-
-@item -fsanitize=enum
-@opindex fsanitize=enum
-
-This option enables instrumentation of loads from an enum type. If
-a value outside the range of values for the enum type is loaded,
-a run-time error is issued.
-
-@item -fsanitize=vptr
-@opindex fsanitize=vptr
-
-This option enables instrumentation of C++ member function calls, member
-accesses and some conversions between pointers to base and derived classes,
-to verify the referenced object has the correct dynamic type.
-
-@end table
-
-While @option{-ftrapv} causes traps for signed overflows to be emitted,
-@option{-fsanitize=undefined} gives a diagnostic message.
-This currently works only for the C family of languages.
-
-@item -fno-sanitize=all
-@opindex fno-sanitize=all
-
-This option disables all previously enabled sanitizers.
-@option{-fsanitize=all} is not allowed, as some sanitizers cannot be used
-together.
-
-@item -fasan-shadow-offset=@var{number}
-@opindex fasan-shadow-offset
-This option forces GCC to use custom shadow offset in AddressSanitizer checks.
-It is useful for experimenting with different shadow memory layouts in
-Kernel AddressSanitizer.
-
-@item -fsanitize-sections=@var{s1},@var{s2},...
-@opindex fsanitize-sections
-Sanitize global variables in selected user-defined sections. @var{si} may
-contain wildcards.
-
-@item -fsanitize-recover@r{[}=@var{opts}@r{]}
-@opindex fsanitize-recover
-@opindex fno-sanitize-recover
-@option{-fsanitize-recover=} controls error recovery mode for sanitizers
-mentioned in comma-separated list of @var{opts}. Enabling this option
-for a sanitizer component causes it to attempt to continue
-running the program as if no error happened. This means multiple
-runtime errors can be reported in a single program run, and the exit
-code of the program may indicate success even when errors
-have been reported. The @option{-fno-sanitize-recover=} option
-can be used to alter
-this behavior: only the first detected error is reported
-and program then exits with a non-zero exit code.
-
-Currently this feature only works for @option{-fsanitize=undefined} (and its suboptions
-except for @option{-fsanitize=unreachable} and @option{-fsanitize=return}),
-@option{-fsanitize=float-cast-overflow}, @option{-fsanitize=float-divide-by-zero},
-@option{-fsanitize=kernel-address} and @option{-fsanitize=address}.
-For these sanitizers error recovery is turned on by default, except @option{-fsanitize=address},
-for which this feature is experimental.
-@option{-fsanitize-recover=all} and @option{-fno-sanitize-recover=all} is also
-accepted, the former enables recovery for all sanitizers that support it,
-the latter disables recovery for all sanitizers that support it.
-
-Syntax without explicit @var{opts} parameter is deprecated. It is equivalent to
-@smallexample
--fsanitize-recover=undefined,float-cast-overflow,float-divide-by-zero
-@end smallexample
-@noindent
-Similarly @option{-fno-sanitize-recover} is equivalent to
-@smallexample
--fno-sanitize-recover=undefined,float-cast-overflow,float-divide-by-zero
-@end smallexample
-
-@item -fsanitize-undefined-trap-on-error
-@opindex fsanitize-undefined-trap-on-error
-The @option{-fsanitize-undefined-trap-on-error} option instructs the compiler to
-report undefined behavior using @code{__builtin_trap} rather than
-a @code{libubsan} library routine. The advantage of this is that the
-@code{libubsan} library is not needed and is not linked in, so this
-is usable even in freestanding environments.
-
-@item -fsanitize-coverage=trace-pc
-@opindex fsanitize-coverage=trace-pc
-Enable coverage-guided fuzzing code instrumentation.
-Inserts call to __sanitizer_cov_trace_pc into every basic block.
-
-@item -fcheck-pointer-bounds
-@opindex fcheck-pointer-bounds
-@opindex fno-check-pointer-bounds
-@cindex Pointer Bounds Checker options
-Enable Pointer Bounds Checker instrumentation. Each memory reference
-is instrumented with checks of the pointer used for memory access against
-bounds associated with that pointer.
-
-Currently there
-is only an implementation for Intel MPX available, thus x86 target
-and @option{-mmpx} are required to enable this feature.
-MPX-based instrumentation requires
-a runtime library to enable MPX in hardware and handle bounds
-violation signals. By default when @option{-fcheck-pointer-bounds}
-and @option{-mmpx} options are used to link a program, the GCC driver
-links against the @file{libmpx} runtime library and @file{libmpxwrappers}
-library. It also passes '-z bndplt' to a linker in case it supports this
-option (which is checked on libmpx configuration). Note that old versions
-of linker may ignore option. Gold linker doesn't support '-z bndplt'
-option. With no '-z bndplt' support in linker all calls to dynamic libraries
-lose passed bounds reducing overall protection level. It's highly
-recommended to use linker with '-z bndplt' support. In case such linker
-is not available it is adviced to always use @option{-static-libmpxwrappers}
-for better protection level or use @option{-static} to completely avoid
-external calls to dynamic libraries. MPX-based instrumentation
-may be used for debugging and also may be included in production code
-to increase program security. Depending on usage, you may
-have different requirements for the runtime library. The current version
-of the MPX runtime library is more oriented for use as a debugging
-tool. MPX runtime library usage implies @option{-lpthread}. See
-also @option{-static-libmpx}. The runtime library behavior can be
-influenced using various @env{CHKP_RT_*} environment variables. See
-@uref{https://gcc.gnu.org/wiki/Intel%20MPX%20support%20in%20the%20GCC%20compiler}
-for more details.
-
-Generated instrumentation may be controlled by various
-@option{-fchkp-*} options and by the @code{bnd_variable_size}
-structure field attribute (@pxref{Type Attributes}) and
-@code{bnd_legacy}, and @code{bnd_instrument} function attributes
-(@pxref{Function Attributes}). GCC also provides a number of built-in
-functions for controlling the Pointer Bounds Checker. @xref{Pointer
-Bounds Checker builtins}, for more information.
-
-@item -fchecking
-@opindex fchecking
-@opindex fno-checking
-Enable internal consistency checking. The default depends on
-the compiler configuration.
-
-@item -fchkp-check-incomplete-type
-@opindex fchkp-check-incomplete-type
-@opindex fno-chkp-check-incomplete-type
-Generate pointer bounds checks for variables with incomplete type.
-Enabled by default.
-
-@item -fchkp-narrow-bounds
-@opindex fchkp-narrow-bounds
-@opindex fno-chkp-narrow-bounds
-Controls bounds used by Pointer Bounds Checker for pointers to object
-fields. If narrowing is enabled then field bounds are used. Otherwise
-object bounds are used. See also @option{-fchkp-narrow-to-innermost-array}
-and @option{-fchkp-first-field-has-own-bounds}. Enabled by default.
-
-@item -fchkp-first-field-has-own-bounds
-@opindex fchkp-first-field-has-own-bounds
-@opindex fno-chkp-first-field-has-own-bounds
-Forces Pointer Bounds Checker to use narrowed bounds for the address of the
-first field in the structure. By default a pointer to the first field has
-the same bounds as a pointer to the whole structure.
-
-@item -fchkp-narrow-to-innermost-array
-@opindex fchkp-narrow-to-innermost-array
-@opindex fno-chkp-narrow-to-innermost-array
-Forces Pointer Bounds Checker to use bounds of the innermost arrays in
-case of nested static array access. By default this option is disabled and
-bounds of the outermost array are used.
-
-@item -fchkp-optimize
-@opindex fchkp-optimize
-@opindex fno-chkp-optimize
-Enables Pointer Bounds Checker optimizations. Enabled by default at
-optimization levels @option{-O}, @option{-O2}, @option{-O3}.
-
-@item -fchkp-use-fast-string-functions
-@opindex fchkp-use-fast-string-functions
-@opindex fno-chkp-use-fast-string-functions
-Enables use of @code{*_nobnd} versions of string functions (not copying bounds)
-by Pointer Bounds Checker. Disabled by default.
-
-@item -fchkp-use-nochk-string-functions
-@opindex fchkp-use-nochk-string-functions
-@opindex fno-chkp-use-nochk-string-functions
-Enables use of @code{*_nochk} versions of string functions (not checking bounds)
-by Pointer Bounds Checker. Disabled by default.
-
-@item -fchkp-use-static-bounds
-@opindex fchkp-use-static-bounds
-@opindex fno-chkp-use-static-bounds
-Allow Pointer Bounds Checker to generate static bounds holding
-bounds of static variables. Enabled by default.
-
-@item -fchkp-use-static-const-bounds
-@opindex fchkp-use-static-const-bounds
-@opindex fno-chkp-use-static-const-bounds
-Use statically-initialized bounds for constant bounds instead of
-generating them each time they are required. By default enabled when
-@option{-fchkp-use-static-bounds} is enabled.
-
-@item -fchkp-treat-zero-dynamic-size-as-infinite
-@opindex fchkp-treat-zero-dynamic-size-as-infinite
-@opindex fno-chkp-treat-zero-dynamic-size-as-infinite
-With this option, objects with incomplete type whose
-dynamically-obtained size is zero are treated as having infinite size
-instead by Pointer Bounds
-Checker. This option may be helpful if a program is linked with a library
-missing size information for some symbols. Disabled by default.
-
-@item -fchkp-check-read
-@opindex fchkp-check-read
-@opindex fno-chkp-check-read
-Instructs Pointer Bounds Checker to generate checks for all read
-accesses to memory. Enabled by default.
-
-@item -fchkp-check-write
-@opindex fchkp-check-write
-@opindex fno-chkp-check-write
-Instructs Pointer Bounds Checker to generate checks for all write
-accesses to memory. Enabled by default.
-
-@item -fchkp-store-bounds
-@opindex fchkp-store-bounds
-@opindex fno-chkp-store-bounds
-Instructs Pointer Bounds Checker to generate bounds stores for
-pointer writes. Enabled by default.
-
-@item -fchkp-instrument-calls
-@opindex fchkp-instrument-calls
-@opindex fno-chkp-instrument-calls
-Instructs Pointer Bounds Checker to pass pointer bounds to calls.
-Enabled by default.
-
-@item -fchkp-instrument-marked-only
-@opindex fchkp-instrument-marked-only
-@opindex fno-chkp-instrument-marked-only
-Instructs Pointer Bounds Checker to instrument only functions
-marked with the @code{bnd_instrument} attribute
-(@pxref{Function Attributes}). Disabled by default.
-
-@item -fchkp-use-wrappers
-@opindex fchkp-use-wrappers
-@opindex fno-chkp-use-wrappers
-Allows Pointer Bounds Checker to replace calls to built-in functions
-with calls to wrapper functions. When @option{-fchkp-use-wrappers}
-is used to link a program, the GCC driver automatically links
-against @file{libmpxwrappers}. See also @option{-static-libmpxwrappers}.
-Enabled by default.
-
@item -fdump-final-insns@r{[}=@var{file}@r{]}
@opindex fdump-final-insns
Dump the final internal representation (RTL) to @var{file}. If the
@@ -6501,22 +6056,6 @@ information describing them as in @file{
Emit DWARF 2 unwind info as compiler generated @code{.eh_frame} section
instead of using GAS @code{.cfi_*} directives.
-@cindex @command{prof}
-@item -p
-@opindex p
-Generate extra code to write profile information suitable for the
-analysis program @command{prof}. You must use this option when compiling
-the source files you want data about, and you must also use it when
-linking.
-
-@cindex @command{gprof}
-@item -pg
-@opindex pg
-Generate extra code to write profile information suitable for the
-analysis program @command{gprof}. You must use this option when compiling
-the source files you want data about, and you must also use it when
-linking.
-
@item -Q
@opindex Q
Makes the compiler print out each function name as it is compiled, and
@@ -6582,83 +6121,6 @@ the function. If it is not present, the
not bounded at compile time and the second field only represents the
bounded part.
-@item -fprofile-arcs
-@opindex fprofile-arcs
-Add code so that program flow @dfn{arcs} are instrumented. During
-execution the program records how many times each branch and call is
-executed and how many times it is taken or returns. When the compiled
-program exits it saves this data to a file called
-@file{@var{auxname}.gcda} for each source file. The data may be used for
-profile-directed optimizations (@option{-fbranch-probabilities}), or for
-test coverage analysis (@option{-ftest-coverage}). Each object file's
-@var{auxname} is generated from the name of the output file, if
-explicitly specified and it is not the final executable, otherwise it is
-the basename of the source file. In both cases any suffix is removed
-(e.g.@: @file{foo.gcda} for input file @file{dir/foo.c}, or
-@file{dir/foo.gcda} for output file specified as @option{-o dir/foo.o}).
-@xref{Cross-profiling}.
-
-@cindex @command{gcov}
-@item --coverage
-@opindex coverage
-
-This option is used to compile and link code instrumented for coverage
-analysis. The option is a synonym for @option{-fprofile-arcs}
-@option{-ftest-coverage} (when compiling) and @option{-lgcov} (when
-linking). See the documentation for those options for more details.
-
-@itemize
-
-@item
-Compile the source files with @option{-fprofile-arcs} plus optimization
-and code generation options. For test coverage analysis, use the
-additional @option{-ftest-coverage} option. You do not need to profile
-every source file in a program.
-
-@item
-Link your object files with @option{-lgcov} or @option{-fprofile-arcs}
-(the latter implies the former).
-
-@item
-Run the program on a representative workload to generate the arc profile
-information. This may be repeated any number of times. You can run
-concurrent instances of your program, and provided that the file system
-supports locking, the data files will be correctly updated. Also
-@code{fork} calls are detected and correctly handled (double counting
-will not happen).
-
-@item
-For profile-directed optimizations, compile the source files again with
-the same optimization and code generation options plus
-@option{-fbranch-probabilities} (@pxref{Optimize Options,,Options that
-Control Optimization}).
-
-@item
-For test coverage analysis, use @command{gcov} to produce human readable
-information from the @file{.gcno} and @file{.gcda} files. Refer to the
-@command{gcov} documentation for further information.
-
-@end itemize
-
-With @option{-fprofile-arcs}, for each function of your program GCC
-creates a program flow graph, then finds a spanning tree for the graph.
-Only arcs that are not on the spanning tree have to be instrumented: the
-compiler adds code to count the number of times that these arcs are
-executed. When an arc is the only exit or only entrance to a block, the
-instrumentation code can be added to the block; otherwise, a new basic
-block must be created to hold the instrumentation code.
-
-@need 2000
-@item -ftest-coverage
-@opindex ftest-coverage
-Produce a notes file that the @command{gcov} code-coverage utility
-(@pxref{Gcov,, @command{gcov}---a Test Coverage Program}) can use to
-show program coverage. Each source file's note file is called
-@file{@var{auxname}.gcno}. Refer to the @option{-fprofile-arcs} option
-above for a description of @var{auxname} and instructions on how to
-generate test coverage data. Coverage data matches the source files
-more closely if you do not optimize.
-
@item -fdbg-cnt-list
@opindex fdbg-cnt-list
Print the name and the counter upper bound for all debug counters.
@@ -9838,31 +9300,6 @@ be inconsistent due to missed counter up
GCC uses heuristics to correct or smooth out such inconsistencies. By
default, GCC emits an error message when an inconsistent profile is detected.
-@item -fprofile-dir=@var{path}
-@opindex fprofile-dir
-
-Set the directory to search for the profile data files in to @var{path}.
-This option affects only the profile data generated by
-@option{-fprofile-generate}, @option{-ftest-coverage}, @option{-fprofile-arcs}
-and used by @option{-fprofile-use} and @option{-fbranch-probabilities}
-and its related options. Both absolute and relative paths can be used.
-By default, GCC uses the current directory as @var{path}, thus the
-profile data file appears in the same directory as the object file.
-
-@item -fprofile-generate
-@itemx -fprofile-generate=@var{path}
-@opindex fprofile-generate
-
-Enable options usually used for instrumenting application to produce
-profile useful for later recompilation with profile feedback based
-optimization. You must use @option{-fprofile-generate} both when
-compiling and when linking your program.
-
-The following options are enabled: @option{-fprofile-arcs}, @option{-fprofile-values}, @option{-fvpt}.
-
-If @var{path} is specified, GCC looks at the @var{path} to find
-the profile feedback data files. See @option{-fprofile-dir}.
-
@item -fprofile-use
@itemx -fprofile-use=@var{path}
@opindex fprofile-use
@@ -9873,6 +9310,10 @@ which are generally profitable only with
@option{-funroll-loops}, @option{-fpeel-loops}, @option{-ftracer},
@option{-ftree-vectorize}, and @option{ftree-loop-distribute-patterns}.
+Before you can use this option, you must first generate profiling information.
+@xref{Optimize Options}, for information about the @option{-fprofile-generate}
+option.
+
By default, GCC emits an error message if the feedback profiles do not
match the source code. This error can be turned into a warning by using
@option{-Wcoverage-mismatch}. Note this may result in poorly optimized
@@ -10156,8 +9597,8 @@ section includes experimental options th
@item -fbranch-probabilities
@opindex fbranch-probabilities
After running a program compiled with @option{-fprofile-arcs}
-(@pxref{Debugging Options,, Options for Debugging Your Program or
-@command{gcc}}), you can compile it a second time using
+(@pxref{Instrumentation Options}),
+you can compile it a second time using
@option{-fbranch-probabilities}, to improve optimizations based on
the number of times each branch was taken. When a program
compiled with @option{-fprofile-arcs} exits, it saves arc execution
@@ -10304,30 +9745,6 @@ threading.
When performing branch target register load optimization, don't reuse
branch target registers within any basic block.
-@item -fstack-protector
-@opindex fstack-protector
-Emit extra code to check for buffer overflows, such as stack smashing
-attacks. This is done by adding a guard variable to functions with
-vulnerable objects. This includes functions that call @code{alloca}, and
-functions with buffers larger than 8 bytes. The guards are initialized
-when a function is entered and then checked when the function exits.
-If a guard check fails, an error message is printed and the program exits.
-
-@item -fstack-protector-all
-@opindex fstack-protector-all
-Like @option{-fstack-protector} except that all functions are protected.
-
-@item -fstack-protector-strong
-@opindex fstack-protector-strong
-Like @option{-fstack-protector} but includes additional functions to
-be protected --- those that have local array definitions, or have
-references to local frame addresses.
-
-@item -fstack-protector-explicit
-@opindex fstack-protector-explicit
-Like @option{-fstack-protector} but only protects those functions which
-have the @code{stack_protect} attribute.
-
@item -fstdarg-opt
@opindex fstdarg-opt
Optimize the prologue of variadic argument functions with respect to usage of
@@ -11283,6 +10700,792 @@ use-def chain.
@end table
@end table
+@node Instrumentation Options
+@section Program Instrumentation Options
+@cindex instrumentation options
+@cindex program instrumentation options
+@cindex run-time error checking options
+@cindex profiling options
+@cindex options, program instrumentation
+@cindex options, run-time error checking
+@cindex options, profiling
+
+GCC supports a number of command-line options that control adding
+run-time instrumentation to the code it normally generates.
+For example, one purpose of instrumentation is collect profiling
+statistics for use in finding program hot spots, code coverage
+analysis, or profile-guided optimizations.
+Another class of program instrumentation is adding run-time checking
+to detect programming errors like invalid pointer
+dereferences or out-of-bounds array accesses, as well as deliberately
+hostile attacks such as stack smashing or C++ vtable hijacking.
+There is also a general hook which can be used to implement other
+forms of tracing or function-level instrumentation for debug or
+program analysis purposes.
+
+@table @gcctabopt
+@cindex @command{prof}
+@item -p
+@opindex p
+Generate extra code to write profile information suitable for the
+analysis program @command{prof}. You must use this option when compiling
+the source files you want data about, and you must also use it when
+linking.
+
+@cindex @command{gprof}
+@item -pg
+@opindex pg
+Generate extra code to write profile information suitable for the
+analysis program @command{gprof}. You must use this option when compiling
+the source files you want data about, and you must also use it when
+linking.
+
+@item -fprofile-arcs
+@opindex fprofile-arcs
+Add code so that program flow @dfn{arcs} are instrumented. During
+execution the program records how many times each branch and call is
+executed and how many times it is taken or returns. When the compiled
+program exits it saves this data to a file called
+@file{@var{auxname}.gcda} for each source file. The data may be used for
+profile-directed optimizations (@option{-fbranch-probabilities}), or for
+test coverage analysis (@option{-ftest-coverage}). Each object file's
+@var{auxname} is generated from the name of the output file, if
+explicitly specified and it is not the final executable, otherwise it is
+the basename of the source file. In both cases any suffix is removed
+(e.g.@: @file{foo.gcda} for input file @file{dir/foo.c}, or
+@file{dir/foo.gcda} for output file specified as @option{-o dir/foo.o}).
+@xref{Cross-profiling}.
+
+@cindex @command{gcov}
+@item --coverage
+@opindex coverage
+
+This option is used to compile and link code instrumented for coverage
+analysis. The option is a synonym for @option{-fprofile-arcs}
+@option{-ftest-coverage} (when compiling) and @option{-lgcov} (when
+linking). See the documentation for those options for more details.
+
+@itemize
+
+@item
+Compile the source files with @option{-fprofile-arcs} plus optimization
+and code generation options. For test coverage analysis, use the
+additional @option{-ftest-coverage} option. You do not need to profile
+every source file in a program.
+
+@item
+Link your object files with @option{-lgcov} or @option{-fprofile-arcs}
+(the latter implies the former).
+
+@item
+Run the program on a representative workload to generate the arc profile
+information. This may be repeated any number of times. You can run
+concurrent instances of your program, and provided that the file system
+supports locking, the data files will be correctly updated. Also
+@code{fork} calls are detected and correctly handled (double counting
+will not happen).
+
+@item
+For profile-directed optimizations, compile the source files again with
+the same optimization and code generation options plus
+@option{-fbranch-probabilities} (@pxref{Optimize Options,,Options that
+Control Optimization}).
+
+@item
+For test coverage analysis, use @command{gcov} to produce human readable
+information from the @file{.gcno} and @file{.gcda} files. Refer to the
+@command{gcov} documentation for further information.
+
+@end itemize
+
+With @option{-fprofile-arcs}, for each function of your program GCC
+creates a program flow graph, then finds a spanning tree for the graph.
+Only arcs that are not on the spanning tree have to be instrumented: the
+compiler adds code to count the number of times that these arcs are
+executed. When an arc is the only exit or only entrance to a block, the
+instrumentation code can be added to the block; otherwise, a new basic
+block must be created to hold the instrumentation code.
+
+@need 2000
+@item -ftest-coverage
+@opindex ftest-coverage
+Produce a notes file that the @command{gcov} code-coverage utility
+(@pxref{Gcov,, @command{gcov}---a Test Coverage Program}) can use to
+show program coverage. Each source file's note file is called
+@file{@var{auxname}.gcno}. Refer to the @option{-fprofile-arcs} option
+above for a description of @var{auxname} and instructions on how to
+generate test coverage data. Coverage data matches the source files
+more closely if you do not optimize.
+
+@item -fprofile-dir=@var{path}
+@opindex fprofile-dir
+
+Set the directory to search for the profile data files in to @var{path}.
+This option affects only the profile data generated by
+@option{-fprofile-generate}, @option{-ftest-coverage}, @option{-fprofile-arcs}
+and used by @option{-fprofile-use} and @option{-fbranch-probabilities}
+and its related options. Both absolute and relative paths can be used.
+By default, GCC uses the current directory as @var{path}, thus the
+profile data file appears in the same directory as the object file.
+
+@item -fprofile-generate
+@itemx -fprofile-generate=@var{path}
+@opindex fprofile-generate
+
+Enable options usually used for instrumenting application to produce
+profile useful for later recompilation with profile feedback based
+optimization. You must use @option{-fprofile-generate} both when
+compiling and when linking your program.
+
+The following options are enabled: @option{-fprofile-arcs}, @option{-fprofile-values}, @option{-fvpt}.
+
+If @var{path} is specified, GCC looks at the @var{path} to find
+the profile feedback data files. See @option{-fprofile-dir}.
+
+To optimize the program based on the collected profile information, use
+@option{-fprofile-use}. @xref{Optimize Options}, for more information.
+
+@item -fsanitize=address
+@opindex fsanitize=address
+Enable AddressSanitizer, a fast memory error detector.
+Memory access instructions are instrumented to detect
+out-of-bounds and use-after-free bugs.
+See @uref{https://github.com/google/sanitizers/wiki/AddressSanitizer} for
+more details. The run-time behavior can be influenced using the
+@env{ASAN_OPTIONS} environment variable. When set to @code{help=1},
+the available options are shown at startup of the instrumended program. See
+@url{https://github.com/google/sanitizers/wiki/AddressSanitizerFlags#run-time-flags}
+for a list of supported options.
+
+@item -fsanitize=kernel-address
+@opindex fsanitize=kernel-address
+Enable AddressSanitizer for Linux kernel.
+See @uref{https://github.com/google/kasan/wiki} for more details.
+
+@item -fsanitize=thread
+@opindex fsanitize=thread
+Enable ThreadSanitizer, a fast data race detector.
+Memory access instructions are instrumented to detect
+data race bugs. See @uref{https://github.com/google/sanitizers/wiki#threadsanitizer} for more
+details. The run-time behavior can be influenced using the @env{TSAN_OPTIONS}
+environment variable; see
+@url{https://github.com/google/sanitizers/wiki/ThreadSanitizerFlags} for a list of
+supported options.
+
+@item -fsanitize=leak
+@opindex fsanitize=leak
+Enable LeakSanitizer, a memory leak detector.
+This option only matters for linking of executables and if neither
+@option{-fsanitize=address} nor @option{-fsanitize=thread} is used. In that
+case the executable is linked against a library that overrides @code{malloc}
+and other allocator functions. See
+@uref{https://github.com/google/sanitizers/wiki/AddressSanitizerLeakSanitizer} for more
+details. The run-time behavior can be influenced using the
+@env{LSAN_OPTIONS} environment variable.
+
+@item -fsanitize=undefined
+@opindex fsanitize=undefined
+Enable UndefinedBehaviorSanitizer, a fast undefined behavior detector.
+Various computations are instrumented to detect undefined behavior
+at runtime. Current suboptions are:
+
+@table @gcctabopt
+
+@item -fsanitize=shift
+@opindex fsanitize=shift
+This option enables checking that the result of a shift operation is
+not undefined. Note that what exactly is considered undefined differs
+slightly between C and C++, as well as between ISO C90 and C99, etc.
+
+@item -fsanitize=integer-divide-by-zero
+@opindex fsanitize=integer-divide-by-zero
+Detect integer division by zero as well as @code{INT_MIN / -1} division.
+
+@item -fsanitize=unreachable
+@opindex fsanitize=unreachable
+With this option, the compiler turns the @code{__builtin_unreachable}
+call into a diagnostics message call instead. When reaching the
+@code{__builtin_unreachable} call, the behavior is undefined.
+
+@item -fsanitize=vla-bound
+@opindex fsanitize=vla-bound
+This option instructs the compiler to check that the size of a variable
+length array is positive.
+
+@item -fsanitize=null
+@opindex fsanitize=null
+This option enables pointer checking. Particularly, the application
+built with this option turned on will issue an error message when it
+tries to dereference a NULL pointer, or if a reference (possibly an
+rvalue reference) is bound to a NULL pointer, or if a method is invoked
+on an object pointed by a NULL pointer.
+
+@item -fsanitize=return
+@opindex fsanitize=return
+This option enables return statement checking. Programs
+built with this option turned on will issue an error message
+when the end of a non-void function is reached without actually
+returning a value. This option works in C++ only.
+
+@item -fsanitize=signed-integer-overflow
+@opindex fsanitize=signed-integer-overflow
+This option enables signed integer overflow checking. We check that
+the result of @code{+}, @code{*}, and both unary and binary @code{-}
+does not overflow in the signed arithmetics. Note, integer promotion
+rules must be taken into account. That is, the following is not an
+overflow:
+@smallexample
+signed char a = SCHAR_MAX;
+a++;
+@end smallexample
+
+@item -fsanitize=bounds
+@opindex fsanitize=bounds
+This option enables instrumentation of array bounds. Various out of bounds
+accesses are detected. Flexible array members, flexible array member-like
+arrays, and initializers of variables with static storage are not instrumented.
+
+@item -fsanitize=bounds-strict
+@opindex fsanitize=bounds-strict
+This option enables strict instrumentation of array bounds. Most out of bounds
+accesses are detected, including flexible array members and flexible array
+member-like arrays. Initializers of variables with static storage are not
+instrumented.
+
+@item -fsanitize=alignment
+@opindex fsanitize=alignment
+
+This option enables checking of alignment of pointers when they are
+dereferenced, or when a reference is bound to insufficiently aligned target,
+or when a method or constructor is invoked on insufficiently aligned object.
+
+@item -fsanitize=object-size
+@opindex fsanitize=object-size
+This option enables instrumentation of memory references using the
+@code{__builtin_object_size} function. Various out of bounds pointer
+accesses are detected.
+
+@item -fsanitize=float-divide-by-zero
+@opindex fsanitize=float-divide-by-zero
+Detect floating-point division by zero. Unlike other similar options,
+@option{-fsanitize=float-divide-by-zero} is not enabled by
+@option{-fsanitize=undefined}, since floating-point division by zero can
+be a legitimate way of obtaining infinities and NaNs.
+
+@item -fsanitize=float-cast-overflow
+@opindex fsanitize=float-cast-overflow
+This option enables floating-point type to integer conversion checking.
+We check that the result of the conversion does not overflow.
+Unlike other similar options, @option{-fsanitize=float-cast-overflow} is
+not enabled by @option{-fsanitize=undefined}.
+This option does not work well with @code{FE_INVALID} exceptions enabled.
+
+@item -fsanitize=nonnull-attribute
+@opindex fsanitize=nonnull-attribute
+
+This option enables instrumentation of calls, checking whether null values
+are not passed to arguments marked as requiring a non-null value by the
+@code{nonnull} function attribute.
+
+@item -fsanitize=returns-nonnull-attribute
+@opindex fsanitize=returns-nonnull-attribute
+
+This option enables instrumentation of return statements in functions
+marked with @code{returns_nonnull} function attribute, to detect returning
+of null values from such functions.
+
+@item -fsanitize=bool
+@opindex fsanitize=bool
+
+This option enables instrumentation of loads from bool. If a value other
+than 0/1 is loaded, a run-time error is issued.
+
+@item -fsanitize=enum
+@opindex fsanitize=enum
+
+This option enables instrumentation of loads from an enum type. If
+a value outside the range of values for the enum type is loaded,
+a run-time error is issued.
+
+@item -fsanitize=vptr
+@opindex fsanitize=vptr
+
+This option enables instrumentation of C++ member function calls, member
+accesses and some conversions between pointers to base and derived classes,
+to verify the referenced object has the correct dynamic type.
+
+@end table
+
+While @option{-ftrapv} causes traps for signed overflows to be emitted,
+@option{-fsanitize=undefined} gives a diagnostic message.
+This currently works only for the C family of languages.
+
+@item -fno-sanitize=all
+@opindex fno-sanitize=all
+
+This option disables all previously enabled sanitizers.
+@option{-fsanitize=all} is not allowed, as some sanitizers cannot be used
+together.
+
+@item -fasan-shadow-offset=@var{number}
+@opindex fasan-shadow-offset
+This option forces GCC to use custom shadow offset in AddressSanitizer checks.
+It is useful for experimenting with different shadow memory layouts in
+Kernel AddressSanitizer.
+
+@item -fsanitize-sections=@var{s1},@var{s2},...
+@opindex fsanitize-sections
+Sanitize global variables in selected user-defined sections. @var{si} may
+contain wildcards.
+
+@item -fsanitize-recover@r{[}=@var{opts}@r{]}
+@opindex fsanitize-recover
+@opindex fno-sanitize-recover
+@option{-fsanitize-recover=} controls error recovery mode for sanitizers
+mentioned in comma-separated list of @var{opts}. Enabling this option
+for a sanitizer component causes it to attempt to continue
+running the program as if no error happened. This means multiple
+runtime errors can be reported in a single program run, and the exit
+code of the program may indicate success even when errors
+have been reported. The @option{-fno-sanitize-recover=} option
+can be used to alter
+this behavior: only the first detected error is reported
+and program then exits with a non-zero exit code.
+
+Currently this feature only works for @option{-fsanitize=undefined} (and its suboptions
+except for @option{-fsanitize=unreachable} and @option{-fsanitize=return}),
+@option{-fsanitize=float-cast-overflow}, @option{-fsanitize=float-divide-by-zero},
+@option{-fsanitize=kernel-address} and @option{-fsanitize=address}.
+For these sanitizers error recovery is turned on by default, except @option{-fsanitize=address},
+for which this feature is experimental.
+@option{-fsanitize-recover=all} and @option{-fno-sanitize-recover=all} is also
+accepted, the former enables recovery for all sanitizers that support it,
+the latter disables recovery for all sanitizers that support it.
+
+Syntax without explicit @var{opts} parameter is deprecated. It is equivalent to
+@smallexample
+-fsanitize-recover=undefined,float-cast-overflow,float-divide-by-zero
+@end smallexample
+@noindent
+Similarly @option{-fno-sanitize-recover} is equivalent to
+@smallexample
+-fno-sanitize-recover=undefined,float-cast-overflow,float-divide-by-zero
+@end smallexample
+
+@item -fsanitize-undefined-trap-on-error
+@opindex fsanitize-undefined-trap-on-error
+The @option{-fsanitize-undefined-trap-on-error} option instructs the compiler to
+report undefined behavior using @code{__builtin_trap} rather than
+a @code{libubsan} library routine. The advantage of this is that the
+@code{libubsan} library is not needed and is not linked in, so this
+is usable even in freestanding environments.
+
+@item -fsanitize-coverage=trace-pc
+@opindex fsanitize-coverage=trace-pc
+Enable coverage-guided fuzzing code instrumentation.
+Inserts call to __sanitizer_cov_trace_pc into every basic block.
+
+@item -fbounds-check
+@opindex fbounds-check
+For front ends that support it, generate additional code to check that
+indices used to access arrays are within the declared range. This is
+currently only supported by the Java and Fortran front ends, where
+this option defaults to true and false respectively.
+
+@item -fcheck-pointer-bounds
+@opindex fcheck-pointer-bounds
+@opindex fno-check-pointer-bounds
+@cindex Pointer Bounds Checker options
+Enable Pointer Bounds Checker instrumentation. Each memory reference
+is instrumented with checks of the pointer used for memory access against
+bounds associated with that pointer.
+
+Currently there
+is only an implementation for Intel MPX available, thus x86 target
+and @option{-mmpx} are required to enable this feature.
+MPX-based instrumentation requires
+a runtime library to enable MPX in hardware and handle bounds
+violation signals. By default when @option{-fcheck-pointer-bounds}
+and @option{-mmpx} options are used to link a program, the GCC driver
+links against the @file{libmpx} runtime library and @file{libmpxwrappers}
+library. It also passes '-z bndplt' to a linker in case it supports this
+option (which is checked on libmpx configuration). Note that old versions
+of linker may ignore option. Gold linker doesn't support '-z bndplt'
+option. With no '-z bndplt' support in linker all calls to dynamic libraries
+lose passed bounds reducing overall protection level. It's highly
+recommended to use linker with '-z bndplt' support. In case such linker
+is not available it is adviced to always use @option{-static-libmpxwrappers}
+for better protection level or use @option{-static} to completely avoid
+external calls to dynamic libraries. MPX-based instrumentation
+may be used for debugging and also may be included in production code
+to increase program security. Depending on usage, you may
+have different requirements for the runtime library. The current version
+of the MPX runtime library is more oriented for use as a debugging
+tool. MPX runtime library usage implies @option{-lpthread}. See
+also @option{-static-libmpx}. The runtime library behavior can be
+influenced using various @env{CHKP_RT_*} environment variables. See
+@uref{https://gcc.gnu.org/wiki/Intel%20MPX%20support%20in%20the%20GCC%20compiler}
+for more details.
+
+Generated instrumentation may be controlled by various
+@option{-fchkp-*} options and by the @code{bnd_variable_size}
+structure field attribute (@pxref{Type Attributes}) and
+@code{bnd_legacy}, and @code{bnd_instrument} function attributes
+(@pxref{Function Attributes}). GCC also provides a number of built-in
+functions for controlling the Pointer Bounds Checker. @xref{Pointer
+Bounds Checker builtins}, for more information.
+
+@item -fchecking
+@opindex fchecking
+@opindex fno-checking
+Enable internal consistency checking. The default depends on
+the compiler configuration.
+
+@item -fchkp-check-incomplete-type
+@opindex fchkp-check-incomplete-type
+@opindex fno-chkp-check-incomplete-type
+Generate pointer bounds checks for variables with incomplete type.
+Enabled by default.
+
+@item -fchkp-narrow-bounds
+@opindex fchkp-narrow-bounds
+@opindex fno-chkp-narrow-bounds
+Controls bounds used by Pointer Bounds Checker for pointers to object
+fields. If narrowing is enabled then field bounds are used. Otherwise
+object bounds are used. See also @option{-fchkp-narrow-to-innermost-array}
+and @option{-fchkp-first-field-has-own-bounds}. Enabled by default.
+
+@item -fchkp-first-field-has-own-bounds
+@opindex fchkp-first-field-has-own-bounds
+@opindex fno-chkp-first-field-has-own-bounds
+Forces Pointer Bounds Checker to use narrowed bounds for the address of the
+first field in the structure. By default a pointer to the first field has
+the same bounds as a pointer to the whole structure.
+
+@item -fchkp-narrow-to-innermost-array
+@opindex fchkp-narrow-to-innermost-array
+@opindex fno-chkp-narrow-to-innermost-array
+Forces Pointer Bounds Checker to use bounds of the innermost arrays in
+case of nested static array access. By default this option is disabled and
+bounds of the outermost array are used.
+
+@item -fchkp-optimize
+@opindex fchkp-optimize
+@opindex fno-chkp-optimize
+Enables Pointer Bounds Checker optimizations. Enabled by default at
+optimization levels @option{-O}, @option{-O2}, @option{-O3}.
+
+@item -fchkp-use-fast-string-functions
+@opindex fchkp-use-fast-string-functions
+@opindex fno-chkp-use-fast-string-functions
+Enables use of @code{*_nobnd} versions of string functions (not copying bounds)
+by Pointer Bounds Checker. Disabled by default.
+
+@item -fchkp-use-nochk-string-functions
+@opindex fchkp-use-nochk-string-functions
+@opindex fno-chkp-use-nochk-string-functions
+Enables use of @code{*_nochk} versions of string functions (not checking bounds)
+by Pointer Bounds Checker. Disabled by default.
+
+@item -fchkp-use-static-bounds
+@opindex fchkp-use-static-bounds
+@opindex fno-chkp-use-static-bounds
+Allow Pointer Bounds Checker to generate static bounds holding
+bounds of static variables. Enabled by default.
+
+@item -fchkp-use-static-const-bounds
+@opindex fchkp-use-static-const-bounds
+@opindex fno-chkp-use-static-const-bounds
+Use statically-initialized bounds for constant bounds instead of
+generating them each time they are required. By default enabled when
+@option{-fchkp-use-static-bounds} is enabled.
+
+@item -fchkp-treat-zero-dynamic-size-as-infinite
+@opindex fchkp-treat-zero-dynamic-size-as-infinite
+@opindex fno-chkp-treat-zero-dynamic-size-as-infinite
+With this option, objects with incomplete type whose
+dynamically-obtained size is zero are treated as having infinite size
+instead by Pointer Bounds
+Checker. This option may be helpful if a program is linked with a library
+missing size information for some symbols. Disabled by default.
+
+@item -fchkp-check-read
+@opindex fchkp-check-read
+@opindex fno-chkp-check-read
+Instructs Pointer Bounds Checker to generate checks for all read
+accesses to memory. Enabled by default.
+
+@item -fchkp-check-write
+@opindex fchkp-check-write
+@opindex fno-chkp-check-write
+Instructs Pointer Bounds Checker to generate checks for all write
+accesses to memory. Enabled by default.
+
+@item -fchkp-store-bounds
+@opindex fchkp-store-bounds
+@opindex fno-chkp-store-bounds
+Instructs Pointer Bounds Checker to generate bounds stores for
+pointer writes. Enabled by default.
+
+@item -fchkp-instrument-calls
+@opindex fchkp-instrument-calls
+@opindex fno-chkp-instrument-calls
+Instructs Pointer Bounds Checker to pass pointer bounds to calls.
+Enabled by default.
+
+@item -fchkp-instrument-marked-only
+@opindex fchkp-instrument-marked-only
+@opindex fno-chkp-instrument-marked-only
+Instructs Pointer Bounds Checker to instrument only functions
+marked with the @code{bnd_instrument} attribute
+(@pxref{Function Attributes}). Disabled by default.
+
+@item -fchkp-use-wrappers
+@opindex fchkp-use-wrappers
+@opindex fno-chkp-use-wrappers
+Allows Pointer Bounds Checker to replace calls to built-in functions
+with calls to wrapper functions. When @option{-fchkp-use-wrappers}
+is used to link a program, the GCC driver automatically links
+against @file{libmpxwrappers}. See also @option{-static-libmpxwrappers}.
+Enabled by default.
+
+@item -fstack-protector
+@opindex fstack-protector
+Emit extra code to check for buffer overflows, such as stack smashing
+attacks. This is done by adding a guard variable to functions with
+vulnerable objects. This includes functions that call @code{alloca}, and
+functions with buffers larger than 8 bytes. The guards are initialized
+when a function is entered and then checked when the function exits.
+If a guard check fails, an error message is printed and the program exits.
+
+@item -fstack-protector-all
+@opindex fstack-protector-all
+Like @option{-fstack-protector} except that all functions are protected.
+
+@item -fstack-protector-strong
+@opindex fstack-protector-strong
+Like @option{-fstack-protector} but includes additional functions to
+be protected --- those that have local array definitions, or have
+references to local frame addresses.
+
+@item -fstack-protector-explicit
+@opindex fstack-protector-explicit
+Like @option{-fstack-protector} but only protects those functions which
+have the @code{stack_protect} attribute.
+
+@item -fstack-check
+@opindex fstack-check
+Generate code to verify that you do not go beyond the boundary of the
+stack. You should specify this flag if you are running in an
+environment with multiple threads, but you only rarely need to specify it in
+a single-threaded environment since stack overflow is automatically
+detected on nearly all systems if there is only one stack.
+
+Note that this switch does not actually cause checking to be done; the
+operating system or the language runtime must do that. The switch causes
+generation of code to ensure that they see the stack being extended.
+
+You can additionally specify a string parameter: @samp{no} means no
+checking, @samp{generic} means force the use of old-style checking,
+@samp{specific} means use the best checking method and is equivalent
+to bare @option{-fstack-check}.
+
+Old-style checking is a generic mechanism that requires no specific
+target support in the compiler but comes with the following drawbacks:
+
+@enumerate
+@item
+Modified allocation strategy for large objects: they are always
+allocated dynamically if their size exceeds a fixed threshold.
+
+@item
+Fixed limit on the size of the static frame of functions: when it is
+topped by a particular function, stack checking is not reliable and
+a warning is issued by the compiler.
+
+@item
+Inefficiency: because of both the modified allocation strategy and the
+generic implementation, code performance is hampered.
+@end enumerate
+
+Note that old-style stack checking is also the fallback method for
+@samp{specific} if no target support has been added in the compiler.
+
+@item -fstack-limit-register=@var{reg}
+@itemx -fstack-limit-symbol=@var{sym}
+@itemx -fno-stack-limit
+@opindex fstack-limit-register
+@opindex fstack-limit-symbol
+@opindex fno-stack-limit
+Generate code to ensure that the stack does not grow beyond a certain value,
+either the value of a register or the address of a symbol. If a larger
+stack is required, a signal is raised at run time. For most targets,
+the signal is raised before the stack overruns the boundary, so
+it is possible to catch the signal without taking special precautions.
+
+For instance, if the stack starts at absolute address @samp{0x80000000}
+and grows downwards, you can use the flags
+@option{-fstack-limit-symbol=__stack_limit} and
+@option{-Wl,--defsym,__stack_limit=0x7ffe0000} to enforce a stack limit
+of 128KB@. Note that this may only work with the GNU linker.
+
+You can locally override stack limit checking by using the
+@code{no_stack_limit} function attribute (@pxref{Function Attributes}).
+
+@item -fsplit-stack
+@opindex fsplit-stack
+Generate code to automatically split the stack before it overflows.
+The resulting program has a discontiguous stack which can only
+overflow if the program is unable to allocate any more memory. This
+is most useful when running threaded programs, as it is no longer
+necessary to calculate a good stack size to use for each thread. This
+is currently only implemented for the x86 targets running
+GNU/Linux.
+
+When code compiled with @option{-fsplit-stack} calls code compiled
+without @option{-fsplit-stack}, there may not be much stack space
+available for the latter code to run. If compiling all code,
+including library code, with @option{-fsplit-stack} is not an option,
+then the linker can fix up these calls so that the code compiled
+without @option{-fsplit-stack} always has a large stack. Support for
+this is implemented in the gold linker in GNU binutils release 2.21
+and later.
+
+@item -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]}
+@opindex fvtable-verify
+This option is only available when compiling C++ code.
+It turns on (or off, if using @option{-fvtable-verify=none}) the security
+feature that verifies at run time, for every virtual call, that
+the vtable pointer through which the call is made is valid for the type of
+the object, and has not been corrupted or overwritten. If an invalid vtable
+pointer is detected at run time, an error is reported and execution of the
+program is immediately halted.
+
+This option causes run-time data structures to be built at program startup,
+which are used for verifying the vtable pointers.
+The options @samp{std} and @samp{preinit}
+control the timing of when these data structures are built. In both cases the
+data structures are built before execution reaches @code{main}. Using
+@option{-fvtable-verify=std} causes the data structures to be built after
+shared libraries have been loaded and initialized.
+@option{-fvtable-verify=preinit} causes them to be built before shared
+libraries have been loaded and initialized.
+
+If this option appears multiple times in the command line with different
+values specified, @samp{none} takes highest priority over both @samp{std} and
+@samp{preinit}; @samp{preinit} takes priority over @samp{std}.
+
+@item -fvtv-debug
+@opindex fvtv-debug
+When used in conjunction with @option{-fvtable-verify=std} or
+@option{-fvtable-verify=preinit}, causes debug versions of the
+runtime functions for the vtable verification feature to be called.
+This flag also causes the compiler to log information about which
+vtable pointers it finds for each class.
+This information is written to a file named @file{vtv_set_ptr_data.log}
+in the directory named by the environment variable @env{VTV_LOGS_DIR}
+if that is defined or the current working directory otherwise.
+
+Note: This feature @emph{appends} data to the log file. If you want a fresh log
+file, be sure to delete any existing one.
+
+@item -fvtv-counts
+@opindex fvtv-counts
+This is a debugging flag. When used in conjunction with
+@option{-fvtable-verify=std} or @option{-fvtable-verify=preinit}, this
+causes the compiler to keep track of the total number of virtual calls
+it encounters and the number of verifications it inserts. It also
+counts the number of calls to certain run-time library functions
+that it inserts and logs this information for each compilation unit.
+The compiler writes this information to a file named
+@file{vtv_count_data.log} in the directory named by the environment
+variable @env{VTV_LOGS_DIR} if that is defined or the current working
+directory otherwise. It also counts the size of the vtable pointer sets
+for each class, and writes this information to @file{vtv_class_set_sizes.log}
+in the same directory.
+
+Note: This feature @emph{appends} data to the log files. To get fresh log
+files, be sure to delete any existing ones.
+
+@item -finstrument-functions
+@opindex finstrument-functions
+Generate instrumentation calls for entry and exit to functions. Just
+after function entry and just before function exit, the following
+profiling functions are called with the address of the current
+function and its call site. (On some platforms,
+@code{__builtin_return_address} does not work beyond the current
+function, so the call site information may not be available to the
+profiling functions otherwise.)
+
+@smallexample
+void __cyg_profile_func_enter (void *this_fn,
+ void *call_site);
+void __cyg_profile_func_exit (void *this_fn,
+ void *call_site);
+@end smallexample
+
+The first argument is the address of the start of the current function,
+which may be looked up exactly in the symbol table.
+
+This instrumentation is also done for functions expanded inline in other
+functions. The profiling calls indicate where, conceptually, the
+inline function is entered and exited. This means that addressable
+versions of such functions must be available. If all your uses of a
+function are expanded inline, this may mean an additional expansion of
+code size. If you use @code{extern inline} in your C code, an
+addressable version of such functions must be provided. (This is
+normally the case anyway, but if you get lucky and the optimizer always
+expands the functions inline, you might have gotten away without
+providing static copies.)
+
+A function may be given the attribute @code{no_instrument_function}, in
+which case this instrumentation is not done. This can be used, for
+example, for the profiling functions listed above, high-priority
+interrupt routines, and any functions from which the profiling functions
+cannot safely be called (perhaps signal handlers, if the profiling
+routines generate output or allocate memory).
+
+@item -finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{}
+@opindex finstrument-functions-exclude-file-list
+
+Set the list of functions that are excluded from instrumentation (see
+the description of @option{-finstrument-functions}). If the file that
+contains a function definition matches with one of @var{file}, then
+that function is not instrumented. The match is done on substrings:
+if the @var{file} parameter is a substring of the file name, it is
+considered to be a match.
+
+For example:
+
+@smallexample
+-finstrument-functions-exclude-file-list=/bits/stl,include/sys
+@end smallexample
+
+@noindent
+excludes any inline function defined in files whose pathnames
+contain @file{/bits/stl} or @file{include/sys}.
+
+If, for some reason, you want to include letter @samp{,} in one of
+@var{sym}, write @samp{\,}. For example,
+@option{-finstrument-functions-exclude-file-list='\,\,tmp'}
+(note the single quote surrounding the option).
+
+@item -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{}
+@opindex finstrument-functions-exclude-function-list
+
+This is similar to @option{-finstrument-functions-exclude-file-list},
+but this option sets the list of function names to be excluded from
+instrumentation. The function name to be matched is its user-visible
+name, such as @code{vector<int> blah(const vector<int> &)}, not the
+internal mangled name (e.g., @code{_Z4blahRSt6vectorIiSaIiEE}). The
+match is done on substrings: if the @var{sym} parameter is a substring
+of the function name, it is considered to be a match. For C99 and C++
+extended identifiers, the function name must be given in UTF-8, not
+using universal character names.
+
+@end table
+
+
@node Preprocessor Options
@section Options Controlling the Preprocessor
@cindex preprocessor options
@@ -11861,13 +12064,6 @@ can figure out the other form by either
it.
@table @gcctabopt
-@item -fbounds-check
-@opindex fbounds-check
-For front ends that support it, generate additional code to check that
-indices used to access arrays are within the declared range. This is
-currently only supported by the Java and Fortran front ends, where
-this option defaults to true and false respectively.
-
@item -fstack-reuse=@var{reuse-level}
@opindex fstack_reuse
This option controls stack space reuse for user declared local/auto variables
@@ -12282,160 +12478,6 @@ code that is not binary compatible with
Additionally, it makes the code suboptimal.
Use it to conform to a non-default application binary interface.
-@item -finstrument-functions
-@opindex finstrument-functions
-Generate instrumentation calls for entry and exit to functions. Just
-after function entry and just before function exit, the following
-profiling functions are called with the address of the current
-function and its call site. (On some platforms,
-@code{__builtin_return_address} does not work beyond the current
-function, so the call site information may not be available to the
-profiling functions otherwise.)
-
-@smallexample
-void __cyg_profile_func_enter (void *this_fn,
- void *call_site);
-void __cyg_profile_func_exit (void *this_fn,
- void *call_site);
-@end smallexample
-
-The first argument is the address of the start of the current function,
-which may be looked up exactly in the symbol table.
-
-This instrumentation is also done for functions expanded inline in other
-functions. The profiling calls indicate where, conceptually, the
-inline function is entered and exited. This means that addressable
-versions of such functions must be available. If all your uses of a
-function are expanded inline, this may mean an additional expansion of
-code size. If you use @code{extern inline} in your C code, an
-addressable version of such functions must be provided. (This is
-normally the case anyway, but if you get lucky and the optimizer always
-expands the functions inline, you might have gotten away without
-providing static copies.)
-
-A function may be given the attribute @code{no_instrument_function}, in
-which case this instrumentation is not done. This can be used, for
-example, for the profiling functions listed above, high-priority
-interrupt routines, and any functions from which the profiling functions
-cannot safely be called (perhaps signal handlers, if the profiling
-routines generate output or allocate memory).
-
-@item -finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{}
-@opindex finstrument-functions-exclude-file-list
-
-Set the list of functions that are excluded from instrumentation (see
-the description of @option{-finstrument-functions}). If the file that
-contains a function definition matches with one of @var{file}, then
-that function is not instrumented. The match is done on substrings:
-if the @var{file} parameter is a substring of the file name, it is
-considered to be a match.
-
-For example:
-
-@smallexample
--finstrument-functions-exclude-file-list=/bits/stl,include/sys
-@end smallexample
-
-@noindent
-excludes any inline function defined in files whose pathnames
-contain @file{/bits/stl} or @file{include/sys}.
-
-If, for some reason, you want to include letter @samp{,} in one of
-@var{sym}, write @samp{\,}. For example,
-@option{-finstrument-functions-exclude-file-list='\,\,tmp'}
-(note the single quote surrounding the option).
-
-@item -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{}
-@opindex finstrument-functions-exclude-function-list
-
-This is similar to @option{-finstrument-functions-exclude-file-list},
-but this option sets the list of function names to be excluded from
-instrumentation. The function name to be matched is its user-visible
-name, such as @code{vector<int> blah(const vector<int> &)}, not the
-internal mangled name (e.g., @code{_Z4blahRSt6vectorIiSaIiEE}). The
-match is done on substrings: if the @var{sym} parameter is a substring
-of the function name, it is considered to be a match. For C99 and C++
-extended identifiers, the function name must be given in UTF-8, not
-using universal character names.
-
-@item -fstack-check
-@opindex fstack-check
-Generate code to verify that you do not go beyond the boundary of the
-stack. You should specify this flag if you are running in an
-environment with multiple threads, but you only rarely need to specify it in
-a single-threaded environment since stack overflow is automatically
-detected on nearly all systems if there is only one stack.
-
-Note that this switch does not actually cause checking to be done; the
-operating system or the language runtime must do that. The switch causes
-generation of code to ensure that they see the stack being extended.
-
-You can additionally specify a string parameter: @samp{no} means no
-checking, @samp{generic} means force the use of old-style checking,
-@samp{specific} means use the best checking method and is equivalent
-to bare @option{-fstack-check}.
-
-Old-style checking is a generic mechanism that requires no specific
-target support in the compiler but comes with the following drawbacks:
-
-@enumerate
-@item
-Modified allocation strategy for large objects: they are always
-allocated dynamically if their size exceeds a fixed threshold.
-
-@item
-Fixed limit on the size of the static frame of functions: when it is
-topped by a particular function, stack checking is not reliable and
-a warning is issued by the compiler.
-
-@item
-Inefficiency: because of both the modified allocation strategy and the
-generic implementation, code performance is hampered.
-@end enumerate
-
-Note that old-style stack checking is also the fallback method for
-@samp{specific} if no target support has been added in the compiler.
-
-@item -fstack-limit-register=@var{reg}
-@itemx -fstack-limit-symbol=@var{sym}
-@itemx -fno-stack-limit
-@opindex fstack-limit-register
-@opindex fstack-limit-symbol
-@opindex fno-stack-limit
-Generate code to ensure that the stack does not grow beyond a certain value,
-either the value of a register or the address of a symbol. If a larger
-stack is required, a signal is raised at run time. For most targets,
-the signal is raised before the stack overruns the boundary, so
-it is possible to catch the signal without taking special precautions.
-
-For instance, if the stack starts at absolute address @samp{0x80000000}
-and grows downwards, you can use the flags
-@option{-fstack-limit-symbol=__stack_limit} and
-@option{-Wl,--defsym,__stack_limit=0x7ffe0000} to enforce a stack limit
-of 128KB@. Note that this may only work with the GNU linker.
-
-You can locally override stack limit checking by using the
-@code{no_stack_limit} function attribute (@pxref{Function Attributes}).
-
-@item -fsplit-stack
-@opindex fsplit-stack
-Generate code to automatically split the stack before it overflows.
-The resulting program has a discontiguous stack which can only
-overflow if the program is unable to allocate any more memory. This
-is most useful when running threaded programs, as it is no longer
-necessary to calculate a good stack size to use for each thread. This
-is currently only implemented for the x86 targets running
-GNU/Linux.
-
-When code compiled with @option{-fsplit-stack} calls code compiled
-without @option{-fsplit-stack}, there may not be much stack space
-available for the latter code to run. If compiling all code,
-including library code, with @option{-fsplit-stack} is not an option,
-then the linker can fix up these calls so that the code compiled
-without @option{-fsplit-stack} always has a large stack. Support for
-this is implemented in the gold linker in GNU binutils release 2.21
-and later.
-
@item -fleading-underscore
@opindex fleading-underscore
This option and its counterpart, @option{-fno-leading-underscore}, forcibly
This patch consolidates the documentation of GCC options that add runtime profiling, error checking, or other instrumentation into a single section. Currently these are scattered all over, variously classified as debugging options, code generation options, optimization options, etc. Here is the list of options that I moved into the new section: @gccoptlist{-p -pg -fprofile-arcs --coverage -ftest-coverage @gol -fprofile-dir=@var{path} -fprofile-generate -fprofile-generate=@var{path} @gol -fsanitize=@var{style} -fsanitize-recover -fsanitize-recover=@var{style} @gol -fasan-shadow-offset=@var{number} -fsanitize-sections=@var{s1},@var{s2},... @gol -fsanitize-undefined-trap-on-error -fbounds-check @gol -fcheck-pointer-bounds -fchecking -fchkp-check-incomplete-type @gol -fchkp-first-field-has-own-bounds -fchkp-narrow-bounds @gol -fchkp-narrow-to-innermost-array -fchkp-optimize @gol -fchkp-use-fast-string-functions -fchkp-use-nochk-string-functions @gol -fchkp-use-static-bounds -fchkp-use-static-const-bounds @gol -fchkp-treat-zero-dynamic-size-as-infinite -fchkp-check-read @gol -fchkp-check-read -fchkp-check-write -fchkp-store-bounds @gol -fchkp-instrument-calls -fchkp-instrument-marked-only @gol -fchkp-use-wrappers @gol -fstack-protector -fstack-protector-all -fstack-protector-strong @gol -fstack-protector-explicit fstack-check @gol -fstack-limit-register=@var{reg} -fstack-limit-symbol=@var{sym} @gol -fno-stack-limit -fsplit-stack @gol -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]} @gol -fvtv-counts -fvtv-debug @gol -finstrument-functions @gol -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} @gol -finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{}} Note that I moved -fprofile-generate here, but left -fprofile-use and the options that control specific profile-guided optimizations in the optimization section. Except for the introductory paragraph for the new section and added cross-references between -fprofile-generate and -fprofile-use, I did not touch any of the option descriptions, just moved them around. I will commit this patch in a day or two if I don't get any suggestions for improving it meanwhile. -Sandra