| Message ID | 20180227082936.GB5867@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | Fix debug for -mcall-ms2sysv-xlogues stubs fallout (PR target/83917) | expand |
On Tue, Feb 27, 2018 at 09:29:36AM +0100, Jakub Jelinek wrote: > So here is a new (I've committed the previous patch since then), only lightly > tested (only on x86_64-linux and don't have too old binutils around), patch: > > 2018-02-27 Jakub Jelinek <jakub@redhat.com> > > PR debug/83917 > * configure.ac (AS_HIDDEN_DIRECTIVE): AC_DEFINE_UNQUOTED this to > $asm_hidden_op if visibility ("hidden") attribute works. > (HAVE_AS_CFI_SECTIONS): New AC_DEFINE. > * config/i386/i386-asm.h: Don't include auto-host.h. > (PACKAGE_VERSION, PACKAGE_NAME, PACKAGE_STRING, PACKAGE_TARNAME, > PACKAGE_URL): Don't undefine. > (USE_GAS_CFI_DIRECTIVES): Don't use nor define this macro, instead > guard cfi_startproc only on ifdef __GCC_HAVE_DWARF2_CFI_ASM. > (FN_HIDDEN): Change guard from #ifdef HAVE_GAS_HIDDEN to > #ifdef AS_HIDDEN_DIRECTIVE, use AS_HIDDEN_DIRECTIVE macro in the > definition instead of hardcoded .hidden. > * config/i386/cygwin.S: Include i386-asm.h first before .cfi_sections > directive. Use #ifdef HAVE_AS_CFI_SECTIONS rather than > #ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE to guard .cfi_sections. > (USE_GAS_CFI_DIRECTIVES): Don't define. > * configure: Regenerated. > * config.in: Likewise. Now successfully bootstrapped/regtested on x86_64-linux and i686-linux. Jakub
On 02/27/2018 01:29 AM, Jakub Jelinek wrote: > On Mon, Feb 26, 2018 at 08:05:56PM -0600, Daniel Santos wrote: >>>>> --- libgcc/config/i386/cygwin.S.jj 2018-01-03 10:42:56.309763515 +0100 >>>>> +++ libgcc/config/i386/cygwin.S 2018-02-22 15:30:34.597925496 +0100 >>>>> @@ -23,31 +23,13 @@ >>>>> * <http://www.gnu.org/licenses/>. >>>>> */ >>>>> >>>>> -#include "auto-host.h" >>>> The following include should be here. >>>> >>>> +#include "i386-asm.h" >>> I don't understand this. i386-asm.h needs (both before my patch and after >>> it) both auto-host.h and auto-target.h, as it tests >>> HAVE_GAS_SECTIONS_DIRECTIVE (this one newly, comes from cygwin.S) >> >> The problem is that HAVE_GAS_SECTIONS_DIRECTIVE gets defined (or not) in >> ../../gcc/auto-host.h, but you are testing it before including >> auto-host.h, either directly or via i386-asm.h. So if i386-asm.h >> depends upon HAVE_GAS_SECTIONS_DIRECTIVE first being defined then it is >> a circular dependency. >> >> In its current form, cygwin.S would never define USE_GAS_CFI_DIRECTIVES >> prior to including i386-asm.h and also never emit >> .cfi_sections .debug_frame >> and rather or not USE_GAS_CFI_DIRECTIVES ends up being defined to 1 or 0 >> depends upon the test of __GCC_HAVE_DWARF2_CFI_ASM in i386-asm.h. > > Ugh, you're right. I was trying to preserve existing behavior for cygwin.S, > but failed to do so. Unfortunately the patch which added this stuff from > Kai T. and Richard H. from 2010 is not in gcc-patches archives; in any case, > I think nothing seriously bad happens if with older gas versions which do > support .cfi_* directives but not .cfi_sections .debug_frame we emit the CFI > into .eh_frame section rather than .debug_frame. > > So this patch simplifies it, with only one guard for the non-trivial > vs. trivial cfi_* definitions (based on whether GCC itself would use it) > and only guard the .cfi_sections directive on whether it is really > available. > > The __GCC_HAVE_DWARF2_CFI_ASM definition actually sometimes depends on the > .cfi_sections presence too: > /* If we can't get the assembler to emit only .debug_frame, and we don't need > dwarf2 unwind info for exceptions, then emit .debug_frame by hand. */ > if (!HAVE_GAS_CFI_SECTIONS_DIRECTIVE && !dwarf2out_do_eh_frame ()) > return false; > but doesn't actually guarantee it always, as when doing .eh_frame it will > not require .cfi_sections. > > This spot brings in another, preexisting bug in cygwin.S though - > the HAVE_GAS_CFI_SECTIONS_DIRECTIVE macro is always defined, to 0 or 1, > rather than sometimes #define and sometines #undef. > >> Ultimately, the proper cleanup will be moving these tests out of >> {gcc,libgcc}/configure.ac and into .m4 files in the root config >> directory so that we don't uglify them with massive copy & pastes. >> These tests are also fairly complex as there are a lot of dependencies. >> m4 isn't my strong suite, but I can look at this after we're out of code >> freeze. > > Not really sure about that, because we really want to do a different thing > in gcc/configure.ac (need to test the assembler directly, use > GCC_TARGET_TEMPLATE) while in libgcc it does usually something different. > > The libgcc configure already has all the code for the .hidden directive, > as it uses it too, just it is only a pair of AC_SUBSTs rather than > AC_DEFINE_UNQUOTED. > The test for HAVE_GAS_CFI_SECTIONS_DIRECTIVE alternative can be compile > int foo (int, char *); > int bar (int x) { char *y = __builtin_alloca (x); return foo (x + 1, y) + 1; } > with -g -fno-asynchronous-unwind-tables -fno-unwind-tables -fno-exceptions > and scan for .cfi_sections .debug_frame. > > So here is a new (I've committed the previous patch since then), only lightly > tested (only on x86_64-linux and don't have too old binutils around), patch: > > 2018-02-27 Jakub Jelinek <jakub@redhat.com> > > PR debug/83917 > * configure.ac (AS_HIDDEN_DIRECTIVE): AC_DEFINE_UNQUOTED this to > $asm_hidden_op if visibility ("hidden") attribute works. > (HAVE_AS_CFI_SECTIONS): New AC_DEFINE. > * config/i386/i386-asm.h: Don't include auto-host.h. > (PACKAGE_VERSION, PACKAGE_NAME, PACKAGE_STRING, PACKAGE_TARNAME, > PACKAGE_URL): Don't undefine. > (USE_GAS_CFI_DIRECTIVES): Don't use nor define this macro, instead > guard cfi_startproc only on ifdef __GCC_HAVE_DWARF2_CFI_ASM. > (FN_HIDDEN): Change guard from #ifdef HAVE_GAS_HIDDEN to > #ifdef AS_HIDDEN_DIRECTIVE, use AS_HIDDEN_DIRECTIVE macro in the > definition instead of hardcoded .hidden. > * config/i386/cygwin.S: Include i386-asm.h first before .cfi_sections > directive. Use #ifdef HAVE_AS_CFI_SECTIONS rather than > #ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE to guard .cfi_sections. > (USE_GAS_CFI_DIRECTIVES): Don't define. > * configure: Regenerated. > * config.in: Likewise. OK. jeff
--- libgcc/configure.ac.jj 2017-11-20 11:02:56.877786488 +0100 +++ libgcc/configure.ac 2018-02-27 09:20:45.939385138 +0100 @@ -486,11 +486,29 @@ AC_CACHE_CHECK([for __attribute__((visib if test $libgcc_cv_hidden_visibility_attribute = yes; then vis_hide='-fvisibility=hidden -DHIDE_EXPORTS' + AC_DEFINE_UNQUOTED(AS_HIDDEN_DIRECTIVE, $asm_hidden_op, [Define to the .hidden-like directive if it exists.]) else vis_hide= fi AC_SUBST(vis_hide) +# Check for .cfi_sections .debug_frame support. +AC_CACHE_CHECK([for .cfi_sections .debug_frame], + libgcc_cv_cfi_sections_directive, [ + echo 'int foo (int, char *);' > conftest.c + echo 'int bar (int x) { char *y = __builtin_alloca (x); return foo (x + 1, y) + 1; }' >> conftest.c + libgcc_cv_cfi_sections_directive=no + if AC_TRY_COMMAND(${CC-cc} -Werror -g -fno-asynchronous-unwind-tables -fno-unwind-tables -fno-exceptions -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then + if grep "\\.cfi_sections.*\\.debug_frame" conftest.s >/dev/null; then + libgcc_cv_cfi_sections_directive=yes + fi + fi + rm -f conftest.* + ]) +if test $libgcc_cv_cfi_sections_directive = yes; then + AC_DEFINE(HAVE_AS_CFI_SECTIONS, 1, [Define to 1 if the assembler supports .cfi_sections .debug_frame directive.]) +fi + # See if we have thread-local storage. We can only test assembler # since link-time and run-time tests require the newly built # gcc, which can't be used to build executable due to that libgcc --- libgcc/config/i386/i386-asm.h.jj 2018-02-26 20:46:08.493354695 +0100 +++ libgcc/config/i386/i386-asm.h 2018-02-27 09:15:23.533496520 +0100 @@ -27,21 +27,8 @@ see the files COPYING3 and COPYING.RUNTI #define I386_ASM_H #include "auto-target.h" -#undef PACKAGE_VERSION -#undef PACKAGE_NAME -#undef PACKAGE_STRING -#undef PACKAGE_TARNAME -#undef PACKAGE_URL -#include "auto-host.h" -#ifndef USE_GAS_CFI_DIRECTIVES -# ifdef __GCC_HAVE_DWARF2_CFI_ASM -# define USE_GAS_CFI_DIRECTIVES 1 -# else -# define USE_GAS_CFI_DIRECTIVES 0 -# endif -#endif -#if USE_GAS_CFI_DIRECTIVES +#ifdef __GCC_HAVE_DWARF2_CFI_ASM # define cfi_startproc() .cfi_startproc # define cfi_endproc() .cfi_endproc # define cfi_adjust_cfa_offset(X) .cfi_adjust_cfa_offset X @@ -76,8 +63,8 @@ see the files COPYING3 and COPYING.RUNTI #ifdef __ELF__ # define FN_TYPE(fn) .type fn,@function # define FN_SIZE(fn) .size fn,.-fn -# ifdef HAVE_GAS_HIDDEN -# define FN_HIDDEN(fn) .hidden fn +# ifdef AS_HIDDEN_DIRECTIVE +# define FN_HIDDEN(fn) AS_HIDDEN_DIRECTIVE fn # endif #else # define FN_TYPE(fn) --- libgcc/config/i386/cygwin.S.jj 2018-02-26 20:46:08.494354695 +0100 +++ libgcc/config/i386/cygwin.S 2018-02-27 09:16:32.077472841 +0100 @@ -23,13 +23,11 @@ * <http://www.gnu.org/licenses/>. */ -#ifdef HAVE_GAS_CFI_SECTIONS_DIRECTIVE -# define USE_GAS_CFI_DIRECTIVES 1 +#include "i386-asm.h" + +#ifdef HAVE_AS_CFI_SECTIONS .cfi_sections .debug_frame -#else -# define USE_GAS_CFI_DIRECTIVES 0 #endif -#include "i386-asm.h" #ifdef L_chkstk /* Function prologue calls __chkstk to probe the stack when allocating more --- libgcc/configure.jj 2018-02-19 19:57:05.758280231 +0100 +++ libgcc/configure 2018-02-27 09:20:57.346381203 +0100 @@ -5214,11 +5214,47 @@ $as_echo "$libgcc_cv_hidden_visibility_a if test $libgcc_cv_hidden_visibility_attribute = yes; then vis_hide='-fvisibility=hidden -DHIDE_EXPORTS' + +cat >>confdefs.h <<_ACEOF +#define AS_HIDDEN_DIRECTIVE $asm_hidden_op +_ACEOF + else vis_hide= fi +# Check for .cfi_sections .debug_frame support. +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for .cfi_sections .debug_frame" >&5 +$as_echo_n "checking for .cfi_sections .debug_frame... " >&6; } +if test "${libgcc_cv_cfi_sections_directive+set}" = set; then : + $as_echo_n "(cached) " >&6 +else + + echo 'int foo (int, char *);' > conftest.c + echo 'int bar (int x) { char *y = __builtin_alloca (x); return foo (x + 1, y) + 1; }' >> conftest.c + libgcc_cv_cfi_sections_directive=no + if { ac_try='${CC-cc} -Werror -g -fno-asynchronous-unwind-tables -fno-unwind-tables -fno-exceptions -S conftest.c -o conftest.s 1>&5' + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5 + (eval $ac_try) 2>&5 + ac_status=$? + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5 + test $ac_status = 0; }; }; then + if grep "\\.cfi_sections.*\\.debug_frame" conftest.s >/dev/null; then + libgcc_cv_cfi_sections_directive=yes + fi + fi + rm -f conftest.* + +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgcc_cv_cfi_sections_directive" >&5 +$as_echo "$libgcc_cv_cfi_sections_directive" >&6; } +if test $libgcc_cv_cfi_sections_directive = yes; then + +$as_echo "#define HAVE_AS_CFI_SECTIONS 1" >>confdefs.h + +fi + # See if we have thread-local storage. We can only test assembler # since link-time and run-time tests require the newly built # gcc, which can't be used to build executable due to that libgcc --- libgcc/config.in.jj 2017-09-25 10:38:45.182468927 +0200 +++ libgcc/config.in 2018-02-27 09:12:08.000000000 +0100 @@ -1,8 +1,15 @@ /* config.in. Generated from configure.ac by autoheader. */ +/* Define to the .hidden-like directive if it exists. */ +#undef AS_HIDDEN_DIRECTIVE + /* Define to 1 if the assembler supports AVX. */ #undef HAVE_AS_AVX +/* Define to 1 if the assembler supports .cfi_sections .debug_frame directive. + */ +#undef HAVE_AS_CFI_SECTIONS + /* Define to 1 if the target assembler supports thread-local storage. */ #undef HAVE_CC_TLS