| Message ID | 2067154.q9SCchci8G@polaris |
|---|---|
| State | New |
| Headers | show |
| Series | Restore functional DONT_USE_BUILTIN_SETJMP support | expand |
On Okt 08 2017, Eric Botcazou <ebotcazou@adacore.com> wrote: > * builtins.def (BUILT_IN_SETJMP): Declare as library builtin instead > of GCC builtin if DONT_USE_BUILTIN_SETJMP is defined. This breaks gcc.dg/plugin/must-tail-call-2.c, gcc.dg/torture/pr81083.c and gcc.dg/torture/pr82264.c: warning: conflicting types for built-in function 'setjmp' [-Wbuiltin-declaration-mismatch] Andreas.
On Okt 08 2017, Eric Botcazou <ebotcazou@adacore.com> wrote: > * builtins.def (BUILT_IN_SETJMP): Declare as library builtin instead > of GCC builtin if DONT_USE_BUILTIN_SETJMP is defined. > * except.c (sjlj_emit_function_enter): If DONT_USE_BUILTIN_SETJMP is > defined, force the creation of a new block for a dispatch label. This also breaks gcc.c-torture/compile/951222-1.c: during GIMPLE pass: lower /opt/gcc/gcc-20171008/gcc/testsuite/gcc.c-torture/compile/951222-1.c:4:1: internal compiler error: in gimple_call_arg, at gimple.h:3159 0x118ab1b gimple_call_arg ../../gcc/gimple.h:3159 0x118ab1b gimple_call_arg ../../gcc/gimple.h:3167 0x118ab1b lower_stmt ../../gcc/gimple-low.c:327 0x118ab1b lower_sequence ../../gcc/gimple-low.c:205 0x1189df3 lower_stmt ../../gcc/gimple-low.c:274 0x1189df3 lower_sequence ../../gcc/gimple-low.c:205 0x118997f lower_gimple_bind ../../gcc/gimple-low.c:441 0x118afff lower_function_body ../../gcc/gimple-low.c:109 0x118afff execute ../../gcc/gimple-low.c:183 Andreas.
> This also breaks gcc.c-torture/compile/951222-1.c: > > during GIMPLE pass: lower > /opt/gcc/gcc-20171008/gcc/testsuite/gcc.c-torture/compile/951222-1.c:4:1: > internal compiler error: in gimple_call_arg, at gimple.h:3159 0x118ab1b > gimple_call_arg You're right, not clear why I didn't spot it on Aarch64. Hunk reverted.
On Sun, 8 Oct 2017, Andreas Schwab wrote: > On Okt 08 2017, Eric Botcazou <ebotcazou@adacore.com> wrote: > > > * builtins.def (BUILT_IN_SETJMP): Declare as library builtin instead > > of GCC builtin if DONT_USE_BUILTIN_SETJMP is defined. > > This breaks gcc.dg/plugin/must-tail-call-2.c, gcc.dg/torture/pr81083.c > and gcc.dg/torture/pr82264.c: > > warning: conflicting types for built-in function 'setjmp' [-Wbuiltin-declaration-mismatch] It also breaks the glibc testsuite for AArch64 and IA64 (setjmp/check-installed-headers-cxx). https://sourceware.org/ml/libc-testresults/2017-q4/msg00057.html In file included from ../include/setjmp.h:2:0, from /tmp/cih_test_epu39R.cc:8: ../setjmp/setjmp.h:49:12: error: declaration of 'int setjmp(__jmp_buf_tag*)' conflicts with built-in declaration 'int setjmp(void*)' [-Werror=builtin-declaration-mismatch] extern int setjmp (jmp_buf __env) __THROWNL; ^~~~~~ cc1plus: all warnings being treated as errors That is, the C++ front end does not consider this built-in declaration compatible with <setjmp.h>'s declaration of setjmp (GCC of course does not know the exact type of jmp_buf in libc, so can't know the exact argument type for the library function, so when you use DEF_LIB_BUILTIN instead of DEF_GCC_BUILTIN you get this conflict; the C front end is apparently more lenient about this particular built-in type conflict).
> You're right, not clear why I didn't spot it on Aarch64. Hunk reverted.
The attached patch replaces it with an ad-hoc definition of setjmp, like the
ones used for the coverage routines. Tested on Aarch64/Linux with and without
--enable-sjlj-exceptions and on IA-64/Linux without --enable-sjlj-exceptions.
Applied on the mainline as obvious.
2017-10-09 Eric Botcazou <ebotcazou@adacore.com>
* except.c (setjmp_fn): New global variable.
(init_eh): Initialize it if DONT_USE_BUILTIN_SETJMP is defined.
(sjlj_emit_function_enter): Call it instead of BUILTIN_SETJMP if
DONT_USE_BUILTIN_SETJMP is defined.
Index: builtins.def =================================================================== --- builtins.def (revision 253506) +++ builtins.def (working copy) @@ -890,7 +890,11 @@ DEF_LIB_BUILTIN (BUILT_IN_REALLOC DEF_GCC_BUILTIN (BUILT_IN_RETURN, "return", BT_FN_VOID_PTR, ATTR_NORETURN_NOTHROW_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_RETURN_ADDRESS, "return_address", BT_FN_PTR_UINT, ATTR_LEAF_LIST) DEF_GCC_BUILTIN (BUILT_IN_SAVEREGS, "saveregs", BT_FN_PTR_VAR, ATTR_NULL) +#ifdef DONT_USE_BUILTIN_SETJMP +DEF_LIB_BUILTIN (BUILT_IN_SETJMP, "setjmp", BT_FN_INT_PTR, ATTR_RT_NOTHROW_LEAF_LIST) +#else DEF_GCC_BUILTIN (BUILT_IN_SETJMP, "setjmp", BT_FN_INT_PTR, ATTR_RT_NOTHROW_LEAF_LIST) +#endif DEF_EXT_LIB_BUILTIN (BUILT_IN_STRFMON, "strfmon", BT_FN_SSIZE_STRING_SIZE_CONST_STRING_VAR, ATTR_FORMAT_STRFMON_NOTHROW_3_4) DEF_LIB_BUILTIN (BUILT_IN_STRFTIME, "strftime", BT_FN_SIZE_STRING_SIZE_CONST_STRING_CONST_TM_PTR, ATTR_FORMAT_STRFTIME_NOTHROW_3_0) DEF_GCC_BUILTIN (BUILT_IN_TRAP, "trap", BT_FN_VOID, ATTR_NORETURN_NOTHROW_LEAF_COLD_LIST) Index: except.c =================================================================== --- except.c (revision 253506) +++ except.c (working copy) @@ -1209,6 +1209,28 @@ sjlj_emit_function_enter (rtx_code_label fn_begin_outside_block = false; } +#ifdef DONT_USE_BUILTIN_SETJMP + if (dispatch_label) + { + /* The sequence contains a branch in the middle so we need to force + the creation of a new basic block by means of BB_SUPERBLOCK. */ + if (fn_begin_outside_block) + { + basic_block bb + = split_edge (single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))); + if (JUMP_P (BB_END (bb))) + emit_insn_before (seq, BB_END (bb)); + else + emit_insn_after (seq, BB_END (bb)); + } + else + emit_insn_after (seq, fn_begin); + + single_succ (ENTRY_BLOCK_PTR_FOR_FN (cfun))->flags |= BB_SUPERBLOCK; + return; + } +#endif + if (fn_begin_outside_block) insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun))); else