Hi. Following patch adds checking of noreturn attribute when we merge DECLs in LTO. Note that proper fix is probably https://gcc.gnu.org/bugzilla/attachment.cgi?id=43884&action=diff but that would be applicable after MPX is removed. Thus in next stage1.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests. Ready to be installed? Martin gcc/lto/ChangeLog: 2018-04-06 Richard Biener <rguent...@suse.de> Martin Liska <mli...@suse.cz> PR lto/85248 * lto-symtab.c (lto_symtab_merge_p): Handle noreturn attribute. gcc/testsuite/ChangeLog: 2018-04-06 Jakub Jelinek <ja...@redhat.com> PR lto/85248 * gcc.dg/lto/pr85248_0.c: New test. * gcc.dg/lto/pr85248_1.c: New test. --- gcc/lto/lto-symtab.c | 17 ++++++++++++++ gcc/testsuite/gcc.dg/lto/pr85248_0.c | 45 ++++++++++++++++++++++++++++++++++++ gcc/testsuite/gcc.dg/lto/pr85248_1.c | 9 ++++++++ 3 files changed, 71 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/lto/pr85248_0.c create mode 100644 gcc/testsuite/gcc.dg/lto/pr85248_1.c
diff --git a/gcc/lto/lto-symtab.c b/gcc/lto/lto-symtab.c index 4f186aed059..fbad96c0707 100644 --- a/gcc/lto/lto-symtab.c +++ b/gcc/lto/lto-symtab.c @@ -572,6 +572,9 @@ lto_symtab_merge_p (tree prevailing, tree decl) return false; } } + + /* FIXME: after MPX is removed, use flags_from_decl_or_type + function instead. PR lto/85248. */ if (DECL_ATTRIBUTES (prevailing) != DECL_ATTRIBUTES (decl)) { tree prev_attr = lookup_attribute ("error", DECL_ATTRIBUTES (prevailing)); @@ -599,6 +602,20 @@ lto_symtab_merge_p (tree prevailing, tree decl) "warning attribute mismatch\n"); return false; } + + prev_attr = lookup_attribute ("noreturn", DECL_ATTRIBUTES (prevailing)); + attr = lookup_attribute ("noreturn", DECL_ATTRIBUTES (decl)); + if ((prev_attr == NULL) != (attr == NULL) + || (prev_attr + && TREE_VALUE (TREE_VALUE (prev_attr)) + != TREE_VALUE (TREE_VALUE (attr)))) + { + if (symtab->dump_file) + fprintf (symtab->dump_file, "Not merging decls; " + "noreturn attribute mismatch\n"); + return false; + } + } return true; } diff --git a/gcc/testsuite/gcc.dg/lto/pr85248_0.c b/gcc/testsuite/gcc.dg/lto/pr85248_0.c new file mode 100644 index 00000000000..df61ac976a5 --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/pr85248_0.c @@ -0,0 +1,45 @@ +/* PR lto/85248 */ +/* { dg-lto-do run } */ +/* { dg-lto-options { { -flto -O2 } } } */ + +extern void test_alias (int s, int e) __asm__ (__USER_LABEL_PREFIX__ "test"); +extern void test_noreturn (int s, int e) __asm__ (__USER_LABEL_PREFIX__ "test") + __attribute__ ((__noreturn__)); + +extern inline __attribute__ ((__always_inline__, __gnu_inline__)) void +test (int s, int e) +{ + if (__builtin_constant_p (s) && s != 0) + test_noreturn (s, e); + else + test_alias (s, e); +} + +int +foo (void) +{ + static volatile int a; + return a; +} + +static void +bar (void) +{ + test (0, 1); + __builtin_exit (0); +} + +static void +baz () +{ + test (1, 0); +} + +int +main () +{ + if (foo ()) + baz (); + bar (); + __builtin_abort (); +} diff --git a/gcc/testsuite/gcc.dg/lto/pr85248_1.c b/gcc/testsuite/gcc.dg/lto/pr85248_1.c new file mode 100644 index 00000000000..418c0697028 --- /dev/null +++ b/gcc/testsuite/gcc.dg/lto/pr85248_1.c @@ -0,0 +1,9 @@ +/* { dg-options "-fno-lto" } */ + +__attribute__((__noipa__)) void +test (int s, int e) +{ + asm volatile ("" : "+g" (s), "+g" (e) : : "memory"); + if (s) + __builtin_abort (); +}