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 ();
+}
