Hi!
When this builtin has no parameters, speculation_safe_value_resolve_call
returns BUILT_IN_NONE, but resolve_overloaded_builtin uselessly
dereferences the first param just to return error_mark_node immediately.
The following patch rearranges it so that we only read the first parameter
if fncode is not BUILT_IN_NONE.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2020-04-25 Jakub Jelinek <ja...@redhat.com>
PR c/94755
* c-common.c (resolve_overloaded_builtin): Return error_mark_node for
fncode == BUILT_IN_NONE before initialization of first_param.
* c-c++-common/pr94755.c: New test.
--- gcc/c-family/c-common.c.jj 2020-03-21 18:29:58.989160193 +0100
+++ gcc/c-family/c-common.c 2020-04-25 10:13:14.158722031 +0200
@@ -7402,9 +7402,11 @@ resolve_overloaded_builtin (location_t l
enum built_in_function fncode
= speculation_safe_value_resolve_call (function, params);;
+ if (fncode == BUILT_IN_NONE)
+ return error_mark_node;
+
first_param = (*params)[0];
- if (fncode == BUILT_IN_NONE
- || !speculation_safe_value_resolve_params (loc, function, params))
+ if (!speculation_safe_value_resolve_params (loc, function, params))
return error_mark_node;
if (targetm.have_speculation_safe_value (true))
--- gcc/testsuite/c-c++-common/pr94755.c.jj 2020-04-25 10:17:53.297502562
+0200
+++ gcc/testsuite/c-c++-common/pr94755.c 2020-04-25 10:18:32.261916902
+0200
@@ -0,0 +1,11 @@
+/* PR c/94755 */
+/* { dg-do compile } */
+
+extern void foo (void);
+
+void
+bar (double x)
+{
+ if (x == __builtin_speculation_safe_value ()) /* { dg-error "too few
arguments to function" } */
+ foo ();
+}
Jakub
