[gcc(refs/users/marxin/heads/PR99108-target-attr-local-fn)] C++: target attribute - local decl

[Martin Liska]

https://gcc.gnu.org/g:4a135c94a60da5ec0e47671e1a947d9268fd2756

commit 4a135c94a60da5ec0e47671e1a947d9268fd2756
Author: Martin Liska <mliska@suse.cz>
Date:   Thu Feb 18 12:23:46 2021 +0100

    C++: target attribute - local decl
    
    gcc/cp/ChangeLog:
    
            PR c++/99108
            * call.c (get_function_version_dispatcher): Do not parse
            target attribute for a function with a missing declaration.
    
    gcc/testsuite/ChangeLog:
    
            PR c++/99108
            * g++.target/i386/pr99108.C: New test.

Diff:
---
 gcc/cp/call.c                           |  8 +++++++-
 gcc/testsuite/g++.target/i386/pr99108.C | 18 ++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 186feef6fe3..844853e504e 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -8386,8 +8386,14 @@ get_function_version_dispatcher (tree fn)
 	      && DECL_FUNCTION_VERSIONED (fn));
 
   gcc_assert (targetm.get_function_versions_dispatcher);
-  dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
+  if (cgraph_node::get (fn) == NULL)
+    {
+      error_at (DECL_SOURCE_LOCATION (fn), "missing declaration "
+		"for a multiversioned function");
+      return NULL;
+    }
 
+  dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
   if (dispatcher_decl == NULL)
     {
       error_at (input_location, "use of multiversioned function "
diff --git a/gcc/testsuite/g++.target/i386/pr99108.C b/gcc/testsuite/g++.target/i386/pr99108.C
new file mode 100644
index 00000000000..b0c4ffa2688
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/pr99108.C
@@ -0,0 +1,18 @@
+/* PR c++/99108 */
+/* { dg-do compile { target c++20 } } */
+/* { dg-require-ifunc "" }  */
+
+struct A {
+  void foo(auto);
+};
+void A::foo(auto)
+{
+  int f(void) __attribute__((target("default")));
+  int f(void) __attribute__((target("arch=atom"))); /* { dg-error "missing declaration for a multiversioned function" } */
+  int b = f();
+}
+void bar(void)
+{
+  A c;
+  c.foo(7);
+}