c++: local function versioning [PR104669]

There were two problems with this testcase: we weren't copying the target
attribute from the second declaration to the global alias for the first
one (duplicate_decls hunk), and then we were treating the third one as
matching the earlier one even though both are versioned (decls_match hunk).
The latter change required a fix to find_last_decl (used for attribute
mismatch warnings) to give up if we see a versioned function, as in that
case we can't determine whether the decls match, because we are still in the
process of setting the attributes on the new decl.

	PR c++/104669

gcc/cp/ChangeLog:

	* decl.cc (decls_match): Compare versions even if not recording.
	(duplicate_decls): Propagate attributes to alias.
	* decl2.cc (find_last_decl): Give up if versioned.

gcc/testsuite/ChangeLog:

	* g++.target/i386/mv31.C: New test.

diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc
index 31cae4d..5f59612 100644 (file)
--- a/gcc/cp/decl.cc
+++ b/gcc/cp/decl.cc
@@ -1069,11 +1069,14 @@ decls_match (tree newdecl, tree olddecl, bool record_versions /* = true */)
       if (types_match
          && !DECL_EXTERN_C_P (newdecl)
          && !DECL_EXTERN_C_P (olddecl)
-         && record_versions
-         && maybe_version_functions (newdecl, olddecl,
-                                     (!DECL_FUNCTION_VERSIONED (newdecl)
-                                      || !DECL_FUNCTION_VERSIONED (olddecl))))
-       return 0;
+         && targetm.target_option.function_versions (newdecl, olddecl))
+       {
+         if (record_versions)
+           maybe_version_functions (newdecl, olddecl,
+                                    (!DECL_FUNCTION_VERSIONED (newdecl)
+                                     || !DECL_FUNCTION_VERSIONED (olddecl)));
+         return 0;
+       }
     }
   else if (TREE_CODE (newdecl) == TEMPLATE_DECL)
     {
@@ -2598,7 +2601,12 @@ duplicate_decls (tree newdecl, tree olddecl, bool hiding, bool was_hidden)
       else
        {
          retrofit_lang_decl (newdecl);
-         DECL_LOCAL_DECL_ALIAS (newdecl) = DECL_LOCAL_DECL_ALIAS (olddecl);
+         tree alias = DECL_LOCAL_DECL_ALIAS (newdecl)
+           = DECL_LOCAL_DECL_ALIAS (olddecl);
+         DECL_ATTRIBUTES (alias)
+           = (*targetm.merge_decl_attributes) (alias, newdecl);
+         if (TREE_CODE (newdecl) == FUNCTION_DECL)
+           merge_attribute_bits (newdecl, alias);
        }
     }
 

diff --git a/gcc/cp/decl2.cc b/gcc/cp/decl2.cc
index c780702..e10331f 100644 (file)
--- a/gcc/cp/decl2.cc
+++ b/gcc/cp/decl2.cc
@@ -1637,8 +1637,16 @@ find_last_decl (tree decl)
          if (TREE_CODE (*iter) == OVERLOAD)
            continue;
 
-         if (decls_match (decl, *iter, /*record_decls=*/false))
-           return *iter;
+         tree d = *iter;
+
+         /* We can't compare versions in the middle of processing the
+            attribute that has the version.  */
+         if (TREE_CODE (d) == FUNCTION_DECL
+             && DECL_FUNCTION_VERSIONED (d))
+           return NULL_TREE;
+
+         if (decls_match (decl, d, /*record_decls=*/false))
+           return d;
        }
       return NULL_TREE;
     }

diff --git a/gcc/testsuite/g++.target/i386/mv31.C b/gcc/testsuite/g++.target/i386/mv31.C
new file mode 100644 (file)
index 0000000..5d8fd1d
--- /dev/null
+++ b/gcc/testsuite/g++.target/i386/mv31.C
@@ -0,0 +1,10 @@
+// PR c++/104669
+
+void bar()
+{
+  int foo(void);
+  int foo(void) __attribute__((target("sse")));
+  int foo(void) __attribute__((target("default")));
+  int (*p)(void) = &foo;
+  return;
+}