This is another place where our one-true-decl representation breaks
down. The fix here propagates the assembly name to the ns-scope alias.
that fixes the reported problem but changes the behaviour when the user
has explicitly declared the entity in its namespace. However, we didn't
handle that case 'correctly' anyway before. Previously we'd also ignore
the explicitly specified assembler name, now we propagate it. It's not
clear to me what the desired semantics would be in decorating just one
of the local extern declarations this way. I don't think we can really
do better without propagating this aliasing property into the middle end
(which is also needed for some constexpr handling, see PR97306). I
tried that before and it turned into a rat-hole.
PR c++/99508
gcc/cp/
* decl.c (make_rtl_for_nonlocal_decl): Propagate local-extern's
assembler name to the ns alias.
gcc/testsuite/
* g++.dg/ext/pr99508.C: New.
--
Nathan Sidwell
diff --git c/gcc/cp/decl.c w/gcc/cp/decl.c
index 1742e286d9f..9c7f6e59bbb 100644
--- c/gcc/cp/decl.c
+++ w/gcc/cp/decl.c
@@ -7157,6 +7157,13 @@ make_rtl_for_nonlocal_decl (tree decl, tree init, const char* asmspec)
&& fndecl_built_in_p (decl, BUILT_IN_NORMAL))
set_builtin_user_assembler_name (decl, asmspec);
set_user_assembler_name (decl, asmspec);
+ if (DECL_LOCAL_DECL_P (decl))
+ if (auto ns_decl = DECL_LOCAL_DECL_ALIAS (decl))
+ /* We have to propagate the name to the ns-alias.
+ This is horrible, as we're affecting a
+ possibly-shared decl. Again, a one-true-decl
+ model breaks down. */
+ set_user_assembler_name (ns_decl, asmspec);
}
}
diff --git c/gcc/testsuite/g++.dg/ext/pr99508.C w/gcc/testsuite/g++.dg/ext/pr99508.C
new file mode 100644
index 00000000000..201a287bf61
--- /dev/null
+++ w/gcc/testsuite/g++.dg/ext/pr99508.C
@@ -0,0 +1,20 @@
+// PR 99508, local exerns with aliased names
+// { dg-do link }
+int foo()
+{
+ void bar() asm ("bar_assembler");
+ extern unsigned buzz asm("buzz_assembler");
+ bar();
+ return buzz;
+}
+
+void ALIASbar () asm ("bar_assembler");
+void ALIASbar ()
+{
+}
+
+unsigned ALIASbuz asm ("buzz_assembler") = 5;
+
+int main ()
+{
+}
