Apparently the Solaris C library headers play games with #pragma
redefine_extname such that we need the pragma to affect extern "C"
declarations in namespaces such as std, not just declarations at file scope.
To implement this, I added another C-family hook "c_linkage_bindings"
that returns a list of C-linkage decls with the name in question. In
C/ObjC this just returns identifier_global_value, but it is more
involved in C++.
Tested x86_64-pc-linux-gnu, applied to trunk.
commit 322a8559a2b12b06c13951494807fc9525fa1763
Author: Jason Merrill <ja...@redhat.com>
Date: Thu Jul 21 12:27:34 2011 -0400
PR c++/30112
gcc/c-family/
* c-common.h: Declare c_linkage_bindings.
* c-pragma.c (handle_pragma_redefine_extname): Use it.
gcc/
* c-decl.c (c_linkage_bindings): Define.
gcc/cp/
* decl.c (cp_finish_decl): Apply pragma redefine_extname in
other namespaces as well.
* name-lookup.c (c_linkage_bindings): Define.
(lookup_extern_c_fun_in_all_ns): Rename from
lookup_extern_c_fun_binding_in_all_ns. Return tree.
(pushdecl_maybe_friend_1): Adjust. Copy DECL_ASSEMBLER_NAME.
diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index 3ed3c46..33d2615 100644
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -8501,6 +8501,14 @@ identifier_global_value (tree t)
return 0;
}
+/* In C, the only C-linkage public declaration is at file scope. */
+
+tree
+c_linkage_bindings (tree name)
+{
+ return identifier_global_value (name);
+}
+
/* Record a builtin type for C. If NAME is non-NULL, it is the name used;
otherwise the name is found in ridpointers from RID_INDEX. */
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index 13aae0f..202be02 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -710,6 +710,7 @@ extern void c_register_addr_space (const char *str, addr_space_t as);
extern bool in_late_binary_op;
extern const char *c_addr_space_name (addr_space_t as);
extern tree identifier_global_value (tree);
+extern tree c_linkage_bindings (tree);
extern void record_builtin_type (enum rid, const char *, tree);
extern tree build_void_list_node (void);
extern void start_fname_decls (void);
diff --git a/gcc/c-family/c-pragma.c b/gcc/c-family/c-pragma.c
index 93735aa..5c8bc1f 100644
--- a/gcc/c-family/c-pragma.c
+++ b/gcc/c-family/c-pragma.c
@@ -417,8 +417,9 @@ static void handle_pragma_redefine_extname (cpp_reader *);
static void
handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
{
- tree oldname, newname, decl, x;
+ tree oldname, newname, decls, x;
enum cpp_ttype t;
+ bool found;
if (pragma_lex (&oldname) != CPP_NAME)
GCC_BAD ("malformed #pragma redefine_extname, ignored");
@@ -428,26 +429,42 @@ handle_pragma_redefine_extname (cpp_reader * ARG_UNUSED (dummy))
if (t != CPP_EOF)
warning (OPT_Wpragmas, "junk at end of %<#pragma redefine_extname%>");
- decl = identifier_global_value (oldname);
- if (decl
- && (TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
- && (TREE_CODE (decl) == FUNCTION_DECL
- || TREE_CODE (decl) == VAR_DECL)
- && has_c_linkage (decl))
+ found = false;
+ for (decls = c_linkage_bindings (oldname);
+ decls; )
{
- if (DECL_ASSEMBLER_NAME_SET_P (decl))
+ tree decl;
+ if (TREE_CODE (decls) == TREE_LIST)
{
- const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
- name = targetm.strip_name_encoding (name);
-
- if (strcmp (name, IDENTIFIER_POINTER (newname)))
- warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
- "conflict with previous rename");
+ decl = TREE_VALUE (decls);
+ decls = TREE_CHAIN (decls);
}
else
- change_decl_assembler_name (decl, newname);
+ {
+ decl = decls;
+ decls = NULL_TREE;
+ }
+
+ if ((TREE_PUBLIC (decl) || DECL_EXTERNAL (decl))
+ && (TREE_CODE (decl) == FUNCTION_DECL
+ || TREE_CODE (decl) == VAR_DECL))
+ {
+ found = true;
+ if (DECL_ASSEMBLER_NAME_SET_P (decl))
+ {
+ const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
+ name = targetm.strip_name_encoding (name);
+
+ if (strcmp (name, IDENTIFIER_POINTER (newname)))
+ warning (OPT_Wpragmas, "#pragma redefine_extname ignored due to "
+ "conflict with previous rename");
+ }
+ else
+ change_decl_assembler_name (decl, newname);
+ }
}
- else
+
+ if (!found)
/* We have to add this to the rename list even if there's already
a global value that doesn't meet the above criteria, because in
C++ "struct foo {...};" puts "foo" in the current namespace but
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 0679303..2000bd4 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -5919,7 +5919,7 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
cleanup = NULL_TREE;
/* If a name was specified, get the string. */
- if (global_scope_p (current_binding_level))
+ if (at_namespace_scope_p ())
asmspec_tree = maybe_apply_renaming_pragma (decl, asmspec_tree);
if (asmspec_tree && asmspec_tree != error_mark_node)
asmspec = TREE_STRING_POINTER (asmspec_tree);
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index 00d21d2..1afd9ed 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -52,7 +52,7 @@ static bool qualified_lookup_using_namespace (tree, tree,
struct scope_binding *, int);
static tree lookup_type_current_level (tree);
static tree push_using_directive (tree);
-static cxx_binding* lookup_extern_c_fun_binding_in_all_ns (tree);
+static tree lookup_extern_c_fun_in_all_ns (tree);
/* The :: namespace. */
@@ -768,18 +768,12 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
&& !DECL_ARTIFICIAL (x)
&& !DECL_IN_SYSTEM_HEADER (x))
{
- cxx_binding *function_binding =
- lookup_extern_c_fun_binding_in_all_ns (x);
- tree previous = (function_binding
- ? function_binding->value
- : NULL_TREE);
+ tree previous = lookup_extern_c_fun_in_all_ns (x);
if (previous
&& !DECL_ARTIFICIAL (previous)
&& !DECL_IN_SYSTEM_HEADER (previous)
&& DECL_CONTEXT (previous) != DECL_CONTEXT (x))
{
- tree previous = function_binding->value;
-
/* In case either x or previous is declared to throw an exception,
make sure both exception specifications are equal. */
if (decls_match (x, previous))
@@ -805,6 +799,9 @@ pushdecl_maybe_friend_1 (tree x, bool is_friend)
"due to different exception specifications");
return error_mark_node;
}
+ if (DECL_ASSEMBLER_NAME_SET_P (previous))
+ SET_DECL_ASSEMBLER_NAME (x,
+ DECL_ASSEMBLER_NAME (previous));
}
else
{
@@ -1996,14 +1993,14 @@ binding_for_name (cp_binding_level *scope, tree name)
}
/* Walk through the bindings associated to the name of FUNCTION,
- and return the first binding that declares a function with a
+ and return the first declaration of a function with a
"C" linkage specification, a.k.a 'extern "C"'.
This function looks for the binding, regardless of which scope it
has been defined in. It basically looks in all the known scopes.
Note that this function does not lookup for bindings of builtin functions
or for functions declared in system headers. */
-static cxx_binding*
-lookup_extern_c_fun_binding_in_all_ns (tree function)
+static tree
+lookup_extern_c_fun_in_all_ns (tree function)
{
tree name;
cxx_binding *iter;
@@ -2017,17 +2014,52 @@ lookup_extern_c_fun_binding_in_all_ns (tree function)
iter;
iter = iter->previous)
{
- if (iter->value
- && TREE_CODE (iter->value) == FUNCTION_DECL
- && DECL_EXTERN_C_P (iter->value)
- && !DECL_ARTIFICIAL (iter->value))
+ tree ovl;
+ for (ovl = iter->value; ovl; ovl = OVL_NEXT (ovl))
{
- return iter;
+ tree decl = OVL_CURRENT (ovl);
+ if (decl
+ && TREE_CODE (decl) == FUNCTION_DECL
+ && DECL_EXTERN_C_P (decl)
+ && !DECL_ARTIFICIAL (decl))
+ {
+ return decl;
+ }
}
}
return NULL;
}
+/* Returns a list of C-linkage decls with the name NAME. */
+
+tree
+c_linkage_bindings (tree name)
+{
+ tree decls = NULL_TREE;
+ cxx_binding *iter;
+
+ for (iter = IDENTIFIER_NAMESPACE_BINDINGS (name);
+ iter;
+ iter = iter->previous)
+ {
+ tree ovl;
+ for (ovl = iter->value; ovl; ovl = OVL_NEXT (ovl))
+ {
+ tree decl = OVL_CURRENT (ovl);
+ if (decl
+ && DECL_EXTERN_C_P (decl)
+ && !DECL_ARTIFICIAL (decl))
+ {
+ if (decls == NULL_TREE)
+ decls = decl;
+ else
+ decls = tree_cons (NULL_TREE, decl, decls);
+ }
+ }
+ }
+ return decls;
+}
+
/* Insert another USING_DECL into the current binding level, returning
this declaration. If this is a redeclaration, do nothing, and
return NULL_TREE if this not in namespace scope (in namespace
diff --git a/gcc/testsuite/g++.dg/other/pragma-re-1.C b/gcc/testsuite/g++.dg/other/pragma-re-1.C
index 35ffab1..6a94c5d 100644
--- a/gcc/testsuite/g++.dg/other/pragma-re-1.C
+++ b/gcc/testsuite/g++.dg/other/pragma-re-1.C
@@ -2,6 +2,12 @@
/* { dg-final { scan-assembler-not "foo" } } */
/* { dg-final { scan-assembler "_Z3bazv" } } */
/* { dg-final { scan-assembler-not "baq" } } */
+/* { dg-final { scan-assembler "tut" } } */
+/* { dg-final { scan-assembler-not "gee" } } */
+/* { dg-final { scan-assembler "bang" } } */
+/* { dg-final { scan-assembler-not "whiz" } } */
+/* { dg-final { scan-assembler "eek" } } */
+/* { dg-final { scan-assembler-not "boo" } } */
#ifndef __PRAGMA_REDEFINE_EXTNAME
#error
@@ -17,3 +23,35 @@ int (*p)(void) = foo;
#pragma redefine_extname baz baq
extern int baz(void);
int (*q)(void) = baz;
+
+// PR c++/30112
+// These are expected to work.
+#pragma redefine_extname gee tut
+namespace somewhere {
+ extern "C" int gee(void);
+ int (*r)(void) = gee;
+
+ extern "C" int whiz(void);
+ int whiz(int);
+}
+#pragma redefine_extname whiz bang
+int (*s)() = somewhere::whiz;
+
+namespace elsewhere {
+ extern "C" int whiz(void);
+}
+int (*t)() = elsewhere::whiz;
+
+namespace A
+{
+ extern "C" int boo(void);
+}
+
+namespace B
+{
+ extern "C" int boo(void);
+}
+#pragma redefine_extname boo eek
+
+int (*u)() = A::boo;
+int (*v)() = B::boo;
