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[lto][patch] Fix linking error
- From: Rafael Espindola <espindola at google dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Diego Novillo <dnovillo at google dot com>
- Date: Wed, 11 Mar 2009 18:58:03 +0000
- Subject: [lto][patch] Fix linking error
The attached patch fixes the include testcase. The problem was that
cc1plus was writing function decls to disk that were only reachable
via the DECL_INITIAL of a vtable. It was doing so even if the vtable
had a home in another file and the vtable VAR_DECL was DECL_EXTERNAL.
Since the function decl was not really used, there was no cgraph node
for it.
In wpa we assume that if a decl has a node, then the prevailing decl
also has. This was false if the file described above (with a decl but
no cgraph node for it) was linked with a file that actually used the
function and therefore had both a function decl and a node.
One option would be to make wpa handle that case, but it is much
easier to just ovoid writing decls that are not used.
Bootstrapped and regression tested.
2009-03-11 Rafael Avila de Espindola <espindola@google.com>
* g++.dg/lto/20090311_0.C: New.
* g++.dg/lto/20090311_1.C: New.
2009-03-11 Rafael Avila de Espindola <espindola@google.com>
* tree.c (free_lang_data_in_decl): Free DECL_INITIAL of DECL_EXTERNAL
VAR_DECLs.
Cheers,
--
Rafael Avila de Espindola
Google | Gordon House | Barrow Street | Dublin 4 | Ireland
Registered in Dublin, Ireland | Registration Number: 368047
diff --git a/gcc/testsuite/g++.dg/lto/20090311_0.C b/gcc/testsuite/g++.dg/lto/20090311_0.C
new file mode 100644
index 0000000..6c6e197
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/20090311_0.C
@@ -0,0 +1,12 @@
+class C1 {
+public: virtual ~C1() {
+}
+};
+class C2 : public C1 {
+public:
+ C2(void *q);
+ virtual void A();
+};
+int main(int argc, char **argv) {
+ C2 h(0);
+}
diff --git a/gcc/testsuite/g++.dg/lto/20090311_1.C b/gcc/testsuite/g++.dg/lto/20090311_1.C
new file mode 100644
index 0000000..e78da72
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/20090311_1.C
@@ -0,0 +1,13 @@
+class C1 {
+public: virtual ~C1() {
+}
+};
+class C2 : public C1 {
+ C2(void *q);
+ virtual void A();
+};
+void C2::A() {
+}
+C2::C2(void *q)
+{
+}
diff --git a/gcc/tree.c b/gcc/tree.c
index 8e94d0c..fee59cd 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4034,6 +4034,9 @@ free_lang_data_in_decl (tree decl)
&& TREE_CODE (expr) == VAR_DECL
&& !TREE_STATIC (expr) && !DECL_EXTERNAL (expr))
SET_DECL_DEBUG_EXPR (decl, NULL_TREE);
+
+ if (DECL_EXTERNAL (decl))
+ DECL_INITIAL (decl) = NULL_TREE;
}
else if (TREE_CODE (decl) == TYPE_DECL)
{