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authorRafael Espindola <rafael.espindola@gmail.com>2013-11-22 17:58:12 +0000
committerRafael Espindola <rafael.espindola@gmail.com>2013-11-22 17:58:12 +0000
commit4799cdb81ef26645292d7183cdcd81946d76353c (patch)
tree34cbf940ac47e52027684dd5fcd64585eb9815be /lib/Transforms
parent089443891249760b2a81b5f9da1503290a35d13f (diff)
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Add a fixed version of r195470 back.
The fix is simply to use CurI instead of I when handling aliases to avoid accessing a invalid iterator. original message: Convert linkonce* to weak* instead of strong. Also refactor the logic into a helper function. This is an important improve on mingw where the linker complains about mixed weak and strong symbols. Converting to weak ensures that the symbol is not dropped, but keeps in a comdat, making the linker happy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195477 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms')
-rw-r--r--lib/Transforms/IPO/ExtractGV.cpp54
1 files changed, 37 insertions, 17 deletions
diff --git a/lib/Transforms/IPO/ExtractGV.cpp b/lib/Transforms/IPO/ExtractGV.cpp
index fa3d72ddcf..50fb3e691c 100644
--- a/lib/Transforms/IPO/ExtractGV.cpp
+++ b/lib/Transforms/IPO/ExtractGV.cpp
@@ -21,6 +21,38 @@
#include <algorithm>
using namespace llvm;
+/// Make sure GV is visible from both modules. Delete is true if it is
+/// being deleted from this module.
+/// This also makes sure GV cannot be dropped so that references from
+/// the split module remain valid.
+static void makeVisible(GlobalValue &GV, bool Delete) {
+ bool Local = GV.hasLocalLinkage();
+ if (Local)
+ GV.setVisibility(GlobalValue::HiddenVisibility);
+
+ if (Local || Delete) {
+ GV.setLinkage(GlobalValue::ExternalLinkage);
+ return;
+ }
+
+ if (!GV.hasLinkOnceLinkage()) {
+ assert(!GV.isDiscardableIfUnused());
+ return;
+ }
+
+ // Map linkonce* to weak* so that llvm doesn't drop this GV.
+ switch(GV.getLinkage()) {
+ default:
+ llvm_unreachable("Unexpected linkage");
+ case GlobalValue::LinkOnceAnyLinkage:
+ GV.setLinkage(GlobalValue::WeakAnyLinkage);
+ return;
+ case GlobalValue::LinkOnceODRLinkage:
+ GV.setLinkage(GlobalValue::WeakODRLinkage);
+ return;
+ }
+}
+
namespace {
/// @brief A pass to extract specific functions and their dependencies.
class GVExtractorPass : public ModulePass {
@@ -60,12 +92,7 @@ namespace {
continue;
}
- bool Local = I->isDiscardableIfUnused();
- if (Local)
- I->setVisibility(GlobalValue::HiddenVisibility);
-
- if (Local || Delete)
- I->setLinkage(GlobalValue::ExternalLinkage);
+ makeVisible(*I, Delete);
if (Delete)
I->setInitializer(0);
@@ -80,12 +107,7 @@ namespace {
continue;
}
- bool Local = I->isDiscardableIfUnused();
- if (Local)
- I->setVisibility(GlobalValue::HiddenVisibility);
-
- if (Local || Delete)
- I->setLinkage(GlobalValue::ExternalLinkage);
+ makeVisible(*I, Delete);
if (Delete)
I->deleteBody();
@@ -97,12 +119,10 @@ namespace {
Module::alias_iterator CurI = I;
++I;
- if (CurI->isDiscardableIfUnused()) {
- CurI->setVisibility(GlobalValue::HiddenVisibility);
- CurI->setLinkage(GlobalValue::ExternalLinkage);
- }
+ bool Delete = deleteStuff == (bool)Named.count(CurI);
+ makeVisible(*CurI, Delete);
- if (deleteStuff == (bool)Named.count(CurI)) {
+ if (Delete) {
Type *Ty = CurI->getType()->getElementType();
CurI->removeFromParent();