Emission of global variable initialializer was broken in rare
situation where a tentative decl was emitted *after* the actual
initialization. This occurs in some rare situations with static decls.
- PR3613.
- I'm not particularly happy with this fix, but I don't see a simpler
or more elegant solution yet.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65018 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index ca6ba14..17662ef 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -444,7 +444,7 @@
// FIXME: This is missing some important cases. For example, we
// need to check for uses in an alias.
if (!GlobalDeclMap.count(getMangledName(D))) {
- i++;
+ ++i;
continue;
}
@@ -623,6 +623,8 @@
Init = llvm::Constant::getNullValue(InitTy);
} else {
Init = EmitConstantExpr(D->getInit());
+ if (!Init)
+ ErrorUnsupported(D, "static initializer");
}
const llvm::Type* InitType = Init->getType();
@@ -634,6 +636,26 @@
llvm::GlobalValue::ExternalLinkage,
0, getMangledName(D),
&getModule(), 0, ASTTy.getAddressSpace());
+
+ } else if (GV->hasInitializer() && !GV->getInitializer()->isNullValue()) {
+ // If we already have this global and it has an initializer, then
+ // we are in the rare situation where we emitted the defining
+ // declaration of the global and are now being asked to emit a
+ // definition which would be common. This occurs, for example, in
+ // the following situation because statics can be emitted out of
+ // order:
+ //
+ // static int x;
+ // static int *y = &x;
+ // static int x = 10;
+ // int **z = &y;
+ //
+ // Bail here so we don't blow away the definition. Note that if we
+ // can't distinguish here if we emitted a definition with a null
+ // initializer, but this case is safe.
+ assert(!D->getInit() && "Emitting multiple definitions of a decl!");
+ return;
+
} else if (GV->getType() !=
llvm::PointerType::get(InitType, ASTTy.getAddressSpace())) {
// We have a definition after a prototype with the wrong type.