Allow constant initializers to reference their defining decl.

 - PR3662.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@65472 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 20 insertions, 0 deletions

diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 349656f58b..ee2516a850 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -106,6 +106,10 @@ void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {
   llvm::GlobalVariable *GV = 
     CreateStaticBlockVarDecl(D, ".", llvm::GlobalValue::InternalLinkage);
 
+  // Store into LocalDeclMap before generating initializer to handle
+  // circular references.
+  DMEntry = GV;
+
   if (D.getInit()) {
     llvm::Constant *Init = CGM.EmitConstantExpr(D.getInit(), this);
 
@@ -162,6 +166,11 @@ void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {
   if (D.getAttr<UsedAttr>())
     CGM.AddUsedGlobal(GV);
 
+  // We may have to cast the constant because of the initializer
+  // mismatch above.
+  //
+  // FIXME: It is really dangerous to store this in the map; if anyone
+  // RAUW's the GV uses of this constant will be invalid.
   const llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(D.getType());
   const llvm::Type *LPtrTy =
     llvm::PointerType::get(LTy, D.getType().getAddressSpace());
diff --git a/test/CodeGen/const-init.c b/test/CodeGen/const-init.c
index f6199815ed..d88add36a9 100644
--- a/test/CodeGen/const-init.c
+++ b/test/CodeGen/const-init.c
@@ -85,4 +85,15 @@ void g18(void) {
   static int *p[] = { &g19 };
 }
 
+// RUN: grep '@g20.l0 = internal global .struct.g20_s1 <{ .struct.g20_s0\* null, .struct.g20_s0\*\* getelementptr (.struct.g20_s1\* @g20.l0, i32 0, i32 0) }>'  %t &&
+
+struct g20_s0;
+struct g20_s1 {
+  struct g20_s0 *f0, **f1;
+};
+void *g20(void) {
+  static struct g20_s1 l0 = { ((void*) 0), &l0.f0 };
+  return l0.f1;
+}
+
 // RUN: true