Implement codegen for the following static var init.

void g() {
  static char a[10];
  static char *b = a;
}

Now we can compile wget!

llvm-svn: 47627

clang/CodeGen/CGDecl.cpp

@@ -77,7 +77,7 @@ void CodeGenFunction::EmitStaticBlockVarDecl(const BlockVarDecl &D) {
   if (D.getInit() == 0) {
     Init = llvm::Constant::getNullValue(LTy);
   } else {
-    Init = CGM.EmitGlobalInit(D.getInit());
+    Init = CGM.EmitConstantExpr(D.getInit(), this);
   }
 
   assert(Init && "Unable to create initialiser for static decl");

clang/CodeGen/CGExprConstant.cpp

@@ -25,9 +25,10 @@ namespace  {
 class VISIBILITY_HIDDEN ConstExprEmitter : 
   public StmtVisitor<ConstExprEmitter, llvm::Constant*> {
   CodeGenModule &CGM;
+  CodeGenFunction *CGF;
 public:
-  ConstExprEmitter(CodeGenModule &cgm)
-    : CGM(cgm) {
+  ConstExprEmitter(CodeGenModule &cgm, CodeGenFunction *cgf)
+    : CGM(cgm), CGF(cgf) {
   }
     
   //===--------------------------------------------------------------------===//
@@ -534,8 +535,10 @@ public:
         return CGM.GetAddrOfFunctionDecl(FD, false);
       if (const FileVarDecl* VD = dyn_cast<FileVarDecl>(Decl))
         return CGM.GetAddrOfGlobalVar(VD, false);
-      // We can end up here with static block-scope variables (and others?)
-      // FIXME: How do we implement block-scope variables?!
+      if (const BlockVarDecl* BVD = dyn_cast<BlockVarDecl>(Decl)) {
+        assert(CGF && "Can't access static local vars without CGF");
+        return CGF->GetAddrOfStaticLocalVar(BVD);
+      }
       break;
     }
     case Expr::MemberExprClass: {
@@ -604,7 +607,8 @@ public:
 }  // end anonymous namespace.
 
 
-llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E)
+llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E,
+                                                CodeGenFunction *CGF)
 {
   QualType type = E->getType().getCanonicalType();
   
@@ -616,5 +620,5 @@ llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E)
     } 
   }
   
-  return ConstExprEmitter(*this).Visit(const_cast<Expr*>(E));
+  return ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E));
 }

clang/CodeGen/CodeGenFunction.cpp

@@ -40,6 +40,10 @@ llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) {
   return BB = new llvm::BasicBlock(S->getName());
 }
 
+llvm::Constant *
+CodeGenFunction::GetAddrOfStaticLocalVar(const BlockVarDecl *BVD) {
+  return cast<llvm::Constant>(LocalDeclMap[BVD]);
+}
 
 const llvm::Type *CodeGenFunction::ConvertType(QualType T) {
   return CGM.getTypes().ConvertType(T);

clang/CodeGen/CodeGenFunction.h

@@ -335,6 +335,9 @@ public:
 
   /// getCGRecordLayout - Return record layout info.
   const CGRecordLayout *getCGRecordLayout(CodeGenTypes &CGT, QualType RTy);
+
+  /// GetAddrOfStaticLocalVar - Return the address of a static local variable.
+  llvm::Constant *GetAddrOfStaticLocalVar(const BlockVarDecl *BVD);
   //===--------------------------------------------------------------------===//
   //                            Declaration Emission
   //===--------------------------------------------------------------------===//

clang/CodeGen/CodeGenModule.h

@@ -41,6 +41,8 @@ namespace clang {
     
 namespace CodeGen {
 
+  class CodeGenFunction;
+
 /// CodeGenModule - This class organizes the cross-module state that is used
 /// while generating LLVM code.
 class CodeGenModule {
@@ -95,7 +97,7 @@ public:
   void EmitGlobalVarDeclarator(const FileVarDecl *D);
   void UpdateCompletedType(const TagDecl *D);
   llvm::Constant *EmitGlobalInit(const Expr *E);
-  llvm::Constant *EmitConstantExpr(const Expr *E);
+  llvm::Constant *EmitConstantExpr(const Expr *E, CodeGenFunction *CGF = 0);
     
   /// WarnUnsupported - Print out a warning that codegen doesn't support the
   /// specified stmt yet.

clang/test/CodeGen/staticinit.c

@@ -1,4 +1,4 @@
-// RUN: clang -emit-llvm %s
+// RUN: clang -emit-llvm < %s | grep "g.b = internal global i8. getelementptr"
 
 struct AStruct { 
 	int i;
@@ -13,3 +13,8 @@ void f() {
   static char* strs[] = { "one", "two", "three", "four" };
   static struct AStruct myStruct = { 1, "two", 3.0 };
 }
+
+void g() {
+  static char a[10];
+  static char *b = a;
+}