From 2f72c427cfac0277fdc2e1f4fb19432d09d6fb45 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Tue, 13 Nov 2007 18:05:45 +0000
Subject: [PATCH] improve handling of address of global when checking for
 constants and initializers.  Patch by Sanghyeon Seo, thanks!

llvm-svn: 44049
---
 clang/AST/Expr.cpp                 | 22 ++++++++++++++++++++++
 clang/include/clang/AST/Expr.h     |  4 ++++
 clang/test/Sema/address-constant.c |  7 +++++++
 3 files changed, 33 insertions(+)
 create mode 100644 clang/test/Sema/address-constant.c

diff --git a/clang/AST/Expr.cpp b/clang/AST/Expr.cpp
index 4505feca77e8..10f0895695eb 100644
--- a/clang/AST/Expr.cpp
+++ b/clang/AST/Expr.cpp
@@ -359,6 +359,22 @@ Expr::isModifiableLvalueResult Expr::isModifiableLvalue() const {
   return MLV_Valid;    
 }
 
+bool Expr::hasStaticStorage() const {
+  switch (getStmtClass()) {
+  default:
+    return false;
+  case DeclRefExprClass: {
+    const Decl *D = cast<DeclRefExpr>(this)->getDecl();
+    if (const VarDecl *VD = dyn_cast<VarDecl>(D))
+      return VD->hasStaticStorage();
+    return false;
+  }
+  case MemberExprClass:
+    const MemberExpr *M = cast<MemberExpr>(this);
+    return !M->isArrow() && M->getBase()->hasStaticStorage();
+  }
+}
+
 bool Expr::isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const {
   switch (getStmtClass()) {
   default:
@@ -391,11 +407,17 @@ bool Expr::isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const {
     if (isa<EnumConstantDecl>(D) || isa<FunctionDecl>(D))
       return true;
     if (Loc) *Loc = getLocStart();
+    if (isa<VarDecl>(D))
+      return TR->isArrayType();
     return false;
   }
   case UnaryOperatorClass: {
     const UnaryOperator *Exp = cast<UnaryOperator>(this);
     
+    // C99 6.6p9
+    if (Exp->getOpcode() == UnaryOperator::AddrOf)
+      return Exp->getSubExpr()->hasStaticStorage();
+
     // Get the operand value.  If this is sizeof/alignof, do not evalute the
     // operand.  This affects C99 6.6p3.
     if (!Exp->isSizeOfAlignOfOp() &&
diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
index 7f47a299b3d9..e69344690ddd 100644
--- a/clang/include/clang/AST/Expr.h
+++ b/clang/include/clang/AST/Expr.h
@@ -105,6 +105,10 @@ public:
   /// isConstantExpr - Return true if this expression is a valid constant expr.
   bool isConstantExpr(ASTContext &Ctx, SourceLocation *Loc) const;
   
+  /// hasStaticStorage - Return true if this expression has static storage
+  /// duration.
+  bool hasStaticStorage() const;
+
   static bool classof(const Stmt *T) { 
     return T->getStmtClass() >= firstExprConstant &&
            T->getStmtClass() <= lastExprConstant; 
diff --git a/clang/test/Sema/address-constant.c b/clang/test/Sema/address-constant.c
new file mode 100644
index 000000000000..0b451cc39c0c
--- /dev/null
+++ b/clang/test/Sema/address-constant.c
@@ -0,0 +1,7 @@
+// RUN: clang -fsyntax-only -verify %s
+
+int i;
+int a[] = {0};
+struct { int i; } s;
+
+int *array[] = {&i, a, &s.i};