From 9e09f5d361c50373435b9e142da8538034d84601 Mon Sep 17 00:00:00 2001
From: Anders Carlsson <andersca@mac.com>
Date: Fri, 5 Dec 2008 05:09:56 +0000
Subject: [PATCH] Make Sema::CheckForConstantInitializer use Expr::Evaluate.
 This fixes PR3130.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@60580 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaDecl.cpp               | 8 ++++++++
 test/CodeGen/PR3130-cond-constant.c | 3 +++
 test/Sema/constant-builtins.c       | 3 ++-
 3 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/PR3130-cond-constant.c

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 65abc36cb0..411307522b 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1651,8 +1651,13 @@ bool Sema::CheckArithmeticConstantExpression(const Expr* Init) {
 }
 
 bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
+  Expr::EvalResult Result;
+
   Init = Init->IgnoreParens();
 
+  if (Init->Evaluate(Result, Context) && !Result.HasSideEffects)
+    return false;
+
   // Look through CXXDefaultArgExprs; they have no meaning in this context.
   if (CXXDefaultArgExpr* DAE = dyn_cast<CXXDefaultArgExpr>(Init))
     return CheckForConstantInitializer(DAE->getExpr(), DclT);
@@ -1672,6 +1677,9 @@ bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
     return false;
   }
 
+  // FIXME: We can probably remove some of this code below, now that 
+  // Expr::Evaluate is doing the heavy lifting for scalars.
+  
   if (Init->isNullPointerConstant(Context))
     return false;
   if (Init->getType()->isArithmeticType()) {
diff --git a/test/CodeGen/PR3130-cond-constant.c b/test/CodeGen/PR3130-cond-constant.c
new file mode 100644
index 0000000000..7aa2ce1bc0
--- /dev/null
+++ b/test/CodeGen/PR3130-cond-constant.c
@@ -0,0 +1,3 @@
+// RUN: clang -emit-llvm %s -o -
+
+int a = 2.0 ? 1 : 2;
diff --git a/test/Sema/constant-builtins.c b/test/Sema/constant-builtins.c
index d6cf45755d..b1c5e2af10 100644
--- a/test/Sema/constant-builtins.c
+++ b/test/Sema/constant-builtins.c
@@ -19,5 +19,6 @@ int h0 = __builtin_types_compatible_p(int,float); // expected-warning {{extensio
 
 short somefunc();
 
-short t = __builtin_constant_p(5353) ? 42 : somefunc(); // expected-warning {{expression is not a constant, but is accepted as one by GNU extensions}}
+short t = __builtin_constant_p(5353) ? 42 : somefunc();
+