r260675 - Fix ICE with constexpr and friend functions

[Olivier Goffart via cfe-commits]

Author: ogoffart
Date: Fri Feb 12 06:34:44 2016
New Revision: 260675

URL: http://llvm.org/viewvc/llvm-project?rev=260675&view=rev
Log:
Fix ICE with constexpr and friend functions

Fix a crash while parsing this code:

  struct X  {
    friend constexpr int foo(X*) { return 12; }
    static constexpr int j = foo(static_cast<X*>(nullptr));
  };

Differential Revision: http://reviews.llvm.org/D16973

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=260675&r1=260674&r2=260675&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Fri Feb 12 06:34:44 2016
@@ -3736,7 +3736,8 @@ static bool CheckTrivialDefaultConstruct
 /// expression.
 static bool CheckConstexprFunction(EvalInfo &Info, SourceLocation CallLoc,
                                    const FunctionDecl *Declaration,
-                                   const FunctionDecl *Definition) {
+                                   const FunctionDecl *Definition,
+                                   const Stmt *Body) {
   // Potential constant expressions can contain calls to declared, but not yet
   // defined, constexpr functions.
   if (Info.checkingPotentialConstantExpression() && !Definition &&
@@ -3749,7 +3750,8 @@ static bool CheckConstexprFunction(EvalI
     return false;
 
   // Can we evaluate this function call?
-  if (Definition && Definition->isConstexpr() && !Definition->isInvalidDecl())
+  if (Definition && Definition->isConstexpr() &&
+      !Definition->isInvalidDecl() && Body)
     return true;
 
   if (Info.getLangOpts().CPlusPlus11) {
@@ -4275,7 +4277,7 @@ public:
     const FunctionDecl *Definition = nullptr;
     Stmt *Body = FD->getBody(Definition);
 
-    if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition) ||
+    if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body) ||
         !HandleFunctionCall(E->getExprLoc(), Definition, This, Args, Body, Info,
                             Result, ResultSlot))
       return false;
@@ -5483,9 +5485,9 @@ bool RecordExprEvaluator::VisitCXXConstr
   }
 
   const FunctionDecl *Definition = nullptr;
-  FD->getBody(Definition);
+  auto Body = FD->getBody(Definition);
 
-  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition))
+  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
     return false;
 
   // Avoid materializing a temporary for an elidable copy/move constructor.
@@ -5971,9 +5973,9 @@ bool ArrayExprEvaluator::VisitCXXConstru
   }
 
   const FunctionDecl *Definition = nullptr;
-  FD->getBody(Definition);
+  auto Body = FD->getBody(Definition);
 
-  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition))
+  if (!CheckConstexprFunction(Info, E->getExprLoc(), FD, Definition, Body))
     return false;
 
   if (ZeroInit && !HadZeroInit) {

Modified: cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp?rev=260675&r1=260674&r2=260675&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp (original)
+++ cfe/trunk/test/SemaCXX/constant-expression-cxx11.cpp Fri Feb 12 06:34:44 2016
@@ -2005,3 +2005,13 @@ namespace PR24597 {
   constexpr int a = *f().p;
   constexpr int b = *g().p;
 }
+
+namespace IncompleteClass {
+  struct XX {
+    static constexpr int f(XX*) { return 1; } // expected-note {{here}}
+    friend constexpr int g(XX*) { return 2; } // expected-note {{here}}
+
+    static constexpr int i = f(static_cast<XX*>(nullptr)); // expected-error {{constexpr variable 'i' must be initialized by a constant expression}}  expected-note {{undefined function 'f' cannot be used in a constant expression}}
+    static constexpr int j = g(static_cast<XX*>(nullptr)); // expected-error {{constexpr variable 'j' must be initialized by a constant expression}}  expected-note {{undefined function 'g' cannot be used in a constant expression}}
+  };
+}