r204308 - [-Wunreachable-code] constexpr functions can be used as configuration values.

[Ted Kremenek]

Author: kremenek
Date: Thu Mar 20 01:07:35 2014
New Revision: 204308

URL: http://llvm.org/viewvc/llvm-project?rev=204308&view=rev
Log:
[-Wunreachable-code] constexpr functions can be used as configuration values.

Modified:
    cfe/trunk/lib/Analysis/ReachableCode.cpp
    cfe/trunk/test/SemaCXX/warn-unreachable.cpp

Modified: cfe/trunk/lib/Analysis/ReachableCode.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/ReachableCode.cpp?rev=204308&r1=204307&r2=204308&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/ReachableCode.cpp (original)
+++ cfe/trunk/lib/Analysis/ReachableCode.cpp Thu Mar 20 01:07:35 2014
@@ -139,6 +139,11 @@ static bool isConfigurationValue(const S
     S = Ex->IgnoreParenCasts();
 
   switch (S->getStmtClass()) {
+    case Stmt::CallExprClass: {
+      const FunctionDecl *Callee =
+        dyn_cast_or_null<FunctionDecl>(cast<CallExpr>(S)->getCalleeDecl());
+      return Callee ? Callee->isConstexpr() : false;
+    }
     case Stmt::DeclRefExprClass: {
       const DeclRefExpr *DR = cast<DeclRefExpr>(S);
       const ValueDecl *D = DR->getDecl();

Modified: cfe/trunk/test/SemaCXX/warn-unreachable.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-unreachable.cpp?rev=204308&r1=204307&r2=204308&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-unreachable.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-unreachable.cpp Thu Mar 20 01:07:35 2014
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 %s -fcxx-exceptions -fexceptions -fsyntax-only -verify -fblocks -Wunreachable-code-aggressive -Wno-unused-value
+// RUN: %clang_cc1 %s -fcxx-exceptions -fexceptions -fsyntax-only -verify -fblocks -std=c++11 -Wunreachable-code-aggressive -Wno-unused-value
 
 int &halt() __attribute__((noreturn));
 int &live();
@@ -234,3 +234,24 @@ Frobozz test_return_object_control_flow(
   return Frobozz(flag ? 42 : 24); // expected-warning {{code will never be executed}}
 }
 
+void somethingToCall();
+
+ static constexpr bool isConstExprConfigValue() { return true; }
+ 
+ int test_const_expr_config_value() {
+   if (isConstExprConfigValue()) {
+     somethingToCall();
+     return 0;
+   }
+   somethingToCall(); // no-warning
+   return 1;
+ }
+ int test_const_expr_config_value_2() {
+   if (!isConstExprConfigValue()) {
+     somethingToCall(); // no-warning
+     return 0;
+   }
+   somethingToCall();
+   return 1;
+ }
+