r315638 - [Sema][Crash] Correctly handle an non-dependent noexcept expr in function template

[Erich Keane via cfe-commits]

Author: erichkeane
Date: Thu Oct 12 16:01:53 2017
New Revision: 315638

URL: http://llvm.org/viewvc/llvm-project?rev=315638&view=rev
Log:
[Sema][Crash] Correctly handle an non-dependent noexcept expr in function template

It seems that all of the other templated cases are handled correctly,
however the function template case was not correctly handled. This
patch recovers from this condition by setting the function to noexcept
after diagnosing. Previously it simply set NoexceptExpr to null,
which caused an Assert when this was evaluated during substitution.

Differential Revision:https://reviews.llvm.org/D38700


Modified:
    cfe/trunk/lib/Sema/SemaDeclCXX.cpp
    cfe/trunk/test/CXX/except/except.spec/p1.cpp

Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=315638&r1=315637&r2=315638&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Thu Oct 12 16:01:53 2017
@@ -14865,10 +14865,16 @@ void Sema::checkExceptionSpecification(
         return;
       }
 
-      if (!NoexceptExpr->isValueDependent())
-        NoexceptExpr = VerifyIntegerConstantExpression(NoexceptExpr, nullptr,
-                         diag::err_noexcept_needs_constant_expression,
-                         /*AllowFold*/ false).get();
+      if (!NoexceptExpr->isValueDependent()) {
+        ExprResult Result = VerifyIntegerConstantExpression(
+            NoexceptExpr, nullptr, diag::err_noexcept_needs_constant_expression,
+            /*AllowFold*/ false);
+        if (Result.isInvalid()) {
+          ESI.Type = EST_BasicNoexcept;
+          return;
+        }
+        NoexceptExpr = Result.get();
+      }
       ESI.NoexceptExpr = NoexceptExpr;
     }
     return;

Modified: cfe/trunk/test/CXX/except/except.spec/p1.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/except/except.spec/p1.cpp?rev=315638&r1=315637&r2=315638&view=diff
==============================================================================
--- cfe/trunk/test/CXX/except/except.spec/p1.cpp (original)
+++ cfe/trunk/test/CXX/except/except.spec/p1.cpp Thu Oct 12 16:01:53 2017
@@ -86,3 +86,12 @@ namespace PR11084 {
     f<0>(); // expected-note{{in instantiation of function template specialization}}
   }
 }
+
+namespace FuncTmplNoexceptError {
+  int a = 0;
+  // expected-error at +1{{argument to noexcept specifier must be a constant expression}}
+  template <class T> T f() noexcept(a++){ return {};}
+  void g(){
+    f<int>();
+  }
+};