[clang] 038edf6 - Don't reject uses of void-returning consteval functions.

[Richard Smith via cfe-commits]

Author: Richard Smith
Date: 2020-08-20T15:40:09-07:00
New Revision: 038edf6029bafe70b1f7165abe2b0e61ddf506b3

URL: https://github.com/llvm/llvm-project/commit/038edf6029bafe70b1f7165abe2b0e61ddf506b3
DIFF: https://github.com/llvm/llvm-project/commit/038edf6029bafe70b1f7165abe2b0e61ddf506b3.diff

LOG: Don't reject uses of void-returning consteval functions.

Added: 
    

Modified: 
    clang/lib/AST/ExprConstant.cpp
    clang/test/SemaCXX/consteval-return-void.cpp

Removed: 
    


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diff  --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index 2c2dd6a3ef3a..b22797b5c3c0 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -2299,6 +2299,10 @@ static bool
 CheckConstantExpression(EvalInfo &Info, SourceLocation DiagLoc, QualType Type,
                         const APValue &Value,
                         Expr::ConstExprUsage Usage = Expr::EvaluateForCodeGen) {
+  // Nothing to check for a constant expression of type 'cv void'.
+  if (Type->isVoidType())
+    return true;
+
   CheckedTemporaries CheckedTemps;
   return CheckEvaluationResult(CheckEvaluationResultKind::ConstantExpression,
                                Info, DiagLoc, Type, Value, Usage,

diff  --git a/clang/test/SemaCXX/consteval-return-void.cpp b/clang/test/SemaCXX/consteval-return-void.cpp
index 39e1418306f5..da1fd8b7cdf7 100644
--- a/clang/test/SemaCXX/consteval-return-void.cpp
+++ b/clang/test/SemaCXX/consteval-return-void.cpp
@@ -18,3 +18,12 @@ template <typename T> constexpr E operator*(E,E);
 template <typename T> consteval E operator/(E,E);
 template <> constexpr E operator*<int>(E,E) { return; } // expected-error {{non-void constexpr function 'operator*<int>' should return a value}}
 template <> consteval E operator/<int>(E,E) { return; } // expected-error {{non-void consteval function 'operator/<int>' should return a value}}
+
+consteval void no_return() {}
+consteval void with_return() { return; }
+consteval void with_return_void() { return void(); }
+void use_void_fn() {
+  no_return();
+  with_return();
+  with_return_void();
+}