[clang] 7ebcb7c - PR50641: Properly handle AttributedStmts when checking for a valid

[Richard Smith via cfe-commits]

Author: Richard Smith
Date: 2021-10-06T15:13:05-07:00
New Revision: 7ebcb7ce78f6abb73c5a29e7c8b9dd360acb65bc

URL: https://github.com/llvm/llvm-project/commit/7ebcb7ce78f6abb73c5a29e7c8b9dd360acb65bc
DIFF: https://github.com/llvm/llvm-project/commit/7ebcb7ce78f6abb73c5a29e7c8b9dd360acb65bc.diff

LOG: PR50641: Properly handle AttributedStmts when checking for a valid
constexpr function body.

Added: 
    

Modified: 
    clang/lib/Sema/SemaDeclCXX.cpp
    clang/test/SemaCXX/attr-likelihood.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 88af1f7556c2..b7f84eab2f7e 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -2050,6 +2050,13 @@ CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
     ReturnStmts.push_back(S->getBeginLoc());
     return true;
 
+  case Stmt::AttributedStmtClass:
+    // Attributes on a statement don't affect its formal kind and hence don't
+    // affect its validity in a constexpr function.
+    return CheckConstexprFunctionStmt(SemaRef, Dcl,
+                                      cast<AttributedStmt>(S)->getSubStmt(),
+                                      ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind);
+
   case Stmt::CompoundStmtClass: {
     // C++1y allows compound-statements.
     if (!Cxx1yLoc.isValid())
@@ -2064,11 +2071,6 @@ CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
     return true;
   }
 
-  case Stmt::AttributedStmtClass:
-    if (!Cxx1yLoc.isValid())
-      Cxx1yLoc = S->getBeginLoc();
-    return true;
-
   case Stmt::IfStmtClass: {
     // C++1y allows if-statements.
     if (!Cxx1yLoc.isValid())

diff  --git a/clang/test/SemaCXX/attr-likelihood.cpp b/clang/test/SemaCXX/attr-likelihood.cpp
index 03ba301251d7..f7503fed49b9 100644
--- a/clang/test/SemaCXX/attr-likelihood.cpp
+++ b/clang/test/SemaCXX/attr-likelihood.cpp
@@ -154,4 +154,9 @@ void o()
                                   // expected-note {{conflicting attribute is here}}
   }
 }
+
+constexpr int constexpr_function() {
+  [[likely]] return 0;
+}
+static_assert(constexpr_function() == 0);
 #endif