[PATCH] D82284: [AST][RecoveryAST] Preseve invalid return stmt, and suppress the diagnostics for missing return stmt in constexpr func.

[Haojian Wu via Phabricator via cfe-commits]

hokein created this revision.
hokein added a reviewer: sammccall.
Herald added a project: clang.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D82284

Files:
  clang/lib/Sema/SemaStmt.cpp
  clang/test/AST/ast-dump-recovery.cpp
  clang/test/SemaCXX/constant-expression-cxx11.cpp
  clang/test/SemaCXX/lambda-expressions.cpp
  clang/test/SemaCXX/typo-correction-crash.cpp


Index: clang/test/SemaCXX/typo-correction-crash.cpp
===================================================================
--- clang/test/SemaCXX/typo-correction-crash.cpp
+++ clang/test/SemaCXX/typo-correction-crash.cpp
@@ -16,7 +16,8 @@
 
 auto L1 = [] { return s; }; // expected-error {{use of undeclared identifier 's'}}
 using T1 = decltype(L1());
-static_assert(is_same<T1, void>::value, "Return statement should be discarded");
+// FIXME: Suppress the 'undeclared identifier T1' diagnostic, the UsingDecl T1 is discarded because of an invalid L1().
+static_assert(is_same<T1, void>::value, "Return statement should be discarded"); // expected-error {{use of undeclared identifier 'T1'}}
 auto L2 = [] { return tes; }; // expected-error {{use of undeclared identifier 'tes'; did you mean 'test'?}}
 using T2 = decltype(L2());
 static_assert(is_same<T2, int>::value, "Return statement was corrected");
Index: clang/test/SemaCXX/lambda-expressions.cpp
===================================================================
--- clang/test/SemaCXX/lambda-expressions.cpp
+++ clang/test/SemaCXX/lambda-expressions.cpp
@@ -519,7 +519,7 @@
   auto blk = [](bool b) {
     if (b)
       return undeclared_error; // expected-error {{use of undeclared identifier}}
-    return 0;
+    return 0; // expected-error {{cannot initialize return object of type 'auto' with an rvalue of type 'int'}}
   };
 }
 }
Index: clang/test/SemaCXX/constant-expression-cxx11.cpp
===================================================================
--- clang/test/SemaCXX/constant-expression-cxx11.cpp
+++ clang/test/SemaCXX/constant-expression-cxx11.cpp
@@ -1794,11 +1794,11 @@
 }
 
 namespace AfterError {
-  // FIXME: Suppress the 'no return statements' diagnostic if the body is invalid.
-  constexpr int error() { // expected-error {{no return statement}}
-    return foobar; // expected-error {{undeclared identifier}}
+  constexpr int error() { // expected-error {{constexpr function never produces a constant expression}}
+    return foobar; // expected-error {{undeclared identifier}} expected-note 2{{subexpression not valid in a constant expression}}
   }
-  constexpr int k = error();
+  constexpr int k = error(); // expected-error {{constexpr variable 'k' must be initialized by a constant expression}} \
+                             // expected-note {{in call to 'error()'}}
 }
 
 namespace std {
Index: clang/test/AST/ast-dump-recovery.cpp
===================================================================
--- clang/test/AST/ast-dump-recovery.cpp
+++ clang/test/AST/ast-dump-recovery.cpp
@@ -125,6 +125,12 @@
 // CHECK-NEXT:|   `-UnresolvedLookupExpr {{.*}} 'invalid'
 struct alignas(invalid()) Aligned {};
 
+void InvalidReturn() {
+  // CHECK:     `-ReturnStmt {{.*}}
+  // CHECK-NEXT:  `-RecoveryExpr {{.*}} '<dependent type>' contains-errors
+  return undef;
+}
+
 void InvalidInitalizer(int x) {
   struct Bar { Bar(); };
   // CHECK:     `-VarDecl {{.*}} a1 'Bar'
Index: clang/lib/Sema/SemaStmt.cpp
===================================================================
--- clang/lib/Sema/SemaStmt.cpp
+++ clang/lib/Sema/SemaStmt.cpp
@@ -3586,7 +3586,8 @@
                       Scope *CurScope) {
   // Correct typos, in case the containing function returns 'auto' and
   // RetValExp should determine the deduced type.
-  ExprResult RetVal = CorrectDelayedTyposInExpr(RetValExp);
+  ExprResult RetVal = CorrectDelayedTyposInExpr(
+      RetValExp, nullptr, /*RecoverUncorrectedTypos=*/true);
   if (RetVal.isInvalid())
     return StmtError();
   StmtResult R = BuildReturnStmt(ReturnLoc, RetVal.get());


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D82284.272340.patch
Type: text/x-patch
Size: 3598 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200622/3ab0be21/attachment.bin>