[PATCH] D80221: [AST][RecoveryExpr] Make DeduceAutoType fail if the auto is deduced from recovery exprs.

[Haojian Wu via Phabricator via cfe-commits]

hokein updated this revision to Diff 264951.
hokein added a comment.

small update


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D80221/new/

https://reviews.llvm.org/D80221

Files:
  clang/lib/Sema/SemaStmt.cpp
  clang/lib/Sema/SemaTemplateDeduction.cpp
  clang/test/AST/ast-dump-invalid-auto-return-funcs.cpp
  clang/test/AST/ast-dump-recovery.cpp
  clang/test/Sema/invalid-bitwidth-expr.mm


Index: clang/test/Sema/invalid-bitwidth-expr.mm
===================================================================
--- clang/test/Sema/invalid-bitwidth-expr.mm
+++ clang/test/Sema/invalid-bitwidth-expr.mm
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -fobjc-runtime=gcc -frecovery-ast -verify %s
-// RUN: %clang_cc1 -fobjc-runtime=gcc -fno-recovery-ast -verify %s
 
 @interface Ivar
 {
@@ -11,3 +10,11 @@
 
 constexpr int s = sizeof(Ivar);
 constexpr int ss = sizeof(X);
+
+auto func() {
+  return undef(); // expected-error {{use of undeclared identifier}}
+}
+struct Y {
+  int X : func();
+};
+constexpr int sss = sizeof(Y);
Index: clang/test/AST/ast-dump-recovery.cpp
===================================================================
--- clang/test/AST/ast-dump-recovery.cpp
+++ clang/test/AST/ast-dump-recovery.cpp
@@ -178,10 +178,6 @@
   auto unresolved_typo = gned.*[] {};
 }
 
-// CHECK:      `-TypeAliasDecl {{.*}} Escape 'decltype([] {
-// CHECK-NEXT:   return <recovery-expr>(undef);
-// CHECK-NEXT: }())'
-// CHECK-NEXT:   `-DecltypeType {{.*}} 'decltype([] {
-// CHECK-NEXT:     return <recovery-expr>(undef);
-// CHECK-NEXT:   }())' dependent
+// Verified that the generated call operator is invalid.
+// CHECK: |-CXXMethodDecl {{.*}} invalid operator() 'auto () const -> auto'
 using Escape = decltype([] { return undef(); }());
Index: clang/test/AST/ast-dump-invalid-auto-return-funcs.cpp
===================================================================
--- /dev/null
+++ clang/test/AST/ast-dump-invalid-auto-return-funcs.cpp
@@ -0,0 +1,27 @@
+// RUN: not %clang_cc1 -triple x86_64-unknown-unknown -Wno-unused-value -fcxx-exceptions -frecovery-ast -std=gnu++17 -ast-dump %s | FileCheck -strict-whitespace %s
+
+// CHECK: FunctionDecl {{.*}} s1 'auto ()'
+auto s1(); // valid
+// CHECK: FunctionDecl {{.*}} invalid s2 'auto () -> int'
+auto s2() -> undef();
+// CHECK: FunctionDecl {{.*}} invalid s3 'auto () -> int'
+auto s3() -> decltype(undef());
+// CHECK: FunctionDecl {{.*}} invalid s4 'auto ()'
+auto s4() {
+  return undef();
+}
+// CHECK: FunctionDecl {{.*}} s5 'void ()'
+auto s5() {} // valid, no return stmt, fallback to void
+
+class Foo {
+  // CHECK: CXXMethodDecl {{.*}} foo1 'auto ()'
+  auto foo1(); // valid
+  // CHECK: CXXMethodDecl {{.*}} invalid foo2 'auto () -> int'
+  auto foo2() -> undef();
+  // CHECK: CXXMethodDecl {{.*}} invalid foo3 'auto () -> int'
+  auto foo3() -> decltype(undef());
+  // CHECK: CXXMethodDecl {{.*}} invalid foo4 'auto ()'
+  auto foo4() { return undef(); }
+  // CHECK: CXXMethodDecl {{.*}} foo5 'void ()'
+  auto foo5() {} // valid, no return stmt, fallback to void.
+};
Index: clang/lib/Sema/SemaTemplateDeduction.cpp
===================================================================
--- clang/lib/Sema/SemaTemplateDeduction.cpp
+++ clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -4655,6 +4655,9 @@
 Sema::DeduceAutoType(TypeLoc Type, Expr *&Init, QualType &Result,
                      Optional<unsigned> DependentDeductionDepth,
                      bool IgnoreConstraints) {
+  // FIXME: continue the following steps if the type is known.
+  if (Init->containsErrors())
+    return DAR_FailedAlreadyDiagnosed;
   if (Init->getType()->isNonOverloadPlaceholderType()) {
     ExprResult NonPlaceholder = CheckPlaceholderExpr(Init);
     if (NonPlaceholder.isInvalid())
Index: clang/lib/Sema/SemaStmt.cpp
===================================================================
--- clang/lib/Sema/SemaStmt.cpp
+++ clang/lib/Sema/SemaStmt.cpp
@@ -3309,6 +3309,7 @@
     assert(AT && "lost auto type from lambda return type");
     if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) {
       FD->setInvalidDecl();
+      // FIXME: preserve the ill-formed return expression.
       return StmtError();
     }
     CurCap->ReturnType = FnRetType = FD->getReturnType();


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D80221.264951.patch
Type: text/x-patch
Size: 3844 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20200519/440066fd/attachment-0001.bin>