[PATCH] D89946: [clang] Suppress "follow-up" diagnostics on recovery call expressions.

[Haojian Wu via Phabricator via cfe-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGefa9aaad703e: [clang] Suppress "follow-up" diagnostics on recovery call expressions. (authored by hokein).

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D89946/new/

https://reviews.llvm.org/D89946

Files:
  clang/lib/Sema/SemaOverload.cpp
  clang/test/AST/ast-dump-recovery.cpp
  clang/test/SemaCXX/typo-correction-delayed.cpp


Index: clang/test/SemaCXX/typo-correction-delayed.cpp
===================================================================
--- clang/test/SemaCXX/typo-correction-delayed.cpp
+++ clang/test/SemaCXX/typo-correction-delayed.cpp
@@ -209,6 +209,15 @@
 // expected-error-re at -1 {{use of undeclared identifier 'N'{{$}}}}
 }
 
+namespace noSecondaryDiags {
+void abcc(); // expected-note {{'abcc' declared here}}
+
+void test() {
+  // Verify the secondary diagnostic ".. convertible to 'bool'" is suppressed.
+  if (abc()) {} // expected-error {{use of undeclared identifier 'abc'; did you mean 'abcc'?}}
+}
+}
+
 // PR 23285. This test must be at the end of the file to avoid additional,
 // unwanted diagnostics.
 // expected-error-re at +2 {{use of undeclared identifier 'uintmax_t'{{$}}}}
Index: clang/test/AST/ast-dump-recovery.cpp
===================================================================
--- clang/test/AST/ast-dump-recovery.cpp
+++ clang/test/AST/ast-dump-recovery.cpp
@@ -271,3 +271,14 @@
   // CHECK-NEXT: `-IntegerLiteral {{.*}} 'int' 2
   invalid() ? 1 : 2;
 }
+
+void abcc();
+void TypoCorrection() {
+  // RecoveryExpr is always dependent-type in this case in order to suppress
+  // following diagnostics.
+  // CHECK:      RecoveryExpr {{.*}} '<dependent type>'
+  // CHECK-NEXT: `-CallExpr {{.*}} 'void'
+  // CHECK-NEXT:   `-ImplicitCastExpr
+  // CHECK-NEXT:     `-DeclRefExpr {{.*}} 'abcc'
+  abc();
+}
Index: clang/lib/Sema/SemaOverload.cpp
===================================================================
--- clang/lib/Sema/SemaOverload.cpp
+++ clang/lib/Sema/SemaOverload.cpp
@@ -12735,8 +12735,6 @@
 }
 
 /// Attempts to recover from a call where no functions were found.
-///
-/// Returns true if new candidates were found.
 static ExprResult
 BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn,
                       UnresolvedLookupExpr *ULE,
@@ -12793,7 +12791,7 @@
     return ExprError();
   }
 
-  // Build an implicit member call if appropriate.  Just drop the
+  // Build an implicit member access expression if appropriate. Just drop the
   // casts and such from the call, we don't really care.
   ExprResult NewFn = ExprError();
   if ((*R.begin())->isCXXClassMember())
@@ -12808,12 +12806,19 @@
   if (NewFn.isInvalid())
     return ExprError();
 
-  // This shouldn't cause an infinite loop because we're giving it
-  // an expression with viable lookup results, which should never
-  // end up here.
-  return SemaRef.BuildCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
-                               MultiExprArg(Args.data(), Args.size()),
-                               RParenLoc);
+  auto CallE =
+      SemaRef.BuildCallExpr(/*Scope*/ nullptr, NewFn.get(), LParenLoc,
+                            MultiExprArg(Args.data(), Args.size()), RParenLoc);
+  if (CallE.isInvalid())
+    return ExprError();
+  // We now have recovered a callee. However, building a real call may lead to
+  // incorrect secondary diagnostics if our recovery wasn't correct.
+  // We keep the recovery behavior but suppress all following diagnostics by
+  // using RecoveryExpr. We deliberately drop the return type of the recovery
+  // function, and rely on clang's dependent mechanism to suppress following
+  // diagnostics.
+  return SemaRef.CreateRecoveryExpr(CallE.get()->getBeginLoc(),
+                                    CallE.get()->getEndLoc(), {CallE.get()});
 }
 
 /// Constructs and populates an OverloadedCandidateSet from


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