[clangd] ExpandAutoType: Do not offer code action on lambdas.

We can't expand lambda types anyway. Now we simply not offer the code
action instead of showing it and then returning an error in apply().

Differential Revision: https://reviews.llvm.org/D92847

diff --git a/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp b/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
index 61f68a6..6d38eb1 100644 (file)
--- a/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
+++ b/clang-tools-extra/clangd/refactor/tweaks/ExpandAutoType.cpp
@@ -63,6 +63,25 @@ bool isStructuredBindingType(const SelectionTree::Node *N) {
   return N && N->ASTNode.get<DecompositionDecl>();
 }
 
+// Returns true iff Node is a lambda, and thus should not be expanded. Loc is
+// the location of the auto type.
+bool isDeducedAsLambda(const SelectionTree::Node *Node, SourceLocation Loc) {
+  // getDeducedType() does a traversal, which we want to avoid in prepare().
+  // But at least check this isn't auto x = []{...};, which can't ever be
+  // expanded.
+  // (It would be nice if we had an efficient getDeducedType(), instead).
+  for (const auto *It = Node; It; It = It->Parent) {
+    if (const auto *DD = It->ASTNode.get<DeclaratorDecl>()) {
+      if (DD->getTypeSourceInfo() &&
+          DD->getTypeSourceInfo()->getTypeLoc().getBeginLoc() == Loc) {
+        if (auto *RD = DD->getType()->getAsRecordDecl())
+          return RD->isLambda();
+      }
+    }
+  }
+  return false;
+}
+
 bool ExpandAutoType::prepare(const Selection& Inputs) {
   CachedLocation = llvm::None;
   if (auto *Node = Inputs.ASTSelection.commonAncestor()) {
@@ -70,11 +89,13 @@ bool ExpandAutoType::prepare(const Selection& Inputs) {
       if (const AutoTypeLoc Result = TypeNode->getAs<AutoTypeLoc>()) {
         // Code in apply() does handle 'decltype(auto)' yet.
         if (!Result.getTypePtr()->isDecltypeAuto() &&
-            !isStructuredBindingType(Node))
+            !isStructuredBindingType(Node) &&
+            !isDeducedAsLambda(Node, Result.getBeginLoc()))
           CachedLocation = Result;
       }
     }
   }
+
   return (bool) CachedLocation;
 }
 

diff --git a/clang-tools-extra/clangd/test/check-fail.test b/clang-tools-extra/clangd/test/check-fail.test
index 0ee777f..dd50b59 100644 (file)
--- a/clang-tools-extra/clangd/test/check-fail.test
+++ b/clang-tools-extra/clangd/test/check-fail.test
@@ -11,4 +11,5 @@
 // CHECK: All checks completed, 2 errors
 
 #include "missing.h"
-auto x = []{};
+void fun();
+auto x = fun;

diff --git a/clang-tools-extra/clangd/unittests/TweakTests.cpp b/clang-tools-extra/clangd/unittests/TweakTests.cpp
index 85edd92..0dcf8fe 100644 (file)
--- a/clang-tools-extra/clangd/unittests/TweakTests.cpp
+++ b/clang-tools-extra/clangd/unittests/TweakTests.cpp
@@ -559,8 +559,7 @@ TEST_F(ExpandAutoTypeTest, Test) {
   EXPECT_THAT(apply("au^to x = &ns::Func;"),
               StartsWith("fail: Could not expand type of function pointer"));
   // lambda types are not replaced
-  EXPECT_THAT(apply("au^to x = []{};"),
-              StartsWith("fail: Could not expand type of lambda expression"));
+  EXPECT_UNAVAILABLE("au^to x = []{};");
   // inline namespaces
   EXPECT_EQ(apply("au^to x = inl_ns::Visible();"),
             "Visible x = inl_ns::Visible();");