[PATCH] D92408: [clangd] ExtractFunction: disable on regions that sometimes, but not always return.

[Adam Czachorowski via Phabricator via cfe-commits]

adamcz updated this revision to Diff 309958.
adamcz marked 2 inline comments as done.
adamcz added a comment.

addressed review comments


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D92408/new/

https://reviews.llvm.org/D92408

Files:
  clang-tools-extra/clangd/refactor/tweaks/ExtractFunction.cpp
  clang-tools-extra/clangd/unittests/TweakTests.cpp


Index: clang-tools-extra/clangd/unittests/TweakTests.cpp
===================================================================
--- clang-tools-extra/clangd/unittests/TweakTests.cpp
+++ clang-tools-extra/clangd/unittests/TweakTests.cpp
@@ -607,7 +607,11 @@
   // Extract certain return
   EXPECT_THAT(apply(" if(true) [[{ return; }]] "), HasSubstr("extracted"));
   // Don't extract uncertain return
-  EXPECT_THAT(apply(" if(true) [[if (false) return;]] "), StartsWith("fail"));
+  EXPECT_THAT(apply(" if(true) [[if (false) return;]] "),
+              StartsWith("unavailable"));
+  EXPECT_THAT(
+      apply("#define RETURN_IF_ERROR(x) if (x) return\nRETU^RN_IF_ERROR(4);"),
+      StartsWith("unavailable"));
 
   FileName = "a.c";
   EXPECT_THAT(apply(" for([[int i = 0;]];);"), HasSubstr("unavailable"));
Index: clang-tools-extra/clangd/refactor/tweaks/ExtractFunction.cpp
===================================================================
--- clang-tools-extra/clangd/refactor/tweaks/ExtractFunction.cpp
+++ clang-tools-extra/clangd/refactor/tweaks/ExtractFunction.cpp
@@ -708,6 +708,27 @@
   return tooling::Replacement(SM, ExtractedFunc.InsertionPoint, 0, FunctionDef);
 }
 
+// Returns true if ExtZone contains any ReturnStmts.
+bool hasReturnStmt(const ExtractionZone &ExtZone) {
+  class ReturnStmtVisitor
+      : public clang::RecursiveASTVisitor<ReturnStmtVisitor> {
+  public:
+    bool VisitReturnStmt(ReturnStmt *Return) {
+      Found = true;
+      return false; // We found the answer, abort the scan.
+    }
+    bool Found = false;
+  };
+
+  ReturnStmtVisitor V;
+  for (const Stmt *RootStmt : ExtZone.RootStmts) {
+    V.TraverseStmt(const_cast<Stmt *>(RootStmt));
+    if (V.Found)
+      break;
+  }
+  return V.Found;
+}
+
 bool ExtractFunction::prepare(const Selection &Inputs) {
   const LangOptions &LangOpts = Inputs.AST->getLangOpts();
   if (!LangOpts.CPlusPlus)
@@ -715,8 +736,12 @@
   const Node *CommonAnc = Inputs.ASTSelection.commonAncestor();
   const SourceManager &SM = Inputs.AST->getSourceManager();
   auto MaybeExtZone = findExtractionZone(CommonAnc, SM, LangOpts);
+  if (!MaybeExtZone ||
+      (hasReturnStmt(*MaybeExtZone) && !alwaysReturns(*MaybeExtZone)))
+    return false;
+
   // FIXME: Get rid of this check once we support hoisting.
-  if (!MaybeExtZone || MaybeExtZone->requiresHoisting(SM))
+  if (MaybeExtZone->requiresHoisting(SM))
     return false;
 
   ExtZone = std::move(*MaybeExtZone);


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