go back to the hacky string manipulation

on-behalf-of: @amd <[email protected]>

Author: jjmarr-amd

clang-tools-extra/clang-tidy/readability/AvoidDefaultLambdaCaptureCheck.cpp

@@ -20,45 +20,6 @@ AST_MATCHER(LambdaExpr, hasDefaultCapture) {
   return Node.getCaptureDefault() != LCD_None;
 }
 
-// Find the source range of the default capture token (= or &)
-SourceRange getDefaultCaptureRange(const LambdaExpr *Lambda,
-                                   const SourceManager &SM,
-                                   const LangOptions &LangOpts) {
-  SourceLocation DefaultLoc = Lambda->getCaptureDefaultLoc();
-  if (DefaultLoc.isInvalid())
-    return SourceRange();
-
-  // The default capture is a single token
-  SourceLocation EndLoc =
-      Lexer::getLocForEndOfToken(DefaultLoc, 0, SM, LangOpts);
-  return SourceRange(DefaultLoc, EndLoc);
-}
-
-// Find where to insert implicit captures
-SourceLocation getImplicitCaptureInsertionLoc(const LambdaExpr *Lambda,
-                                              const SourceManager &SM,
-                                              const LangOptions &LangOpts) {
-  // If there are explicit captures, insert after the last one
-  if (Lambda->explicit_capture_begin() != Lambda->explicit_capture_end()) {
-    // Find the location after the last explicit capture
-    const auto *LastExplicit = Lambda->explicit_capture_end() - 1;
-    SourceLocation LastLoc = LastExplicit->getLocation();
-    if (LastLoc.isValid()) {
-      return Lexer::getLocForEndOfToken(LastLoc, 0, SM, LangOpts);
-    }
-  }
-
-  // If no explicit captures, insert after the default capture
-  SourceLocation DefaultLoc = Lambda->getCaptureDefaultLoc();
-  if (DefaultLoc.isValid()) {
-    return Lexer::getLocForEndOfToken(DefaultLoc, 0, SM, LangOpts);
-  }
-
-  // Fallback: insert at the beginning of the capture list
-  return Lambda->getIntroducerRange().getBegin().getLocWithOffset(1);
-}
-
-// Generate the text for an implicit capture
 std::optional<std::string>
 generateImplicitCaptureText(const LambdaCapture &Capture) {
   if (Capture.capturesThis()) {
@@ -74,15 +35,13 @@ generateImplicitCaptureText(const LambdaCapture &Capture) {
     return Result;
   }
 
-  // TODO: handle VLAs and other weird captures
-  return std::nullopt;
-}
+  if (Capture.capturesVLAType()) {
+    // VLA captures are rare and complex - for now we skip them
+    // A full implementation would need to handle the VLA type properly
+    return std::nullopt;
+  }
 
-// Check if we need a comma before inserting captures
-bool needsCommaBefore(const LambdaExpr *Lambda, SourceLocation InsertLoc,
-                      const SourceManager &SM, const LangOptions &LangOpts) {
-  // If there are explicit captures, we need a comma
-  return Lambda->explicit_capture_begin() != Lambda->explicit_capture_end();
+  return std::nullopt;
 }
 
 } // namespace
@@ -96,9 +55,6 @@ void AvoidDefaultLambdaCaptureCheck::check(
   const auto *Lambda = Result.Nodes.getNodeAs<LambdaExpr>("lambda");
   assert(Lambda);
 
-  const SourceManager &SM = *Result.SourceManager;
-  const LangOptions &LangOpts = Result.Context->getLangOpts();
-
   const SourceLocation DefaultCaptureLoc = Lambda->getCaptureDefaultLoc();
   if (DefaultCaptureLoc.isInvalid())
     return;
@@ -107,61 +63,35 @@ void AvoidDefaultLambdaCaptureCheck::check(
                    "lambda default captures are discouraged; "
                    "prefer to capture specific variables explicitly");
 
-  // Get the range of the default capture token to remove
-  SourceRange DefaultRange = getDefaultCaptureRange(Lambda, SM, LangOpts);
-  if (!DefaultRange.isValid())
-    return;
+  // Build the complete replacement capture list
+  std::vector<std::string> AllCaptures;
 
-  // Collect all implicit captures that need to be made explicit
-  std::vector<std::string> ImplicitCaptureTexts;
-  for (const auto &Capture : Lambda->implicit_captures()) {
+  // Add explicit captures first (preserve their order)
+  for (const auto &Capture : Lambda->explicit_captures()) {
     if (const auto CaptureText = generateImplicitCaptureText(Capture)) {
-      ImplicitCaptureTexts.push_back(CaptureText.value());
+      AllCaptures.push_back(CaptureText.value());
     }
   }
 
-  // If there are no implicit captures, just remove the default capture
-  if (ImplicitCaptureTexts.empty()) {
-    // Also remove any trailing comma if it exists
-    SourceLocation AfterDefault = DefaultRange.getEnd();
-    SourceLocation CommaLoc = Lexer::findLocationAfterToken(
-        AfterDefault, tok::comma, SM, LangOpts, false);
-
-    if (CommaLoc.isValid()) {
-      // Remove default capture and the comma
-      SourceRange RemovalRange(DefaultRange.getBegin(), CommaLoc);
-      Diag << FixItHint::CreateRemoval(RemovalRange);
-    } else {
-      // Just remove the default capture
-      Diag << FixItHint::CreateRemoval(DefaultRange);
+  // Add implicit captures (convert to explicit)
+  for (const auto &Capture : Lambda->implicit_captures()) {
+    if (const auto CaptureText = generateImplicitCaptureText(Capture)) {
+      AllCaptures.push_back(CaptureText.value());
     }
-    return;
   }
 
-  // Find where to insert the implicit captures
-  SourceLocation InsertLoc =
-      getImplicitCaptureInsertionLoc(Lambda, SM, LangOpts);
-  if (!InsertLoc.isValid())
-    return;
-
-  // Apply the transformations:
-  // 1. Remove the default capture
-  Diag << FixItHint::CreateRemoval(DefaultRange);
-
-  // 2. Insert the explicit captures if any
-  if (!ImplicitCaptureTexts.empty()) {
-    // Build the insertion text for implicit captures
-    std::string InsertionText;
-    bool NeedsComma = needsCommaBefore(Lambda, InsertLoc, SM, LangOpts);
-
-    for (size_t I = 0; I < ImplicitCaptureTexts.size(); ++I) {
-      if (NeedsComma || I > 0) {
-        InsertionText += ", ";
-      }
-      InsertionText += ImplicitCaptureTexts[I];
-    }
+  // Build the final capture list
+  std::string ReplacementText;
+  if (AllCaptures.empty()) {
+    ReplacementText = "[]";
+  } else {
+    ReplacementText = "[" + llvm::join(AllCaptures, ", ") + "]";
+  }
 
-    Diag << FixItHint::CreateInsertion(InsertLoc, InsertionText);
+  // Replace the entire capture list with the explicit version
+  SourceRange IntroducerRange = Lambda->getIntroducerRange();
+  if (IntroducerRange.isValid()) {
+    Diag << FixItHint::CreateReplacement(IntroducerRange, ReplacementText);
   }
 }