[clang-tools-extra] [clang-tidy] Preserve line endings in macro-to-enum fixes (PR #202054)

[via cfe-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tidy

Author: Zeyi Xu (zeyi2)

<details>
<summary>Changes</summary>

Use `StringRef::detectEOL()` when inserting enum braces so fix-its do not mix LF into CRLF source files.

Closes https://github.com/llvm/llvm-project/issues/61593

---
Full diff: https://github.com/llvm/llvm-project/pull/202054.diff


3 Files Affected:

- (modified) clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp (+9-2) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+4) 
- (added) clang-tools-extra/test/clang-tidy/checkers/modernize/macro-to-enum-crlf.cpp (+3) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
index 1c49c32f9fecb..1036d08883195 100644
--- a/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/MacroToEnumCheck.cpp
@@ -470,11 +470,18 @@ void MacroToEnumCallbacks::warnMacroEnum(const EnumMacro &Macro) const {
 void MacroToEnumCallbacks::fixEnumMacro(const MacroList &MacroList) const {
   SourceLocation Begin =
       MacroList.front().Directive->getMacroInfo()->getDefinitionLoc();
+  const StringRef LineEnding =
+      SM.getBufferData(SM.getFileID(Begin)).detectEOL();
+  std::string EnumBegin = "enum {";
+  EnumBegin += LineEnding;
+  std::string EnumEnd = "};";
+  EnumEnd += LineEnding;
+
   Begin = SM.translateLineCol(SM.getFileID(Begin),
                               SM.getSpellingLineNumber(Begin), 1);
   const DiagnosticBuilder Diagnostic =
       Check->diag(Begin, "replace macro with enum")
-      << FixItHint::CreateInsertion(Begin, "enum {\n");
+      << FixItHint::CreateInsertion(Begin, EnumBegin);
 
   for (size_t I = 0U; I < MacroList.size(); ++I) {
     const EnumMacro &Macro = MacroList[I];
@@ -503,7 +510,7 @@ void MacroToEnumCallbacks::fixEnumMacro(const MacroList &MacroList) const {
       LangOpts);
   End = SM.translateLineCol(SM.getFileID(End),
                             SM.getSpellingLineNumber(End) + 1, 1);
-  Diagnostic << FixItHint::CreateInsertion(End, "};\n");
+  Diagnostic << FixItHint::CreateInsertion(End, EnumEnd);
 }
 
 void MacroToEnumCheck::registerPPCallbacks(const SourceManager &SM,
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 3bc902529a1dc..602c0b8ba3663 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -568,6 +568,10 @@ Changes in existing checks
   positives on project headers that use the same name as a standard library
   header.
 
+- Improved :doc:`modernize-macro-to-enum
+  <clang-tidy/checks/modernize/macro-to-enum>` check by preserving source file
+  line endings in fix-it replacements.
+
 - Improved :doc:`modernize-pass-by-value
   <clang-tidy/checks/modernize/pass-by-value>` check by adding `IgnoreMacros`
   option to suppress warnings in macros.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/macro-to-enum-crlf.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/macro-to-enum-crlf.cpp
new file mode 100644
index 0000000000000..49ced9b4a632c
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/macro-to-enum-crlf.cpp
@@ -0,0 +1,3 @@
+// RUN: %python -c "from pathlib import Path; Path(r'%/t.cpp').write_bytes(b'#define RED 1\r\n#define GREEN 2\r\n')"
+// RUN: clang-tidy %t.cpp -fix --checks='-*,modernize-macro-to-enum' --config={} -- --std=c++14 > %t.out 2>&1
+// RUN: %python -c "from pathlib import Path; data = Path(r'%/t.cpp').read_bytes(); expected = b'enum {\r\nRED = 1,\r\nGREEN = 2\r\n};\r\n'; assert data == expected, data"

``````````

</details>


https://github.com/llvm/llvm-project/pull/202054