[clang-tools-extra] [clang-tidy] Detect string literals in macros in modernize-raw-string… (PR #133636)

[Carlos Galvez via cfe-commits]

https://github.com/carlosgalvezp created https://github.com/llvm/llvm-project/pull/133636

…-literal

Fixes #133618

>From 2baffdbd656723b15370d3dd3560f3bd62262664 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carlos=20G=C3=A1lvez?= <carlos.galvez at zenseact.com>
Date: Sun, 30 Mar 2025 12:24:32 +0000
Subject: [PATCH] [clang-tidy] Detect string literals in macros in
 modernize-raw-string-literal

Fixes #133618
---
 .../clang-tidy/modernize/RawStringLiteralCheck.cpp    | 11 ++++++-----
 clang-tools-extra/docs/ReleaseNotes.rst               |  4 ++++
 .../checkers/modernize/raw-string-literal.cpp         |  3 ++-
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/modernize/RawStringLiteralCheck.cpp b/clang-tools-extra/clang-tidy/modernize/RawStringLiteralCheck.cpp
index 24674a407cb36..1be0d6cc23935 100644
--- a/clang-tools-extra/clang-tidy/modernize/RawStringLiteralCheck.cpp
+++ b/clang-tools-extra/clang-tidy/modernize/RawStringLiteralCheck.cpp
@@ -58,7 +58,7 @@ bool containsEscapedCharacters(const MatchFinder::MatchResult &Result,
       *Result.SourceManager, Result.Context->getLangOpts());
   StringRef Text = Lexer::getSourceText(CharRange, *Result.SourceManager,
                                         Result.Context->getLangOpts());
-  if (Text.empty() || isRawStringLiteral(Text))
+  if (Text.empty() || !Text.contains('"') || isRawStringLiteral(Text))
     return false;
 
   return containsEscapes(Text, R"('\"?x01)");
@@ -156,14 +156,14 @@ static bool compareStringLength(StringRef Replacement,
                                 const SourceManager &SM,
                                 const LangOptions &LangOpts) {
   return Replacement.size() <=
-         Lexer::MeasureTokenLength(Literal->getBeginLoc(), SM, LangOpts);
+         Lexer::MeasureTokenLength(SM.getSpellingLoc(Literal->getBeginLoc()), SM, LangOpts);
 }
 
 void RawStringLiteralCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *Literal = Result.Nodes.getNodeAs<StringLiteral>("lit");
-  if (Literal->getBeginLoc().isMacroID())
-    return;
   const SourceManager &SM = *Result.SourceManager;
+  if (SM.getSpellingLoc(Literal->getBeginLoc()).isMacroID())
+    return;
   const LangOptions &LangOpts = getLangOpts();
   if (containsEscapedCharacters(Result, Literal, DisallowedChars)) {
     const std::string Replacement =
@@ -172,7 +172,8 @@ void RawStringLiteralCheck::check(const MatchFinder::MatchResult &Result) {
         compareStringLength(Replacement, Literal, SM, LangOpts)) {
       diag(Literal->getBeginLoc(),
            "escaped string literal can be written as a raw string literal")
-          << FixItHint::CreateReplacement(Literal->getSourceRange(),
+          << FixItHint::CreateReplacement(SourceRange(SM.getSpellingLoc(Literal->getBeginLoc()),
+                                                      SM.getSpellingLoc(Literal->getEndLoc())),
                                           Replacement);
     }
   }
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 6cb8d572d3a78..c7c5ac75986be 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -181,6 +181,10 @@ Changes in existing checks
   <clang-tidy/checks/modernize/use-std-numbers>` check to support math
   functions of different precisions.
 
+- Improved :doc:`modernize-raw-string-literal
+  <clang-tidy/checks/modernize/raw-string-literal>` check to detect string
+  literals passed into macros.
+
 - Improved :doc:`performance-move-const-arg
   <clang-tidy/checks/performance/move-const-arg>` check by fixing false
   negatives on ternary operators calling ``std::move``.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/raw-string-literal.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/raw-string-literal.cpp
index 5856b8882574a..fc4e966e92e07 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/modernize/raw-string-literal.cpp
+++ b/clang-tools-extra/test/clang-tidy/checkers/modernize/raw-string-literal.cpp
@@ -105,7 +105,8 @@ char const *const StringizedMacroArgument = HAT(foo\\bar);
 
 #define SUBST(lit_) lit_
 char const *const MacroArgument = SUBST("foo\\bar");
-// FIXME: We should be able to replace this string literal macro argument
+// CHECK-MESSAGES: :[[@LINE-1]]:41: warning: {{.*}} can be written as a raw string literal
+// CHECK-FIXES: {{^}}char const *const MacroArgument = SUBST(R"(foo\bar)");{{$}}
 
 template <typename T>
 void fn(char const *const Arg) {