[clang-tools-extra] [clang-tidy] Do not emit file path for anonymous enums in `readability-enum-initial-value` check (PR #112496)

[via cfe-commits]

https://github.com/Discookie created https://github.com/llvm/llvm-project/pull/112496

Previously the name of anonymous enums in the check were `enum 'enum (unnamed at /full/path/to/file.c:1:1)'`, which breaks reproducibility of clang-tidy reports when the analyzed project is in a different folder.

We should think about removing emitted file paths globally from clang-tidy as well, if appropriate. Or at least removing the file paths from all locations where the warning/note tag already points to the declaration.

>From be0bee7948a8a6394ba93df619d76048847c1ca8 Mon Sep 17 00:00:00 2001
From: Viktor <viktor.cseh at ericsson.com>
Date: Wed, 16 Oct 2024 08:07:19 +0000
Subject: [PATCH] [clang-tidy] Do not emit file path for anonymous enums in
 `readability-enum-initial-value` check

---
 .../readability/EnumInitialValueCheck.cpp     | 22 ++++++++++++++-----
 clang-tools-extra/docs/ReleaseNotes.rst       |  3 ++-
 .../checkers/readability/enum-initial-value.c | 12 +++++++++-
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
index 1cb95c2b2347b7..5a48b103b9d602 100644
--- a/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/EnumInitialValueCheck.cpp
@@ -123,6 +123,13 @@ AST_MATCHER(EnumDecl, hasSequentialInitialValues) {
   return !AllEnumeratorsArePowersOfTwo;
 }
 
+std::string getName(const EnumDecl *Decl) {
+  if (!Decl->getDeclName())
+    return "<unnamed>";
+
+  return Decl->getQualifiedNameAsString();
+}
+
 } // namespace
 
 EnumInitialValueCheck::EnumInitialValueCheck(StringRef Name,
@@ -158,12 +165,15 @@ void EnumInitialValueCheck::registerMatchers(MatchFinder *Finder) {
 }
 
 void EnumInitialValueCheck::check(const MatchFinder::MatchResult &Result) {
+  PrintingPolicy PP = Result.Context->getPrintingPolicy();
+  PP.AnonymousTagLocations = false;
+
   if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("inconsistent")) {
     DiagnosticBuilder Diag =
         diag(Enum->getBeginLoc(),
-             "initial values in enum %0 are not consistent, consider explicit "
+             "initial values in enum '%0' are not consistent, consider explicit "
              "initialization of all, none or only the first enumerator")
-        << Enum;
+        << getName(Enum);
     for (const EnumConstantDecl *ECD : Enum->enumerators())
       if (ECD->getInitExpr() == nullptr) {
         const SourceLocation EndLoc = Lexer::getLocForEndOfToken(
@@ -183,16 +193,16 @@ void EnumInitialValueCheck::check(const MatchFinder::MatchResult &Result) {
     if (Loc.isInvalid() || Loc.isMacroID())
       return;
     DiagnosticBuilder Diag = diag(Loc, "zero initial value for the first "
-                                       "enumerator in %0 can be disregarded")
-                             << Enum;
+                                       "enumerator in '%0' can be disregarded")
+                             << getName(Enum);
     cleanInitialValue(Diag, ECD, *Result.SourceManager, getLangOpts());
     return;
   }
   if (const auto *Enum = Result.Nodes.getNodeAs<EnumDecl>("sequential")) {
     DiagnosticBuilder Diag =
         diag(Enum->getBeginLoc(),
-             "sequential initial value in %0 can be ignored")
-        << Enum;
+             "sequential initial value in '%0' can be ignored")
+        << getName(Enum);
     for (const EnumConstantDecl *ECD : llvm::drop_begin(Enum->enumerators()))
       cleanInitialValue(Diag, ECD, *Result.SourceManager, getLangOpts());
     return;
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 95be0a89cd6c93..a4427ac222b475 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -232,7 +232,8 @@ Changes in existing checks
 
 - Improved :doc:`readability-enum-initial-value
   <clang-tidy/checks/readability/enum-initial-value>` check by only issuing
-  diagnostics for the definition of an ``enum``, and by fixing a typo in the
+  diagnostics for the definition of an ``enum``, by not emitting a redundant
+  file path for anonymous enums in the diagnostic, and by fixing a typo in the
   diagnostic.
 
 - Improved :doc:`readability-implicit-bool-conversion
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
index b9a34d0683d7f3..54108585f030f8 100644
--- a/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
+++ b/clang-tools-extra/test/clang-tidy/checkers/readability/enum-initial-value.c
@@ -53,6 +53,17 @@ enum EMacro2 {
   // CHECK-FIXES: EMacro2_c = 3,
 };
 
+
+enum {
+  // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: initial values in enum '<unnamed>' are not consistent
+  // CHECK-MESSAGES-ENABLE: :[[@LINE-2]]:1: warning: initial values in enum '<unnamed>' are not consistent
+  EAnonymous_a = 1,
+  EAnonymous_b,
+  // CHECK-FIXES: EAnonymous_b = 2,
+  EAnonymous_c = 3,
+};
+
+
 enum EnumZeroFirstInitialValue {
   EnumZeroFirstInitialValue_0 = 0,
   // CHECK-MESSAGES-ENABLE: :[[@LINE-1]]:3: warning: zero initial value for the first enumerator in 'EnumZeroFirstInitialValue' can be disregarded
@@ -114,4 +125,3 @@ enum WithFwdDeclSequential : int {
   EFS2 = 4,
   // CHECK-FIXES-ENABLE: EFS2 ,
 };
-