[clang-tools-extra] [clang-tidy] Improve "-quiet" option by suppressing warnings generated count (PR #154012)

via cfe-commits cfe-commits at lists.llvm.org
Sun Aug 17 04:29:28 PDT 2025 

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang-tools-extra

Author: Baranov Victor (vbvictor)

<details>
<summary>Changes</summary>

Before this change, `-quiet` mode in clang-tidy generated meaningless messages `xxx warnings generated` in output:
```cpp
// main.cpp
#include <iostream>

int main() {
  std::cout << 42;
}
```
```console
> clang-tidy -checks='-*,readability-magic-numbers' -quiet main.cpp

82 warnings generated.
main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
    4 |   std::cout << 42;
      |                ^
```

As you can see, `82 warnings generated.` does not say much `quiet` mode, this patch removes this message completely:

```console
> ./build/bin/clang-tidy -p build -checks='-*,readability-magic-numbers' -quiet main.cpp

main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
    4 |   std::cout << 42;
      |                ^
```

In contrast, when running without `quiet`, It gives some meaningful information because we know how many messages were suppressed thus calculating total messages count:
```console
> clang-tidy -checks='-*,readability-magic-numbers' main.cpp

82 warnings generated.
main.cpp:4:16: warning: 42 is a magic number; consider replacing it with a named constant [readability-magic-numbers]
    4 |   std::cout << 42;
      |                ^
Suppressed 81 warnings (81 in non-user code).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
```

---
Full diff: https://github.com/llvm/llvm-project/pull/154012.diff


6 Files Affected:

- (modified) clang-tools-extra/clang-tidy/ClangTidy.cpp (+8-4) 
- (modified) clang-tools-extra/clang-tidy/ClangTidy.h (+2-1) 
- (modified) clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp (+1-1) 
- (modified) clang-tools-extra/docs/ReleaseNotes.rst (+3) 
- (modified) clang-tools-extra/test/clang-tidy/infrastructure/file-filter-symlinks.cpp (+1-1) 
- (added) clang-tools-extra/test/clang-tidy/infrastructure/quiet-flag.cpp (+14) 


``````````diff
diff --git a/clang-tools-extra/clang-tidy/ClangTidy.cpp b/clang-tools-extra/clang-tidy/ClangTidy.cpp
index 4ae2864d310d0..8f5728dea8c2a 100644
--- a/clang-tools-extra/clang-tidy/ClangTidy.cpp
+++ b/clang-tools-extra/clang-tidy/ClangTidy.cpp
@@ -540,7 +540,7 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
              ArrayRef<std::string> InputFiles,
              llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> BaseFS,
              bool ApplyAnyFix, bool EnableCheckProfile,
-             llvm::StringRef StoreCheckProfile) {
+             llvm::StringRef StoreCheckProfile, bool Quiet) {
   ClangTool Tool(Compilations, InputFiles,
                  std::make_shared<PCHContainerOperations>(), BaseFS);
 
@@ -577,8 +577,9 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
   class ActionFactory : public FrontendActionFactory {
   public:
     ActionFactory(ClangTidyContext &Context,
-                  IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> BaseFS)
-        : ConsumerFactory(Context, std::move(BaseFS)) {}
+                  IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> BaseFS,
+                  bool Quiet)
+        : ConsumerFactory(Context, std::move(BaseFS)), Quiet(Quiet) {}
     std::unique_ptr<FrontendAction> create() override {
       return std::make_unique<Action>(&ConsumerFactory);
     }
@@ -589,6 +590,8 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
                        DiagnosticConsumer *DiagConsumer) override {
       // Explicitly ask to define __clang_analyzer__ macro.
       Invocation->getPreprocessorOpts().SetUpStaticAnalyzer = true;
+      if (Quiet)
+        Invocation->getDiagnosticOpts().ShowCarets = false;
       return FrontendActionFactory::runInvocation(
           Invocation, Files, PCHContainerOps, DiagConsumer);
     }
@@ -607,9 +610,10 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
     };
 
     ClangTidyASTConsumerFactory ConsumerFactory;
+    bool Quiet;
   };
 
-  ActionFactory Factory(Context, std::move(BaseFS));
+  ActionFactory Factory(Context, std::move(BaseFS), Quiet);
   Tool.run(&Factory);
   return DiagConsumer.take();
 }
diff --git a/clang-tools-extra/clang-tidy/ClangTidy.h b/clang-tools-extra/clang-tidy/ClangTidy.h
index 454261bbd6840..d37d68ec0a5b9 100644
--- a/clang-tools-extra/clang-tidy/ClangTidy.h
+++ b/clang-tools-extra/clang-tidy/ClangTidy.h
@@ -94,7 +94,8 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
              ArrayRef<std::string> InputFiles,
              llvm::IntrusiveRefCntPtr<llvm::vfs::OverlayFileSystem> BaseFS,
              bool ApplyAnyFix, bool EnableCheckProfile = false,
-             llvm::StringRef StoreCheckProfile = StringRef());
+             llvm::StringRef StoreCheckProfile = StringRef(),
+             bool Quiet = false);
 
 /// Controls what kind of fixes clang-tidy is allowed to apply.
 enum FixBehaviour {
diff --git a/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp b/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp
index df3a8b22b1e24..bef3b938b5afd 100644
--- a/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp
+++ b/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp
@@ -717,7 +717,7 @@ int clangTidyMain(int argc, const char **argv) {
                            EnableModuleHeadersParsing);
   std::vector<ClangTidyError> Errors =
       runClangTidy(Context, OptionsParser->getCompilations(), PathList, BaseFS,
-                   FixNotes, EnableCheckProfile, ProfilePrefix);
+                   FixNotes, EnableCheckProfile, ProfilePrefix, Quiet);
   bool FoundErrors = llvm::any_of(Errors, [](const ClangTidyError &E) {
     return E.DiagLevel == ClangTidyError::Error;
   });
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index b481c56c262c4..e4b470026ef08 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -112,6 +112,9 @@ Improvements to clang-tidy
 - Improved documentation of the `-line-filter` command-line flag of
   :program:`clang-tidy` and :program:`run-clang-tidy.py`.
 
+- Improved :program:`clang-tidy` option `quiet` to suppresses diagnostic count
+  messages.
+
 New checks
 ^^^^^^^^^^
 
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/file-filter-symlinks.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/file-filter-symlinks.cpp
index 7efa7d070f69f..58f3b23cb1dbf 100644
--- a/clang-tools-extra/test/clang-tidy/infrastructure/file-filter-symlinks.cpp
+++ b/clang-tools-extra/test/clang-tidy/infrastructure/file-filter-symlinks.cpp
@@ -10,7 +10,7 @@
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header_alias\.h' %s -- -I %t 2>&1 | FileCheck --check-prefix=CHECK_HEADER_ALIAS %s
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header_alias\.h' -quiet %s -- -I %t 2>&1 | FileCheck --check-prefix=CHECK_HEADER_ALIAS %s
 // RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header\.h' %s -- -I %t 2>&1 | FileCheck --check-prefix=CHECK_HEADER %s
-// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header\.h' -quiet %s -- -I %t 2>&1 | FileCheck --check-prefix=CHECK_HEADER %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' -header-filter='header\.h' -quiet %s -- -I %t 2>&1 | FileCheck --check-prefix=CHECK_HEADER --allow-empty %s
 
 // Check that `-header-filter` operates on the same file paths as paths in
 // diagnostics printed by ClangTidy.
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/quiet-flag.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/quiet-flag.cpp
new file mode 100644
index 0000000000000..0e3d6164163a4
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/infrastructure/quiet-flag.cpp
@@ -0,0 +1,14 @@
+// RUN: clang-tidy -checks=-*,readability-magic-numbers %t.cpp -- 2>&1 | FileCheck %s --check-prefix=CHECK-NORMAL
+// RUN: clang-tidy -checks=-*,readability-magic-numbers -quiet %t.cpp -- 2>&1 | FileCheck %s --check-prefix=CHECK-QUIET
+
+// Normal mode should show warning count
+// CHECK-NORMAL: 1 warning generated
+// CHECK-NORMAL: warning: 42 is a magic number
+
+// Quiet mode should suppress warning count 
+// CHECK-QUIET-NOT: 1 warning generated
+// CHECK-QUIET: warning: 42 is a magic number
+
+int main() {
+  int x = 42;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/154012

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