[clang-tidy] Emit warnings from headers by default

vbvictor · vbvictor · commit 2617825b31af · 2025-10-26T22:54:42.000+03:00
diff --git a/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp b/clang-tools-extra/clang-tidy/ClangTidyOptions.cpp
@@ -247,7 +247,7 @@ ClangTidyOptions ClangTidyOptions::getDefaults() {
   Options.WarningsAsErrors = "";
   Options.HeaderFileExtensions = {"", "h", "hh", "hpp", "hxx"};
   Options.ImplementationFileExtensions = {"c", "cc", "cpp", "cxx"};
-  Options.HeaderFilterRegex = "";
+  Options.HeaderFilterRegex = ".*";
   Options.ExcludeHeaderFilterRegex = "";
   Options.SystemHeaders = false;
   Options.FormatStyle = "none";
diff --git a/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp b/clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp
@@ -93,7 +93,7 @@ Configuration files:
     WarningsAsErrors:             ''
     HeaderFileExtensions:         ['', 'h','hh','hpp','hxx']
     ImplementationFileExtensions: ['c','cc','cpp','cxx']
-    HeaderFilterRegex:            ''
+    HeaderFilterRegex:            '.*'
     FormatStyle:                  none
     InheritParentConfig:          true
     User:                         user
@@ -133,13 +133,15 @@ file, if any.
 static cl::opt<std::string> HeaderFilter("header-filter", desc(R"(
 Regular expression matching the names of the
 headers to output diagnostics from. Diagnostics
-from the main file of each translation unit are
-always displayed.
+from the main file and all non-system headers 
+of each translation unit are always displayed.
+Set this option to an empty string to disable 
+diagnostics from non-system headers.
 Can be used together with -line-filter.
 This option overrides the 'HeaderFilterRegex'
 option in .clang-tidy file, if any.
 )"),
-                                         cl::init(""),
+                                         cl::init(".*"),
                                          cl::cat(ClangTidyCategory));
 
 static cl::opt<std::string> ExcludeHeaderFilter("exclude-header-filter",
@@ -379,9 +381,9 @@ static void printStats(const ClangTidyStats &Stats) {
                    << " with check filters";
     llvm::errs() << ").\n";
     if (Stats.ErrorsIgnoredNonUserCode)
-      llvm::errs() << "Use -header-filter=.* to display errors from all "
-                      "non-system headers. Use -system-headers to display "
-                      "errors from system headers as well.\n";
+      llvm::errs() << "Use -header-filter=.* or leave it as default to display "
+                      "errors from all non-system headers. Use -system-headers "
+                      "to display errors from system headers as well.\n";
   }
 }
 
diff --git a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
@@ -470,8 +470,8 @@ async def main() -> None:
         default=None,
         help="Regular expression matching the names of the "
         "headers to output diagnostics from. Diagnostics from "
-        "the main file of each translation unit are always "
-        "displayed.",
+        "the main file and all non-system headers of each "
+        "translation unit are always displayed.",
     )
     parser.add_argument(
         "-source-filter",
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -70,6 +70,11 @@ Potentially Breaking Changes
     :doc:`bugprone-signed-char-misuse
     <clang-tidy/checks/bugprone/signed-char-misuse>`
 
+- :program:`clang-tidy` now displays warnings from all non-system headers by
+  default. Previously, users had to explicitly opt-in to header warnings using
+  `-header-filter='.*'`. To disable warnings from non-system, set `-header-filter`
+  to an empty string.
+
 Improvements to clangd
 ----------------------
 
@@ -132,6 +137,11 @@ Improvements to clang-tidy
   when run over C files. If ``-std`` is not specified, it defaults to
   ``c99-or-later``.
 
+- :program:`clang-tidy` now displays warnings from all non-system headers by
+  default. Previously, users had to explicitly opt-in to header warnings using
+  `-header-filter='.*'`. To disable warnings from non-system, set `-header-filter`
+  to an empty string.
+
 - :program:`clang-tidy` no longer attempts to analyze code from system headers
   by default, greatly improving performance. This behavior is disabled if the
   `SystemHeaders` option is enabled.
diff --git a/clang-tools-extra/docs/clang-tidy/index.rst b/clang-tools-extra/docs/clang-tidy/index.rst
@@ -216,8 +216,10 @@ An overview of all the command-line options:
                                        .clang-tidy file, if any.
     --header-filter=<string>         - Regular expression matching the names of the
                                        headers to output diagnostics from. Diagnostics
-                                       from the main file of each translation unit are
-                                       always displayed.
+                                       from the main file and all non-system headers
+                                       of each translation unit are always displayed.
+                                       Set this option to an empty string to disable 
+                                       diagnostics from non-system headers.
                                        Can be used together with -line-filter.
                                        This option overrides the 'HeaderFilterRegex'
                                        option in .clang-tidy file, if any.
@@ -338,7 +340,7 @@ An overview of all the command-line options:
       WarningsAsErrors:    ''
       HeaderFileExtensions:         ['', 'h','hh','hpp','hxx']
       ImplementationFileExtensions: ['c','cc','cpp','cxx']
-      HeaderFilterRegex:   ''
+      HeaderFilterRegex:   '.*'
       FormatStyle:         none
       InheritParentConfig: true
       User:                user
diff --git a/clang-tools-extra/test/clang-tidy/checkers/abseil/no-internal-dependencies.cpp b/clang-tools-extra/test/clang-tidy/checkers/abseil/no-internal-dependencies.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s abseil-no-internal-dependencies %t,  -- -- -I %S/Inputs
+// RUN: %check_clang_tidy %s abseil-no-internal-dependencies %t,  -- -header-filter='' -- -I %S/Inputs
 // RUN: clang-tidy -checks='-*, abseil-no-internal-dependencies' -header-filter='.*' %s -- -I %S/Inputs 2>&1 | FileCheck %s
 
 #include "absl/strings/internal-file.h"
diff --git a/clang-tools-extra/test/clang-tidy/checkers/abseil/no-namespace.cpp b/clang-tools-extra/test/clang-tidy/checkers/abseil/no-namespace.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s abseil-no-namespace %t -- -- -I %S/Inputs
+// RUN: %check_clang_tidy %s abseil-no-namespace %t -- -header-filter='' -- -I %S/Inputs
 // RUN: clang-tidy -checks='-*, abseil-no-namespace' -header-filter='.*' %s -- -I %S/Inputs 2>&1 | FileCheck %s
 
 /// Warning will not be triggered on internal Abseil code that is included.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/reserved-identifier.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/reserved-identifier.cpp
@@ -1,8 +1,9 @@
-// RUN: %check_clang_tidy %s bugprone-reserved-identifier %t -- -- \
+// RUN: %check_clang_tidy %s bugprone-reserved-identifier %t -- \
+// RUN:   -header-filter='' -- \
 // RUN:   -I%S/Inputs/reserved-identifier \
 // RUN:   -isystem %S/Inputs/reserved-identifier/system
 
-// no warnings expected without -header-filter=
+// no warnings expected with -header-filter=''
 #include "user-header.h"
 #include <system-header.h>
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/google/upgrade-googletest-case.cpp b/clang-tools-extra/test/clang-tidy/checkers/google/upgrade-googletest-case.cpp
@@ -1,5 +1,5 @@
-// RUN: %check_clang_tidy %s google-upgrade-googletest-case %t -- -- -I%S/Inputs
-// RUN: %check_clang_tidy -check-suffix=NOSUITE %s google-upgrade-googletest-case %t -- -- -DNOSUITE -I%S/Inputs/gtest/nosuite
+// RUN: %check_clang_tidy %s google-upgrade-googletest-case %t -- -- -isystem%S/Inputs
+// RUN: %check_clang_tidy -check-suffix=NOSUITE %s google-upgrade-googletest-case %t -- -- -DNOSUITE -isystem%S/Inputs/gtest/nosuite
 
 #include "gtest/gtest.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/replace-auto-ptr.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/replace-auto-ptr.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s modernize-replace-auto-ptr %t -- -- -I %S/Inputs/replace-auto-ptr
+// RUN: %check_clang_tidy %s modernize-replace-auto-ptr %t -- -- -isystem %S/Inputs/replace-auto-ptr
 
 // CHECK-FIXES: #include <utility>
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-using.cpp
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s modernize-use-using %t -- -- -fno-delayed-template-parsing -I %S/Inputs/use-using/
+// RUN: %check_clang_tidy %s modernize-use-using %t -- -- -fno-delayed-template-parsing -isystem %S/Inputs/use-using/
 
 typedef int Type;
 // CHECK-MESSAGES: :[[@LINE-1]]:1: warning: use 'using' instead of 'typedef' [modernize-use-using]
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/duplicate-include.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/duplicate-include.cpp
@@ -1,4 +1,6 @@
-// RUN: %check_clang_tidy %s readability-duplicate-include %t -- -- -isystem %S/Inputs/duplicate-include/system -I %S/Inputs/duplicate-include
+// RUN: %check_clang_tidy %s readability-duplicate-include %t -- \
+// RUN:   -header-filter='' \
+// RUN:   -- -isystem %S/Inputs/duplicate-include/system -I %S/Inputs/duplicate-include
 
 int a;
 #include <string.h>
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming.cpp b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming.cpp
@@ -82,7 +82,9 @@
 // RUN:     readability-identifier-naming.LocalPointerPrefix: 'l_', \
 // RUN:     readability-identifier-naming.LocalConstantPointerCase: CamelCase, \
 // RUN:     readability-identifier-naming.LocalConstantPointerPrefix: 'lc_', \
-// RUN:   }}' -- -fno-delayed-template-parsing -Dbad_macro \
+// RUN:   }}' \
+// RUN:   -header-filter='' \
+// RUN:   -- -fno-delayed-template-parsing -Dbad_macro \
 // RUN:   -I%S/Inputs/identifier-naming \
 // RUN:   -isystem %S/Inputs/identifier-naming/system
 
@@ -91,8 +93,7 @@
 #include <system-header.h>
 #include <coroutines.h>
 #include "user-header.h"
-// NO warnings or fixes expected from declarations within header files without
-// the -header-filter= option
+// NO warnings or fixes expected from declarations with the -header-filter='' option
 
 namespace FOO_NS {
 // CHECK-MESSAGES: :[[@LINE-1]]:11: warning: invalid case style for namespace 'FOO_NS' [readability-identifier-naming]
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/default-header-filter.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/default-header-filter.cpp
@@ -0,0 +1,27 @@
+
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' --config='{}' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK-DEFAULT %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' --config='{}' -header-filter='' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK-EMPTY %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' --config='{}' -header-filter='.*' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK-EXPLICIT %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' --config='{}' %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK-NO-SYSTEM %s
+// RUN: clang-tidy -checks='-*,google-explicit-constructor' --config='{}' -system-headers %s -- -I %S/Inputs/file-filter -isystem %S/Inputs/file-filter/system 2>&1 | FileCheck --check-prefix=CHECK-WITH-SYSTEM %s
+
+#include "header1.h"
+// CHECK-DEFAULT: header1.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK-EMPTY-NOT: header1.h:1:12: warning:
+// CHECK-EXPLICIT: header1.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK-NO-SYSTEM: header1.h:1:12: warning: single-argument constructors must be marked explicit
+// CHECK-WITH-SYSTEM: header1.h:1:12: warning: single-argument constructors must be marked explicit
+
+#include <system-header.h>
+// CHECK-DEFAULT-NOT: system-header.h:1:12: warning:
+// CHECK-EMPTY-NOT: system-header.h:1:12: warning:
+// CHECK-EXPLICIT-NOT: system-header.h:1:12: warning:
+// CHECK-NO-SYSTEM-NOT: system-header.h:1:12: warning:
+// CHECK-WITH-SYSTEM: system-header.h:1:12: warning: single-argument constructors must be marked explicit
+
+class A { A(int); };
+// CHECK-DEFAULT: :[[@LINE-1]]:11: warning: single-argument constructors must be marked explicit
+// CHECK-EMPTY: :[[@LINE-2]]:11: warning: single-argument constructors must be marked explicit
+// CHECK-EXPLICIT: :[[@LINE-3]]:11: warning: single-argument constructors must be marked explicit
+// CHECK-NO-SYSTEM: :[[@LINE-4]]:11: warning: single-argument constructors must be marked explicit
+// CHECK-WITH-SYSTEM: :[[@LINE-5]]:11: warning: single-argument constructors must be marked explicit
diff --git a/clang-tools-extra/test/clang-tidy/infrastructure/file-filter.cpp b/clang-tools-extra/test/clang-tidy/infrastructure/file-filter.cpp
@@ -66,7 +66,7 @@ class A { A(int); };
 // CHECK4-NOT: warning:
 // CHECK4-QUIET-NOT: warning:
 
-// CHECK: Use -header-filter=.* to display errors from all non-system headers.
+// CHECK: Use -header-filter=.* or leave it as default to display errors from all non-system headers.
 // CHECK-QUIET-NOT: Suppressed
 // CHECK2-QUIET-NOT: Suppressed
 // CHECK3: Use -header-filter=.* {{.*}}

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-// RUN: %check_clang_tidy %s abseil-no-internal-dependencies %t, -- -- -I %S/Inputs`
	`1`	`+// RUN: %check_clang_tidy %s abseil-no-internal-dependencies %t, -- -header-filter='' -- -I %S/Inputs`
`2`	`2`	`// RUN: clang-tidy -checks='-, abseil-no-internal-dependencies' -header-filter='.' %s -- -I %S/Inputs 2>&1 \| FileCheck %s`
`3`	`3`
`4`	`4`	`#include "absl/strings/internal-file.h"`
Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-// RUN: %check_clang_tidy %s modernize-replace-auto-ptr %t -- -- -I %S/Inputs/replace-auto-ptr`
	`1`	`+// RUN: %check_clang_tidy %s modernize-replace-auto-ptr %t -- -- -isystem %S/Inputs/replace-auto-ptr`
`2`	`2`
`3`	`3`	`// CHECK-FIXES: #include <utility>`
`4`	`4`