[clang-tidy] Add -std argument in check_clang_tidy.py for C files (#150791)

localspook · web-flow · commit 230b9b202611 · 2025-08-23T02:34:31.000-07:00
Before, the `-std` argument in C tests was simply ignored, and they were
run with whatever Clang defaults to when you don't specify a standard.
The new default is `-std=c99-or-later`. This means a bunch of tests are
suddenly being run in C23 mode, and so need to be adapted to account for
various things:

- `typeof` is changed to `__typeof__`; the non-`__ugly__` spelling is
only available with GNU extensions or C23.
- In C23, `bool` is a keyword, so `typedef foo bool;` is invalid.
- In C23, `f()` means `f(void)`, not "takes arbitrary parameters".
- In C23, K&amp;R-style function definitions are removed.
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -104,6 +104,10 @@ Improvements to clang-query
 Improvements to clang-tidy
 --------------------------
 
+- The :program:`check_clang_tidy.py` tool now recognizes the ``-std`` argument
+  when run over C files. If ``-std`` is not specified, it defaults to
+  ``c99-or-later``.
+
 - :program:`clang-tidy` no longer attemps 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/test/clang-tidy/check_clang_tidy.py b/clang-tools-extra/test/clang-tidy/check_clang_tidy.py
@@ -135,8 +135,7 @@ def __init__(self, args: argparse.Namespace, extra_args: List[str]) -> None:
                 "-fblocks",
             ] + self.clang_extra_args
 
-        if extension in [".cpp", ".hpp", ".mm"]:
-            self.clang_extra_args.append("-std=" + self.std)
+        self.clang_extra_args.append("-std=" + self.std)
 
         # Tests should not rely on STL being available, and instead provide mock
         # implementations of relevant APIs.
@@ -374,15 +373,23 @@ def parse_arguments() -> Tuple[argparse.Namespace, List[str]]:
     parser.add_argument(
         "-std",
         type=csv,
-        default=["c++11-or-later"],
+        default=None,
         help="Passed to clang. Special -or-later values are expanded.",
     )
     parser.add_argument(
         "--match-partial-fixes",
         action="store_true",
         help="allow partial line matches for fixes",
     )
-    return parser.parse_known_args()
+
+    args, extra_args = parser.parse_known_args()
+    if args.std is None:
+        _, extension = os.path.splitext(args.assume_filename or args.input_file_name)
+        args.std = [
+            "c++11-or-later" if extension in [".cpp", ".hpp", ".mm"] else "c99-or-later"
+        ]
+
+    return (args, extra_args)
 
 
 def main() -> None:
diff --git a/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/system-other.h b/clang-tools-extra/test/clang-tidy/checkers/Inputs/Headers/system-other.h
@@ -11,6 +11,8 @@
 
 // Special system calls.
 
+#if __STDC_VERSION__ < 202311L
 void other_call();
+#endif
 
 #endif // _SYSTEM_OTHER_H_
diff --git a/clang-tools-extra/test/clang-tidy/checkers/android/comparison-in-temp-failure-retry-custom-macro.c b/clang-tools-extra/test/clang-tidy/checkers/android/comparison-in-temp-failure-retry-custom-macro.c
@@ -2,7 +2,7 @@
 
 #define MY_TEMP_FAILURE_RETRY(x) \
   ({                             \
-    typeof(x) __z;               \
+    __typeof__(x) __z;           \
     do                           \
       __z = (x);                 \
     while (__z == -1);           \
@@ -11,7 +11,7 @@
 
 #define MY_OTHER_TEMP_FAILURE_RETRY(x) \
   ({                                   \
-    typeof(x) __z;                     \
+    __typeof__(x) __z;                 \
     do                                 \
       __z = (x);                       \
     while (__z == -1);                 \
diff --git a/clang-tools-extra/test/clang-tidy/checkers/android/comparison-in-temp-failure-retry.c b/clang-tools-extra/test/clang-tidy/checkers/android/comparison-in-temp-failure-retry.c
@@ -2,7 +2,7 @@
 
 #define TEMP_FAILURE_RETRY(x)                                                  \
   ({                                                                           \
-    typeof(x) __z;                                                             \
+    __typeof__(x) __z;                                                         \
     do                                                                         \
       __z = (x);                                                               \
     while (__z == -1);                                                         \
@@ -130,7 +130,7 @@ void obscured_temp_failure_retry(void) {
 #undef TEMP_FAILURE_RETRY
 #define IMPL(x)                                                                \
   ({                                                                           \
-    typeof(x) __z;                                                             \
+    __typeof__(x) __z;                                                         \
     do                                                                         \
       __z = (x);                                                               \
     while (__z == -1);                                                         \
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone-macro-crash.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/branch-clone-macro-crash.c
@@ -1,11 +1,11 @@
 // RUN: %check_clang_tidy %s bugprone-branch-clone %t
 int x = 0;
 int y = 1;
-#define a(b, c) \
-  typeof(b) d;  \
-  if (b)        \
-    d = b;      \
-  else if (c)   \
+#define a(b, c)    \
+  __typeof__(b) d; \
+  if (b)           \
+    d = b;         \
+  else if (c)      \
     d = b;
 
 void f(void) {
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/easily-swappable-parameters-relatedness.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/easily-swappable-parameters-relatedness.c
@@ -1,4 +1,15 @@
-// RUN: %check_clang_tidy %s bugprone-easily-swappable-parameters %t \
+// RUN: %check_clang_tidy -std=c99,c11,c17 -check-suffixes=,BEFORE-C23 %s bugprone-easily-swappable-parameters %t \
+// RUN:   -config='{CheckOptions: { \
+// RUN:     bugprone-easily-swappable-parameters.MinimumLength: 2, \
+// RUN:     bugprone-easily-swappable-parameters.IgnoredParameterNames: "", \
+// RUN:     bugprone-easily-swappable-parameters.IgnoredParameterTypeSuffixes: "", \
+// RUN:     bugprone-easily-swappable-parameters.QualifiersMix: 0, \
+// RUN:     bugprone-easily-swappable-parameters.ModelImplicitConversions: 0, \
+// RUN:     bugprone-easily-swappable-parameters.SuppressParametersUsedTogether: 1, \
+// RUN:     bugprone-easily-swappable-parameters.NamePrefixSuffixSilenceDissimilarityTreshold: 0 \
+// RUN:  }}' -- -Wno-strict-prototypes -x c
+//
+// RUN: %check_clang_tidy -std=c23-or-later %s bugprone-easily-swappable-parameters %t \
 // RUN:   -config='{CheckOptions: { \
 // RUN:     bugprone-easily-swappable-parameters.MinimumLength: 2, \
 // RUN:     bugprone-easily-swappable-parameters.IgnoredParameterNames: "", \
@@ -9,7 +20,6 @@
 // RUN:     bugprone-easily-swappable-parameters.NamePrefixSuffixSilenceDissimilarityTreshold: 0 \
 // RUN:  }}' -- -Wno-strict-prototypes -x c
 
-int myprint();
 int add(int X, int Y);
 
 void notRelated(int A, int B) {}
@@ -19,13 +29,18 @@ void notRelated(int A, int B) {}
 
 int addedTogether(int A, int B) { return add(A, B); } // NO-WARN: Passed to same function.
 
+#if __STDC_VERSION__ < 202311L
+int myprint();
 void passedToSameKNRFunction(int A, int B) {
   myprint("foo", A);
   myprint("bar", B);
 }
-// CHECK-MESSAGES: :[[@LINE-4]]:30: warning: 2 adjacent parameters of 'passedToSameKNRFunction' of similar type ('int')
-// CHECK-MESSAGES: :[[@LINE-5]]:34: note: the first parameter in the range is 'A'
-// CHECK-MESSAGES: :[[@LINE-6]]:41: note: the last parameter in the range is 'B'
-// This is actually a false positive: the "passed to same function" heuristic
+// CHECK-MESSAGES-BEFORE-C23: :[[@LINE-4]]:30: warning: 2 adjacent parameters of 'passedToSameKNRFunction' of similar type ('int')
+// CHECK-MESSAGES-BEFORE-C23: :[[@LINE-5]]:34: note: the first parameter in the range is 'A'
+// CHECK-MESSAGES-BEFORE-C23: :[[@LINE-6]]:41: note: the last parameter in the range is 'B'
+// FIXME: This is actually a false positive: the "passed to same function" heuristic
 // can't map the parameter index 1 to A and B because myprint() has no
 // parameters.
+// If you fix this, you should be able to combine the `%check_clang_tidy` invocations
+// in this file into one and remove the `-std` and `-check-suffixes` arguments.
+#endif
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/easily-swappable-parameters.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/easily-swappable-parameters.c
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s bugprone-easily-swappable-parameters %t \
+// RUN: %check_clang_tidy -std=c99,c11,c17 -check-suffixes=,BEFORE-23 %s bugprone-easily-swappable-parameters %t \
 // RUN:   -config='{CheckOptions: { \
 // RUN:     bugprone-easily-swappable-parameters.MinimumLength: 2, \
 // RUN:     bugprone-easily-swappable-parameters.IgnoredParameterNames: "", \
@@ -7,7 +7,18 @@
 // RUN:     bugprone-easily-swappable-parameters.ModelImplicitConversions: 0, \
 // RUN:     bugprone-easily-swappable-parameters.SuppressParametersUsedTogether: 0, \
 // RUN:     bugprone-easily-swappable-parameters.NamePrefixSuffixSilenceDissimilarityTreshold: 0 \
-// RUN:  }}' -- -Wno-strict-prototypes -x c
+// RUN:  }}' -- -Wno-strict-prototypes
+//
+// RUN: %check_clang_tidy -std=c23-or-later %s bugprone-easily-swappable-parameters %t \
+// RUN:   -config='{CheckOptions: { \
+// RUN:     bugprone-easily-swappable-parameters.MinimumLength: 2, \
+// RUN:     bugprone-easily-swappable-parameters.IgnoredParameterNames: "", \
+// RUN:     bugprone-easily-swappable-parameters.IgnoredParameterTypeSuffixes: "bool;MyBool;struct U;MAKE_LOGICAL_TYPE(int)", \
+// RUN:     bugprone-easily-swappable-parameters.QualifiersMix: 0, \
+// RUN:     bugprone-easily-swappable-parameters.ModelImplicitConversions: 0, \
+// RUN:     bugprone-easily-swappable-parameters.SuppressParametersUsedTogether: 0, \
+// RUN:     bugprone-easily-swappable-parameters.NamePrefixSuffixSilenceDissimilarityTreshold: 0 \
+// RUN:  }}' -- -Wno-strict-prototypes
 
 #define bool _Bool
 #define true 1
@@ -45,8 +56,11 @@ void pointerConversion(int *IP, long *LP) {}
 
 void testVariadicsCall() {
   int IVal = 1;
+
+#if __STDC_VERSION__ < 202311L
   decl(IVal); // NO-WARN: Particular calls to "variadics" are like template
               // instantiations, and we do not model them.
+#endif
 
   variadic(IVal);          // NO-WARN.
   variadic(IVal, 2, 3, 4); // NO-WARN.
@@ -64,13 +78,15 @@ void taggedTypes2(struct S SVar1, struct S SVar2) {}
 
 void wrappers(struct { int I; } I1, struct { int I; } I2) {} // NO-WARN: Distinct anonymous types.
 
+#if __STDC_VERSION__ < 202311L
 void knr(I, J)
   int I;
   int J;
 {}
-// CHECK-MESSAGES: :[[@LINE-3]]:3: warning: 2 adjacent parameters of 'knr' of similar type ('int')
-// CHECK-MESSAGES: :[[@LINE-4]]:7: note: the first parameter in the range is 'I'
-// CHECK-MESSAGES: :[[@LINE-4]]:7: note: the last parameter in the range is 'J'
+// CHECK-MESSAGES-BEFORE-23: :[[@LINE-3]]:3: warning: 2 adjacent parameters of 'knr' of similar type ('int')
+// CHECK-MESSAGES-BEFORE-23: :[[@LINE-4]]:7: note: the first parameter in the range is 'I'
+// CHECK-MESSAGES-BEFORE-23: :[[@LINE-4]]:7: note: the last parameter in the range is 'J'
+#endif
 
 void boolAsWritten(bool B1, bool B2) {} // NO-WARN: The type name is ignored.
 // Note that "bool" is a macro that expands to "_Bool" internally, but it is
@@ -145,7 +161,7 @@ void thisIsGettingRidiculous(MAKE_PRIMITIVE_WRAPPER(int) I1,
 void macroMagic3(MAKE_LOGICAL_TYPE(char) B1, MAKE_LOGICAL_TYPE(long) B2) {}
 // CHECK-MESSAGES: :[[@LINE-1]]:18: warning: 2 adjacent parameters of 'macroMagic3' of similar type ('bool')
 // CHECK-MESSAGES: :[[@LINE-4]]:30: note: expanded from macro 'MAKE_LOGICAL_TYPE'
-// CHECK-MESSAGES: :[[@LINE-136]]:14: note: expanded from macro 'bool'
+// CHECK-MESSAGES: :[[@LINE-141]]:14: note: expanded from macro 'bool'
 // CHECK-MESSAGES: :[[@LINE-4]]:42: note: the first parameter in the range is 'B1'
 // CHECK-MESSAGES: :[[@LINE-5]]:70: note: the last parameter in the range is 'B2'
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-in-initialization-strlen.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-in-initialization-strlen.c
@@ -1,5 +1,5 @@
 // RUN: %check_clang_tidy --match-partial-fixes %s bugprone-not-null-terminated-result %t -- \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 #include "not-null-terminated-result-c.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-memcpy-before-safe.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-memcpy-before-safe.c
@@ -1,7 +1,7 @@
 // RUN: %check_clang_tidy %s bugprone-not-null-terminated-result %t -- \
 // RUN: -config="{CheckOptions: \
 // RUN: {bugprone-not-null-terminated-result.WantToUseSafeFunction: true}}" \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 #include "not-null-terminated-result-c.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-memcpy-safe.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-memcpy-safe.c
@@ -1,5 +1,5 @@
 // RUN: %check_clang_tidy %s bugprone-not-null-terminated-result %t -- \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 #include "not-null-terminated-result-c.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-stdc-want-lib-ext1-not-a-literal.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-stdc-want-lib-ext1-not-a-literal.c
@@ -1,5 +1,5 @@
 // RUN: %check_clang_tidy %s bugprone-not-null-terminated-result %t -- \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 #include "not-null-terminated-result-c.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-strlen.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-strlen.c
@@ -1,5 +1,5 @@
 // RUN: %check_clang_tidy --match-partial-fixes %s bugprone-not-null-terminated-result %t -- \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 // FIXME: Something wrong with the APInt un/signed conversion on Windows:
 // in 'strncmp(str6, "string", 7);' it tries to inject '4294967302' as length.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-undef-stdc-want-lib-ext1.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/not-null-terminated-result-undef-stdc-want-lib-ext1.c
@@ -1,5 +1,5 @@
 // RUN: %check_clang_tidy %s bugprone-not-null-terminated-result %t -- \
-// RUN: -- -std=c11 -I %S/Inputs/not-null-terminated-result
+// RUN: -- -I %S/Inputs/not-null-terminated-result
 
 #include "not-null-terminated-result-c.h"
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/signal-handler.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/signal-handler.c
@@ -1,4 +1,5 @@
-// RUN: %check_clang_tidy %s bugprone-signal-handler %t -- -- -isystem %clang_tidy_headers
+// RUN: %check_clang_tidy -std=c99,c11,c17 -check-suffixes=,BEFORE-23 %s bugprone-signal-handler %t -- -- -isystem %clang_tidy_headers
+// RUN: %check_clang_tidy -std=c23-or-later %s bugprone-signal-handler %t -- -- -isystem %clang_tidy_headers
 
 #include "signal.h"
 #include "stdlib.h"
@@ -174,8 +175,10 @@ void test_other(void) {
   signal(SIGINT, handler_signal);
 
   signal(SIGINT, _Exit);
+#if __STDC_VERSION__ < 202311L
   signal(SIGINT, other_call);
-  // CHECK-NOTES: :[[@LINE-1]]:18: warning: standard function 'other_call' may not be asynchronous-safe; using it as a signal handler may be dangerous [bugprone-signal-handler]
+  // CHECK-NOTES-BEFORE-23: :[[@LINE-1]]:18: warning: standard function 'other_call' may not be asynchronous-safe; using it as a signal handler may be dangerous [bugprone-signal-handler]
+#endif
   signal(SIGINT, f_extern_handler);
   // CHECK-NOTES: :[[@LINE-1]]:18: warning: cannot verify that external function 'f_extern_handler' is asynchronous-safe; using it as a signal handler may be dangerous [bugprone-signal-handler]
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/signed-char-misuse-c23.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/signed-char-misuse-c23.c
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s bugprone-signed-char-misuse %t -- -- -std=c23
+// RUN: %check_clang_tidy -std=c23-or-later %s bugprone-signed-char-misuse %t
 
 ///////////////////////////////////////////////////////////////////
 /// Test cases correctly caught by the check.
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/sizeof-expression.c
@@ -1,5 +1,5 @@
-// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t -- --
-// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t -- -- -x c++
+// RUN: %check_clang_tidy %s bugprone-sizeof-expression %t
+// RUN: %check_clang_tidy -std=c++11-or-later %s bugprone-sizeof-expression %t -- -- -x c++
 
 #ifdef __cplusplus
 #define STRKWD
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/unsafe-functions.c b/clang-tools-extra/test/clang-tidy/checkers/bugprone/unsafe-functions.c
@@ -5,14 +5,14 @@
 // parsing and preprocessor state will not have that case.
 // UNSUPPORTED: target={{.*-(ps4|ps5)}}
 //
-// RUN: %check_clang_tidy -check-suffix=WITH-ANNEX-K            %s bugprone-unsafe-functions %t -- -- -D__STDC_LIB_EXT1__=1 -D__STDC_WANT_LIB_EXT1__=1
-// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K         %s bugprone-unsafe-functions %t -- -- -U__STDC_LIB_EXT1__   -U__STDC_WANT_LIB_EXT1__
-// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K         %s bugprone-unsafe-functions %t -- -- -D__STDC_LIB_EXT1__=1 -U__STDC_WANT_LIB_EXT1__
-// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K         %s bugprone-unsafe-functions %t -- -- -U__STDC_LIB_EXT1__   -D__STDC_WANT_LIB_EXT1__=1
-// RUN: %check_clang_tidy -check-suffix=WITH-ANNEX-K-CERT-ONLY  %s bugprone-unsafe-functions %t -- \
+// RUN: %check_clang_tidy -std=c11-or-later -check-suffix=WITH-ANNEX-K %s bugprone-unsafe-functions %t -- -- -D__STDC_LIB_EXT1__=1 -D__STDC_WANT_LIB_EXT1__=1
+// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K %s bugprone-unsafe-functions %t -- -- -U__STDC_LIB_EXT1__   -U__STDC_WANT_LIB_EXT1__
+// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K %s bugprone-unsafe-functions %t -- -- -D__STDC_LIB_EXT1__=1 -U__STDC_WANT_LIB_EXT1__
+// RUN: %check_clang_tidy -check-suffix=WITHOUT-ANNEX-K %s bugprone-unsafe-functions %t -- -- -U__STDC_LIB_EXT1__   -D__STDC_WANT_LIB_EXT1__=1
+// RUN: %check_clang_tidy -std=c11-or-later -check-suffix=WITH-ANNEX-K-CERT-ONLY  %s bugprone-unsafe-functions %t -- \
 // RUN:   -config="{CheckOptions: {bugprone-unsafe-functions.ReportMoreUnsafeFunctions: false}}" \
 // RUN:                                                                                            -- -D__STDC_LIB_EXT1__=1 -D__STDC_WANT_LIB_EXT1__=1
-// RUN: %check_clang_tidy -check-suffix=WITH-NONE-ENABLED       %s bugprone-unsafe-functions %t --\
+// RUN: %check_clang_tidy -check-suffix=WITH-NONE-ENABLED %s bugprone-unsafe-functions %t --\
 // RUN:   -config="{CheckOptions: {bugprone-unsafe-functions.ReportDefaultFunctions: false}}" \
 // RUN:                                                                                            -- -D__STDC_LIB_EXT1__=1 -D__STDC_WANT_LIB_EXT1__=1
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/google/objc-function-naming.m b/clang-tools-extra/test/clang-tidy/checkers/google/objc-function-naming.m
@@ -8,7 +8,7 @@ static void TestImplicitFunctionDeclaration(int a) {
   printf("%d", a);
 }
 
-typedef _Bool bool;
+#define bool _Bool
 
 static bool ispositive(int a) { return a > 0; }
 // CHECK-MESSAGES: :[[@LINE-1]]:13: warning: static function named 'ispositive'
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/static-assert.c b/clang-tools-extra/test/clang-tidy/checkers/misc/static-assert.c
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s misc-static-assert %t -- -- -std=c11
+// RUN: %check_clang_tidy -std=c11-or-later %s misc-static-assert %t
 // RUN: clang-tidy %s -checks=-*,misc-static-assert -- -std=c99 | count 0
 
 void abort(void) {}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/misc/unused-parameters.c b/clang-tools-extra/test/clang-tidy/checkers/misc/unused-parameters.c
@@ -1,19 +1,23 @@
-// RUN: %check_clang_tidy %s misc-unused-parameters %t -- -- -Wno-strict-prototypes -xc
+// RUN: %check_clang_tidy %s misc-unused-parameters %t -- -- -Wno-strict-prototypes
 
 // Basic removal
 // =============
 void a(int i) {;}
 // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: parameter 'i' is unused [misc-unused-parameters]
 // CHECK-FIXES: {{^}}void a(int i) {;}{{$}}
 
-static void b(); // In C, forward declarations can leave out parameters.
+#if __STDC_VERSION__ < 202311L
+static void b(); // In C before C23, forward declarations can leave out parameters.
+#endif
 static void b(int i) {;}
 // CHECK-MESSAGES: :[[@LINE-1]]:19: warning: parameter 'i' is unused [misc-unused-parameters]
 // CHECK-FIXES: {{^}}static void b() {;}{{$}}
 
 // Unchanged cases
 // ===============
+#if __STDC_VERSION__ < 202311L
 void h(i, c, d) int i; char *c, *d; {} // Don't mess with K&R style
+#endif
 
 // Do not warn on naked functions.
 __attribute__((naked)) void nakedFunction(int a, int b) { ; }
diff --git a/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr-c23.c b/clang-tools-extra/test/clang-tidy/checkers/modernize/use-nullptr-c23.c
@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s modernize-use-nullptr %t -- -- -std=c23
+// RUN: %check_clang_tidy -std=c23-or-later %s modernize-use-nullptr %t
 
 #define NULL 0
 
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/bitint-no-crash.c b/clang-tools-extra/test/clang-tidy/checkers/readability/bitint-no-crash.c
@@ -1,6 +1,5 @@
-// RUN: %check_clang_tidy %s readability-magic-numbers %t --
+// RUN: %check_clang_tidy -std=c23-or-later %s readability-magic-numbers %t
 
 // Don't crash
 
 _BitInt(128) A = 4533629751480627964421wb;
-// CHECK-MESSAGES: warning
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-standard-types.h b/clang-tools-extra/test/clang-tidy/checkers/readability/identifier-naming-standard-types.h
@@ -50,8 +50,8 @@ typedef void*               FILE;       // NOLINT
 #define NULL                (0)         // NOLINT
 
 #ifndef __cplusplus
-typedef _Bool               bool;       // NOLINT
 typedef __WCHAR_TYPE__      wchar_t;    // NOLINT
+#define bool                _Bool       // NOLINT
 #define true                1           // NOLINT
 #define false               0           // NOLINT
 #endif
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.c b/clang-tools-extra/test/clang-tidy/checkers/readability/implicit-bool-conversion.c
@@ -1,8 +1,8 @@
-// RUN: %check_clang_tidy --match-partial-fixes %s readability-implicit-bool-conversion %t -- -- -std=c23
-// RUN: %check_clang_tidy -check-suffix=UPPER-CASE %s readability-implicit-bool-conversion %t -- \
+// RUN: %check_clang_tidy -std=c23-or-later --match-partial-fixes %s readability-implicit-bool-conversion %t
+// RUN: %check_clang_tidy -std=c23-or-later -check-suffix=UPPER-CASE %s readability-implicit-bool-conversion %t -- \
 // RUN:     -config='{CheckOptions: { \
 // RUN:         readability-implicit-bool-conversion.UseUpperCaseLiteralSuffix: true \
-// RUN:     }}' -- -std=c23
+// RUN:     }}'
 
 #undef NULL
 #define NULL 0L
diff --git a/clang-tools-extra/test/clang-tidy/checkers/readability/non-const-parameter.c b/clang-tools-extra/test/clang-tidy/checkers/readability/non-const-parameter.c
