[clang-tidy] New option to remove arguments from the command line

When using clang-tidy from a compilation database, some options might not be
recognized by clang if the compilation database was generated for another compiler.
This forces the user to add conditional code in their CMakeLists.txt to remove
those arguments when using clang-tidy.
A new option was added to the .clang-tidy config to remove
those unknown flags without the need to generate a second compilation_commands.json

Fixes #108455

Author: felix642

clang-tools-extra/clang-tidy/ClangTidy.cpp

@@ -586,6 +586,24 @@ runClangTidy(clang::tidy::ClangTidyContext &Context,
         return AdjustedArgs;
       };
 
+  // Remove unwanted arguments passed to the compiler
+  ArgumentsAdjuster PerFileArgumentRemover =
+      [&Context](const CommandLineArguments &Args, StringRef Filename) {
+        ClangTidyOptions Opts = Context.getOptionsForFile(Filename);
+        CommandLineArguments AdjustedArgs = Args;
+
+        if (Opts.RemovedArgs) {
+          for (StringRef ArgToRemove : *Opts.RemovedArgs) {
+            AdjustedArgs.erase(std::remove(AdjustedArgs.begin(),
+                                           AdjustedArgs.end(), ArgToRemove),
+                               AdjustedArgs.end());
+          }
+        }
+
+        return AdjustedArgs;
+      };
+
+  Tool.appendArgumentsAdjuster(PerFileArgumentRemover);
   Tool.appendArgumentsAdjuster(PerFileExtraArgumentsInserter);
   Tool.appendArgumentsAdjuster(getStripPluginsAdjuster());
   Context.setEnableProfiling(EnableCheckProfile);

clang-tools-extra/clang-tidy/ClangTidyOptions.cpp

@@ -230,6 +230,7 @@ template <> struct MappingTraits<ClangTidyOptions> {
     IO.mapOptional("CheckOptions", Options.CheckOptions);
     IO.mapOptional("ExtraArgs", Options.ExtraArgs);
     IO.mapOptional("ExtraArgsBefore", Options.ExtraArgsBefore);
+    IO.mapOptional("RemovedArgs", Options.RemovedArgs);
     IO.mapOptional("InheritParentConfig", Options.InheritParentConfig);
     IO.mapOptional("UseColor", Options.UseColor);
     IO.mapOptional("SystemHeaders", Options.SystemHeaders);
@@ -252,6 +253,7 @@ ClangTidyOptions ClangTidyOptions::getDefaults() {
   Options.SystemHeaders = false;
   Options.FormatStyle = "none";
   Options.User = std::nullopt;
+  Options.RemovedArgs = std::nullopt;
   for (const ClangTidyModuleRegistry::entry &Module :
        ClangTidyModuleRegistry::entries())
     Options.mergeWith(Module.instantiate()->getModuleOptions(), 0);
@@ -295,6 +297,7 @@ ClangTidyOptions &ClangTidyOptions::mergeWith(const ClangTidyOptions &Other,
   overrideValue(UseColor, Other.UseColor);
   mergeVectors(ExtraArgs, Other.ExtraArgs);
   mergeVectors(ExtraArgsBefore, Other.ExtraArgsBefore);
+  mergeVectors(RemovedArgs, Other.RemovedArgs);
   // FIXME: how to handle duplicate names check?
   mergeVectors(CustomChecks, Other.CustomChecks);
   for (const auto &KeyValue : Other.CheckOptions) {

clang-tools-extra/clang-tidy/ClangTidyOptions.h

@@ -85,7 +85,7 @@ struct ClangTidyOptions {
   /// main files will always be displayed.
   std::optional<std::string> HeaderFilterRegex;
 
-  /// \brief Exclude warnings from headers matching this filter, even if they
+  /// Exclude warnings from headers matching this filter, even if they
   /// match \c HeaderFilterRegex.
   std::optional<std::string> ExcludeHeaderFilterRegex;
 
@@ -151,6 +151,9 @@ struct ClangTidyOptions {
   /// Add extra compilation arguments to the start of the list.
   std::optional<ArgList> ExtraArgsBefore;
 
+  /// Remove command line arguments sent to the compiler matching this.
+  std::optional<ArgList> RemovedArgs;
+
   /// Only used in the FileOptionsProvider and ConfigOptionsProvider. If true
   /// and using a FileOptionsProvider, it will take a configuration file in the
   /// parent directory (if any exists) and apply this config file on top of the

clang-tools-extra/clang-tidy/tool/ClangTidyMain.cpp

@@ -18,6 +18,7 @@
 #include "../ClangTidy.h"
 #include "../ClangTidyForceLinker.h"
 #include "../GlobList.h"
+#include "../utils/OptionsUtils.h"
 #include "clang/Tooling/CommonOptionsParser.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/CommandLine.h"
@@ -77,6 +78,7 @@ Configuration files:
                                  (if any exists) will be taken and the current
                                  config file will be applied on top of the
                                  parent one.
+  RemovedArgs                  - Same as '--removed-arg'.
   SystemHeaders                - Same as '--system-headers'.
   UseColor                     - Same as '--use-color'.
   User                         - Specifies the name or e-mail of the user
@@ -357,6 +359,16 @@ see https://clang.llvm.org/extra/clang-tidy/QueryBasedCustomChecks.html.
                                               cl::init(false),
                                               cl::cat(ClangTidyCategory));
 
+static cl::list<std::string> RemovedArgs("removed-arg", desc(R"(
+List of arguments to remove from the command
+line sent to the compiler. Please note that
+removing arguments might change the semantic
+of the analzed code, possibly leading to
+compiler errors, false positives or
+false negatives. This option is applied 
+before --extra-arg and --extra-arg-before)"),
+                                         cl::cat(ClangTidyCategory));
+
 namespace clang::tidy {
 
 static void printStats(const ClangTidyStats &Stats) {
@@ -423,6 +435,8 @@ createOptionsProvider(llvm::IntrusiveRefCntPtr<vfs::FileSystem> FS) {
     OverrideOptions.FormatStyle = FormatStyle;
   if (UseColor.getNumOccurrences() > 0)
     OverrideOptions.UseColor = UseColor;
+  if (RemovedArgs.getNumOccurrences() > 0)
+    OverrideOptions.RemovedArgs = RemovedArgs;
 
   auto LoadConfig =
       [&](StringRef Configuration,

clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py

@@ -228,6 +228,13 @@ def main():
         default=[],
         help="Additional argument to prepend to the compiler " "command line.",
     )
+    parser.add_argument(
+        "-removed-arg",
+        dest="removed_arg",
+        action="append",
+        default=[],
+        help="Arguments to remove from the compiler command line.",
+    )
     parser.add_argument(
         "-quiet",
         action="store_true",
@@ -378,6 +385,8 @@ def main():
         common_clang_tidy_args.append("-extra-arg=%s" % arg)
     for arg in args.extra_arg_before:
         common_clang_tidy_args.append("-extra-arg-before=%s" % arg)
+    for arg in args.removed_arg:
+        common_clang_tidy_args.append("-removed-arg=%s" % arg)
     for plugin in args.plugins:
         common_clang_tidy_args.append("-load=%s" % plugin)
     if args.warnings_as_errors:

clang-tools-extra/clang-tidy/tool/run-clang-tidy.py

@@ -96,6 +96,7 @@ def get_tidy_invocation(
     allow_enabling_alpha_checkers: bool,
     extra_arg: List[str],
     extra_arg_before: List[str],
+    removed_arg: List[str],
     quiet: bool,
     config_file_path: str,
     config: str,
@@ -135,6 +136,8 @@ def get_tidy_invocation(
         start.append(f"-extra-arg={arg}")
     for arg in extra_arg_before:
         start.append(f"-extra-arg-before={arg}")
+    for arg in removed_arg:
+        start.append(f"-removed-arg={arg}")
     start.append(f"-p={build_path}")
     if quiet:
         start.append("-quiet")
@@ -377,6 +380,7 @@ async def run_tidy(
         args.allow_enabling_alpha_checkers,
         args.extra_arg,
         args.extra_arg_before,
+        args.removed_arg,
         args.quiet,
         args.config_file,
         args.config,
@@ -551,6 +555,13 @@ async def main() -> None:
         default=[],
         help="Additional argument to prepend to the compiler command line.",
     )
+    parser.add_argument(
+        "-removed-arg",
+        dest="removed_arg",
+        action="append",
+        default=[],
+        help="Arguments to remove from the compiler command line.",
+    )
     parser.add_argument(
         "-quiet", action="store_true", help="Run clang-tidy in quiet mode."
     )
@@ -638,6 +649,7 @@ async def main() -> None:
             args.allow_enabling_alpha_checkers,
             args.extra_arg,
             args.extra_arg_before,
+            args.removed_arg,
             args.quiet,
             args.config_file,
             args.config,

clang-tools-extra/docs/ReleaseNotes.rst

@@ -177,6 +177,11 @@ Improvements to clang-tidy
   scripts by adding the `-hide-progress` option to suppress progress and
   informational messages.
 
+- Improved :program:`clang-tidy` by adding the `--removed-arg` option to remove
+  arguments sent to the compiler when invoking Clang-Tidy. This option was also
+  added to :program:`run-clang-tidy.py` and :program:`clang-tidy-diff.py` and 
+  can be configured in the config file through the `RemovedArgs` option.
+
 - Deprecated the :program:`clang-tidy` ``zircon`` module. All checks have been
   moved to the ``fuchsia`` module instead. The ``zircon`` module will be removed
   in the 24th release.

clang-tools-extra/docs/clang-tidy/index.rst

@@ -331,6 +331,7 @@ An overview of all the command-line options:
                                    example, to place the correct user name in
                                    TODO() comments in the relevant check.
     WarningsAsErrors             - Same as '--warnings-as-errors'.
+    RemovedArgs                  - Same as '--removed-arg'
 
     The effective configuration can be inspected using --dump-config:
 

clang-tools-extra/test/clang-tidy/infrastructure/invalid-command-line.cpp

@@ -1,4 +1,4 @@
 // RUN: not clang-tidy --invalid-arg 2>&1 | FileCheck %s
 
 // CHECK: error: clang-tidy{{(\.exe)?}}: Unknown command line argument '--invalid-arg'.  Try: '{{.*}}clang-tidy{{(\.exe)?}} --help'
-// CHECK-NEXT: clang-tidy{{(\.exe)?}}: Did you mean '--extra-arg'?
+// CHECK-NEXT: clang-tidy{{(\.exe)?}}: Did you mean '--removed-arg'?

clang-tools-extra/test/clang-tidy/infrastructure/removed-args.cpp

@@ -0,0 +1,8 @@
+// RUN: not clang-tidy %s -- -fnot-an-option | FileCheck %s -check-prefix=INVALID-A
+// RUN: clang-tidy %s --config="{RemovedArgs: ['-fnot-an-option']}" -- -fnot-an-option
+// RUN: clang-tidy %s --config="{RemovedArgs: ['-fnot-another-option', '-fnot-an-option']}" -- -fnot-an-option -fnot-another-option
+// RUN: clang-tidy %s --removed-arg="-fnot-an-option" -- -fnot-an-option
+// RUN: not clang-tidy %s --removed-arg="-fnot-an-option" -- -fnot-an-option -fnot-another-option | FileCheck %s -check-prefix=INVALID-B
+
+// INVALID-A: error: unknown argument: '-fnot-an-option' [clang-diagnostic-error]
+// INVALID-B: error: unknown argument: '-fnot-another-option' [clang-diagnostic-error]