bugprone-argument-comment: ignore mismatches from system headers

As of 2a3498e, we ignore parameter name mismatches for functions
in the `std::` namespace, since those aren't standardized. It seems
reasonable to extend this to all functions which are declared in system
headers, since this lint can be a bit noisy otherwise
(https://bugs.chromium.org/p/chromium/issues/detail?id=1191507).

Differential Revision: https://reviews.llvm.org/D99993

Author: gburgessiv

clang-tools-extra/clang-tidy/bugprone/ArgumentCommentCheck.cpp

@@ -20,10 +20,12 @@ namespace clang {
 namespace tidy {
 namespace bugprone {
 namespace {
-AST_MATCHER(Decl, isFromStdNamespace) {
+AST_MATCHER(Decl, isFromStdNamespaceOrSystemHeader) {
   if (const auto *D = Node.getDeclContext()->getEnclosingNamespaceContext())
-    return D->isStdNamespace();
-  return false;
+    if (D->isStdNamespace())
+      return true;
+  return Node.getASTContext().getSourceManager().isInSystemHeader(
+      Node.getLocation());
 }
 } // namespace
 
@@ -66,13 +68,13 @@ void ArgumentCommentCheck::registerMatchers(MatchFinder *Finder) {
                // not specified by the standard, and standard library
                // implementations in practice have to use reserved names to
                // avoid conflicts with same-named macros.
-               unless(hasDeclaration(isFromStdNamespace())))
-          .bind("expr"),
-      this);
-  Finder->addMatcher(
-      cxxConstructExpr(unless(hasDeclaration(isFromStdNamespace())))
+               unless(hasDeclaration(isFromStdNamespaceOrSystemHeader())))
           .bind("expr"),
       this);
+  Finder->addMatcher(cxxConstructExpr(unless(hasDeclaration(
+                                          isFromStdNamespaceOrSystemHeader())))
+                         .bind("expr"),
+                     this);
 }
 
 static std::vector<std::pair<SourceLocation, StringRef>>

clang-tools-extra/test/clang-tidy/checkers/Inputs/bugprone-argument-comment/header-with-decl.h

@@ -0,0 +1 @@
+void my_header_function(int arg);

clang-tools-extra/test/clang-tidy/checkers/Inputs/bugprone-argument-comment/system-header-with-decl.h

@@ -0,0 +1,3 @@
+#pragma clang system_header
+
+void my_system_header_function(int arg);

clang-tools-extra/test/clang-tidy/checkers/bugprone-argument-comment.cpp

@@ -1,4 +1,4 @@
-// RUN: %check_clang_tidy %s bugprone-argument-comment %t
+// RUN: %check_clang_tidy %s bugprone-argument-comment %t -- -- -I %S/Inputs/bugprone-argument-comment
 
 // FIXME: clang-tidy should provide a -verify mode to make writing these checks
 // easier and more accurate.
@@ -134,3 +134,20 @@ void test(int a, int b) {
   std::swap(a, /*num=*/b);
 }
 } // namespace ignore_std_functions
+
+namespace regular_header {
+#include "header-with-decl.h"
+void test() {
+  my_header_function(/*not_arg=*/1);
+// CHECK-NOTES: [[@LINE-1]]:22: warning: argument name 'not_arg' in comment does not match parameter name 'arg'
+// CHECK-NOTES: header-with-decl.h:1:29: note: 'arg' declared here
+// CHECK-FIXES: my_header_function(/*not_arg=*/1);
+}
+} // namespace regular_header
+
+namespace system_header {
+#include "system-header-with-decl.h"
+void test() {
+  my_system_header_function(/*not_arg=*/1);
+}
+} // namespace system_header