[clang-tidy] fix false positives for the functions with the same name as standard library functions in misc-include-cleaner

Fixes: #93335

Author: HerrCai0907

clang-tools-extra/docs/ReleaseNotes.rst

@@ -286,6 +286,10 @@ Changes in existing checks
   Additionally, the option `UseHeaderFileExtensions` is removed, so that the
   check uses the `HeaderFileExtensions` option unconditionally.
 
+- Improved :doc:`misc-include-cleaner
+  <clang-tidy/checks/misc/include-cleaner>` check by avoiding false positives for
+  the functions with the same name as standard library functions.
+
 - Improved :doc:`misc-unused-using-decls
   <clang-tidy/checks/misc/unused-using-decls>` check by replacing the local
   option `HeaderFileExtensions` by the global option of the same name.

clang-tools-extra/include-cleaner/lib/LocateSymbol.cpp

@@ -14,6 +14,7 @@
 #include "clang/AST/DeclTemplate.h"
 #include "clang/Tooling/Inclusions/StandardLibrary.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/raw_ostream.h"
 #include <utility>
 #include <vector>
 
@@ -40,8 +41,11 @@ Hints declHints(const Decl *D) {
 std::vector<Hinted<SymbolLocation>> locateDecl(const Decl &D) {
   std::vector<Hinted<SymbolLocation>> Result;
   // FIXME: Should we also provide physical locations?
-  if (auto SS = tooling::stdlib::Recognizer()(&D))
-    return {{*SS, Hints::CompleteSymbol}};
+  if (auto SS = tooling::stdlib::Recognizer()(&D)) {
+    Result.push_back({*SS, Hints::CompleteSymbol});
+    if (!D.hasBody())
+      return Result;
+  }
   // FIXME: Signal foreign decls, e.g. a forward declaration not owned by a
   // library. Some useful signals could be derived by checking the DeclContext.
   // Most incidental forward decls look like:

clang-tools-extra/include-cleaner/unittests/FindHeadersTest.cpp

@@ -628,6 +628,17 @@ TEST_F(HeadersForSymbolTest, StandardHeaders) {
                            tooling::stdlib::Header::named("<assert.h>")));
 }
 
+TEST_F(HeadersForSymbolTest, NonStandardHeaders) {
+  Inputs.Code = "void assert() {}";
+  buildAST();
+  EXPECT_THAT(
+      headersFor("assert"),
+      // Respect the ordering from the stdlib mapping.
+      UnorderedElementsAre(physicalHeader("input.mm"),
+                           tooling::stdlib::Header::named("<cassert>"),
+                           tooling::stdlib::Header::named("<assert.h>")));
+}
+
 TEST_F(HeadersForSymbolTest, ExporterNoNameMatch) {
   Inputs.Code = R"cpp(
     #include "exporter/foo.h"

clang-tools-extra/test/clang-tidy/checkers/misc/include-cleaner.cpp

@@ -15,3 +15,5 @@ std::string HelloString;
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: no header providing "std::string" is directly included [misc-include-cleaner]
 int FooBarResult = foobar();
 // CHECK-MESSAGES: :[[@LINE-1]]:20: warning: no header providing "foobar" is directly included [misc-include-cleaner]
+
+void log2() {}