[clang] [analyzer] Ignore system headers in WebKit checkers. (PR #91103)

[Ryosuke Niwa via cfe-commits]

https://github.com/rniwa updated https://github.com/llvm/llvm-project/pull/91103

>From e2dbb580ff7fe1f2db1ad7c81902cb8a8b5a58ed Mon Sep 17 00:00:00 2001
From: Ryosuke Niwa <rniwa at webkit.org>
Date: Sat, 4 May 2024 20:41:29 -0700
Subject: [PATCH 1/2] [analyzer] Ignore system headers in WebKit checkers.

---
 .../Checkers/WebKit/UncountedCallArgsChecker.cpp               | 3 +++
 .../Checkers/WebKit/UncountedLocalVarsChecker.cpp              | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
index 0f40ecc7ba300..9a178a690ff24 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
@@ -150,6 +150,9 @@ class UncountedCallArgsChecker
   bool shouldSkipCall(const CallExpr *CE) const {
     const auto *Callee = CE->getDirectCallee();
 
+    if (BR->getSourceManager().isInSystemHeader(CE->getExprLoc()))
+      return true;
+
     if (Callee && TFA.isTrivial(Callee))
       return true;
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
index 6036ad58cf253..98a73810b7afc 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
@@ -230,6 +230,9 @@ class UncountedLocalVarsChecker
     if (!V->isLocalVarDecl())
       return true;
 
+    if (BR->getSourceManager().isInSystemHeader(V->getLocation()))
+      return true;
+
     return false;
   }
 

>From 83abd95771468333a213d952593196d400f55ecc Mon Sep 17 00:00:00 2001
From: Ryosuke Niwa <rniwa at webkit.org>
Date: Tue, 7 May 2024 16:47:02 -0700
Subject: [PATCH 2/2] Add tests.

---
 .../Checkers/WebKit/mock-system-header.h        | 17 +++++++++++++++++
 .../Checkers/WebKit/uncounted-local-vars.cpp    | 11 +++++++++++
 .../Checkers/WebKit/uncounted-members.cpp       | 10 ++++++++++
 .../Checkers/WebKit/uncounted-obj-arg.cpp       |  6 ++++++
 4 files changed, 44 insertions(+)
 create mode 100644 clang/test/Analysis/Checkers/WebKit/mock-system-header.h

diff --git a/clang/test/Analysis/Checkers/WebKit/mock-system-header.h b/clang/test/Analysis/Checkers/WebKit/mock-system-header.h
new file mode 100644
index 0000000000000..a1d30957b19cb
--- /dev/null
+++ b/clang/test/Analysis/Checkers/WebKit/mock-system-header.h
@@ -0,0 +1,17 @@
+#pragma clang system_header
+
+template <typename T, typename CreateFunction>
+void callMethod(CreateFunction createFunction) {
+  createFunction()->method();
+}
+
+template <typename T, typename CreateFunction>
+inline void localVar(CreateFunction createFunction) {
+  T* obj = createFunction();
+  obj->method();
+}
+
+template <typename T>
+struct MemberVariable {
+    T* obj { nullptr };
+};
diff --git a/clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp b/clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
index 00673e91f471e..8da1dc557a5a3 100644
--- a/clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/uncounted-local-vars.cpp
@@ -1,6 +1,7 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=alpha.webkit.UncountedLocalVarsChecker -verify %s
 
 #include "mock-types.h"
+#include "mock-system-header.h"
 
 void someFunction();
 
@@ -187,3 +188,13 @@ void bar() {
 }
 
 } // namespace ignore_for_if
+
+namespace ignore_system_headers {
+
+RefCountable *provide_ref_ctnbl();
+
+void system_header() {
+  localVar<RefCountable>(provide_ref_ctnbl);
+}
+
+} // ignore_system_headers
diff --git a/clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp b/clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
index 108d5effdd2e8..bca7b3bad3a15 100644
--- a/clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/uncounted-members.cpp
@@ -1,6 +1,7 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=webkit.NoUncountedMemberChecker -verify %s
 
 #include "mock-types.h"
+#include "mock-system-header.h"
 
 namespace members {
   struct Foo {
@@ -50,3 +51,12 @@ namespace ignore_unions {
 
   void forceTmplToInstantiate(RefPtr<RefCountable>) {}
 }
+
+namespace ignore_system_header {
+
+void foo(RefCountable* t) {
+  MemberVariable<RefCountable> var { t };
+  var.obj->method();
+}
+
+} // ignore_system_header
diff --git a/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp b/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp
index 63a68a994a5c6..e75d42b9f1491 100644
--- a/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp
+++ b/clang/test/Analysis/Checkers/WebKit/uncounted-obj-arg.cpp
@@ -1,6 +1,7 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=alpha.webkit.UncountedCallArgsChecker -verify %s
 
 #include "mock-types.h"
+#include "mock-system-header.h"
 
 void WTFBreakpointTrap();
 void WTFCrashWithInfo(int, const char*, const char*, int);
@@ -147,6 +148,7 @@ class RefCounted {
   void ref() const;
   void deref() const;
 
+  void method();
   void someFunction();
   int otherFunction();
 
@@ -399,3 +401,7 @@ void someFunction(const RefCounted&);
 void test2() {
     someFunction(*object());
 }
+
+void system_header() {
+  callMethod<RefCountable>(object);
+}