[PATCH] D45335: [analyzer] RetainCount: Accept more "safe" CFRetain wrappers.

[Artem Dergachev via Phabricator via cfe-commits]

NoQ created this revision.
NoQ added reviewers: dcoughlin, george.karpenkov.
Herald added subscribers: cfe-commits, a.sidorin, JDevlieghere, szepet, xazax.hun.

https://reviews.llvm.org/D38877 added support for the misplaced `CF_RETURNS_RETAINED` annotation on `CFRetain()` wrappers. It works by trusting the function's name (seeing if it confirms to the CoreFoundation naming convention) rather than the annotation.

There are more false positives caused by users using a different naming convention, namely starting the function name with "retain" or "release" rather than suffixing it with "retain" or "release" respectively.

Because this isn't according to the naming convention, these functions are usually inlined and the annotation is therefore ignored, which is correct. But sometimes we run out of inlining stack depth and the function is evaluated conservatively and then the annotation is trusted.

Add support for the "alternative" naming convention and test the situation when we're running out of inlining stack depth.


Repository:
  rC Clang

https://reviews.llvm.org/D45335

Files:
  lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
  test/Analysis/retain-release-safe.c


Index: test/Analysis/retain-release-safe.c
===================================================================
--- test/Analysis/retain-release-safe.c
+++ test/Analysis/retain-release-safe.c
@@ -1,4 +1,5 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=core,osx.coreFoundation.CFRetainRelease,osx.cocoa.RetainCount -verify %s
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,osx.coreFoundation.CFRetainRelease,osx.cocoa.RetainCount -analyzer-inline-max-stack-depth=0 -verify %s
 
 #pragma clang arc_cf_code_audited begin
 typedef const void * CFTypeRef;
@@ -35,6 +36,19 @@
     CFRelease(cf); // no-warning (when inlined)
 }
 
+// The same thing, just with a different naming style.
+CFTypeRef retainCFType(CFTypeRef cf) CF_RETURNS_RETAINED {
+  if (cf) {
+    return CFRetain(cf);
+  }
+  return cf;
+}
+
+void releaseCFType(CFTypeRef CF_CONSUMED cf) {
+  if (cf)
+    CFRelease(cf); // no-warning (when inlined)
+}
+
 void escape(CFTypeRef cf);
 
 void makeSureTestsWork() {
@@ -70,3 +84,10 @@
   SafeCFRelease(cf);
   SafeCFRelease(cf); // no-warning after inlining this.
 }
+
+void testTheOtherNamingConvention(CFTypeRef cf) {
+  retainCFType(cf);
+  retainCFType(cf);
+  releaseCFType(cf);
+  releaseCFType(cf); // no-warning
+}
Index: lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
+++ lib/StaticAnalyzer/Checkers/RetainCountChecker.cpp
@@ -883,21 +883,22 @@
 //===----------------------------------------------------------------------===//
 
 static bool isRetain(const FunctionDecl *FD, StringRef FName) {
-  return FName.endswith("Retain");
+  return FName.startswith_lower("retain") || FName.endswith_lower("retain");
 }
 
 static bool isRelease(const FunctionDecl *FD, StringRef FName) {
-  return FName.endswith("Release");
+  return FName.startswith_lower("release") || FName.endswith_lower("release");
 }
 
 static bool isAutorelease(const FunctionDecl *FD, StringRef FName) {
-  return FName.endswith("Autorelease");
+  return FName.startswith_lower("autorelease") ||
+         FName.endswith_lower("autorelease");
 }
 
 static bool isMakeCollectable(const FunctionDecl *FD, StringRef FName) {
   // FIXME: Remove FunctionDecl parameter.
   // FIXME: Is it really okay if MakeCollectable isn't a suffix?
-  return FName.find("MakeCollectable") != StringRef::npos;
+  return FName.find_lower("MakeCollectable") != StringRef::npos;
 }
 
 static ArgEffect getStopTrackingHardEquivalent(ArgEffect E) {


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