From: Jordan Rose <jordan_rose@apple.com>
Date: Mon, 25 Jun 2012 20:48:28 +0000 (+0000)
Subject: [analyzer] Be careful about implicitly-declared operator new/delete. (PR13090)
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=ee681111c713f300884550b1503713ade3b32374;p=clang

[analyzer] Be careful about implicitly-declared operator new/delete. (PR13090)

The implicit global allocation functions do not have valid source locations,
but we still want to treat them as being "system header" functions for the
purposes of how they affect program state.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159160 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h b/include/clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h
index f01bad02c2..8fc4050c7e 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h
@@ -199,10 +199,16 @@ public:
 
   /// Check if the callee is declared in the system header.
   bool isInSystemHeader() const {
-    if (const Decl *FD = getDecl()) {
+    if (const Decl *D = getDecl()) {
       const SourceManager &SM =
         State->getStateManager().getContext().getSourceManager();
-      return SM.isInSystemHeader(FD->getLocation());
+      SourceLocation Loc = D->getLocation();
+      // Be careful: the implicit declarations of operator new/delete have
+      // invalid source locations but should still count as system files.
+      if (Loc.isValid())
+        return SM.isInSystemHeader(D->getLocation());
+      else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
+        return FD->isOverloadedOperator() && FD->isImplicit() && FD->isGlobal();
     }
     return false;
   }
diff --git a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
index 50d4273e48..1aa9b824e3 100644
--- a/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -1338,8 +1338,7 @@ bool MallocChecker::doesNotFreeMemory(const CallOrObjCMessage *Call,
   }
 
   // If it's not a system call, assume it frees memory.
-  SourceManager &SM = ASTC.getSourceManager();
-  if (!SM.isInSystemHeader(D->getLocation()))
+  if (!Call->isInSystemHeader())
     return false;
 
   // Process C/ObjC functions.
diff --git a/test/Analysis/new.cpp b/test/Analysis/new.cpp
index 8093eff3a1..723d033bc7 100644
--- a/test/Analysis/new.cpp
+++ b/test/Analysis/new.cpp
@@ -5,6 +5,21 @@ void clang_analyzer_eval(bool);
 typedef typeof(sizeof(int)) size_t;
 extern "C" void *malloc(size_t);
 
+int someGlobal;
+void testImplicitlyDeclaredGlobalNew() {
+  if (someGlobal != 0)
+    return;
+
+  // This used to crash because the global operator new is being implicitly
+  // declared and it does not have a valid source location. (PR13090)
+  void *x = ::operator new(0);
+  ::operator delete(x);
+
+  // Check that the new/delete did not invalidate someGlobal;
+  clang_analyzer_eval(someGlobal == 0); // expected-warning{{TRUE}}
+}
+
+
 // This is the standard placement new.
 inline void* operator new(size_t, void* __p) throw()
 {