r323382 - [analyzer] Do not attempt to get the pointee of void*

[Alexander Shaposhnikov via cfe-commits]

Author: alexshap
Date: Wed Jan 24 14:17:30 2018
New Revision: 323382

URL: http://llvm.org/viewvc/llvm-project?rev=323382&view=rev
Log:
[analyzer] Do not attempt to get the pointee of void*

Do not attempt to get the pointee of void* while generating a bug report 
(otherwise it will trigger an assert inside RegionStoreManager::getBinding 
assert(!T->isVoidType() && "Attempting to dereference a void pointer!")).

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D42396

Modified:
    cfe/trunk/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
    cfe/trunk/test/Analysis/malloc.c

Modified: cfe/trunk/lib/StaticAnalyzer/Core/PathDiagnostic.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/StaticAnalyzer/Core/PathDiagnostic.cpp?rev=323382&r1=323381&r2=323382&view=diff
==============================================================================
--- cfe/trunk/lib/StaticAnalyzer/Core/PathDiagnostic.cpp (original)
+++ cfe/trunk/lib/StaticAnalyzer/Core/PathDiagnostic.cpp Wed Jan 24 14:17:30 2018
@@ -1211,6 +1211,9 @@ std::string StackHintGeneratorForSymbol:
 
     // Check if the parameter is a pointer to the symbol.
     if (Optional<loc::MemRegionVal> Reg = SV.getAs<loc::MemRegionVal>()) {
+      // Do not attempt to dereference void*.
+      if ((*I)->getType()->isVoidPointerType())
+        continue;
       SVal PSV = N->getState()->getSVal(Reg->getRegion());
       SymbolRef AS = PSV.getAsLocSymbol();
       if (AS == Sym) {

Modified: cfe/trunk/test/Analysis/malloc.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Analysis/malloc.c?rev=323382&r1=323381&r2=323382&view=diff
==============================================================================
--- cfe/trunk/test/Analysis/malloc.c (original)
+++ cfe/trunk/test/Analysis/malloc.c Wed Jan 24 14:17:30 2018
@@ -1786,6 +1786,18 @@ void cstringchecker_bounds_nocrash() {
   free(p);
 }
 
+void allocateSomeMemory(void *offendingParameter, void **ptr) {
+  *ptr = malloc(1);
+}
+
+void testNoCrashOnOffendingParameter() {
+  // "extern" is necessary to avoid unrelated warnings 
+  // on passing uninitialized value.
+  extern void *offendingParameter;
+  void* ptr;
+  allocateSomeMemory(offendingParameter, &ptr);
+} // expected-warning {{Potential leak of memory pointed to by 'ptr'}}
+
 // ----------------------------------------------------------------------------
 // False negatives.