[PATCH] D159412: [analyzer]FieldRegion in getStaticSize should return size of pointee type

[Qizhi Hu via Phabricator via cfe-commits]

jcsxky created this revision.
jcsxky added reviewers: steakhal, balazske, aaron.ballman, NoQ.
jcsxky added projects: clang, clang-c.
Herald added subscribers: manas, ASDenysPetrov, martong, dkrupp, donat.nagy, Szelethus, mikhail.ramalho, a.sidorin, szepet, baloghadamsoftware, xazax.hun.
Herald added a project: All.
jcsxky requested review of this revision.
Herald added a subscriber: cfe-commits.

In `getStaticSize`, case of FieldRegionKind should return size of pointee type of the member. In the following example:

  struct B {
  	int x;
  	int y;
  	int z;
  };
  
  class A{
  public:
  	void foo(){
  		m++;
  	}
  private:
  	B *m;
  };

`getDynamicElementCount` of `m` region, if `getDynamicExtent` return the pointer size, `getDynamicElementCount` returns 0 in 64bit architecture(since pointer size is 8 while size of pointee type is 12). Use pointee type instead, it will return 1.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D159412

Files:
  clang/lib/StaticAnalyzer/Core/MemRegion.cpp


Index: clang/lib/StaticAnalyzer/Core/MemRegion.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -800,6 +800,12 @@
       return UnknownVal();
 
     QualType Ty = cast<TypedValueRegion>(SR)->getDesugaredValueType(Ctx);
+    if (Ty->isPointerType()) {
+      QualType PointeeTy = Ty->getPointeeType();
+      if(!PointeeTy->isIncompleteType() && PointeeTy->isObjectType()){
+        Ty = PointeeTy;
+      }
+    }
     const DefinedOrUnknownSVal Size = getElementExtent(Ty, SVB);
 
     // We currently don't model flexible array members (FAMs), which are:


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D159412.555645.patch
Type: text/x-patch
Size: 679 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20230904/f42df6d3/attachment.bin>