[PATCH] D128056: [clang][dataflow] Singleton pointer values for null pointers.

[weiyi via Phabricator via cfe-commits]

wyt created this revision.
Herald added subscribers: martong, tschuett, xazax.hun.
Herald added a project: All.
wyt requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

When a `nullptr` is assigned to a pointer variable, it is wrapped in a `ImplicitCastExpr` with cast kind `CK_NullTo(Member)Pointer`. This patch assigns singleton pointer values representing null to these expressions.

For each pointee type, a singleton null `PointerValue` is created and stored in the `NullPointerVals` map of the `DataflowAnalysisContext` class. The pointee type is retrieved from the implicit cast expression, and used to initialise the `PointeeLoc` field of the `PointerValue`. The `PointeeLoc` created is not mapped to any `Value`, reflecting the absence of value indicated by null pointers.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D128056

Files:
  clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
  clang/include/clang/Analysis/FlowSensitive/DataflowEnvironment.h
  clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
  clang/lib/Analysis/FlowSensitive/Transfer.cpp
  clang/unittests/Analysis/FlowSensitive/TransferTest.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D128056.437890.patch
Type: text/x-patch
Size: 7582 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20220617/6129c71a/attachment-0001.bin>