[PATCH] D156312: [analyzer] Upstream BitwiseShiftChecker

[Donát Nagy via Phabricator via cfe-commits]

donat.nagy updated this revision to Diff 550318.
donat.nagy edited the summary of this revision.
donat.nagy added a comment.

I verified that the checker handles the examples in the documentation correctly (and added them to the test suite). However, as I was tweaking the examples in the documentation, I accidentally found a situation where the checker produces a very surprising and arguably incorrect error message.

After investigating this issue, I added the testcases `signed_aritmetic_{good,bad}` which document the current sub-optimal state. The root cause of this problem is a high-level property of the engine (that it assumes that signed overflows are always possible and acceptable) and I don't see a local workaround that would silence or fix these incorrect error messages.

@steakhal @NoQ What do you know about these signed overflow issues (I presume that analogous issues also appear in other checkers)? How should we handle this limitation of this checker?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156312/new/

https://reviews.llvm.org/D156312

Files:
  clang/docs/analyzer/checkers.rst
  clang/include/clang/StaticAnalyzer/Checkers/Checkers.td
  clang/lib/StaticAnalyzer/Checkers/BitwiseShiftChecker.cpp
  clang/lib/StaticAnalyzer/Checkers/CMakeLists.txt
  clang/test/Analysis/analyzer-config.c
  clang/test/Analysis/analyzer-enabled-checkers.c
  clang/test/Analysis/bitwise-ops-nocrash.c
  clang/test/Analysis/bitwise-ops.c
  clang/test/Analysis/bitwise-shift-common.c
  clang/test/Analysis/bitwise-shift-pedantic.c
  clang/test/Analysis/bitwise-shift-sanity-checks.c
  clang/test/Analysis/bitwise-shift-state-update.c
  clang/test/Analysis/casts.c
  clang/test/Analysis/diagnostics/track_subexpressions.cpp
  clang/test/Analysis/left-shift-cxx2a.cpp
  clang/test/Analysis/std-c-library-functions-arg-enabled-checkers.c
  clang/test/Analysis/symbol-simplification-nonloc-loc.cpp

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D156312.550318.patch
Type: text/x-patch
Size: 49433 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20230815/a5eab77e/attachment-0001.bin>