[PATCH] D103314: [Analyzer][solver] Simplify existing constraints when a new constraint is added

[Gabor Marton via Phabricator via cfe-commits]

martong created this revision.
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Update `setConstraint` to simplify existing constraints (and adding the
simplified constraint) when a new constraint is added. In this patch we just
simply iterate over all existing constraints and try to simplfy them with
simplifySVal. This solves the simplest problematic cases where we have two
symbols in the tree, e.g.:

  int test_rhs_further_constrained(int x, int y) {
    if (x + y != 0)
      return 0;
    if (y != 0)
      return 0;
    clang_analyzer_eval(x + y == 0); // expected-warning{{TRUE}}
    clang_analyzer_eval(y == 0);     // expected-warning{{TRUE}}
    return 0;
  }

This patch is the first step of a sequence of patches, and not intended to be
commited as a standalone change. The sequence of patches (and the plan) is
described here: https://reviews.llvm.org/D102696#2784624


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D103314

Files:
  clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
  clang/test/Analysis/find-binop-constraints.cpp

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