codeql/cpp/change-notes/2020-09-29-range-analysis-rollup.md

lgtm,codescanning

• The SimpleRangeAnalysis library has gained support for several language constructs it did not support previously. These improvements primarily affect the queries cpp/constant-comparison, cpp/comparison-with-wider-type, and cpp/integer-multiplication-cast-to-long. The newly supported language features are:
  • Multiplication of unsigned numbers.
  • Multiplication by a constant.
  • Reference-typed function parameters.
  • Comparing a variable not equal to an endpoint of its range, thus narrowing the range by one.
  • Using if (x) or if (!x) or similar to test for equality to zero.
• The SimpleRangeAnalysis library can now be extended with custom rules. See examples in cpp/ql/src/experimental/semmle/code/cpp/rangeanalysis/extensions/.