https://github.com/guillem-bartrina-sonarsource created https://github.com/llvm/llvm-project/pull/161537
The first thing `SValBuilder::evalBinOpNN` does is simplify both operators ([here](https://github.com/llvm/llvm-project/blob/main/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp#L430-L437)), why wouldn't we simplify the RHS in `SValBuilder::evalBinOpLN`? When the LHS is an `Element`, the right side is simplified incidentally when calling `evalBinOpNN` ([here](https://github.com/llvm/llvm-project/blob/main/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp#L1169-L1170)). Without this patch, the “base_complex” test case is **UNKNOWN** instead of **TRUE**. >From 1aeac20735676070c8549688bb9348d261a5d669 Mon Sep 17 00:00:00 2001 From: guillem-bartrina-sonarsource <[email protected]> Date: Wed, 1 Oct 2025 17:14:11 +0200 Subject: [PATCH] [analyzer] SValBuilder::evalBinOpLN: try simplifying the RHS first --- .../StaticAnalyzer/Core/SimpleSValBuilder.cpp | 6 ++ clang/test/Analysis/loc-folding.cpp | 60 +++++++++++++++++++ 2 files changed, 66 insertions(+) create mode 100644 clang/test/Analysis/loc-folding.cpp diff --git a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp index 84a9c43d3572e..975172a2b1f79 100644 --- a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp +++ b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp @@ -1111,6 +1111,12 @@ SVal SimpleSValBuilder::evalBinOpLN(ProgramStateRef state, assert(!BinaryOperator::isComparisonOp(op) && "arguments to comparison ops must be of the same type"); + // Constraints may have changed since the creation of a bound SVal. Check if + // the value can be simplified based on those new constraints. + SVal simplifiedRhs = simplifySVal(state, rhs); + if (auto simplifiedRhsAsNonLoc = simplifiedRhs.getAs<NonLoc>()) + rhs = *simplifiedRhsAsNonLoc; + // Special case: rhs is a zero constant. if (rhs.isZeroConstant()) return lhs; diff --git a/clang/test/Analysis/loc-folding.cpp b/clang/test/Analysis/loc-folding.cpp new file mode 100644 index 0000000000000..ec70143b972ef --- /dev/null +++ b/clang/test/Analysis/loc-folding.cpp @@ -0,0 +1,60 @@ +// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify -Wno-tautological-compare -analyzer-config eagerly-assume=false %s + +void clang_analyzer_eval(bool); + +void element_constant() { + char arr[10]; + clang_analyzer_eval(arr + 1 > arr); // expected-warning{{TRUE}} +} + +void element_known() { + char arr[10]; + int off = 1; + clang_analyzer_eval(arr + off > arr); // expected-warning{{TRUE}} +} + +void element_constrained(int off) { + char arr[10]; + if (off == 1) { + clang_analyzer_eval(arr + off > arr); // expected-warning{{TRUE}} + } +} + +void element_unknown(int off) { + char arr[10]; + clang_analyzer_eval(arr + off > arr); // expected-warning{{UNKNOWN}} +} + +void element_complex(int off) { + char arr[10]; + int comp = off * 2; + if (off == 1) { + clang_analyzer_eval(arr + comp); // expected-warning{{TRUE}} + } +} + +void base_constant(int *arr) { + clang_analyzer_eval(arr + 1 > arr); // expected-warning{{TRUE}} +} + +void base_known(int *arr) { + int off = 1; + clang_analyzer_eval(arr + off > arr); // expected-warning{{TRUE}} +} + +void base_constrained(int *arr, int off) { + if (off == 1) { + clang_analyzer_eval(arr + off > arr); // expected-warning{{TRUE}} + } +} + +void base_unknown(int *arr, int off) { + clang_analyzer_eval(arr + off > arr); // expected-warning{{UNKNOWN}} +} + +void base_complex(int *arr, int off) { + int comp = off * 2; + if (off == 1) { + clang_analyzer_eval(arr + comp > arr); // expected-warning{{TRUE}} + } +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
