baloghadamsoftware added inline comments.
================ Comment at: lib/StaticAnalyzer/Core/RangeConstraintManager.cpp:511 + SSE->getLHS()->getType()->isSignedIntegerOrEnumerationType() || + SSE->getLHS()->getType()->isPointerType()) { + return negV->Negate(BV, F); ---------------- NoQ wrote: > baloghadamsoftware wrote: > > NoQ wrote: > > > Pointer types are currently treated as unsigned, so i'm not sure you want > > > them here. > > For me it seems that pointer differences are still pointer types and they > > are signed. (The range becomes negative upon negative assumption. From test > > `ptr-arith.c`: > > > > ``` > > void use_symbols(int *lhs, int *rhs) { > > clang_analyzer_eval(lhs < rhs); // expected-warning{{UNKNOWN}} > > if (lhs < rhs) > > return; > > clang_analyzer_eval(lhs < rhs); // expected-warning{{FALSE}} > > > > clang_analyzer_eval(lhs - rhs); // expected-warning{{UNKNOWN}} > > if ((lhs - rhs) != 5) > > return; > > clang_analyzer_eval((lhs - rhs) == 5); // expected-warning{{TRUE}} > > } > > ``` > > > > If I put `clang_analyzer_printState()` into the empty line in the middle, I > > get the following range for the difference: `[-9223372036854775808, 0]`. If > > I replace `int*` with `unsigned`, this range becomes `[0, 0]`, so `int*` is > > handled as a signed type here. > Umm, yeah, i was wrong. > > *looks closer* > > `T` is the type of the difference, right? I don't think i'd expect pointer > type as the type of the difference. > > Could you add test cases for pointers if you intend to support them (and > maybe for unsigned types)? I do not know exactly the type, but if I remove the `T->isPointerType()` condition the test in `ptr_arith.c` will fail with `UNKNOWN`. So the type of the difference is a type that returns `true` from `T->isPointerType()`. Pointer tests are already there in `ptr_arith.c`. Should I duplicate them? https://reviews.llvm.org/D35110 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits