steakhal added a comment. In D124349#3490524 <https://reviews.llvm.org/D124349#3490524>, @martong wrote:
> Can we have a test for this, got idea from here > (https://stackoverflow.com/questions/4129961/how-is-the-size-of-a-struct-with-bit-fields-determined-measured) > > typedef struct > { > unsigned int a:1; > unsigned int x:31; > unsigned int c:1; > int b[2]; > } mystruct; > ... > ff.b[0] = 3; > clang_analyzer_eval(*((int *)pff + 2) == 3); // expected-warning{{TRUE}} > // Or should this be `pff + 3` ??? Generally, you are right. But in this case, we are talking about a *single bit* bitfield. That bitfield cannot span across multiple `unsigned` objects. And `int` is supposed to be at least one byte large, hence there is plenty of room for an additional `CHAR_BIT - 1` bits along with this one and we would be still portable. ================ Comment at: clang/test/Analysis/array-struct-region.c:1 // RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.core,debug.ExprInspection -verify -analyzer-config eagerly-assume=false %s ---------------- martong wrote: > Should we pin the target, shouldn't we? There is no need for that. The `sizeof(int)` might change, but the `operator+` will accommodate for that in the pointer arithmetic. And the field after bitfields is by default aligned to its preferred alignment. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D124349/new/ https://reviews.llvm.org/D124349 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
