efriedma added inline comments.
================ Comment at: clang/lib/AST/ExprConstant.cpp:11737 bool Ret = HandleSizeof(Info, ExprLoc, Ty, Result); if (Ty->isStructureType() && Ty->getAsStructureType()->getDecl()->hasFlexibleArrayMember()) { ---------------- nickdesaulniers wrote: > efriedma wrote: > > For the second call to CheckHandleSizeof (line 11791), is the type of > > consistent with the type of the variable? If Ty refers to a field, I'm not > > sure it makes sense to call getFlexibleArrayInitChars(). Something along > > the lines of "struct Z { struct A { int x, y[]; } z; int a; };" > Can such an object even be initialized? > ``` > cat /tmp/x.c > struct Z { struct A { int x, y[]; } z; int a; }; > > static struct Z my_z = { > .z = { > .x = 42, > .y = { > 0, 1, 2, > }, > }, > .a = 42, > }; > > unsigned long foo (void) { > return __builtin_object_size(&my_z, 1); > } > $ clang -O2 /tmp/x.c -S -o - > /tmp/x.c:1:37: warning: field 'z' with variable sized type 'struct A' not at > the end of a struct or class is a GNU extension > [-Wgnu-variable-sized-type-not-at-end] > struct Z { struct A { int x, y[]; } z; int a; }; > ^ > /tmp/x.c:6:10: error: initialization of flexible array member is not allowed > .y = { > ^ > /tmp/x.c:1:30: note: initialized flexible array member 'y' is here > struct Z { struct A { int x, y[]; } z; int a; }; > ^ > 1 warning and 1 error generated. > ``` > or did you have something else in mind? I was thinking something more along the lines of ``` struct Z { struct A { int x, y[]; } z; int a; int b[]; }; static struct Z my_z = { .b = {1,2,3} }; unsigned long foo (void) { return __builtin_object_size(&my_z.z, 1); } ``` The idea being that you're adding the length of the flexible member even though the caller isn't trying to ask about it. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D151148/new/ https://reviews.llvm.org/D151148 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits