================ @@ -1,13 +1,158 @@ -// RUN: %clang_cc1 %s -verify=c -fsyntax-only -// RUN: %clang_cc1 %s -verify -fsyntax-only -x c++ -// RUN: %clang_cc1 %s -verify -fsyntax-only -fms-compatibility -// RUN: %clang_cc1 %s -verify -fsyntax-only -fms-compatibility -x c++ +// RUN: %clang_cc1 %s -verify=stock,c -fsyntax-only +// RUN: %clang_cc1 %s -verify=stock,cpp -fsyntax-only -x c++ +// RUN: %clang_cc1 %s -verify=stock,cpp -fsyntax-only -fms-compatibility -x c++ +// RUN: %clang_cc1 %s -verify=stock,c,gnu -fsyntax-only -Wgnu-flexible-array-union-member -Wgnu-empty-struct +// RUN: %clang_cc1 %s -verify=stock,c,microsoft -fsyntax-only -fms-compatibility -Wmicrosoft // The test checks that an attempt to initialize union with flexible array // member with an initializer list doesn't crash clang. -union { char x[]; } r = {0}; // c-error {{flexible array member 'x' in a union is not allowed}} +union { char x[]; } r = {0}; /* gnu-warning {{flexible array member 'x' in a union is a GNU extension}} + microsoft-warning {{flexible array member 'x' in a union is a Microsoft extension}} + */ +struct _name1 { + int a; + union { + int b; + char x[]; /* gnu-warning {{flexible array member 'x' in a union is a GNU extension}} + microsoft-warning {{flexible array member 'x' in a union is a Microsoft extension}} + */ + }; +} name1 = { + 10, + 42, /* initializes "b" */ +}; -// expected-no-diagnostics +struct _name1i { + int a; + union { + int b; + char x[]; /* gnu-warning {{flexible array member 'x' in a union is a GNU extension}} + microsoft-warning {{flexible array member 'x' in a union is a Microsoft extension}} + */ + }; +} name1i = { + .a = 10, + .b = 42, +}; + +/* Initialization of flexible array in a union is never allowed. */ +struct _name2 { + int a; + union { + int b; + char x[]; /* gnu-warning {{flexible array member 'x' in a union is a GNU extension}} + microsoft-warning {{flexible array member 'x' in a union is a Microsoft extension}} + stock-note {{initialized flexible array member 'x' is here}} + */ + }; +} name2 = { + 12, + 13, + { 'c' }, /* stock-error {{initialization of flexible array member is not allowed}} */ ---------------- hvdijk wrote:
I think this is more than just a confusing error message. Consider `struct S { int a; union { int b; char x[]; }; int c; } s = {1, 2, 3};`. If `x` is given type `char[0]`, or `char[1]`, or `char[2]`, the `3` initializer applies to `s.c`. Yet inexplicably, if `x` has type `char[]`, the `3` initializer applies to `s.x` and any initializer is an error? That looks like a bug. We can even turn this into wrong-code: `struct S { int a; union { int b; char x[]; }; int c; int d; } s = {1, 2, {}, 3};`. This should initialise `a`, `b`, `c`, `d`, to `1`, `2`, `0`, `3`, but instead initialises them to `1`, `2`, `3`, `0`. https://github.com/llvm/llvm-project/pull/84428 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits