1 // Test the __VA_ARGS__ comma swallowing extensions of various compiler dialects. 2 3 // RUN: %clang_cc1 -E %s | FileCheck -check-prefix=GCC -strict-whitespace %s 4 // RUN: %clang_cc1 -E -std=c99 %s | FileCheck -check-prefix=C99 -strict-whitespace %s 5 // RUN: %clang_cc1 -E -std=c11 %s | FileCheck -check-prefix=C99 -strict-whitespace %s 6 // RUN: %clang_cc1 -E -x c++ %s | FileCheck -check-prefix=GCC -strict-whitespace %s 7 // RUN: %clang_cc1 -E -std=gnu99 %s | FileCheck -check-prefix=GCC -strict-whitespace %s 8 // RUN: %clang_cc1 -E -fms-compatibility %s | FileCheck -check-prefix=MS -strict-whitespace %s 9 // RUN: %clang_cc1 -E -DNAMED %s | FileCheck -check-prefix=GCC -strict-whitespace %s 10 // RUN: %clang_cc1 -E -std=c99 -DNAMED %s | FileCheck -check-prefix=C99 -strict-whitespace %s 11 12 13 #ifndef NAMED 14 # define A(...) [ __VA_ARGS__ ] 15 # define B(...) [ , __VA_ARGS__ ] 16 # define C(...) [ , ## __VA_ARGS__ ] 17 # define D(A,...) [ A , ## __VA_ARGS__ ] 18 # define E(A,...) [ __VA_ARGS__ ## A ] 19 #else 20 // These are the GCC named argument versions of the C99-style variadic macros. 21 // Note that __VA_ARGS__ *may* be used as the name, this is not prohibited! 22 # define A(__VA_ARGS__...) [ __VA_ARGS__ ] 23 # define B(__VA_ARGS__...) [ , __VA_ARGS__ ] 24 # define C(__VA_ARGS__...) [ , ## __VA_ARGS__ ] 25 # define D(A,__VA_ARGS__...) [ A , ## __VA_ARGS__ ] 26 # define E(A,__VA_ARGS__...) [ __VA_ARGS__ ## A ] 27 #endif 28 29 30 1: A() B() C() D() E() 31 2: A(a) B(a) C(a) D(a) E(a) 32 3: A(,) B(,) C(,) D(,) E(,) 33 4: A(a,b,c) B(a,b,c) C(a,b,c) D(a,b,c) E(a,b,c) 34 5: A(a,b,) B(a,b,) C(a,b,) D(a,b,) 35 36 // The GCC ", ## __VA_ARGS__" extension swallows the comma when followed by 37 // empty __VA_ARGS__. This extension does not apply in -std=c99 mode, but 38 // does apply in C++. 39 // 40 // GCC: 1: [ ] [ , ] [ ] [ ] [ ] 41 // GCC: 2: [ a ] [ , a ] [ ,a ] [ a ] [ a ] 42 // GCC: 3: [ , ] [ , , ] [ ,, ] [ , ] [ ] 43 // GCC: 4: [ a,b,c ] [ , a,b,c ] [ ,a,b,c ] [ a ,b,c ] [ b,ca ] 44 // GCC: 5: [ a,b, ] [ , a,b, ] [ ,a,b, ] [ a ,b, ] 45 46 // Under C99 standard mode, the GCC ", ## __VA_ARGS__" extension *does not* 47 // swallow the comma when followed by empty __VA_ARGS__. 48 // 49 // C99: 1: [ ] [ , ] [ , ] [ ] [ ] 50 // C99: 2: [ a ] [ , a ] [ ,a ] [ a ] [ a ] 51 // C99: 3: [ , ] [ , , ] [ ,, ] [ , ] [ ] 52 // C99: 4: [ a,b,c ] [ , a,b,c ] [ ,a,b,c ] [ a ,b,c ] [ b,ca ] 53 // C99: 5: [ a,b, ] [ , a,b, ] [ ,a,b, ] [ a ,b, ] 54 55 // Microsoft's extension is on ", __VA_ARGS__" (without explicit ##) where 56 // the comma is swallowed when followed by empty __VA_ARGS__. 57 // 58 // MS: 1: [ ] [ ] [ ] [ ] [ ] 59 // MS: 2: [ a ] [ , a ] [ ,a ] [ a ] [ a ] 60 // MS: 3: [ , ] [ , , ] [ ,, ] [ , ] [ ] 61 // MS: 4: [ a,b,c ] [ , a,b,c ] [ ,a,b,c ] [ a ,b,c ] [ b,ca ] 62 // MS: 5: [ a,b, ] [ , a,b, ] [ ,a,b, ] [ a ,b, ] 63 64 // FIXME: Item 3(d) in MS output should be [ ] not [ , ] 65