1 // RUN: rm -rf %t 2 // RUN: split-file %s %t 3 // RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/no-lsv -I%t %t/stddef.cpp -verify 4 // RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-local-submodule-visibility -fmodules-cache-path=%t/lsv -I%t %t/stddef.cpp -verify 5 6 //--- stddef.cpp 7 #include <b.h> 8 9 void *pointer = NULL; 10 size_t size = 0; 11 12 // When building with modules, a pcm is never re-imported, so re-including 13 // stddef.h will not re-import _Builtin_stddef.null to restore the definition of 14 // NULL, even though stddef.h will unconditionally include __stddef_null.h when 15 // building with modules. 16 #undef NULL 17 #include <stddef.h> 18 19 void *anotherPointer = NULL; // expected-error{{use of undeclared identifier 'NULL'}} 20 21 // stddef.h needs to be a `textual` header to support clients doing things like 22 // this. 23 // 24 // #define __need_NULL 25 // #include <stddef.h> 26 // 27 // As a textual header designed to be included multiple times, it can't directly 28 // declare anything, or those declarations would go into every module that 29 // included it. e.g. if stddef.h contained all of its declarations, and modules 30 // A and B included stddef.h, they would both have the declaration for size_t. 31 // That breaks Swift, which uses the module name as part of the type name, i.e. 32 // A.size_t and B.size_t are treated as completely different types in Swift and 33 // cannot be interchanged. To fix that, stddef.h (and stdarg.h) are split out 34 // into a separate file per __need macro that can be normal headers in explicit 35 // submodules. That runs into yet another wrinkle though. When modules build, 36 // declarations from previous submodules leak into subsequent ones when not 37 // using local submodule visibility. Consider if stddef.h did the normal thing. 38 // 39 // #ifndef __STDDEF_H 40 // #define __STDDEF_H 41 // // include all of the sub-headers 42 // #endif 43 // 44 // When SM builds without local submodule visibility, it will precompile a.h 45 // first. When it gets to b.h, the __STDDEF_H declaration from precompiling a.h 46 // will leak, and so when b.h includes stddef.h, it won't include any of its 47 // sub-headers, and SM.B will thus not import _Builtin_stddef or make any of its 48 // submodules visible. Precompiling b.h will be fine since it sees all of the 49 // declarations from a.h including stddef.h, but clients that only include b.h 50 // will not see any of the stddef.h types. stddef.h thus has to make sure to 51 // always include the necessary sub-headers, even if they've been included 52 // already. They all have their own header guards to allow this. 53 // __stddef_null.h is extra special, so this test makes sure to cover NULL plus 54 // one of the normal stddef.h types. 55 56 //--- module.modulemap 57 module SM { 58 module A { 59 header "a.h" 60 export * 61 } 62 63 module B { 64 header "b.h" 65 export * 66 } 67 } 68 69 //--- a.h 70 #include <stddef.h> 71 72 //--- b.h 73 #include <stddef.h> 74