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| 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> |
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