michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* mfbt foundational types and macros. */
michael@0: 
michael@0: #ifndef mozilla_Types_h
michael@0: #define mozilla_Types_h
michael@0: 
michael@0: /*
michael@0:  * This header must be valid C and C++, includable by code embedding either
michael@0:  * SpiderMonkey or Gecko.
michael@0:  */
michael@0: 
michael@0: /* Expose all <stdint.h> types and size_t. */
michael@0: #include <stddef.h>
michael@0: #include <stdint.h>
michael@0: 
michael@0: /* Implement compiler and linker macros needed for APIs. */
michael@0: 
michael@0: /*
michael@0:  * MOZ_EXPORT is used to declare and define a symbol or type which is externally
michael@0:  * visible to users of the current library.  It encapsulates various decorations
michael@0:  * needed to properly export the method's symbol.
michael@0:  *
michael@0:  *   api.h:
michael@0:  *     extern MOZ_EXPORT int MeaningOfLife(void);
michael@0:  *     extern MOZ_EXPORT int LuggageCombination;
michael@0:  *
michael@0:  *   api.c:
michael@0:  *     int MeaningOfLife(void) { return 42; }
michael@0:  *     int LuggageCombination = 12345;
michael@0:  *
michael@0:  * If you are merely sharing a method across files, just use plain |extern|.
michael@0:  * These macros are designed for use by library interfaces -- not for normal
michael@0:  * methods or data used cross-file.
michael@0:  */
michael@0: #if defined(WIN32)
michael@0: #  define MOZ_EXPORT   __declspec(dllexport)
michael@0: #else /* Unix */
michael@0: #  ifdef HAVE_VISIBILITY_ATTRIBUTE
michael@0: #    define MOZ_EXPORT       __attribute__((visibility("default")))
michael@0: #  elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
michael@0: #    define MOZ_EXPORT      __global
michael@0: #  else
michael@0: #    define MOZ_EXPORT /* nothing */
michael@0: #  endif
michael@0: #endif
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * Whereas implementers use MOZ_EXPORT to declare and define library symbols,
michael@0:  * users use MOZ_IMPORT_API and MOZ_IMPORT_DATA to access them.  Most often the
michael@0:  * implementer of the library will expose an API macro which expands to either
michael@0:  * the export or import version of the macro, depending upon the compilation
michael@0:  * mode.
michael@0:  */
michael@0: #ifdef _WIN32
michael@0: #  if defined(__MWERKS__)
michael@0: #    define MOZ_IMPORT_API /* nothing */
michael@0: #  else
michael@0: #    define MOZ_IMPORT_API __declspec(dllimport)
michael@0: #  endif
michael@0: #else
michael@0: #  define MOZ_IMPORT_API MOZ_EXPORT
michael@0: #endif
michael@0: 
michael@0: #if defined(_WIN32) && !defined(__MWERKS__)
michael@0: #  define MOZ_IMPORT_DATA  __declspec(dllimport)
michael@0: #else
michael@0: #  define MOZ_IMPORT_DATA  MOZ_EXPORT
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:  * Consistent with the above comment, the MFBT_API and MFBT_DATA macros expose
michael@0:  * export mfbt declarations when building mfbt, and they expose import mfbt
michael@0:  * declarations when using mfbt.
michael@0:  */
michael@0: #if defined(IMPL_MFBT)
michael@0: #  define MFBT_API     MOZ_EXPORT
michael@0: #  define MFBT_DATA    MOZ_EXPORT
michael@0: #else
michael@0:   /*
michael@0:    * On linux mozglue is linked in the program and we link libxul.so with
michael@0:    * -z,defs. Normally that causes the linker to reject undefined references in
michael@0:    * libxul.so, but as a loophole it allows undefined references to weak
michael@0:    * symbols. We add the weak attribute to the import version of the MFBT API
michael@0:    * macros to exploit this.
michael@0:    */
michael@0: #  if defined(MOZ_GLUE_IN_PROGRAM)
michael@0: #    define MFBT_API   __attribute__((weak)) MOZ_IMPORT_API
michael@0: #    define MFBT_DATA  __attribute__((weak)) MOZ_IMPORT_DATA
michael@0: #  else
michael@0: #    define MFBT_API   MOZ_IMPORT_API
michael@0: #    define MFBT_DATA  MOZ_IMPORT_DATA
michael@0: #  endif
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:  * C symbols in C++ code must be declared immediately within |extern "C"|
michael@0:  * blocks.  However, in C code, they need not be declared specially.  This
michael@0:  * difference is abstracted behind the MOZ_BEGIN_EXTERN_C and MOZ_END_EXTERN_C
michael@0:  * macros, so that the user need not know whether he is being used in C or C++
michael@0:  * code.
michael@0:  *
michael@0:  *   MOZ_BEGIN_EXTERN_C
michael@0:  *
michael@0:  *   extern MOZ_EXPORT int MostRandomNumber(void);
michael@0:  *   ...other declarations...
michael@0:  *
michael@0:  *   MOZ_END_EXTERN_C
michael@0:  *
michael@0:  * This said, it is preferable to just use |extern "C"| in C++ header files for
michael@0:  * its greater clarity.
michael@0:  */
michael@0: #ifdef __cplusplus
michael@0: #  define MOZ_BEGIN_EXTERN_C    extern "C" {
michael@0: #  define MOZ_END_EXTERN_C      }
michael@0: #else
michael@0: #  define MOZ_BEGIN_EXTERN_C
michael@0: #  define MOZ_END_EXTERN_C
michael@0: #endif
michael@0: 
michael@0: /*
michael@0:  * GCC's typeof is available when decltype is not.
michael@0:  */
michael@0: #if defined(__GNUC__) && defined(__cplusplus) && \
michael@0:   !defined(__GXX_EXPERIMENTAL_CXX0X__) && __cplusplus < 201103L
michael@0: #  define decltype __typeof__
michael@0: #endif
michael@0: 
michael@0: #endif /* mozilla_Types_h */