Common Macros¶

The header abs_common.h defines the small set of macros shared by every other header. You rarely include it directly — abs.h pulls it in for you.

#include "abscom/abs.h"        /* brings in abs_common.h */

ABI and export macros¶

Macro	Purpose
`ABS_API`	Export/import annotation on every public function. On Windows it expands to `__declspec(dllexport)` when the library itself is being built and `__declspec(dllimport)` for consumers; on GCC/Clang it expands to `__attribute__((visibility("default")))`.
`ABS_BUILDING_LIBRARY`	Define this when compiling the library sources so `ABS_API` becomes `dllexport`. `meson.build` sets it via `c_args`.
`ABS_USE_LIBRARY`	Define this in your own build when linking against the shared library on Windows so `ABS_API` becomes `dllimport`.

If neither ABS_BUILDING_LIBRARY nor ABS_USE_LIBRARY is defined, ABS_API expands to nothing and you link the static library.

C++ interop¶

Macro	Purpose
`ABS_BEGIN_C_DECLS`	Expands to `extern "C" {` when compiling as C++, otherwise nothing.
`ABS_END_C_DECLS`	Expands to `}` when compiling as C++, otherwise nothing.

Every public header wraps its declarations in these two macros so the library links cleanly from C++ programs.

Utilities¶

Macro	Purpose
`ABS_UNUSED(x)`	Casts `x` to `void`, suppressing unused-variable warnings. Useful in callback parameters you do not use.

static int visit(const char *key, void *value, void *user) {
    ABS_UNUSED(key);
    ABS_UNUSED(value);
    (*(size_t *)user)++;
    return 0;
}

For the large suite of everyday numeric, bitwise, and struct macros (MIN, CLAMP, LERP, SWAP, ARRAY_LEN, CONTAINER_OF, ...), see Macro Utilities.

Include guards¶

Each header uses a unique guard of the form ABSCOM_ABS_<NAME>_H, e.g. ABSCOM_ABS_STRING_H. You never need to touch these; they only prevent double inclusion.

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