memdesc

Make C struct definitions available in other languages to facilitate bidirectional 0-copy cross-language in-or-out-of-process communication.

An example input is given in src/examples/importer_with_preamble.mdesc:

#import "importee_with_preamble.mdesc"

struct ImporterStruct {
  float a;
  ImporteeStruct b;
};

which refers to src/examples/importee_with_preamble.mdesc:

struct ImporteeStruct {
  float a;
  char b;
};

When run with the command:

memdesc src/examples/importer_with_preamble.mdesc -t c

the following output is produced for consumption by a C (or C++) compiler:

#include <stddef.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
  float a;
  char b;
} ImporteeStruct;

#if __cplusplus && (__cplusplus >= 201103L || _MSC_VER >= 1900)       
// Static assertions to verify memdesc's assumptions.
static_assert(sizeof(ImporteeStruct) == 8);
static_assert(alignof(ImporteeStruct) == 4);
static_assert(offsetof(ImporteeStruct, a) == 0);
static_assert(offsetof(ImporteeStruct, b) == 4);
#endif  // __cplusplus && (__cplusplus >= 201103L || _MSC_VER >= 1900)

typedef struct {
  float a;
  ImporteeStruct b;
} ImporterStruct;

#if __cplusplus && (__cplusplus >= 201103L || _MSC_VER >= 1900)
// Static assertions to verify memdesc's assumptions.
static_assert(sizeof(ImporterStruct) == 12);
static_assert(alignof(ImporterStruct) == 4);
static_assert(offsetof(ImporterStruct, a) == 0);
static_assert(offsetof(ImporterStruct, b) == 4);
#endif  // __cplusplus && (__cplusplus >= 201103L || _MSC_VER >= 1900)

#ifdef __cplusplus
}  // extern "C"
#endif

In the command line above, -t c specifies that the target output language should be C. Other languages are also available (but actually not yet because this project is very young and incomplete right now).

Building

If you have Docker installed, you can just run ./build.sh which will setup a Docker Image capable of building memdesc, use it to perform a build, and place the output in out/.

Alternatively, the project can be built with CMake. Even if you don't have Docker installed, you can refer to the build Dockerfile for instructions on how to setup your environment.