diff options
Diffstat (limited to 'libc-bottom-half/sources/__main_void.c')
-rw-r--r-- | libc-bottom-half/sources/__main_void.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/libc-bottom-half/sources/__main_void.c b/libc-bottom-half/sources/__main_void.c new file mode 100644 index 0000000..cba22ef --- /dev/null +++ b/libc-bottom-half/sources/__main_void.c @@ -0,0 +1,54 @@ +#include <wasi/api.h> +#include <stdlib.h> +#include <sysexits.h> + +// The user's `main` function, expecting arguments. +int __main_argc_argv(int argc, char *argv[]); + +// If the user's `main` function expects arguments, the compiler will rename +// it to `__main_argc_argv`, and this version will get linked in, which +// initializes the argument data and calls `__main_argc_argv`. +__attribute__((__weak__, nodebug)) +int __main_void(void) { + __wasi_errno_t err; + + // Get the sizes of the arrays we'll have to create to copy in the args. + size_t argv_buf_size; + size_t argc; + err = __wasi_args_sizes_get(&argc, &argv_buf_size); + if (err != __WASI_ERRNO_SUCCESS) { + _Exit(EX_OSERR); + } + + // Add 1 for the NULL pointer to mark the end, and check for overflow. + size_t num_ptrs = argc + 1; + if (num_ptrs == 0) { + _Exit(EX_SOFTWARE); + } + + // Allocate memory for storing the argument chars. + char *argv_buf = malloc(argv_buf_size); + if (argv_buf == NULL) { + _Exit(EX_SOFTWARE); + } + + // Allocate memory for the array of pointers. This uses `calloc` both to + // handle overflow and to initialize the NULL pointer at the end. + char **argv = calloc(num_ptrs, sizeof(char *)); + if (argv == NULL) { + free(argv_buf); + _Exit(EX_SOFTWARE); + } + + // Fill the argument chars, and the argv array with pointers into those chars. + // TODO: Remove the casts on `argv_ptrs` and `argv_buf` once the witx is updated with char8 support. + err = __wasi_args_get((uint8_t **)argv, (uint8_t *)argv_buf); + if (err != __WASI_ERRNO_SUCCESS) { + free(argv_buf); + free(argv); + _Exit(EX_OSERR); + } + + // Call `__main_argc_argv` with the arguments! + return __main_argc_argv(argc, argv); +} |