Example of a wrapper for Clang.

clang-wrapper.c

#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

#ifndef EXE_PATH
#define EXE_PATH "/usr/bin/clang"
#endif

int main(int argc, char **argv, char **envp) {
	char **newargv = argv;
	const char *newname = EXE_PATH;
	int i, j, first = 0, last = 0;

	// skip processing if called with "-cc1" option
	if (argc < 2 || !strcmp(argv[1], "-cc1")) goto skip;

	newargv = malloc((argc + 3) * sizeof(*newargv));
	if (!newargv) {
		fprintf(stderr, "!!! malloc failed\n");
		return EXIT_FAILURE;
	}

	for (i = 1; i < argc; i++) {
		const char *s = argv[i];
		size_t len = strlen(s);
		if (len <= 2 || strcmp(s + len - 2, ".a")) continue;
		if (!first) first = i;
		last = i;
	}

	newargv[0] = (char*)newname; // argv[0];
	for (i = j = 1; i < argc; i++) {
		if (i == first) newargv[j++] = "-Wl,--start-group";
		newargv[j++] = (char*)argv[i];
		if (i == last) newargv[j++] = "-Wl,--end-group";
	}
	newargv[j] = NULL;
skip:
	execve(newname, newargv, envp);
	perror(newname);
	return EXIT_FAILURE;
}