text: #include <stdio.h>
  #include <sys/utsname.h>
  #include "common.h"
  #include "../util/debug.h"
  
  const char *const arm_triplets[] = {
  	"arm-eabi-",
  	"arm-linux-androideabi-",
  	"arm-unknown-linux-",
  	"arm-unknown-linux-gnu-",
  	"arm-unknown-linux-gnueabi-",
  	NULL
  };
  
  const char *const arm64_triplets[] = {
  	"aarch64-linux-android-",
  	NULL
  };
  
  const char *const powerpc_triplets[] = {
  	"powerpc-unknown-linux-gnu-",
  	"powerpc64-unknown-linux-gnu-",
  	NULL
  };
  
  const char *const s390_triplets[] = {
  	"s390-ibm-linux-",
  	NULL
  };
  
  const char *const sh_triplets[] = {
  	"sh-unknown-linux-gnu-",
  	"sh64-unknown-linux-gnu-",
  	NULL
  };
  
  const char *const sparc_triplets[] = {
  	"sparc-unknown-linux-gnu-",
  	"sparc64-unknown-linux-gnu-",
  	NULL
  };
  
  const char *const x86_triplets[] = {
  	"x86_64-pc-linux-gnu-",
  	"x86_64-unknown-linux-gnu-",
  	"i686-pc-linux-gnu-",
  	"i586-pc-linux-gnu-",
  	"i486-pc-linux-gnu-",
  	"i386-pc-linux-gnu-",
  	"i686-linux-android-",
  	"i686-android-linux-",
  	NULL
  };
  
  const char *const mips_triplets[] = {
  	"mips-unknown-linux-gnu-",
  	"mipsel-linux-android-",
  	NULL
  };
  
  static bool lookup_path(char *name)
  {
  	bool found = false;
  	char *path, *tmp = NULL;
  	char buf[PATH_MAX];
  	char *env = getenv("PATH");
  
  	if (!env)
  		return false;
  
  	env = strdup(env);
  	if (!env)
  		return false;
  
  	path = strtok_r(env, ":", &tmp);
  	while (path) {
  		scnprintf(buf, sizeof(buf), "%s/%s", path, name);
  		if (access(buf, F_OK) == 0) {
  			found = true;
  			break;
  		}
  		path = strtok_r(NULL, ":", &tmp);
  	}
  	free(env);
  	return found;
  }
  
  static int lookup_triplets(const char *const *triplets, const char *name)
  {
  	int i;
  	char buf[PATH_MAX];
  
  	for (i = 0; triplets[i] != NULL; i++) {
  		scnprintf(buf, sizeof(buf), "%s%s", triplets[i], name);
  		if (lookup_path(buf))
  			return i;
  	}
  	return -1;
  }
  
  /*
   * Return architecture name in a normalized form.
   * The conversion logic comes from the Makefile.
   */
  static const char *normalize_arch(char *arch)
  {
  	if (!strcmp(arch, "x86_64"))
  		return "x86";
  	if (arch[0] == 'i' && arch[2] == '8' && arch[3] == '6')
  		return "x86";
  	if (!strcmp(arch, "sun4u") || !strncmp(arch, "sparc", 5))
  		return "sparc";
  	if (!strcmp(arch, "aarch64") || !strcmp(arch, "arm64"))
  		return "arm64";
  	if (!strncmp(arch, "arm", 3) || !strcmp(arch, "sa110"))
  		return "arm";
  	if (!strncmp(arch, "s390", 4))
  		return "s390";
  	if (!strncmp(arch, "parisc", 6))
  		return "parisc";
  	if (!strncmp(arch, "powerpc", 7) || !strncmp(arch, "ppc", 3))
  		return "powerpc";
  	if (!strncmp(arch, "mips", 4))
  		return "mips";
  	if (!strncmp(arch, "sh", 2) && isdigit(arch[2]))
  		return "sh";
  
  	return arch;
  }
  
  static int perf_session_env__lookup_binutils_path(struct perf_session_env *env,
  						  const char *name,
  						  const char **path)
  {
  	int idx;
  	const char *arch, *cross_env;
  	struct utsname uts;
  	const char *const *path_list;
  	char *buf = NULL;
  
  	arch = normalize_arch(env->arch);
  
  	if (uname(&uts) < 0)
  		goto out;
  
  	/*
  	 * We don't need to try to find objdump path for native system.
  	 * Just use default binutils path (e.g.: "objdump").
  	 */
  	if (!strcmp(normalize_arch(uts.machine), arch))
  		goto out;
  
  	cross_env = getenv("CROSS_COMPILE");
  	if (cross_env) {
  		if (asprintf(&buf, "%s%s", cross_env, name) < 0)
  			goto out_error;
  		if (buf[0] == '/') {
  			if (access(buf, F_OK) == 0)
  				goto out;
  			goto out_error;
  		}
  		if (lookup_path(buf))
  			goto out;
  		zfree(&buf);
  	}
  
  	if (!strcmp(arch, "arm"))
  		path_list = arm_triplets;
  	else if (!strcmp(arch, "arm64"))
  		path_list = arm64_triplets;
  	else if (!strcmp(arch, "powerpc"))
  		path_list = powerpc_triplets;
  	else if (!strcmp(arch, "sh"))
  		path_list = sh_triplets;
  	else if (!strcmp(arch, "s390"))
  		path_list = s390_triplets;
  	else if (!strcmp(arch, "sparc"))
  		path_list = sparc_triplets;
  	else if (!strcmp(arch, "x86"))
  		path_list = x86_triplets;
  	else if (!strcmp(arch, "mips"))
  		path_list = mips_triplets;
  	else {
  		ui__error("binutils for %s not supported.\n", arch);
  		goto out_error;
  	}
  
  	idx = lookup_triplets(path_list, name);
  	if (idx < 0) {
  		ui__error("Please install %s for %s.\n"
  			  "You can add it to PATH, set CROSS_COMPILE or "
  			  "override the default using --%s.\n",
  			  name, arch, name);
  		goto out_error;
  	}
  
  	if (asprintf(&buf, "%s%s", path_list[idx], name) < 0)
  		goto out_error;
  
  out:
  	*path = buf;
  	return 0;
  out_error:
  	free(buf);
  	*path = NULL;
  	return -1;
  }
  
  int perf_session_env__lookup_objdump(struct perf_session_env *env)
  {
  	/*
  	 * For live mode, env->arch will be NULL and we can use
  	 * the native objdump tool.
  	 */
  	if (env->arch == NULL)
  		return 0;
  
  	return perf_session_env__lookup_binutils_path(env, "objdump",
  						      &objdump_path);
  }
  