kumquat-buildroot/toolchain/toolchain-wrapper.c
Jérôme Pouiller 76838f6341 reproducible: fix DATE/TIME macros in toolchain-wrapper
The use of the __DATE__ and __TIME__ macros are one of the most common
sources of non-reproducible binaries. In order to fix that, gcc 7 supports
the SOURCE_DATE_EPOCH variable:

https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=e3e8c48c4a494d9da741c1c8ea6c4c0b7c4ff934

This patch take advantage of toolchain-wrapper to provide support of
SOURCE_DATE_EPOCH to older gcc versions.

Function get_source_date_epoch() come directly from gcc git.

This work was sponsored by `BA Robotic Systems'.

[Peter: use sizeof for character array sizes, make function static,
	extend commit message, add upstream gcc commit]
Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
Reviewed-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2017-02-07 21:45:01 +01:00

434 lines
11 KiB
C

/**
* Buildroot wrapper for toolchains. This simply executes the real toolchain
* with a number of arguments (sysroot/arch/..) hardcoded, to ensure the
* toolchain uses the correct configuration.
* The hardcoded path arguments are defined relative to the actual location
* of the binary.
*
* (C) 2011 Peter Korsgaard <jacmet@sunsite.dk>
* (C) 2011 Daniel Nyström <daniel.nystrom@timeterminal.se>
* (C) 2012 Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
* (C) 2013 Spenser Gilliland <spenser@gillilanding.com>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#ifdef BR_CCACHE
static char ccache_path[PATH_MAX];
#endif
static char path[PATH_MAX];
static char sysroot[PATH_MAX];
static char source_time[sizeof("-D__TIME__=\"HH:MM:SS\"")];
static char source_date[sizeof("-D__DATE__=\"MMM DD YYYY\"")];
/**
* GCC errors out with certain combinations of arguments (examples are
* -mfloat-abi={hard|soft} and -m{little|big}-endian), so we have to ensure
* that we only pass the predefined one to the real compiler if the inverse
* option isn't in the argument list.
* This specifies the worst case number of extra arguments we might pass
* Currently, we have:
* -mfloat-abi=
* -march=
* -mcpu=
* -D__TIME__=
* -D__DATE__=
* -Wno-builtin-macro-redefined
*/
#define EXCLUSIVE_ARGS 6
static char *predef_args[] = {
#ifdef BR_CCACHE
ccache_path,
#endif
path,
"--sysroot", sysroot,
#ifdef BR_ABI
"-mabi=" BR_ABI,
#endif
#ifdef BR_FPU
"-mfpu=" BR_FPU,
#endif
#ifdef BR_SOFTFLOAT
"-msoft-float",
#endif /* BR_SOFTFLOAT */
#ifdef BR_MODE
"-m" BR_MODE,
#endif
#ifdef BR_64
"-m64",
#endif
#ifdef BR_OMIT_LOCK_PREFIX
"-Wa,-momit-lock-prefix=yes",
#endif
#ifdef BR_NO_FUSED_MADD
"-mno-fused-madd",
#endif
#ifdef BR_BINFMT_FLAT
"-Wl,-elf2flt",
#endif
#ifdef BR_MIPS_TARGET_LITTLE_ENDIAN
"-EL",
#endif
#if defined(BR_MIPS_TARGET_BIG_ENDIAN) || defined(BR_ARC_TARGET_BIG_ENDIAN)
"-EB",
#endif
#ifdef BR_ADDITIONAL_CFLAGS
BR_ADDITIONAL_CFLAGS
#endif
};
/* A {string,length} tuple, to avoid computing strlen() on constants.
* - str must be a \0-terminated string
* - len does not account for the terminating '\0'
*/
struct str_len_s {
const char *str;
size_t len;
};
/* Define a {string,length} tuple. Takes an unquoted constant string as
* parameter. sizeof() on a string literal includes the terminating \0,
* but we don't want to count it.
*/
#define STR_LEN(s) { #s, sizeof(#s)-1 }
/* List of paths considered unsafe for cross-compilation.
*
* An unsafe path is one that points to a directory with libraries or
* headers for the build machine, which are not suitable for the target.
*/
static const struct str_len_s unsafe_paths[] = {
STR_LEN(/lib),
STR_LEN(/usr/include),
STR_LEN(/usr/lib),
STR_LEN(/usr/local/include),
STR_LEN(/usr/local/lib),
{ NULL, 0 },
};
/* Unsafe options are options that specify a potentialy unsafe path,
* that will be checked by check_unsafe_path(), below.
*/
static const struct str_len_s unsafe_opts[] = {
STR_LEN(-I),
STR_LEN(-idirafter),
STR_LEN(-iquote),
STR_LEN(-isystem),
STR_LEN(-L),
{ NULL, 0 },
};
/* Check if path is unsafe for cross-compilation. Unsafe paths are those
* pointing to the standard native include or library paths.
*
* We print the arguments leading to the failure. For some options, gcc
* accepts the path to be concatenated to the argument (e.g. -I/foo/bar)
* or separated (e.g. -I /foo/bar). In the first case, we need only print
* the argument as it already contains the path (arg_has_path), while in
* the second case we need to print both (!arg_has_path).
*
* If paranoid, exit in error instead of just printing a warning.
*/
static void check_unsafe_path(const char *arg,
const char *path,
int paranoid,
int arg_has_path)
{
const struct str_len_s *p;
for (p=unsafe_paths; p->str; p++) {
if (strncmp(path, p->str, p->len))
continue;
fprintf(stderr,
"%s: %s: unsafe header/library path used in cross-compilation: '%s%s%s'\n",
program_invocation_short_name,
paranoid ? "ERROR" : "WARNING",
arg,
arg_has_path ? "" : "' '", /* close single-quote, space, open single-quote */
arg_has_path ? "" : path); /* so that arg and path are properly quoted. */
if (paranoid)
exit(1);
}
}
/* Read SOURCE_DATE_EPOCH from environment to have a deterministic
* timestamp to replace embedded current dates to get reproducible
* results. Returns -1 if SOURCE_DATE_EPOCH is not defined.
*/
static time_t get_source_date_epoch()
{
char *source_date_epoch;
long long epoch;
char *endptr;
source_date_epoch = getenv("SOURCE_DATE_EPOCH");
if (!source_date_epoch)
return (time_t) -1;
errno = 0;
epoch = strtoll(source_date_epoch, &endptr, 10);
if ((errno == ERANGE && (epoch == LLONG_MAX || epoch == LLONG_MIN))
|| (errno != 0 && epoch == 0)) {
fprintf(stderr, "environment variable $SOURCE_DATE_EPOCH: "
"strtoll: %s\n", strerror(errno));
exit(2);
}
if (endptr == source_date_epoch) {
fprintf(stderr, "environment variable $SOURCE_DATE_EPOCH: "
"no digits were found: %s\n", endptr);
exit(2);
}
if (*endptr != '\0') {
fprintf(stderr, "environment variable $SOURCE_DATE_EPOCH: "
"trailing garbage: %s\n", endptr);
exit(2);
}
if (epoch < 0) {
fprintf(stderr, "environment variable $SOURCE_DATE_EPOCH: "
"value must be nonnegative: %lld \n", epoch);
exit(2);
}
return (time_t) epoch;
}
int main(int argc, char **argv)
{
char **args, **cur, **exec_args;
char *relbasedir, *absbasedir;
char *progpath = argv[0];
char *basename;
char *env_debug;
char *paranoid_wrapper;
int paranoid;
int ret, i, count = 0, debug;
time_t source_date_epoch;
/* Calculate the relative paths */
basename = strrchr(progpath, '/');
if (basename) {
*basename = '\0';
basename++;
relbasedir = malloc(strlen(progpath) + 7);
if (relbasedir == NULL) {
perror(__FILE__ ": malloc");
return 2;
}
sprintf(relbasedir, "%s/../..", argv[0]);
absbasedir = realpath(relbasedir, NULL);
} else {
basename = progpath;
absbasedir = malloc(PATH_MAX + 1);
ret = readlink("/proc/self/exe", absbasedir, PATH_MAX);
if (ret < 0) {
perror(__FILE__ ": readlink");
return 2;
}
absbasedir[ret] = '\0';
for (i = ret; i > 0; i--) {
if (absbasedir[i] == '/') {
absbasedir[i] = '\0';
if (++count == 3)
break;
}
}
}
if (absbasedir == NULL) {
perror(__FILE__ ": realpath");
return 2;
}
/* Fill in the relative paths */
#ifdef BR_CROSS_PATH_REL
ret = snprintf(path, sizeof(path), "%s/" BR_CROSS_PATH_REL "/%s" BR_CROSS_PATH_SUFFIX, absbasedir, basename);
#elif defined(BR_CROSS_PATH_ABS)
ret = snprintf(path, sizeof(path), BR_CROSS_PATH_ABS "/%s" BR_CROSS_PATH_SUFFIX, basename);
#else
ret = snprintf(path, sizeof(path), "%s/usr/bin/%s" BR_CROSS_PATH_SUFFIX, absbasedir, basename);
#endif
if (ret >= sizeof(path)) {
perror(__FILE__ ": overflow");
return 3;
}
#ifdef BR_CCACHE
ret = snprintf(ccache_path, sizeof(ccache_path), "%s/usr/bin/ccache", absbasedir);
if (ret >= sizeof(ccache_path)) {
perror(__FILE__ ": overflow");
return 3;
}
#endif
ret = snprintf(sysroot, sizeof(sysroot), "%s/" BR_SYSROOT, absbasedir);
if (ret >= sizeof(sysroot)) {
perror(__FILE__ ": overflow");
return 3;
}
cur = args = malloc(sizeof(predef_args) +
(sizeof(char *) * (argc + EXCLUSIVE_ARGS)));
if (args == NULL) {
perror(__FILE__ ": malloc");
return 2;
}
/* start with predefined args */
memcpy(cur, predef_args, sizeof(predef_args));
cur += sizeof(predef_args) / sizeof(predef_args[0]);
#ifdef BR_FLOAT_ABI
/* add float abi if not overridden in args */
for (i = 1; i < argc; i++) {
if (!strncmp(argv[i], "-mfloat-abi=", strlen("-mfloat-abi=")) ||
!strcmp(argv[i], "-msoft-float") ||
!strcmp(argv[i], "-mhard-float"))
break;
}
if (i == argc)
*cur++ = "-mfloat-abi=" BR_FLOAT_ABI;
#endif
#if defined(BR_ARCH) || \
defined(BR_CPU)
/* Add our -march/cpu flags, but only if none of
* -march/mtune/mcpu are already specified on the commandline
*/
for (i = 1; i < argc; i++) {
if (!strncmp(argv[i], "-march=", strlen("-march=")) ||
!strncmp(argv[i], "-mtune=", strlen("-mtune=")) ||
!strncmp(argv[i], "-mcpu=", strlen("-mcpu=" )))
break;
}
if (i == argc) {
#ifdef BR_ARCH
*cur++ = "-march=" BR_ARCH;
#endif
#ifdef BR_CPU
*cur++ = "-mcpu=" BR_CPU;
#endif
}
#endif /* ARCH || CPU */
source_date_epoch = get_source_date_epoch();
if (source_date_epoch != -1) {
struct tm *tm = localtime(&source_date_epoch);
if (!tm) {
perror("__FILE__: localtime");
return 3;
}
ret = strftime(source_time, sizeof(source_time), "-D__TIME__=\"%T\"", tm);
if (!ret) {
perror("__FILE__: overflow");
return 3;
}
*cur++ = source_time;
ret = strftime(source_date, sizeof(source_date), "-D__DATE__=\"%b %e %Y\"", tm);
if (!ret) {
perror("__FILE__: overflow");
return 3;
}
*cur++ = source_date;
*cur++ = "-Wno-builtin-macro-redefined";
}
paranoid_wrapper = getenv("BR_COMPILER_PARANOID_UNSAFE_PATH");
if (paranoid_wrapper && strlen(paranoid_wrapper) > 0)
paranoid = 1;
else
paranoid = 0;
/* Check for unsafe library and header paths */
for (i = 1; i < argc; i++) {
const struct str_len_s *opt;
for (opt=unsafe_opts; opt->str; opt++ ) {
/* Skip any non-unsafe option. */
if (strncmp(argv[i], opt->str, opt->len))
continue;
/* Handle both cases:
* - path is a separate argument,
* - path is concatenated with option.
*/
if (argv[i][opt->len] == '\0') {
i++;
if (i == argc)
break;
check_unsafe_path(argv[i-1], argv[i], paranoid, 0);
} else
check_unsafe_path(argv[i], argv[i] + opt->len, paranoid, 1);
}
}
/* append forward args */
memcpy(cur, &argv[1], sizeof(char *) * (argc - 1));
cur += argc - 1;
/* finish with NULL termination */
*cur = NULL;
exec_args = args;
#ifdef BR_CCACHE
if (getenv("BR_NO_CCACHE"))
/* Skip the ccache call */
exec_args++;
#endif
/* Debug the wrapper to see actual arguments passed to
* the compiler:
* unset, empty, or 0: do not trace
* set to 1 : trace all arguments on a single line
* set to 2 : trace one argument per line
*/
if ((env_debug = getenv("BR2_DEBUG_WRAPPER"))) {
debug = atoi(env_debug);
if (debug > 0) {
fprintf(stderr, "Toolchain wrapper executing:");
#ifdef BR_CCACHE_HASH
fprintf(stderr, "%sCCACHE_COMPILERCHECK='string:" BR_CCACHE_HASH "'",
(debug == 2) ? "\n " : " ");
#endif
#ifdef BR_CCACHE_BASEDIR
fprintf(stderr, "%sCCACHE_BASEDIR='" BR_CCACHE_BASEDIR "'",
(debug == 2) ? "\n " : " ");
#endif
for (i = 0; exec_args[i]; i++)
fprintf(stderr, "%s'%s'",
(debug == 2) ? "\n " : " ", exec_args[i]);
fprintf(stderr, "\n");
}
}
#ifdef BR_CCACHE_HASH
/* Allow compilercheck to be overridden through the environment */
if (setenv("CCACHE_COMPILERCHECK", "string:" BR_CCACHE_HASH, 0)) {
perror(__FILE__ ": Failed to set CCACHE_COMPILERCHECK");
return 3;
}
#endif
#ifdef BR_CCACHE_BASEDIR
/* Allow compilercheck to be overridden through the environment */
if (setenv("CCACHE_BASEDIR", BR_CCACHE_BASEDIR, 0)) {
perror(__FILE__ ": Failed to set CCACHE_BASEDIR");
return 3;
}
#endif
if (execv(exec_args[0], exec_args))
perror(path);
free(args);
return 2;
}