toolchain-external: move wrapper to toolchain directory

The toolchain wrapper will be reused for the internal toolchain, so it
belongs in the toolchain directory. Also, the ext- prefix is removed
from it. The build commands are moved to a new toolchain-wrapper.mk.

The wrapper arguments that are also relevant for the internal toolchain
wrapper are moved to toolchain-wrapper.mk, the rest stays in
toolchain-external.mk.

While we're at it, move the building of the toolchain wrapper to the
build step of toolchain-external. There is no specific reason to do
this, other than that it fits better semantically. Also remove the
MESSAGE call, otherwise we'd see:
>>> toolchain-external undefined Building
>>> toolchain-external undefined Building toolchain wrapper
/usr/bin/gcc ...
Having an extra "Building toolchain wrapper' message is pointless.

The useless condition on $(BR2_TARGET_OPTIMIZATION) is removed. It was
always true because it wasn't qstrip'ped first, so clearly it works
without that condition as well.

Also rewrapped some comments and removed the 'external' reference.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Cc: Fabio Porcedda <fabio.porcedda@gmail.com>
Cc: Jérôme Oufella <jerome.oufella@savoirfairelinux.com>
Reviewed-by: Romain Naour <romain.naour@openwide.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

1 files changed, 258 insertions, 0 deletions

diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c
new file mode 100644
index 000000000..ac40decd5
--- /dev/null
+++ b/toolchain/toolchain-wrapper.c
@@ -0,0 +1,258 @@
+/**
+ * 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>
+
+static char path[PATH_MAX];
+static char sysroot[PATH_MAX];
+
+/**
+ * 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=
+ */
+#define EXCLUSIVE_ARGS	3
+
+static char *predef_args[] = {
+	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_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
+};
+
+static void check_unsafe_path(const char *path, int paranoid)
+{
+	char **c;
+	static char *unsafe_paths[] = {
+		"/lib", "/usr/include", "/usr/lib", "/usr/local/include", "/usr/local/lib", NULL,
+	};
+
+	for (c = unsafe_paths; *c != NULL; c++) {
+		if (!strncmp(path, *c, strlen(*c))) {
+			fprintf(stderr, "%s: %s: unsafe header/library path used in cross-compilation: '%s'\n",
+				program_invocation_short_name,
+				paranoid ? "ERROR" : "WARNING", path);
+			if (paranoid)
+				exit(1);
+			continue;
+		}
+	}
+}
+
+int main(int argc, char **argv)
+{
+	char **args, **cur;
+	char *relbasedir, *absbasedir;
+	char *progpath = argv[0];
+	char *basename;
+	char *env_debug;
+	char *paranoid_wrapper;
+	int paranoid;
+	int ret, i, count = 0, debug;
+
+	/* 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", absbasedir, basename);
+#else /* BR_CROSS_PATH_ABS */
+	ret = snprintf(path, sizeof(path), BR_CROSS_PATH_ABS "/%s", basename);
+#endif
+	if (ret >= sizeof(path)) {
+		perror(__FILE__ ": overflow");
+		return 3;
+	}
+	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 */
+
+	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++) {
+
+		/* Skip options that do not start with -I and -L */
+		if (strncmp(argv[i], "-I", 2) && strncmp(argv[i], "-L", 2))
+			continue;
+
+		/* We handle two cases: first the case where -I/-L and
+		 * the path are separated by one space and therefore
+		 * visible as two separate options, and then the case
+		 * where they are stuck together forming one single
+		 * option.
+		 */
+		if (argv[i][2] == '\0') {
+			i++;
+			if (i == argc)
+				continue;
+			check_unsafe_path(argv[i], paranoid);
+		} else {
+			check_unsafe_path(argv[i] + 2, paranoid);
+		}
+	}
+
+	/* append forward args */
+	memcpy(cur, &argv[1], sizeof(char *) * (argc - 1));
+	cur += argc - 1;
+
+	/* finish with NULL termination */
+	*cur = NULL;
+
+	/* 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:");
+			for (i = 0; args[i]; i++)
+				fprintf(stderr, "%s'%s'",
+					(debug == 2) ? "\n    " : " ", args[i]);
+			fprintf(stderr, "\n");
+		}
+	}
+
+	if (execv(path, args))
+		perror(path);
+
+	free(args);
+
+	return 2;
+}