[mirror_ubuntu-artful-kernel.git] / tools / perf / util / llvm-utils.c

/*
 * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015, Huawei Inc.
 */

#include <stdio.h>
#include "util.h"
#include "debug.h"
#include "llvm-utils.h"
#include "cache.h"

#define CLANG_BPF_CMD_DEFAULT_TEMPLATE				\
		"$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
		"-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE "	\
		"$CLANG_OPTIONS $KERNEL_INC_OPTIONS "		\
		"-Wno-unused-value -Wno-pointer-sign "		\
		"-working-directory $WORKING_DIR "		\
		"-c \"$CLANG_SOURCE\" -target bpf -O2 -o -"

struct llvm_param llvm_param = {
	.clang_path = "clang",
	.clang_bpf_cmd_template = CLANG_BPF_CMD_DEFAULT_TEMPLATE,
	.clang_opt = NULL,
	.kbuild_dir = NULL,
	.kbuild_opts = NULL,
	.user_set_param = false,
};

int perf_llvm_config(const char *var, const char *value)
{
	if (prefixcmp(var, "llvm."))
		return 0;
	var += sizeof("llvm.") - 1;

	if (!strcmp(var, "clang-path"))
		llvm_param.clang_path = strdup(value);
	else if (!strcmp(var, "clang-bpf-cmd-template"))
		llvm_param.clang_bpf_cmd_template = strdup(value);
	else if (!strcmp(var, "clang-opt"))
		llvm_param.clang_opt = strdup(value);
	else if (!strcmp(var, "kbuild-dir"))
		llvm_param.kbuild_dir = strdup(value);
	else if (!strcmp(var, "kbuild-opts"))
		llvm_param.kbuild_opts = strdup(value);
	else
		return -1;
	llvm_param.user_set_param = true;
	return 0;
}

static int
search_program(const char *def, const char *name,
	       char *output)
{
	char *env, *path, *tmp = NULL;
	char buf[PATH_MAX];
	int ret;

	output[0] = '\0';
	if (def && def[0] != '\0') {
		if (def[0] == '/') {
			if (access(def, F_OK) == 0) {
				strlcpy(output, def, PATH_MAX);
				return 0;
			}
		} else if (def[0] != '\0')
			name = def;
	}

	env = getenv("PATH");
	if (!env)
		return -1;
	env = strdup(env);
	if (!env)
		return -1;

	ret = -ENOENT;
	path = strtok_r(env, ":",  &tmp);
	while (path) {
		scnprintf(buf, sizeof(buf), "%s/%s", path, name);
		if (access(buf, F_OK) == 0) {
			strlcpy(output, buf, PATH_MAX);
			ret = 0;
			break;
		}
		path = strtok_r(NULL, ":", &tmp);
	}

	free(env);
	return ret;
}

#define READ_SIZE	4096
static int
read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
{
	int err = 0;
	void *buf = NULL;
	FILE *file = NULL;
	size_t read_sz = 0, buf_sz = 0;

	file = popen(cmd, "r");
	if (!file) {
		pr_err("ERROR: unable to popen cmd: %s\n",
		       strerror(errno));
		return -EINVAL;
	}

	while (!feof(file) && !ferror(file)) {
		/*
		 * Make buf_sz always have obe byte extra space so we
		 * can put '\0' there.
		 */
		if (buf_sz - read_sz < READ_SIZE + 1) {
			void *new_buf;

			buf_sz = read_sz + READ_SIZE + 1;
			new_buf = realloc(buf, buf_sz);

			if (!new_buf) {
				pr_err("ERROR: failed to realloc memory\n");
				err = -ENOMEM;
				goto errout;
			}

			buf = new_buf;
		}
		read_sz += fread(buf + read_sz, 1, READ_SIZE, file);
	}

	if (buf_sz - read_sz < 1) {
		pr_err("ERROR: internal error\n");
		err = -EINVAL;
		goto errout;
	}

	if (ferror(file)) {
		pr_err("ERROR: error occurred when reading from pipe: %s\n",
		       strerror(errno));
		err = -EIO;
		goto errout;
	}

	err = WEXITSTATUS(pclose(file));
	file = NULL;
	if (err) {
		err = -EINVAL;
		goto errout;
	}

	/*
	 * If buf is string, give it terminal '\0' to make our life
	 * easier. If buf is not string, that '\0' is out of space
	 * indicated by read_sz so caller won't even notice it.
	 */
	((char *)buf)[read_sz] = '\0';

	if (!p_buf)
		free(buf);
	else
		*p_buf = buf;

	if (p_read_sz)
		*p_read_sz = read_sz;
	return 0;

errout:
	if (file)
		pclose(file);
	free(buf);
	if (p_buf)
		*p_buf = NULL;
	if (p_read_sz)
		*p_read_sz = 0;
	return err;
}

static inline void
force_set_env(const char *var, const char *value)
{
	if (value) {
		setenv(var, value, 1);
		pr_debug("set env: %s=%s\n", var, value);
	} else {
		unsetenv(var);
		pr_debug("unset env: %s\n", var);
	}
}

static void
version_notice(void)
{
	pr_err(
"     \tLLVM 3.7 or newer is required. Which can be found from http://llvm.org\n"
"     \tYou may want to try git trunk:\n"
"     \t\tgit clone http://llvm.org/git/llvm.git\n"
"     \t\t     and\n"
"     \t\tgit clone http://llvm.org/git/clang.git\n\n"
"     \tOr fetch the latest clang/llvm 3.7 from pre-built llvm packages for\n"
"     \tdebian/ubuntu:\n"
"     \t\thttp://llvm.org/apt\n\n"
"     \tIf you are using old version of clang, change 'clang-bpf-cmd-template'\n"
"     \toption in [llvm] section of ~/.perfconfig to:\n\n"
"     \t  \"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \\\n"
"     \t     -working-directory $WORKING_DIR -c $CLANG_SOURCE \\\n"
"     \t     -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -\"\n"
"     \t(Replace /path/to/llc with path to your llc)\n\n"
);
}

static int detect_kbuild_dir(char **kbuild_dir)
{
	const char *test_dir = llvm_param.kbuild_dir;
	const char *prefix_dir = "";
	const char *suffix_dir = "";

	char *autoconf_path;

	int err;

	if (!test_dir) {
		/* _UTSNAME_LENGTH is 65 */
		char release[128];

		err = fetch_kernel_version(NULL, release,
					   sizeof(release));
		if (err)
			return -EINVAL;

		test_dir = release;
		prefix_dir = "/lib/modules/";
		suffix_dir = "/build";
	}

	err = asprintf(&autoconf_path, "%s%s%s/include/generated/autoconf.h",
		       prefix_dir, test_dir, suffix_dir);
	if (err < 0)
		return -ENOMEM;

	if (access(autoconf_path, R_OK) == 0) {
		free(autoconf_path);

		err = asprintf(kbuild_dir, "%s%s%s", prefix_dir, test_dir,
			       suffix_dir);
		if (err < 0)
			return -ENOMEM;
		return 0;
	}
	free(autoconf_path);
	return -ENOENT;
}

static const char *kinc_fetch_script =
"#!/usr/bin/env sh\n"
"if ! test -d \"$KBUILD_DIR\"\n"
"then\n"
"	exit -1\n"
"fi\n"
"if ! test -f \"$KBUILD_DIR/include/generated/autoconf.h\"\n"
"then\n"
"	exit -1\n"
"fi\n"
"TMPDIR=`mktemp -d`\n"
"if test -z \"$TMPDIR\"\n"
"then\n"
"    exit -1\n"
"fi\n"
"cat << EOF > $TMPDIR/Makefile\n"
"obj-y := dummy.o\n"
"\\$(obj)/%.o: \\$(src)/%.c\n"
"\t@echo -n \"\\$(NOSTDINC_FLAGS) \\$(LINUXINCLUDE) \\$(EXTRA_CFLAGS)\"\n"
"EOF\n"
"touch $TMPDIR/dummy.c\n"
"make -s -C $KBUILD_DIR M=$TMPDIR $KBUILD_OPTS dummy.o 2>/dev/null\n"
"RET=$?\n"
"rm -rf $TMPDIR\n"
"exit $RET\n";

static inline void
get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
{
	int err;

	if (!kbuild_dir || !kbuild_include_opts)
		return;

	*kbuild_dir = NULL;
	*kbuild_include_opts = NULL;

	if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) {
		pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
		pr_debug("Skip kbuild options detection.\n");
		return;
	}

	err = detect_kbuild_dir(kbuild_dir);
	if (err) {
		pr_warning(
"WARNING:\tunable to get correct kernel building directory.\n"
"Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n"
"     \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n"
"     \tdetection.\n\n");
		return;
	}

	pr_debug("Kernel build dir is set to %s\n", *kbuild_dir);
	force_set_env("KBUILD_DIR", *kbuild_dir);
	force_set_env("KBUILD_OPTS", llvm_param.kbuild_opts);
	err = read_from_pipe(kinc_fetch_script,
			     (void **)kbuild_include_opts,
			     NULL);
	if (err) {
		pr_warning(
"WARNING:\tunable to get kernel include directories from '%s'\n"
"Hint:\tTry set clang include options using 'clang-bpf-cmd-template'\n"
"     \toption in [llvm] section of ~/.perfconfig and set 'kbuild-dir'\n"
"     \toption in [llvm] to \"\" to suppress this detection.\n\n",
			*kbuild_dir);

		free(*kbuild_dir);
		*kbuild_dir = NULL;
		return;
	}

	pr_debug("include option is set to %s\n", *kbuild_include_opts);
}

int llvm__compile_bpf(const char *path, void **p_obj_buf,
		      size_t *p_obj_buf_sz)
{
	size_t obj_buf_sz;
	void *obj_buf = NULL;
	int err, nr_cpus_avail;
	unsigned int kernel_version;
	char linux_version_code_str[64];
	const char *clang_opt = llvm_param.clang_opt;
	char clang_path[PATH_MAX], nr_cpus_avail_str[64];
	char *kbuild_dir = NULL, *kbuild_include_opts = NULL;
	const char *template = llvm_param.clang_bpf_cmd_template;

	if (!template)
		template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;

	err = search_program(llvm_param.clang_path,
			     "clang", clang_path);
	if (err) {
		pr_err(
"ERROR:\tunable to find clang.\n"
"Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
"     \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
		version_notice();
		return -ENOENT;
	}

	/*
	 * This is an optional work. Even it fail we can continue our
	 * work. Needn't to check error return.
	 */
	get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);

	nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
	if (nr_cpus_avail <= 0) {
		pr_err(
"WARNING:\tunable to get available CPUs in this system: %s\n"
"        \tUse 128 instead.\n", strerror(errno));
		nr_cpus_avail = 128;
	}
	snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
		 nr_cpus_avail);

	if (fetch_kernel_version(&kernel_version, NULL, 0))
		kernel_version = 0;

	snprintf(linux_version_code_str, sizeof(linux_version_code_str),
		 "0x%x", kernel_version);

	force_set_env("NR_CPUS", nr_cpus_avail_str);
	force_set_env("LINUX_VERSION_CODE", linux_version_code_str);
	force_set_env("CLANG_EXEC", clang_path);
	force_set_env("CLANG_OPTIONS", clang_opt);
	force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts);
	force_set_env("WORKING_DIR", kbuild_dir ? : ".");

	/*
	 * Since we may reset clang's working dir, path of source file
	 * should be transferred into absolute path, except we want
	 * stdin to be source file (testing).
	 */
	force_set_env("CLANG_SOURCE",
		      (path[0] == '-') ? path :
		      make_nonrelative_path(path));

	pr_debug("llvm compiling command template: %s\n", template);
	err = read_from_pipe(template, &obj_buf, &obj_buf_sz);
	if (err) {
		pr_err("ERROR:\tunable to compile %s\n", path);
		pr_err("Hint:\tCheck error message shown above.\n");
		pr_err("Hint:\tYou can also pre-compile it into .o using:\n");
		pr_err("     \t\tclang -target bpf -O2 -c %s\n", path);
		pr_err("     \twith proper -I and -D options.\n");
		goto errout;
	}

	free(kbuild_dir);
	free(kbuild_include_opts);
	if (!p_obj_buf)
		free(obj_buf);
	else
		*p_obj_buf = obj_buf;

	if (p_obj_buf_sz)
		*p_obj_buf_sz = obj_buf_sz;
	return 0;
errout:
	free(kbuild_dir);
	free(kbuild_include_opts);
	free(obj_buf);
	if (p_obj_buf)
		*p_obj_buf = NULL;
	if (p_obj_buf_sz)
		*p_obj_buf_sz = 0;
	return err;
}

int llvm__search_clang(void)
{
	char clang_path[PATH_MAX];

	return search_program(llvm_param.clang_path, "clang", clang_path);
}
Commit	Line	Data
aa61fd05 WN	1	/*
	2	* Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
	3	* Copyright (C) 2015, Huawei Inc.
	4	*/
	5
	6	#include <stdio.h>
	7	#include "util.h"
	8	#include "debug.h"
	9	#include "llvm-utils.h"
	10	#include "cache.h"
	11
	12	#define CLANG_BPF_CMD_DEFAULT_TEMPLATE \
59f41af9	13	"$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
4a4f66a1	14	"-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
59f41af9 WN	15	"$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \
	16	"-Wno-unused-value -Wno-pointer-sign " \
	17	"-working-directory $WORKING_DIR " \
	18	"-c \"$CLANG_SOURCE\" -target bpf -O2 -o -"
aa61fd05 WN	19
	20	struct llvm_param llvm_param = {
	21	.clang_path = "clang",
	22	.clang_bpf_cmd_template = CLANG_BPF_CMD_DEFAULT_TEMPLATE,
	23	.clang_opt = NULL,
	24	.kbuild_dir = NULL,
	25	.kbuild_opts = NULL,
9bc898c7	26	.user_set_param = false,
aa61fd05 WN	27	};
	28
	29	int perf_llvm_config(const char var, const char value)
	30	{
	31	if (prefixcmp(var, "llvm."))
	32	return 0;
	33	var += sizeof("llvm.") - 1;
	34
	35	if (!strcmp(var, "clang-path"))
	36	llvm_param.clang_path = strdup(value);
	37	else if (!strcmp(var, "clang-bpf-cmd-template"))
	38	llvm_param.clang_bpf_cmd_template = strdup(value);
	39	else if (!strcmp(var, "clang-opt"))
	40	llvm_param.clang_opt = strdup(value);
	41	else if (!strcmp(var, "kbuild-dir"))
	42	llvm_param.kbuild_dir = strdup(value);
	43	else if (!strcmp(var, "kbuild-opts"))
	44	llvm_param.kbuild_opts = strdup(value);
	45	else
	46	return -1;
9bc898c7	47	llvm_param.user_set_param = true;
aa61fd05 WN	48	return 0;
aa61fd05 WN	49	}
4cea3a9c WN	50
	51	static int
	52	search_program(const char def, const char name,
	53	char *output)
	54	{
	55	char env, path, *tmp = NULL;
	56	char buf[PATH_MAX];
	57	int ret;
	58
	59	output[0] = '\0';
	60	if (def && def[0] != '\0') {
	61	if (def[0] == '/') {
	62	if (access(def, F_OK) == 0) {
	63	strlcpy(output, def, PATH_MAX);
	64	return 0;
	65	}
	66	} else if (def[0] != '\0')
	67	name = def;
	68	}
	69
	70	env = getenv("PATH");
	71	if (!env)
	72	return -1;
	73	env = strdup(env);
	74	if (!env)
	75	return -1;
	76
	77	ret = -ENOENT;
	78	path = strtok_r(env, ":", &tmp);
	79	while (path) {
	80	scnprintf(buf, sizeof(buf), "%s/%s", path, name);
	81	if (access(buf, F_OK) == 0) {
	82	strlcpy(output, buf, PATH_MAX);
	83	ret = 0;
	84	break;
	85	}
	86	path = strtok_r(NULL, ":", &tmp);
	87	}
	88
	89	free(env);
	90	return ret;
	91	}
	92
	93	#define READ_SIZE 4096
	94	static int
	95	read_from_pipe(const char cmd, void p_buf, size_t p_read_sz)
	96	{
	97	int err = 0;
	98	void *buf = NULL;
	99	FILE *file = NULL;
	100	size_t read_sz = 0, buf_sz = 0;
	101
	102	file = popen(cmd, "r");
	103	if (!file) {
	104	pr_err("ERROR: unable to popen cmd: %s\n",
	105	strerror(errno));
	106	return -EINVAL;
	107	}
	108
	109	while (!feof(file) && !ferror(file)) {
	110	/*
	111	* Make buf_sz always have obe byte extra space so we
	112	* can put '\0' there.
	113	*/
114	if (buf_sz - read_sz < READ_SIZE + 1) {
115	void *new_buf;
116
117	buf_sz = read_sz + READ_SIZE + 1;
118	new_buf = realloc(buf, buf_sz);
119
120	if (!new_buf) {
121	pr_err("ERROR: failed to realloc memory\n");
122	err = -ENOMEM;
123	goto errout;
124	}
125
126	buf = new_buf;
127	}
128	read_sz += fread(buf + read_sz, 1, READ_SIZE, file);
129	}
130
131	if (buf_sz - read_sz < 1) {
132	pr_err("ERROR: internal error\n");
133	err = -EINVAL;
134	goto errout;
135	}
136
137	if (ferror(file)) {
138	pr_err("ERROR: error occurred when reading from pipe: %s\n",
139	strerror(errno));
140	err = -EIO;
141	goto errout;
142	}
143
144	err = WEXITSTATUS(pclose(file));
145	file = NULL;
146	if (err) {
147	err = -EINVAL;
148	goto errout;
149	}
150
151	/*
152	* If buf is string, give it terminal '\0' to make our life
153	* easier. If buf is not string, that '\0' is out of space
154	* indicated by read_sz so caller won't even notice it.
155	*/
156	((char *)buf)[read_sz] = '\0';
157
158	if (!p_buf)
159	free(buf);
160	else
161	*p_buf = buf;
162
163	if (p_read_sz)
164	*p_read_sz = read_sz;
165	return 0;
166
167	errout:
168	if (file)
169	pclose(file);
170	free(buf);
171	if (p_buf)
172	*p_buf = NULL;
173	if (p_read_sz)
174	*p_read_sz = 0;
175	return err;
176	}
177
178	static inline void
179	force_set_env(const char var, const char value)
180	{
181	if (value) {
182	setenv(var, value, 1);
183	pr_debug("set env: %s=%s\n", var, value);
184	} else {
185	unsetenv(var);
186	pr_debug("unset env: %s\n", var);
187	}
188	}
189
190	static void
191	version_notice(void)
192	{
193	pr_err(
194	" \tLLVM 3.7 or newer is required. Which can be found from http://llvm.org\n"
195	" \tYou may want to try git trunk:\n"
196	" \t\tgit clone http://llvm.org/git/llvm.git\n"
197	" \t\t and\n"
198	" \t\tgit clone http://llvm.org/git/clang.git\n\n"
199	" \tOr fetch the latest clang/llvm 3.7 from pre-built llvm packages for\n"
200	" \tdebian/ubuntu:\n"
201	" \t\thttp://llvm.org/apt\n\n"
202	" \tIf you are using old version of clang, change 'clang-bpf-cmd-template'\n"
203	" \toption in [llvm] section of ~/.perfconfig to:\n\n"
204	" \t \"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \\\n"
205	" \t -working-directory $WORKING_DIR -c $CLANG_SOURCE \\\n"
206	" \t -emit-llvm -o - \| /path/to/llc -march=bpf -filetype=obj -o -\"\n"
207	" \t(Replace /path/to/llc with path to your llc)\n\n"
208	);
209	}
210
d325d788 WN	211	static int detect_kbuild_dir(char **kbuild_dir)
	212	{
	213	const char *test_dir = llvm_param.kbuild_dir;
	214	const char *prefix_dir = "";
	215	const char *suffix_dir = "";
	216
	217	char *autoconf_path;
d325d788 WN	218
	219	int err;
	220
	221	if (!test_dir) {
07bc5c69 WN	222	/* _UTSNAME_LENGTH is 65 */
	223	char release[128];
	224
	225	err = fetch_kernel_version(NULL, release,
	226	sizeof(release));
	227	if (err)
d325d788	228	return -EINVAL;
d325d788	229
07bc5c69	230	test_dir = release;
d325d788 WN	231	prefix_dir = "/lib/modules/";
	232	suffix_dir = "/build";
	233	}
	234
	235	err = asprintf(&autoconf_path, "%s%s%s/include/generated/autoconf.h",
	236	prefix_dir, test_dir, suffix_dir);
	237	if (err < 0)
	238	return -ENOMEM;
	239
	240	if (access(autoconf_path, R_OK) == 0) {
	241	free(autoconf_path);
	242
	243	err = asprintf(kbuild_dir, "%s%s%s", prefix_dir, test_dir,
	244	suffix_dir);
	245	if (err < 0)
	246	return -ENOMEM;
	247	return 0;
	248	}
	249	free(autoconf_path);
	250	return -ENOENT;
	251	}
	252
0c6d18bf WN	253	static const char *kinc_fetch_script =
	254	"#!/usr/bin/env sh\n"
	255	"if ! test -d \"$KBUILD_DIR\"\n"
	256	"then\n"
	257	" exit -1\n"
	258	"fi\n"
	259	"if ! test -f \"$KBUILD_DIR/include/generated/autoconf.h\"\n"
	260	"then\n"
	261	" exit -1\n"
	262	"fi\n"
	263	"TMPDIR=`mktemp -d`\n"
	264	"if test -z \"$TMPDIR\"\n"
	265	"then\n"
	266	" exit -1\n"
	267	"fi\n"
	268	"cat << EOF > $TMPDIR/Makefile\n"
	269	"obj-y := dummy.o\n"
	270	"\\$(obj)/%.o: \\$(src)/%.c\n"
	271	"\t@echo -n \"\\$(NOSTDINC_FLAGS) \\$(LINUXINCLUDE) \\$(EXTRA_CFLAGS)\"\n"
	272	"EOF\n"
	273	"touch $TMPDIR/dummy.c\n"
	274	"make -s -C $KBUILD_DIR M=$TMPDIR $KBUILD_OPTS dummy.o 2>/dev/null\n"
	275	"RET=$?\n"
	276	"rm -rf $TMPDIR\n"
	277	"exit $RET\n";
	278
d325d788	279	static inline void
0c6d18bf	280	get_kbuild_opts(char kbuild_dir, char kbuild_include_opts)
d325d788 WN	281	{
	282	int err;
	283
0c6d18bf	284	if (!kbuild_dir \|\| !kbuild_include_opts)
d325d788 WN	285	return;
	286
	287	*kbuild_dir = NULL;
0c6d18bf	288	*kbuild_include_opts = NULL;
d325d788 WN	289
	290	if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) {
	291	pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
	292	pr_debug("Skip kbuild options detection.\n");
	293	return;
	294	}
	295
	296	err = detect_kbuild_dir(kbuild_dir);
	297	if (err) {
	298	pr_warning(
	299	"WARNING:\tunable to get correct kernel building directory.\n"
	300	"Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n"
	301	" \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n"
	302	" \tdetection.\n\n");
	303	return;
	304	}
0c6d18bf WN	305
	306	pr_debug("Kernel build dir is set to %s\n", *kbuild_dir);
	307	force_set_env("KBUILD_DIR", *kbuild_dir);
	308	force_set_env("KBUILD_OPTS", llvm_param.kbuild_opts);
	309	err = read_from_pipe(kinc_fetch_script,
	310	(void **)kbuild_include_opts,
	311	NULL);
	312	if (err) {
	313	pr_warning(
	314	"WARNING:\tunable to get kernel include directories from '%s'\n"
	315	"Hint:\tTry set clang include options using 'clang-bpf-cmd-template'\n"
	316	" \toption in [llvm] section of ~/.perfconfig and set 'kbuild-dir'\n"
	317	" \toption in [llvm] to \"\" to suppress this detection.\n\n",
	318	*kbuild_dir);
	319
	320	free(*kbuild_dir);
	321	*kbuild_dir = NULL;
	322	return;
	323	}
	324
	325	pr_debug("include option is set to %s\n", *kbuild_include_opts);
d325d788 WN	326	}
d325d788 WN	327
4cea3a9c WN	328	int llvm__compile_bpf(const char path, void *p_obj_buf,
	329	size_t *p_obj_buf_sz)
	330	{
07bc5c69 WN	331	size_t obj_buf_sz;
07bc5c69 WN	332	void *obj_buf = NULL;
59f41af9	333	int err, nr_cpus_avail;
07bc5c69	334	unsigned int kernel_version;
4a4f66a1	335	char linux_version_code_str[64];
4cea3a9c	336	const char *clang_opt = llvm_param.clang_opt;
07bc5c69	337	char clang_path[PATH_MAX], nr_cpus_avail_str[64];
0c6d18bf	338	char kbuild_dir = NULL, kbuild_include_opts = NULL;
07bc5c69	339	const char *template = llvm_param.clang_bpf_cmd_template;
4cea3a9c WN	340
	341	if (!template)
	342	template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
	343
	344	err = search_program(llvm_param.clang_path,
	345	"clang", clang_path);
	346	if (err) {
	347	pr_err(
	348	"ERROR:\tunable to find clang.\n"
	349	"Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
	350	" \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
	351	version_notice();
	352	return -ENOENT;
	353	}
	354
d325d788 WN	355	/*
	356	* This is an optional work. Even it fail we can continue our
	357	* work. Needn't to check error return.
	358	*/
0c6d18bf	359	get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
d325d788	360
59f41af9 WN	361	nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
	362	if (nr_cpus_avail <= 0) {
	363	pr_err(
	364	"WARNING:\tunable to get available CPUs in this system: %s\n"
	365	" \tUse 128 instead.\n", strerror(errno));
	366	nr_cpus_avail = 128;
	367	}
	368	snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
	369	nr_cpus_avail);
	370
07bc5c69 WN	371	if (fetch_kernel_version(&kernel_version, NULL, 0))
	372	kernel_version = 0;
	373
4a4f66a1	374	snprintf(linux_version_code_str, sizeof(linux_version_code_str),
07bc5c69	375	"0x%x", kernel_version);
4a4f66a1	376
59f41af9	377	force_set_env("NR_CPUS", nr_cpus_avail_str);
4a4f66a1	378	force_set_env("LINUX_VERSION_CODE", linux_version_code_str);
4cea3a9c WN	379	force_set_env("CLANG_EXEC", clang_path);
4cea3a9c WN	380	force_set_env("CLANG_OPTIONS", clang_opt);
0c6d18bf	381	force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts);
d325d788	382	force_set_env("WORKING_DIR", kbuild_dir ? : ".");
4cea3a9c WN	383
	384	/*
	385	* Since we may reset clang's working dir, path of source file
	386	* should be transferred into absolute path, except we want
	387	* stdin to be source file (testing).
	388	*/
	389	force_set_env("CLANG_SOURCE",
	390	(path[0] == '-') ? path :
	391	make_nonrelative_path(path));
	392
	393	pr_debug("llvm compiling command template: %s\n", template);
	394	err = read_from_pipe(template, &obj_buf, &obj_buf_sz);
	395	if (err) {
	396	pr_err("ERROR:\tunable to compile %s\n", path);
	397	pr_err("Hint:\tCheck error message shown above.\n");
	398	pr_err("Hint:\tYou can also pre-compile it into .o using:\n");
	399	pr_err(" \t\tclang -target bpf -O2 -c %s\n", path);
	400	pr_err(" \twith proper -I and -D options.\n");
	401	goto errout;
	402	}
	403
d325d788	404	free(kbuild_dir);
0c6d18bf	405	free(kbuild_include_opts);
4cea3a9c WN	406	if (!p_obj_buf)
	407	free(obj_buf);
	408	else
	409	*p_obj_buf = obj_buf;
	410
	411	if (p_obj_buf_sz)
	412	*p_obj_buf_sz = obj_buf_sz;
	413	return 0;
	414	errout:
d325d788	415	free(kbuild_dir);
0c6d18bf	416	free(kbuild_include_opts);
4cea3a9c WN	417	free(obj_buf);
	418	if (p_obj_buf)
	419	*p_obj_buf = NULL;
	420	if (p_obj_buf_sz)
	421	*p_obj_buf_sz = 0;
	422	return err;
	423	}
9bc898c7 WN	424
	425	int llvm__search_clang(void)
	426	{
	427	char clang_path[PATH_MAX];
	428
	429	return search_program(llvm_param.clang_path, "clang", clang_path);
	430	}