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Commit e9c4bcdd authored by Stephane Eranian's avatar Stephane Eranian Committed by Arnaldo Carvalho de Melo
Browse files

perf symbols: add Java demangling support 



Add Java function descriptor demangling support.  Something bfd cannot
do.

Use the JAVA_DEMANGLE_NORET flag to avoid decoding the return type of
functions.

Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-2-git-send-email-eranian@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 89fee59b

tools/perf/util/Build

+1 −0
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ libperf-y += scripting-engines/ 


libperf-$(CONFIG_ZLIB) += zlib.o

libperf-$(CONFIG_LZMA) += lzma.o

libperf-y += demangle-java.o



CFLAGS_config.o   += -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"

tools/perf/util/demangle-java.c

0 → 100644
+199 −0
Original line number Diff line number Diff line 
#include <sys/types.h>

#include <stdio.h>

#include <string.h>

#include "util.h"

#include "debug.h"

#include "symbol.h"



#include "demangle-java.h"



enum {

	MODE_PREFIX = 0,

	MODE_CLASS  = 1,

	MODE_FUNC   = 2,

	MODE_TYPE   = 3,

	MODE_CTYPE  = 3, /* class arg */

};



#define BASE_ENT(c, n)	[c - 'A']=n

static const char *base_types['Z' - 'A' + 1] = {

	BASE_ENT('B', "byte" ),

	BASE_ENT('C', "char" ),

	BASE_ENT('D', "double" ),

	BASE_ENT('F', "float" ),

	BASE_ENT('I', "int" ),

	BASE_ENT('J', "long" ),

	BASE_ENT('S', "short" ),

	BASE_ENT('Z', "bool" ),

};



/*

 * demangle Java symbol between str and end positions and stores

 * up to maxlen characters into buf. The parser starts in mode.

 *

 * Use MODE_PREFIX to process entire prototype till end position

 * Use MODE_TYPE to process return type if str starts on return type char

 *

 *  Return:

 *	success: buf

 *	error  : NULL

 */

static char *

__demangle_java_sym(const char *str, const char *end, char *buf, int maxlen, int mode)

{

	int rlen = 0;

	int array = 0;

	int narg = 0;

	const char *q;



	if (!end)

		end = str + strlen(str);



	for (q = str; q != end; q++) {



		if (rlen == (maxlen - 1))

			break;



		switch (*q) {

		case 'L':

			if (mode == MODE_PREFIX || mode == MODE_CTYPE) {

				if (mode == MODE_CTYPE) {

					if (narg)

						rlen += scnprintf(buf + rlen, maxlen - rlen, ", ");

					narg++;

				}

				rlen += scnprintf(buf + rlen, maxlen - rlen, "class ");

				if (mode == MODE_PREFIX)

					mode = MODE_CLASS;

			} else

				buf[rlen++] = *q;

			break;

		case 'B':

		case 'C':

		case 'D':

		case 'F':

		case 'I':

		case 'J':

		case 'S':

		case 'Z':

			if (mode == MODE_TYPE) {

				if (narg)

					rlen += scnprintf(buf + rlen, maxlen - rlen, ", ");

				rlen += scnprintf(buf + rlen, maxlen - rlen, "%s", base_types[*q - 'A']);

				while (array--)

					rlen += scnprintf(buf + rlen, maxlen - rlen, "[]");

				array = 0;

				narg++;

			} else

				buf[rlen++] = *q;

			break;

		case 'V':

			if (mode == MODE_TYPE) {

				rlen += scnprintf(buf + rlen, maxlen - rlen, "void");

				while (array--)

					rlen += scnprintf(buf + rlen, maxlen - rlen, "[]");

				array = 0;

			} else

				buf[rlen++] = *q;

			break;

		case '[':

			if (mode != MODE_TYPE)

				goto error;

			array++;

			break;

		case '(':

			if (mode != MODE_FUNC)

				goto error;

			buf[rlen++] = *q;

			mode = MODE_TYPE;

			break;

		case ')':

			if (mode != MODE_TYPE)

				goto error;

			buf[rlen++] = *q;

			narg = 0;

			break;

		case ';':

			if (mode != MODE_CLASS && mode != MODE_CTYPE)

				goto error;

			/* safe because at least one other char to process */

			if (isalpha(*(q + 1)))

				rlen += scnprintf(buf + rlen, maxlen - rlen, ".");

			if (mode == MODE_CLASS)

				mode = MODE_FUNC;

			else if (mode == MODE_CTYPE)

				mode = MODE_TYPE;

			break;

		case '/':

			if (mode != MODE_CLASS && mode != MODE_CTYPE)

				goto error;

			rlen += scnprintf(buf + rlen, maxlen - rlen, ".");

			break;

		default :

			buf[rlen++] = *q;

		}

	}

	buf[rlen] = '\0';

	return buf;

error:

	return NULL;

}



/*

 * Demangle Java function signature (openJDK, not GCJ)

 * input:

 * 	str: string to parse. String is not modified

 *    flags: comobination of JAVA_DEMANGLE_* flags to modify demangling

 * return:

 *	if input can be demangled, then a newly allocated string is returned.

 *	if input cannot be demangled, then NULL is returned

 *

 * Note: caller is responsible for freeing demangled string

 */

char *

java_demangle_sym(const char *str, int flags)

{

	char *buf, *ptr;

	char *p;

	size_t len, l1 = 0;



	if (!str)

		return NULL;



	/* find start of retunr type */

	p = strrchr(str, ')');

	if (!p)

		return NULL;



	/*

	 * expansion factor estimated to 3x

	 */

	len = strlen(str) * 3 + 1;

	buf = malloc(len);

	if (!buf)

		return NULL;



	buf[0] = '\0';

	if (!(flags & JAVA_DEMANGLE_NORET)) {

		/*

		 * get return type first

		 */

		ptr = __demangle_java_sym(p + 1, NULL, buf, len, MODE_TYPE);

		if (!ptr)

			goto error;



		/* add space between return type and function prototype */

		l1 = strlen(buf);

		buf[l1++] = ' ';

	}



	/* process function up to return type */

	ptr = __demangle_java_sym(str, p + 1, buf + l1, len - l1, MODE_PREFIX);

	if (!ptr)

		goto error;



	return buf;

error:

	free(buf);

	return NULL;

}

tools/perf/util/demangle-java.h

0 → 100644
+10 −0
Original line number Diff line number Diff line 
#ifndef __PERF_DEMANGLE_JAVA

#define __PERF_DEMANGLE_JAVA 1

/*

 * demangle function flags

 */

#define JAVA_DEMANGLE_NORET	0x1 /* do not process return type */



char * java_demangle_sym(const char *str, int flags);



#endif /* __PERF_DEMANGLE_JAVA */

tools/perf/util/symbol-elf.c

+3 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <inttypes.h>



#include "symbol.h"

#include "demangle-java.h"

#include "machine.h"

#include "vdso.h"

#include <symbol/kallsyms.h>
@@ -1077,6 +1078,8 @@ int dso__load_sym(struct dso *dso, struct map *map, 
				demangle_flags = DMGL_PARAMS | DMGL_ANSI;



			demangled = bfd_demangle(NULL, elf_name, demangle_flags);

			if (demangled == NULL)

				demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);

			if (demangled != NULL)

				elf_name = demangled;

		}