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: Stephane 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: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 5eec53a3f4ac7dbedb54776f746705acfa4fa2b4..edae107416b620a79783bb8702b5e902677f7e57 100644 (file)
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -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))"
 

diff --git a/tools/perf/util/demangle-java.c b/tools/perf/util/demangle-java.c
new file mode 100644 (file)
index 0000000..3e6062a
--- /dev/null
+++ b/tools/perf/util/demangle-java.c
@@ -0,0 +1,199 @@
+#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;
+}

diff --git a/tools/perf/util/demangle-java.h b/tools/perf/util/demangle-java.h
new file mode 100644 (file)
index 0000000..a981c1f
--- /dev/null
+++ b/tools/perf/util/demangle-java.h
@@ -0,0 +1,10 @@
+#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 */

diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 562b8ebeae5b2414b6bac867c928cb22ee9a5f13..b1dd68f358fcd8e7390b5929ed736a357c7853c1 100644 (file)
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -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 @@ new_symbol:
                                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;
                }