perf tools: Add kmod_path__parse function

Provides united way of parsing kernel module path
into several components.

The new kmod_path__parse function and few defines:

  int __kmod_path__parse(struct kmod_path *m, const char *path,
                         bool alloc_name, bool alloc_ext);

  #define kmod_path__parse(__m, __p)      __kmod_path__parse(__m, __p, false, false)
  #define kmod_path__parse_name(__m, __p) __kmod_path__parse(__m, __p, true , false)
  #define kmod_path__parse_ext(__m, __p)  __kmod_path__parse(__m, __p, false, true)

parse kernel module @path and updates @m argument like:

  @comp - true if @path contains supported compression suffix,
          false otherwise
  @kmod - true if @path contains '.ko' suffix in right position,
          false otherwise
  @name - if (@alloc_name && @kmod) is true, it contains strdup-ed base name
          of the kernel module without suffixes, otherwise strudup-ed
          base name of @path
  @ext  - if (@alloc_ext && @comp) is true, it contains strdup-ed string
          the compression suffix

It returns 0 if there's no strdup error, -ENOMEM otherwise.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9t6eqg8j610r94l743hkntiv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 408c65f..384cd29 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -195,6 +195,20 @@
 bool decompress_to_file(const char *ext, const char *filename, int output_fd);
 bool dso__needs_decompress(struct dso *dso);
 
+struct kmod_path {
+	char *name;
+	char *ext;
+	bool  comp;
+	bool  kmod;
+};
+
+int __kmod_path__parse(struct kmod_path *m, const char *path,
+		     bool alloc_name, bool alloc_ext);
+
+#define kmod_path__parse(__m, __p)      __kmod_path__parse(__m, __p, false, false)
+#define kmod_path__parse_name(__m, __p) __kmod_path__parse(__m, __p, true , false)
+#define kmod_path__parse_ext(__m, __p)  __kmod_path__parse(__m, __p, false, true)
+
 /*
  * The dso__data_* external interface provides following functions:
  *   dso__data_fd