perf symbols: Support minimal build without libelf

Now we have isolated all ELF-specific stuff, it's possible to build
without libelf. The output binary can do most of jobs but lacks (user
level) symbol information - kernel symbols are still accessable thanks
to the kallsyms.

To build perf without libelf (elfutils), give NO_LIBELF=1 to make.

For now, only 'perf probe' command is removed since it depends on
libelf/libdw heavily.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344228082-15569-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 56 insertions, 1 deletions

diff --git a/tools/perf/util/generate-cmdlist.sh b/tools/perf/util/generate-cmdlist.sh
index f06f6fd..389590c 100755
--- a/tools/perf/util/generate-cmdlist.sh
+++ b/tools/perf/util/generate-cmdlist.sh
@@ -21,4 +21,19 @@ do
 	    p
      }' "Documentation/perf-$cmd.txt"
 done
+
+echo "#ifndef NO_LIBELF_SUPPORT"
+sed -n -e 's/^perf-\([^ 	]*\)[ 	].* full.*/\1/p' command-list.txt |
+sort |
+while read cmd
+do
+     sed -n '
+     /^NAME/,/perf-'"$cmd"'/H
+     ${
+            x
+            s/.*perf-'"$cmd"' - \(.*\)/  {"'"$cmd"'", "\1"},/
+	    p
+     }' "Documentation/perf-$cmd.txt"
+done
+echo "#endif /* NO_LIBELF_SUPPORT */"
 echo "};"
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 115654c..287cb34 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -156,6 +156,7 @@ int map__load(struct map *self, symbol_filter_t filter)
 		pr_warning(", continuing without symbols\n");
 		return -1;
 	} else if (nr == 0) {
+#ifndef NO_LIBELF_SUPPORT
 		const size_t len = strlen(name);
 		const size_t real_len = len - sizeof(DSO__DELETED);
 
@@ -168,7 +169,7 @@ int map__load(struct map *self, symbol_filter_t filter)
 			pr_warning("no symbols found in %s, maybe install "
 				   "a debug package?\n", name);
 		}
-
+#endif
 		return -1;
 	}
 	/*
diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c
new file mode 100644
index 0000000..416ecf3
--- /dev/null
+++ b/tools/perf/util/symbol-minimal.c
@@ -0,0 +1,39 @@
+#include "symbol.h"
+
+
+int filename__read_build_id(const char *filename __used, void *bf __used,
+			    size_t size __used)
+{
+	return -1;
+}
+
+int sysfs__read_build_id(const char *filename __used, void *build_id __used,
+			 size_t size __used)
+{
+	return -1;
+}
+
+int filename__read_debuglink(const char *filename __used,
+			     char *debuglink __used, size_t size __used)
+{
+	return -1;
+}
+
+int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used,
+				struct map *map __used,
+				symbol_filter_t filter __used)
+{
+	return 0;
+}
+
+int dso__load_sym(struct dso *dso __used, struct map *map __used,
+		  const char *name __used, int fd __used,
+		  symbol_filter_t filter __used, int kmodule __used,
+		  int want_symtab __used)
+{
+	return 0;
+}
+
+void symbol__elf_init(void)
+{
+}