[RFC] perf trace: Fix compilation error for make NO_LIBBPF=1 DEBUG=1

[Jiri Olsa <jolsa@kernel.org>]

I haven't tested if this breaks some perf trace functionality,
hence RFC ;-)

The perf compilation fails for NO_LIBBPF=1 DEBUG=1 with:

  $ make NO_LIBBPF=1 DEBUG=1
    BUILD:   Doing 'make -j8' parallel build
    CC       builtin-trace.o
    LD       perf-in.o
    LINK     perf
  /usr/bin/ld: perf-in.o: in function `trace__find_bpf_map_by_name':
  /home/jolsa/kernel/linux-perf/tools/perf/builtin-trace.c:4608: undefined reference to `bpf_object__find_map_by_name'
  collect2: error: ld returned 1 exit status
  make[2]: *** [Makefile.perf:631: perf] Error 1
  make[1]: *** [Makefile.perf:225: sub-make] Error 2
  make: *** [Makefile:70: all] Error 2

Moving trace__find_bpf_map_by_name calls under HAVE_LIBBPF_SUPPORT
ifdef and add make test for this.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-trace.c | 54 ++++++++++++++++++++++++--------------
 tools/perf/tests/make      |  1 +
 2 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 56bcf1ab19f8..61bafca1018a 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3174,6 +3174,26 @@ static int trace__set_ev_qualifier_tp_filter(struct trace *trace)
 }
 
 #ifdef HAVE_LIBBPF_SUPPORT
+static struct bpf_map *trace__find_bpf_map_by_name(struct trace *trace, const char *name)
+{
+	if (trace->bpf_obj == NULL)
+		return NULL;
+
+	return bpf_object__find_map_by_name(trace->bpf_obj, name);
+}
+
+static void trace__set_bpf_map_filtered_pids(struct trace *trace)
+{
+	trace->filter_pids.map = trace__find_bpf_map_by_name(trace, "pids_filtered");
+}
+
+static void trace__set_bpf_map_syscalls(struct trace *trace)
+{
+	trace->syscalls.map = trace__find_bpf_map_by_name(trace, "syscalls");
+	trace->syscalls.prog_array.sys_enter = trace__find_bpf_map_by_name(trace, "syscalls_sys_enter");
+	trace->syscalls.prog_array.sys_exit  = trace__find_bpf_map_by_name(trace, "syscalls_sys_exit");
+}
+
 static struct bpf_program *trace__find_bpf_program_by_title(struct trace *trace, const char *name)
 {
 	if (trace->bpf_obj == NULL)
@@ -3512,6 +3532,20 @@ static void trace__delete_augmented_syscalls(struct trace *trace)
 	trace->bpf_obj = NULL;
 }
 #else // HAVE_LIBBPF_SUPPORT
+static struct bpf_map *trace__find_bpf_map_by_name(struct trace *trace __maybe_unused,
+						   const char *name __maybe_unused)
+{
+	return NULL;
+}
+
+static void trace__set_bpf_map_filtered_pids(struct trace *trace __maybe_unused)
+{
+}
+
+static void trace__set_bpf_map_syscalls(struct trace *trace __maybe_unused)
+{
+}
+
 static int trace__set_ev_qualifier_bpf_filter(struct trace *trace __maybe_unused)
 {
 	return 0;
@@ -4600,26 +4634,6 @@ static int trace__parse_cgroups(const struct option *opt, const char *str, int u
 	return 0;
 }
 
-static struct bpf_map *trace__find_bpf_map_by_name(struct trace *trace, const char *name)
-{
-	if (trace->bpf_obj == NULL)
-		return NULL;
-
-	return bpf_object__find_map_by_name(trace->bpf_obj, name);
-}
-
-static void trace__set_bpf_map_filtered_pids(struct trace *trace)
-{
-	trace->filter_pids.map = trace__find_bpf_map_by_name(trace, "pids_filtered");
-}
-
-static void trace__set_bpf_map_syscalls(struct trace *trace)
-{
-	trace->syscalls.map = trace__find_bpf_map_by_name(trace, "syscalls");
-	trace->syscalls.prog_array.sys_enter = trace__find_bpf_map_by_name(trace, "syscalls_sys_enter");
-	trace->syscalls.prog_array.sys_exit  = trace__find_bpf_map_by_name(trace, "syscalls_sys_exit");
-}
-
 static int trace__config(const char *var, const char *value, void *arg)
 {
 	struct trace *trace = arg;
diff --git a/tools/perf/tests/make b/tools/perf/tests/make
index 5d0c3a9c47a1..c3c59def9f87 100644
--- a/tools/perf/tests/make
+++ b/tools/perf/tests/make
@@ -84,6 +84,7 @@ make_no_libaudit    := NO_LIBAUDIT=1
 make_no_libbionic   := NO_LIBBIONIC=1
 make_no_auxtrace    := NO_AUXTRACE=1
 make_no_libbpf	    := NO_LIBBPF=1
+make_no_libbpf_DEBUG := NO_LIBBPF=1 DEBUG=1
 make_no_libcrypto   := NO_LIBCRYPTO=1
 make_with_babeltrace:= LIBBABELTRACE=1
 make_no_sdt	    := NO_SDT=1
-- 
2.25.4