[RFC PATCH v9 30/50] perf record: Compile scriptlets if pass '.c' to --event

[Wang Nan <wangnan0@huawei.com>]

This patch enables passing source files to --event directly using:

 # perf record --event bpf-file.c command

This patch does following works:
 1) Allow passing '.c' file to '--event'. parse_events_load_bpf() is
    expanded to allow caller tell it whether the passed file is source
    file or object.

 2) llvm__compile_bpf() is called to compile the '.c' file, the result
    is saved into memory. Use bpf_object__open_buffer() to load the
    in-memory object.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
 tools/perf/util/bpf-loader.c   | 17 +++++++++++++++--
 tools/perf/util/bpf-loader.h   |  5 +++--
 tools/perf/util/parse-events.c |  4 ++--
 tools/perf/util/parse-events.h |  2 +-
 tools/perf/util/parse-events.l |  3 +++
 tools/perf/util/parse-events.y | 15 +++++++++++++--
 6 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index 07673fc..6a3ec3a 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -9,6 +9,7 @@
 #include "perf.h"
 #include "debug.h"
 #include "bpf-loader.h"
+#include "llvm-utils.h"
 
 #define DEFINE_PRINT_FN(name, level) \
 static int libbpf_##name(const char *fmt, ...)	\
@@ -28,7 +29,7 @@ DEFINE_PRINT_FN(debug, 1)
 
 static bool libbpf_initialized;
 
-int bpf__prepare_load(const char *filename)
+int bpf__prepare_load(const char *filename, bool source)
 {
 	struct bpf_object *obj;
 
@@ -37,7 +38,19 @@ int bpf__prepare_load(const char *filename)
 				 libbpf_info,
 				 libbpf_debug);
 
-	obj = bpf_object__open(filename);
+	if (source) {
+		void *obj_buf;
+		size_t obj_buf_sz;
+		int err;
+
+		err = llvm__compile_bpf(filename, &obj_buf, &obj_buf_sz);
+		if (err)
+			return err;
+		obj = bpf_object__open_buffer(obj_buf, obj_buf_sz);
+		free(obj_buf);
+	} else
+		obj = bpf_object__open(filename);
+
 	if (!obj) {
 		pr_err("bpf: failed to load %s\n", filename);
 		return -EINVAL;
diff --git a/tools/perf/util/bpf-loader.h b/tools/perf/util/bpf-loader.h
index 39d8d1a..5566be0 100644
--- a/tools/perf/util/bpf-loader.h
+++ b/tools/perf/util/bpf-loader.h
@@ -9,11 +9,12 @@
 #include "debug.h"
 
 #ifdef HAVE_LIBBPF_SUPPORT
-int bpf__prepare_load(const char *filename);
+int bpf__prepare_load(const char *filename, bool source);
 
 void bpf__clear(void);
 #else
-static inline int bpf__prepare_load(const char *filename __maybe_unused)
+static inline int bpf__prepare_load(const char *filename __maybe_unused,
+				    bool source __maybe_unused)
 {
 	pr_err("ERROR: eBPF object loading is disabled during compiling.\n");
 	return -1;
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 6f7a7b1..aaee24c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -475,7 +475,7 @@ int parse_events_add_tracepoint(struct list_head *list, int *idx,
 
 int parse_events_load_bpf(struct list_head *list __maybe_unused,
 			  int *idx __maybe_unused,
-			  char *bpf_file_name)
+			  char *bpf_file_name, bool source)
 {
 	/*
 	 * Currently don't link any event to list. BPF object files
@@ -485,7 +485,7 @@ int parse_events_load_bpf(struct list_head *list __maybe_unused,
 	 * problem. After that probe events file by file is possible.
 	 * However, probing cost is still need to be considered.
 	 */
-	return bpf__prepare_load(bpf_file_name);
+	return bpf__prepare_load(bpf_file_name, source);
 }
 
 static int
diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
index 41b962a..5841d4f 100644
--- a/tools/perf/util/parse-events.h
+++ b/tools/perf/util/parse-events.h
@@ -115,7 +115,7 @@ int parse_events_name(struct list_head *list, char *name);
 int parse_events_add_tracepoint(struct list_head *list, int *idx,
 				char *sys, char *event);
 int parse_events_load_bpf(struct list_head *list, int *idx,
-			  char *bpf_file_name);
+			  char *bpf_file_name, bool source);
 int parse_events_add_numeric(struct parse_events_evlist *data,
 			     struct list_head *list,
 			     u32 type, u64 config,
diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index 4acea38..eb821d4 100644
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -116,6 +116,7 @@ group		[^,{}/]*[{][^}]*[}][^,{}/]*
 event_pmu	[^,{}/]+[/][^/]*[/][^,{}/]*
 event		[^,{}/]+
 bpf_object	.*\.(o|bpf)
+bpf_source	.*\.c
 
 num_dec		[0-9]+
 num_hex		0x[a-fA-F0-9]+
@@ -161,6 +162,7 @@ modifier_bp	[rwx]{1,3}
 
 {event_pmu}	|
 {bpf_object}	|
+{bpf_source}	|
 {event}		{
 			BEGIN(INITIAL);
 			REWIND(1);
@@ -265,6 +267,7 @@ r{num_raw_hex}		{ return raw(yyscanner); }
 {modifier_event}	{ return str(yyscanner, PE_MODIFIER_EVENT); }
 {name}			{ return pmu_str_check(yyscanner); }
 {bpf_object}		{ return str(yyscanner, PE_BPF_OBJECT); }
+{bpf_source}		{ return str(yyscanner, PE_BPF_SOURCE); }
 "/"			{ BEGIN(config); return '/'; }
 -			{ return '-'; }
 ,			{ BEGIN(event); return ','; }
diff --git a/tools/perf/util/parse-events.y b/tools/perf/util/parse-events.y
index 481f3cd..eeb9768 100644
--- a/tools/perf/util/parse-events.y
+++ b/tools/perf/util/parse-events.y
@@ -42,7 +42,7 @@ static inc_group_count(struct list_head *list,
 %token PE_VALUE PE_VALUE_SYM_HW PE_VALUE_SYM_SW PE_RAW PE_TERM
 %token PE_EVENT_NAME
 %token PE_NAME
-%token PE_BPF_OBJECT
+%token PE_BPF_OBJECT PE_BPF_SOURCE
 %token PE_MODIFIER_EVENT PE_MODIFIER_BP
 %token PE_NAME_CACHE_TYPE PE_NAME_CACHE_OP_RESULT
 %token PE_PREFIX_MEM PE_PREFIX_RAW PE_PREFIX_GROUP
@@ -55,6 +55,7 @@ static inc_group_count(struct list_head *list,
 %type <num> PE_TERM
 %type <str> PE_NAME
 %type <str> PE_BPF_OBJECT
+%type <str> PE_BPF_SOURCE
 %type <str> PE_NAME_CACHE_TYPE
 %type <str> PE_NAME_CACHE_OP_RESULT
 %type <str> PE_MODIFIER_EVENT
@@ -431,7 +432,17 @@ PE_BPF_OBJECT
 	struct list_head *list;
 
 	ALLOC_LIST(list);
-	ABORT_ON(parse_events_load_bpf(list, &data->idx, $1));
+	ABORT_ON(parse_events_load_bpf(list, &data->idx, $1, false));
+	$$ = list;
+}
+|
+PE_BPF_SOURCE
+{
+	struct parse_events_evlist *data = _data;
+	struct list_head *list;
+
+	ALLOC_LIST(list);
+	ABORT_ON(parse_events_load_bpf(list, &data->idx, $1, true));
 	$$ = list;
 }
 
-- 
1.8.3.4