perf annotate: Simplify disasm_line allocation and freeing code

We are allocating disasm_line object in annotation_line__new() instead
of disasm_line__new(). Similarly annotation_line__delete() is actually
freeing disasm_line object as well. This complexity is because of
privsize.  But we don't need privsize anymore so get rid of privsize and
simplify disasm_line allocation and freeing code.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: http://lore.kernel.org/lkml/20200204045233.474937-3-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Author: Ravi Bangoria

tools/perf/util/annotate.c

@@ -1143,7 +1143,6 @@ static int disasm_line__parse(char *line, const char **namep, char **rawp)
 }
 
 struct annotate_args {
-	size_t			 privsize;
 	struct arch		*arch;
 	struct map_symbol	 ms;
 	struct evsel	*evsel;
@@ -1153,83 +1152,61 @@ struct annotate_args {
 	int			 line_nr;
 };
 
-static void annotation_line__delete(struct annotation_line *al)
+static void annotation_line__init(struct annotation_line *al,
+				  struct annotate_args *args,
+				  int nr)
 {
-	void *ptr = (void *) al - al->privsize;
+	al->offset = args->offset;
+	al->line = strdup(args->line);
+	al->line_nr = args->line_nr;
+	al->data_nr = nr;
+}
 
+static void annotation_line__exit(struct annotation_line *al)
+{
 	free_srcline(al->path);
 	zfree(&al->line);
-	free(ptr);
 }
 
-/*
- * Allocating the annotation line data with following
- * structure:
- *
- *    --------------------------------------
- *    private space | struct annotation_line
- *    --------------------------------------
- *
- * Size of the private space is stored in 'struct annotation_line'.
- *
- */
-static struct annotation_line *
-annotation_line__new(struct annotate_args *args, size_t privsize)
+static size_t disasm_line_size(int nr)
 {
 	struct annotation_line *al;
-	struct evsel *evsel = args->evsel;
-	size_t size = privsize + sizeof(*al);
-	int nr = 1;
-
-	if (perf_evsel__is_group_event(evsel))
-		nr = evsel->core.nr_members;
-
-	size += sizeof(al->data[0]) * nr;
 
-	al = zalloc(size);
-	if (al) {
-		al = (void *) al + privsize;
-		al->privsize   = privsize;
-		al->offset     = args->offset;
-		al->line       = strdup(args->line);
-		al->line_nr    = args->line_nr;
-		al->data_nr    = nr;
-	}
-
-	return al;
+	return (sizeof(struct disasm_line) + (sizeof(al->data[0]) * nr));
 }
 
 /*
  * Allocating the disasm annotation line data with
  * following structure:
  *
- *    ------------------------------------------------------------
- *    privsize space | struct disasm_line | struct annotation_line
- *    ------------------------------------------------------------
+ *    -------------------------------------------
+ *    struct disasm_line | struct annotation_line
+ *    -------------------------------------------
  *
  * We have 'struct annotation_line' member as last member
  * of 'struct disasm_line' to have an easy access.
- *
  */
 static struct disasm_line *disasm_line__new(struct annotate_args *args)
 {
 	struct disasm_line *dl = NULL;
-	struct annotation_line *al;
-	size_t privsize = args->privsize + offsetof(struct disasm_line, al);
+	int nr = 1;
 
-	al = annotation_line__new(args, privsize);
-	if (al != NULL) {
-		dl = disasm_line(al);
+	if (perf_evsel__is_group_event(args->evsel))
+		nr = args->evsel->core.nr_members;
 
-		if (dl->al.line == NULL)
-			goto out_delete;
+	dl = zalloc(disasm_line_size(nr));
+	if (!dl)
+		return NULL;
 
-		if (args->offset != -1) {
-			if (disasm_line__parse(dl->al.line, &dl->ins.name, &dl->ops.raw) < 0)
-				goto out_free_line;
+	annotation_line__init(&dl->al, args, nr);
+	if (dl->al.line == NULL)
+		goto out_delete;
 
-			disasm_line__init_ins(dl, args->arch, &args->ms);
-		}
+	if (args->offset != -1) {
+		if (disasm_line__parse(dl->al.line, &dl->ins.name, &dl->ops.raw) < 0)
+			goto out_free_line;
+
+		disasm_line__init_ins(dl, args->arch, &args->ms);
 	}
 
 	return dl;
@@ -1248,7 +1225,8 @@ void disasm_line__free(struct disasm_line *dl)
 	else
 		ins__delete(&dl->ops);
 	zfree(&dl->ins.name);
-	annotation_line__delete(&dl->al);
+	annotation_line__exit(&dl->al);
+	free(dl);
 }
 
 int disasm_line__scnprintf(struct disasm_line *dl, char *bf, size_t size, bool raw, int max_ins_name)
@@ -2152,11 +2130,9 @@ void symbol__calc_percent(struct symbol *sym, struct evsel *evsel)
 int symbol__annotate(struct map_symbol *ms, struct evsel *evsel,
 		     struct annotation_options *options, struct arch **parch)
 {
-	size_t privsize = 0;
 	struct symbol *sym = ms->sym;
 	struct annotation *notes = symbol__annotation(sym);
 	struct annotate_args args = {
-		.privsize	= privsize,
 		.evsel		= evsel,
 		.options	= options,
 	};

tools/perf/util/annotate.h

@@ -139,7 +139,6 @@ struct annotation_line {
 	u64			 cycles;
 	u64			 cycles_max;
 	u64			 cycles_min;
-	size_t			 privsize;
 	char			*path;
 	u32			 idx;
 	int			 idx_asm;