From fb9596d1731cc37da6489de439f8b876f3a12db2 Mon Sep 17 00:00:00 2001 From: He Kuang Date: Mon, 11 May 2015 09:25:02 +0000 Subject: [PATCH] perf probe: Remove length limitation for showing available variables Use struct strbuf instead of bare char[] to remove the length limitation of variables in variable_list, so they will not disappear due to overlength, and make preparation for adding more description for variables. Signed-off-by: He Kuang Acked-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/dwarf-aux.c | 50 +++++++++++++++++++----------------------- tools/perf/util/dwarf-aux.h | 4 ++-- tools/perf/util/probe-finder.c | 17 ++++++++------ 3 files changed, 34 insertions(+), 37 deletions(-) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 16d46e26edac..737c9dbe5643 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -848,19 +848,17 @@ Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, /** * die_get_typename - Get the name of given variable DIE * @vr_die: a variable DIE - * @buf: a buffer for result type name - * @len: a max-length of @buf + * @buf: a strbuf for result type name * - * Get the name of @vr_die and stores it to @buf. Return the actual length - * of type name if succeeded. Return -E2BIG if @len is not enough long, and - * Return -ENOENT if failed to find type name. + * Get the name of @vr_die and stores it to @buf. Return 0 if succeeded. + * and Return -ENOENT if failed to find type name. * Note that the result will stores typedef name if possible, and stores * "*(function_type)" if the type is a function pointer. */ -int die_get_typename(Dwarf_Die *vr_die, char *buf, int len) +int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf) { Dwarf_Die type; - int tag, ret, ret2; + int tag, ret; const char *tmp = ""; if (__die_get_real_type(vr_die, &type) == NULL) @@ -871,8 +869,8 @@ int die_get_typename(Dwarf_Die *vr_die, char *buf, int len) tmp = "*"; else if (tag == DW_TAG_subroutine_type) { /* Function pointer */ - ret = snprintf(buf, len, "(function_type)"); - return (ret >= len) ? -E2BIG : ret; + strbuf_addf(buf, "(function_type)"); + return 0; } else { if (!dwarf_diename(&type)) return -ENOENT; @@ -883,39 +881,35 @@ int die_get_typename(Dwarf_Die *vr_die, char *buf, int len) else if (tag == DW_TAG_enumeration_type) tmp = "enum "; /* Write a base name */ - ret = snprintf(buf, len, "%s%s", tmp, dwarf_diename(&type)); - return (ret >= len) ? -E2BIG : ret; - } - ret = die_get_typename(&type, buf, len); - if (ret > 0) { - ret2 = snprintf(buf + ret, len - ret, "%s", tmp); - ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; + strbuf_addf(buf, "%s%s", tmp, dwarf_diename(&type)); + return 0; } + ret = die_get_typename(&type, buf); + if (ret == 0) + strbuf_addf(buf, "%s", tmp); + return ret; } /** * die_get_varname - Get the name and type of given variable DIE * @vr_die: a variable DIE - * @buf: a buffer for type and variable name - * @len: the max-length of @buf + * @buf: a strbuf for type and variable name * * Get the name and type of @vr_die and stores it in @buf as "type\tname". */ -int die_get_varname(Dwarf_Die *vr_die, char *buf, int len) +int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf) { - int ret, ret2; + int ret; - ret = die_get_typename(vr_die, buf, len); + ret = die_get_typename(vr_die, buf); if (ret < 0) { pr_debug("Failed to get type, make it unknown.\n"); - ret = snprintf(buf, len, "(unknown_type)"); - } - if (ret > 0) { - ret2 = snprintf(buf + ret, len - ret, "\t%s", - dwarf_diename(vr_die)); - ret = (ret2 >= len - ret) ? -E2BIG : ret2 + ret; + strbuf_addf(buf, "(unknown_type)"); } - return ret; + + strbuf_addf(buf, "\t%s", dwarf_diename(vr_die)); + + return 0; } diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index 50a3cdc55fd7..60676fda4824 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -117,8 +117,8 @@ extern Dwarf_Die *die_find_member(Dwarf_Die *st_die, const char *name, Dwarf_Die *die_mem); /* Get the name of given variable DIE */ -extern int die_get_typename(Dwarf_Die *vr_die, char *buf, int len); +extern int die_get_typename(Dwarf_Die *vr_die, struct strbuf *buf); /* Get the name and type of given variable DIE, stored as "type\tname" */ -extern int die_get_varname(Dwarf_Die *vr_die, char *buf, int len); +extern int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf); #endif diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index 8b9e274f940c..d7c2e90ab4ce 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -1255,14 +1255,11 @@ int debuginfo__find_trace_events(struct debuginfo *dbg, return (ret < 0) ? ret : tf.ntevs; } -#define MAX_VAR_LEN 64 - /* Collect available variables in this scope */ static int collect_variables_cb(Dwarf_Die *die_mem, void *data) { struct available_var_finder *af = data; struct variable_list *vl; - char buf[MAX_VAR_LEN]; int tag, ret; vl = &af->vls[af->nvls - 1]; @@ -1274,10 +1271,16 @@ static int collect_variables_cb(Dwarf_Die *die_mem, void *data) af->pf.fb_ops, &af->pf.sp_die, NULL); if (ret == 0) { - ret = die_get_varname(die_mem, buf, MAX_VAR_LEN); - pr_debug2("Add new var: %s\n", buf); - if (ret > 0) - strlist__add(vl->vars, buf); + struct strbuf buf; + + strbuf_init(&buf, 64); + ret = die_get_varname(die_mem, &buf); + pr_debug2("Add new var: %s\n", buf.buf); + if (ret == 0) { + strlist__add(vl->vars, + strbuf_detach(&buf, NULL)); + } + strbuf_release(&buf); } } -- 2.11.0