Trace corresponding Lua state as well as normal C stack frames while
fiber backtracing. This might be useful for debugging purposes.
Fixes: #3538
---
src/lua/fiber.c | 86 +++++++++++++++++++++++++++++++++++------
test/app/fiber.result | 33 ++++++++++++++++
test/app/fiber.test.lua | 12 ++++++
3 files changed, 120 insertions(+), 11 deletions(-)
diff --git a/src/lua/fiber.c b/src/lua/fiber.c
index 147add89b..428c2f938 100644
--- a/src/lua/fiber.c
+++ b/src/lua/fiber.c
@@ -178,20 +178,79 @@ lbox_fiber_id(struct lua_State *L)
return 1;
}
+/**
+ * Lua fiber traceback context.
+ */
+struct lua_fiber_tb_ctx {
+ /* Lua stack to push values. */
+ struct lua_State *L;
+ /* Lua stack to trace. */
+ struct lua_State *R;
+ /* Current Lua frame. */
+ int lua_frame;
+ /* Count of traced frames (both C and Lua). */
+ int tb_frame;
+};
+
#ifdef ENABLE_BACKTRACE
-static int
-fiber_backtrace_cb(int frameno, void *frameret, const char *func, size_t
offset, void *cb_ctx)
+static void
+dump_lua_frame(struct lua_State *L, lua_Debug *ar, int tb_frame, int lua_frame)
{
char buf[512];
- int l = snprintf(buf, sizeof(buf), "#%-2d %p in ", frameno, frameret);
- if (func)
- snprintf(buf + l, sizeof(buf) - l, "%s+%zu", func, offset);
- else
- snprintf(buf + l, sizeof(buf) - l, "?");
- struct lua_State *L = (struct lua_State*)cb_ctx;
- lua_pushnumber(L, frameno + 1);
+ snprintf(buf, sizeof(buf), "LUA#%-2d %s in %s at line %i",
+ lua_frame + 1,
+ ar->name != NULL ? ar->name : "(unnamed)",
+ ar->source, ar->currentline);
+ lua_pushnumber(L, tb_frame);
lua_pushstring(L, buf);
lua_settable(L, -3);
+}
+
+static int
+fiber_backtrace_cb(int frameno, void *frameret, const char *func, size_t
offset, void *cb_ctx)
+{
+ struct lua_fiber_tb_ctx *tb_ctx = (struct lua_fiber_tb_ctx *)cb_ctx;
+ struct lua_State *L = tb_ctx->L;
+ if (strstr(func, "lj_BC_FUNCC") == func) {
+ /* We are in the LUA vm. */
+ lua_Debug ar;
+ while (tb_ctx->R && lua_getstack(tb_ctx->R, tb_ctx->lua_frame,
&ar) > 0) {
+ /* Skip all following C-frames. */
+ lua_getinfo(tb_ctx->R, "Sln", &ar);
+ if (*ar.what != 'C')
+ break;
+ if (ar.name != NULL) {
+ /* Dump frame if it is a C built-in call. */
+ tb_ctx->tb_frame++;
+ dump_lua_frame(L, &ar, tb_ctx->tb_frame,
+ tb_ctx->lua_frame);
+ }
+ tb_ctx->lua_frame++;
+ }
+ while (tb_ctx->R && lua_getstack(tb_ctx->R, tb_ctx->lua_frame,
&ar) > 0) {
+ /* Trace Lua frame. */
+ lua_getinfo(tb_ctx->R, "Sln", &ar);
+ if (*ar.what == 'C') {
+ break;
+ }
+ tb_ctx->tb_frame++;
+ dump_lua_frame(L, &ar, tb_ctx->tb_frame,
+ tb_ctx->lua_frame);
+ tb_ctx->lua_frame++;
+ }
+ } else {
+ char buf[512];
+ int l = snprintf(buf, sizeof(buf), "#%-2d %p in ",
+ frameno + 1, frameret);
+ if (func)
+ snprintf(buf + l, sizeof(buf) - l, "%s+%zu", func,
offset);
+ else
+ snprintf(buf + l, sizeof(buf) - l, "?");
+ tb_ctx->tb_frame++;
+ lua_pushnumber(L, tb_ctx->tb_frame);
+ lua_pushstring(L, buf);
+ lua_settable(L, -3);
+ }
return 0;
}
#endif
@@ -229,10 +288,15 @@ lbox_fiber_statof(struct fiber *f, void *cb_ctx, bool
backtrace)
if (backtrace) {
#ifdef ENABLE_BACKTRACE
+ struct lua_fiber_tb_ctx tb_ctx;
+ tb_ctx.L = L;
+ tb_ctx.R = f->storage.lua.stack;
+ tb_ctx.lua_frame = 0;
+ tb_ctx.tb_frame = 0;
lua_pushstring(L, "backtrace");
lua_newtable(L);
- if (f != fiber())
- backtrace_foreach(fiber_backtrace_cb, &f->ctx, L);
+ backtrace_foreach(fiber_backtrace_cb,
+ f != fiber() ? &f->ctx : NULL, &tb_ctx);
lua_settable(L, -3);
#endif /* ENABLE_BACKTRACE */
}
diff --git a/test/app/fiber.result b/test/app/fiber.result
index 77144e661..1a7827fa1 100644
--- a/test/app/fiber.result
+++ b/test/app/fiber.result
@@ -849,6 +849,39 @@ f2:cancel()
f3:cancel()
---
...
+function sf1() loop() end
+---
+...
+function sf2() sf1() end
+---
+...
+function sf3() sf2() end
+---
+...
+f1 = fiber.create(sf3)
+---
+...
+info = fiber.info()
+---
+...
+backtrace = info[f1:id()].backtrace
+---
+...
+bt_str = table.concat(backtrace, '\n')
+---
+...
+bt_str:find('sf1') ~= nil
+---
+- true
+...
+bt_str:find('loop') ~= nil
+---
+- true
+...
+bt_str:find('sf3') ~= nil
+---
+- true
+...
-- # gh-666: nulls in output
--
getmetatable(fiber.info())
diff --git a/test/app/fiber.test.lua b/test/app/fiber.test.lua
index 98a136090..9df751cc8 100644
--- a/test/app/fiber.test.lua
+++ b/test/app/fiber.test.lua
@@ -334,6 +334,18 @@ f1:cancel()
f2:cancel()
f3:cancel()
+function sf1() loop() end
+function sf2() sf1() end
+function sf3() sf2() end
+f1 = fiber.create(sf3)
+
+info = fiber.info()
+backtrace = info[f1:id()].backtrace
+bt_str = table.concat(backtrace, '\n')
+bt_str:find('sf1') ~= nil
+bt_str:find('loop') ~= nil
+bt_str:find('sf3') ~= nil
+
-- # gh-666: nulls in output
--
getmetatable(fiber.info())
--
2.19.1
