From: Simon Marchi Date: Mon, 31 Aug 2020 17:23:12 +0000 (-0400) Subject: gdb: introduce explicit outer frame id kind X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=84154d166a1a4592c70e2a8296d5df0ad7f89be9;p=binutils-gdb.git gdb: introduce explicit outer frame id kind In the following patch, we'll need to easily differentiate the frame_id of the outer frame (or the frame id of a frame inlined into the outer frame) from a simply invalid frame id. Currently, the frame id of the outer frame has `stack_status` set to FID_STACK_INVALID plus special_addr_p set. A frame inlined into the outer frame would also have `artificial_depth` set to greater than one. That makes the job of differntiating the frame id of the outer frame (or a frame inlined into the outer frame) cumbersome. To make it easier, give the outer frame id its own frame_id_stack_status enum value. outer_frame_id then becomes very similar to sentinel_frame_id, another "special" frame id value. In frame_id_p, we don't need a special case for the outer frame id, as it's no long a special case of FID_STACK_INVALID. Same goes for frame_id_eq. So in the end, FID_STACK_OUTER isn't even used (except in fprint_frame_id). But that's expected: all the times we wanted to identify an outer frame was to differentiate it from an otherwise invalid frame. Since their frame_id_stack_status value is different now, that is done naturally. gdb/ChangeLog: * frame.h (enum frame_id_stack_status) : New. * frame.c (fprint_frame_id): Handle FID_STACK_OUTER. (outer_frame_id): Use FID_STACK_OUTER instead of FID_STACK_INVALID. (frame_id_p): Don't check for outer_frame_id. Change-Id: I654e7f936349debc4f04f7f684b15e71a0c37619 --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a982d917057..3a0d371a87c 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,11 @@ +2020-08-31 Simon Marchi + + * frame.h (enum frame_id_stack_status) : New. + * frame.c (fprint_frame_id): Handle FID_STACK_OUTER. + (outer_frame_id): Use FID_STACK_OUTER instead of + FID_STACK_INVALID. + (frame_id_p): Don't check for outer_frame_id. + 2020-08-31 Simon Marchi * frame-unwind.c (frame_unwind_got_optimized): Don't set diff --git a/gdb/frame.c b/gdb/frame.c index ccaf97dc7e9..54f4c613c9e 100644 --- a/gdb/frame.c +++ b/gdb/frame.c @@ -396,8 +396,11 @@ fprint_frame_id (struct ui_file *file, struct frame_id id) fprintf_unfiltered (file, "stack="); else if (id.stack_status == FID_STACK_SENTINEL) fprintf_unfiltered (file, "stack="); + else if (id.stack_status == FID_STACK_OUTER) + fprintf_unfiltered (file, "stack="); else fprintf_unfiltered (file, "stack=%s", hex_string (id.stack_addr)); + fprintf_unfiltered (file, ","); fprint_field (file, "code", id.code_addr_p, id.code_addr); @@ -672,7 +675,7 @@ frame_unwind_caller_id (struct frame_info *next_frame) const struct frame_id null_frame_id = { 0 }; /* All zeros. */ const struct frame_id sentinel_frame_id = { 0, 0, 0, FID_STACK_SENTINEL, 0, 1, 0 }; -const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_INVALID, 0, 1, 0 }; +const struct frame_id outer_frame_id = { 0, 0, 0, FID_STACK_OUTER, 0, 1, 0 }; struct frame_id frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr, @@ -746,10 +749,6 @@ frame_id_p (frame_id l) /* The frame is valid iff it has a valid stack address. */ bool p = l.stack_status != FID_STACK_INVALID; - /* outer_frame_id is also valid. */ - if (!p && memcmp (&l, &outer_frame_id, sizeof (l)) == 0) - p = true; - if (frame_debug) { fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l="); @@ -774,15 +773,7 @@ frame_id_eq (frame_id l, frame_id r) { bool eq; - if (l.stack_status == FID_STACK_INVALID && l.special_addr_p - && r.stack_status == FID_STACK_INVALID && r.special_addr_p) - /* The outermost frame marker is equal to itself. This is the - dodgy thing about outer_frame_id, since between execution steps - we might step into another function - from which we can't - unwind either. More thought required to get rid of - outer_frame_id. */ - eq = true; - else if (l.stack_status == FID_STACK_INVALID + if (l.stack_status == FID_STACK_INVALID || r.stack_status == FID_STACK_INVALID) /* Like a NaN, if either ID is invalid, the result is false. Note that a frame ID is invalid iff it is the null frame ID. */ diff --git a/gdb/frame.h b/gdb/frame.h index 1c6afad1ae9..3ceb7b32eff 100644 --- a/gdb/frame.h +++ b/gdb/frame.h @@ -85,8 +85,7 @@ struct frame_print_options; enum frame_id_stack_status { - /* Stack address is invalid. E.g., this frame is the outermost - (i.e., _start), and the stack hasn't been setup yet. */ + /* Stack address is invalid. */ FID_STACK_INVALID = 0, /* Stack address is valid, and is found in the stack_addr field. */ @@ -95,6 +94,12 @@ enum frame_id_stack_status /* Sentinel frame. */ FID_STACK_SENTINEL = 2, + /* Outer frame. Since a frame's stack address is typically defined as the + value the stack pointer had prior to the activation of the frame, an outer + frame doesn't have a stack address. The frame ids of frames inlined in the + outer frame are also of this type. */ + FID_STACK_OUTER = 3, + /* Stack address is unavailable. I.e., there's a valid stack, but we don't know where it is (because memory or registers we'd compute it from were not collected). */