[PATCH v3 3/3] btrace, frame: fix crash in get_frame_type

Markus Metzger
2016-02-11T16:15:02Z

In skip_artificial_frames we repeatedly call get_prev_frame_always until we get
a non-inline and non-tailcall frame assuming that there must be such a frame
eventually.

For record targets, however, we may have a frame chain that consists only of
artificial frames. This leads to a crash in get_frame_type when dereferencing a
NULL frame pointer.

Change skip_artificial_frames and skip_tailcall_frames to return NULL in such a
case and modify each caller to cope with a NULL return.

In frame_unwind_caller_pc and frame_unwind_caller_arch, we simply assert that
the returned value is not NULL. Their caller was supposed to check
frame_unwind_caller_id before calling those functions.

In other cases, we thrown an error.

In infcmd further move the skip_tailcall_frames call to the forward-stepping
case since we don't need a frame for reverse execution and we don't want to fail
because of that. Reverse-finish does make sense for a tailcall frame.

2016-02-11 Markus Metzger <markus.t.metzger@intel.com>

gdb/
* frame.h (skip_tailcall_frames): Update comment.
* frame.c (skip_artificial_frames, skip_tailcall_frames): Return NULL
if only artificial frames are found. Update comment.
(frame_unwind_caller_id): Handle NULL return.
(frame_unwind_caller_pc, frame_unwind_caller_arch): Assert that
skip_artificial_frames does not return NULL.
(frame_pop): Add an error if only tailcall frames are found.
* infcmd.c (finish_command): Move skip_tailcall_frames call into forward-
execution case. Add an error if only tailcall frames are found.

testsuite/
* gdb.btrace/tailcall-only.exp: New.
* gdb.btrace/tailcall-only.c: New.
* gdb.btrace/x86_64-tailcall-only.S: New.
* gdb.btrace/i686-tailcall-only.S: New.
---
gdb/frame.c | 48 ++-
gdb/frame.h | 3 +-
gdb/infcmd.c | 15 +-
gdb/testsuite/gdb.btrace/i686-tailcall-only.S | 447 ++++++++++++++++++++++++
gdb/testsuite/gdb.btrace/tailcall-only.c | 53 +++
gdb/testsuite/gdb.btrace/tailcall-only.exp | 97 +++++
gdb/testsuite/gdb.btrace/x86_64-tailcall-only.S | 446 +++++++++++++++++++++++
7 files changed, 1095 insertions(+), 14 deletions(-)
create mode 100644 gdb/testsuite/gdb.btrace/i686-tailcall-only.S
create mode 100644 gdb/testsuite/gdb.btrace/tailcall-only.c
create mode 100644 gdb/testsuite/gdb.btrace/tailcall-only.exp
create mode 100644 gdb/testsuite/gdb.btrace/x86_64-tailcall-only.S

diff --git a/gdb/frame.c b/gdb/frame.c
index b7832c7..d621dd7 100644
--- a/gdb/frame.c
+++ b/gdb/frame.c
@@ -420,7 +420,8 @@ fprint_frame (struct ui_file *file, struct frame_info *fi)

/* Given FRAME, return the enclosing frame as found in real frames read-in from
inferior memory. Skip any previous frames which were made up by GDB.
- Return the original frame if no immediate previous frames exist. */
+ Return FRAME if FRAME is a non-artificial frame.
+ Return NULL if FRAME is the start of an artificial-only chain. */

static struct frame_info *
skip_artificial_frames (struct frame_info *frame)
@@ -428,12 +429,17 @@ skip_artificial_frames (struct frame_info *frame)
/* Note we use get_prev_frame_always, and not get_prev_frame. The
latter will truncate the frame chain, leading to this function
unintentionally returning a null_frame_id (e.g., when the user
- sets a backtrace limit). This is safe, because as these frames
- are made up by GDB, there must be a real frame in the chain
- below. */
+ sets a backtrace limit).
+
+ Note that for record targets we may get a frame chain that consists
+ of artificial frames only. */
while (get_frame_type (frame) == INLINE_FRAME
|| get_frame_type (frame) == TAILCALL_FRAME)
- frame = get_prev_frame_always (frame);
+ {
+ frame = get_prev_frame_always (frame);
+ if (frame == NULL)
+ break;
+ }

return frame;
}
@@ -444,7 +450,13 @@ struct frame_info *
skip_tailcall_frames (struct frame_info *frame)
{
while (get_frame_type (frame) == TAILCALL_FRAME)
- frame = get_prev_frame (frame);
+ {
+ /* Note that for record targets we may get a frame chain that consists of
+ tailcall frames only. */
+ frame = get_prev_frame (frame);
+ if (frame == NULL)
+ break;
+ }

return frame;
}
@@ -507,6 +519,9 @@ frame_unwind_caller_id (struct frame_info *next_frame)
requests the frame ID of "main()"s caller. */

next_frame = skip_artificial_frames (next_frame);
+ if (next_frame == NULL)
+ return null_frame_id;
+
this_frame = get_prev_frame_always (next_frame);
if (this_frame)
return get_frame_id (skip_artificial_frames (this_frame));
@@ -880,7 +895,14 @@ frame_unwind_pc (struct frame_info *this_frame)
CORE_ADDR
frame_unwind_caller_pc (struct frame_info *this_frame)
{
- return frame_unwind_pc (skip_artificial_frames (this_frame));
+ this_frame = skip_artificial_frames (this_frame);
+
+ /* We must have a non-artificial frame. The caller is supposed to check
+ the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID
+ in this case. */
+ gdb_assert (this_frame != NULL);
+
+ return frame_unwind_pc (this_frame);
}

int
@@ -985,6 +1007,9 @@ frame_pop (struct frame_info *this_frame)
entering THISFRAME. */
prev_frame = skip_tailcall_frames (prev_frame);

+ if (prev_frame == NULL)
+ error (_("Cannot find the caller frame."));
+
/* Make a copy of all the register values unwound from this frame.
Save them in a scratch buffer so that there isn't a race between
trying to extract the old values from the current regcache while
@@ -2571,7 +2596,14 @@ frame_unwind_arch (struct frame_info *next_frame)
struct gdbarch *
frame_unwind_caller_arch (struct frame_info *next_frame)
{
- return frame_unwind_arch (skip_artificial_frames (next_frame));
+ next_frame = skip_artificial_frames (next_frame);
+
+ /* We must have a non-artificial frame. The caller is supposed to check
+ the result of frame_unwind_caller_id (), which returns NULL_FRAME_ID
+ in this case. */
+ gdb_assert (next_frame != NULL);
+
+ return frame_unwind_arch (next_frame);
}

/* Gets the language of FRAME. */
diff --git a/gdb/frame.h b/gdb/frame.h
index 7e8b01e..8ee64f1 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -821,7 +821,8 @@ extern int frame_unwinder_is (struct frame_info *fi,
extern enum language get_frame_language (struct frame_info *frame);

/* Return the first non-tailcall frame above FRAME or FRAME if it is not a
- tailcall frame. */
+ tailcall frame. Return NULL if FRAME is the start of a tailcall-only
+ chain. */

extern struct frame_info *skip_tailcall_frames (struct frame_info *frame);

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 930dc61..a80bf0a 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -2000,10 +2000,6 @@ finish_command (char *arg, int from_tty)
return;
}

- /* Ignore TAILCALL_FRAME type frames, they were executed already before
- entering THISFRAME. */
- frame = skip_tailcall_frames (frame);
-
/* Find the function we will return from. */

sm->function = find_pc_function (get_frame_pc (get_selected_frame (NULL)));
@@ -2030,7 +2026,16 @@ finish_command (char *arg, int from_tty)
if (execution_direction == EXEC_REVERSE)
finish_backward (sm);
else
- finish_forward (sm, frame);
+ {
+ /* Ignore TAILCALL_FRAME type frames, they were executed already before
+ entering THISFRAME. */
+ frame = skip_tailcall_frames (frame);
+
+ if (frame == NULL)
+ error (_("Cannot find the caller frame."));
+
+ finish_forward (sm, frame);
+ }
}
\f

diff --git a/gdb/testsuite/gdb.btrace/i686-tailcall-only.S b/gdb/testsuite/gdb.btrace/i686-tailcall-only.S
new file mode 100644
index 0000000..a89f2f2
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/i686-tailcall-only.S
@@ -0,0 +1,447 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+ This file has been generated using:
+ gcc -m32 -march=i686 -S -O2 -dA -g tailcall-only.c -o i686-tailcall-only.S
+ */
+
+ .file "tailcall-only.c"
+ .text
+.Ltext0:
+ .p2align 4,,15
+ .type bar_1, @function
+bar_1:
+.LFB0:
+ .file 1 "tailcall-only.c"
+ # tailcall-only.c:22
+ .loc 1 22 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:24
+ .loc 1 24 0
+ movl $42, %eax
+# SUCC: EXIT [100.0%]
+ ret
+ .cfi_endproc
+.LFE0:
+ .size bar_1, .-bar_1
+ .p2align 4,,15
+ .type bar, @function
+bar:
+.LFB1:
+ # tailcall-only.c:28
+ .loc 1 28 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:29
+ .loc 1 29 0
+ jmp bar_1
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL0:
+ .cfi_endproc
+.LFE1:
+ .size bar, .-bar
+ .p2align 4,,15
+ .type foo_1, @function
+foo_1:
+.LFB2:
+ # tailcall-only.c:34
+ .loc 1 34 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:35
+ .loc 1 35 0
+ jmp bar
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL1:
+ .cfi_endproc
+.LFE2:
+ .size foo_1, .-foo_1
+ .p2align 4,,15
+ .type foo, @function
+foo:
+.LFB3:
+ # tailcall-only.c:40
+ .loc 1 40 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:41
+ .loc 1 41 0
+ jmp foo_1
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL2:
+ .cfi_endproc
+.LFE3:
+ .size foo, .-foo
+ .section .text.startup,"ax",@progbits
+ .p2align 4,,15
+ .globl main
+ .type main, @function
+main:
+.LFB4:
+ # tailcall-only.c:46
+ .loc 1 46 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:49
+ .loc 1 49 0
+ call foo
+.LVL3:
+ # tailcall-only.c:50
+ .loc 1 50 0
+ addl $1, %eax
+.LVL4:
+# SUCC: EXIT [100.0%]
+ # tailcall-only.c:53
+ .loc 1 53 0
+ ret
+ .cfi_endproc
+.LFE4:
+ .size main, .-main
+ .text
+.Letext0:
+ .section .debug_info,"",@progbits
+.Ldebug_info0:
+ .long 0xd5 # Length of Compilation Unit Info
+ .value 0x4 # DWARF version number
+ .long .Ldebug_abbrev0 # Offset Into Abbrev. Section
+ .byte 0x4 # Pointer Size (in bytes)
+ .uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit)
+ .long .LASF1 # DW_AT_producer: "GNU C 4.8.3 20140911 (Red Hat 4.8.3-9) -m32 -march=i686 -g -O2"
+ .byte 0x1 # DW_AT_language
+ .long .LASF2 # DW_AT_name: "tailcall-only.c"
+ .long .LASF3 # DW_AT_comp_dir: ""
+ .long .Ldebug_ranges0+0 # DW_AT_ranges
+ .long 0 # DW_AT_low_pc
+ .long .Ldebug_line0 # DW_AT_stmt_list
+ .uleb128 0x2 # (DIE (0x25) DW_TAG_subprogram)
+ .long .LASF4 # DW_AT_name: "bar_1"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x15 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x3a # DW_AT_type
+ .long .LFB0 # DW_AT_low_pc
+ .long .LFE0-.LFB0 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .uleb128 0x3 # (DIE (0x3a) DW_TAG_base_type)
+ .byte 0x4 # DW_AT_byte_size
+ .byte 0x5 # DW_AT_encoding
+ .ascii "int\0" # DW_AT_name
+ .uleb128 0x4 # (DIE (0x41) DW_TAG_subprogram)
+ .ascii "bar\0" # DW_AT_name
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x1b # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x3a # DW_AT_type
+ .long .LFB1 # DW_AT_low_pc
+ .long .LFE1-.LFB1 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0x64 # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0x5a) DW_TAG_GNU_call_site)
+ .long .LVL0 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x25 # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0x41
+ .uleb128 0x6 # (DIE (0x64) DW_TAG_subprogram)
+ .long .LASF0 # DW_AT_name: "foo_1"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x21 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x3a # DW_AT_type
+ .long .LFB2 # DW_AT_low_pc
+ .long .LFE2-.LFB2 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0x87 # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0x7d) DW_TAG_GNU_call_site)
+ .long .LVL1 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x41 # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0x64
+ .uleb128 0x4 # (DIE (0x87) DW_TAG_subprogram)
+ .ascii "foo\0" # DW_AT_name
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x27 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x3a # DW_AT_type
+ .long .LFB3 # DW_AT_low_pc
+ .long .LFE3-.LFB3 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0xaa # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0xa0) DW_TAG_GNU_call_site)
+ .long .LVL2 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x64 # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0x87
+ .uleb128 0x7 # (DIE (0xaa) DW_TAG_subprogram)
+ # DW_AT_external
+ .long .LASF5 # DW_AT_name: "main"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x2d # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x3a # DW_AT_type
+ .long .LFB4 # DW_AT_low_pc
+ .long .LFE4-.LFB4 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .uleb128 0x8 # (DIE (0xbf) DW_TAG_variable)
+ .long .LASF6 # DW_AT_name: "answer"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x2f # DW_AT_decl_line
+ .long 0x3a # DW_AT_type
+ .long .LLST0 # DW_AT_location
+ .uleb128 0x9 # (DIE (0xce) DW_TAG_GNU_call_site)
+ .long .LVL3 # DW_AT_low_pc
+ .long 0x87 # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0xaa
+ .byte 0 # end of children of DIE 0xb
+ .section .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+ .uleb128 0x1 # (abbrev code)
+ .uleb128 0x11 # (TAG: DW_TAG_compile_unit)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x25 # (DW_AT_producer)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x13 # (DW_AT_language)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x1b # (DW_AT_comp_dir)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x55 # (DW_AT_ranges)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x10 # (DW_AT_stmt_list)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .byte 0
+ .byte 0
+ .uleb128 0x2 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0 # DW_children_no
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x6 # (DW_FORM_data4)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .byte 0
+ .byte 0
+ .uleb128 0x3 # (abbrev code)
+ .uleb128 0x24 # (TAG: DW_TAG_base_type)
+ .byte 0 # DW_children_no
+ .uleb128 0xb # (DW_AT_byte_size)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3e # (DW_AT_encoding)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0x8 # (DW_FORM_string)
+ .byte 0
+ .byte 0
+ .uleb128 0x4 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0x8 # (DW_FORM_string)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x6 # (DW_FORM_data4)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x1 # (DW_AT_sibling)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x5 # (abbrev code)
+ .uleb128 0x4109 # (TAG: DW_TAG_GNU_call_site)
+ .byte 0 # DW_children_no
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x2115 # (DW_AT_GNU_tail_call)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x31 # (DW_AT_abstract_origin)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x6 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x6 # (DW_FORM_data4)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x1 # (DW_AT_sibling)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x7 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3f # (DW_AT_external)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x6 # (DW_FORM_data4)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .byte 0
+ .byte 0
+ .uleb128 0x8 # (abbrev code)
+ .uleb128 0x34 # (TAG: DW_TAG_variable)
+ .byte 0 # DW_children_no
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x2 # (DW_AT_location)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .byte 0
+ .byte 0
+ .uleb128 0x9 # (abbrev code)
+ .uleb128 0x4109 # (TAG: DW_TAG_GNU_call_site)
+ .byte 0 # DW_children_no
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x31 # (DW_AT_abstract_origin)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .byte 0
+ .section .debug_loc,"",@progbits
+.Ldebug_loc0:
+.LLST0:
+ .long .LVL3 # Location list begin address (*.LLST0)
+ .long .LVL4 # Location list end address (*.LLST0)
+ .value 0x3 # Location expression size
+ .byte 0x70 # DW_OP_breg0
+ .sleb128 1
+ .byte 0x9f # DW_OP_stack_value
+ .long .LVL4 # Location list begin address (*.LLST0)
+ .long .LFE4 # Location list end address (*.LLST0)
+ .value 0x1 # Location expression size
+ .byte 0x50 # DW_OP_reg0
+ .long 0 # Location list terminator begin (*.LLST0)
+ .long 0 # Location list terminator end (*.LLST0)
+ .section .debug_aranges,"",@progbits
+ .long 0x24 # Length of Address Ranges Info
+ .value 0x2 # DWARF Version
+ .long .Ldebug_info0 # Offset of Compilation Unit Info
+ .byte 0x4 # Size of Address
+ .byte 0 # Size of Segment Descriptor
+ .value 0 # Pad to 8 byte boundary
+ .value 0
+ .long .Ltext0 # Address
+ .long .Letext0-.Ltext0 # Length
+ .long .LFB4 # Address
+ .long .LFE4-.LFB4 # Length
+ .long 0
+ .long 0
+ .section .debug_ranges,"",@progbits
+.Ldebug_ranges0:
+ .long .Ltext0 # Offset 0
+ .long .Letext0
+ .long .LFB4 # Offset 0x8
+ .long .LFE4
+ .long 0
+ .long 0
+ .section .debug_line,"",@progbits
+.Ldebug_line0:
+ .section .debug_str,"MS",@progbits,1
+.LASF4:
+ .string "bar_1"
+.LASF2:
+ .string "tailcall-only.c"
+.LASF1:
+ .string "GNU C 4.8.3 20140911 (Red Hat 4.8.3-9) -m32 -march=i686 -g -O2"
+.LASF6:
+ .string "answer"
+.LASF5:
+ .string "main"
+.LASF3:
+ .string ""
+.LASF0:
+ .string "foo_1"
+ .ident "GCC: (GNU) 4.8.3 20140911 (Red Hat 4.8.3-9)"
+ .section .note.GNU-stack,"",@progbits
diff --git a/gdb/testsuite/gdb.btrace/tailcall-only.c b/gdb/testsuite/gdb.btrace/tailcall-only.c
new file mode 100644
index 0000000..5913ddc
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/tailcall-only.c
@@ -0,0 +1,53 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016 Free Software Foundation, Inc.
+
+ Contributed by Intel Corp. <markus.t.metzger@intel.com>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+static __attribute__ ((noinline)) int
+bar_1 (void)
+{
+ return 42;
+}
+
+static __attribute__ ((noinline)) int
+bar (void)
+{
+ return bar_1 ();
+}
+
+static __attribute__ ((noinline)) int
+foo_1 (void)
+{
+ return bar ();
+}
+
+static __attribute__ ((noinline)) int
+foo (void)
+{
+ return foo_1 ();
+}
+
+int
+main (void)
+{
+ int answer;
+
+ answer = foo ();
+ answer += 1;
+
+ return answer;
+}
diff --git a/gdb/testsuite/gdb.btrace/tailcall-only.exp b/gdb/testsuite/gdb.btrace/tailcall-only.exp
new file mode 100644
index 0000000..44501f5
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/tailcall-only.exp
@@ -0,0 +1,97 @@
+# This testcase is part of GDB, the GNU debugger.
+#
+# Copyright 2016 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#
+# This is a variant of tailcall.exp where the entire trace contains only tail
+# calls. This used to cause a crash in get_frame_type.
+#
+
+# check for btrace support
+if { [skip_btrace_tests] } { return -1 }
+
+# This test requires the compiler to generate a tail call. To guarantee that
+# we always get one, we use an assembly source file.
+#
+# We use different assembly sources based on the target architecture.
+#
+# Luckily, they are similar enough that a single test script can handle
+# both.
+set opts {}
+if [info exists COMPILE] {
+ # make check RUNTESTFLAGS="gdb.btrace/tailcall-only.exp COMPILE=1"
+ standard_testfile tailcall-only.c
+ lappend opts debug optimize=-O2
+} elseif {[istarget "x86_64-*-*"]} {
+ standard_testfile x86_64-tailcall-only.S
+} elseif {[istarget "i?86-*-*"]} {
+ standard_testfile i686-tailcall-only.S
+} else {
+ verbose "Skipping ${testfile}."
+ return
+}
+
+if [prepare_for_testing tailcall-only.exp $testfile $srcfile $opts] {
+ return -1
+}
+if ![runto_main] {
+ return -1
+}
+
+# we want to see the full trace for this test
+gdb_test_no_output "set record function-call-history-size 0"
+
+# trace foo
+gdb_test "step" ".*" "prepare for recording"
+gdb_test_no_output "record btrace"
+gdb_test "stepi 4" ".*" "record branch trace"
+
+# for debugging
+gdb_test "info record" ".*"
+
+# show the branch trace with calls indented
+gdb_test "record function-call-history /c 1" [multi_line \
+ "1\tfoo" \
+ "2\t foo_1" \
+ "3\t bar" \
+ "4\t bar_1"
+ ] "function-call-history"
+
+# We can step
+gdb_test "record goto begin" ".*foo.*"
+gdb_test "stepi" ".*foo_1.*" "step into foo_1"
+gdb_test "step" ".*bar.*" "step into bar"
+gdb_test "stepi" ".*bar_1.*" "step into bar_1"
+
+# We can neither finish nor return.
+gdb_test "finish" "Cannot find the caller frame.*"
+gdb_test_multiple "return" "return" {
+ -re "Make .* return now.*y or n. $" {
+ send_gdb "y\n"
+ exp_continue
+ }
+ -re "Cannot find the caller frame.*$gdb_prompt $" {
+ pass "return"
+ }
+}
+
+# But we can reverse-finish
+gdb_test "reverse-finish" ".*bar.*"
+gdb_test "reverse-step" ".*foo_1.*"
+
+# Info frame isn't useful but doesn't crash as it used to.
+gdb_test "up" ".*foo.*"
+gdb_test "info frame" ".*"
diff --git a/gdb/testsuite/gdb.btrace/x86_64-tailcall-only.S b/gdb/testsuite/gdb.btrace/x86_64-tailcall-only.S
new file mode 100644
index 0000000..710288a
--- /dev/null
+++ b/gdb/testsuite/gdb.btrace/x86_64-tailcall-only.S
@@ -0,0 +1,446 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2016 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+
+ This file has been generated using:
+ gcc -S -O2 -dA -g tailcall-only.c -o x86_64-tailcall-only.S */
+
+ .file "tailcall-only.c"
+ .text
+.Ltext0:
+ .p2align 4,,15
+ .type bar_1, @function
+bar_1:
+.LFB0:
+ .file 1 "tailcall-only.c"
+ # tailcall-only.c:22
+ .loc 1 22 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:24
+ .loc 1 24 0
+ movl $42, %eax
+# SUCC: EXIT [100.0%]
+ ret
+ .cfi_endproc
+.LFE0:
+ .size bar_1, .-bar_1
+ .p2align 4,,15
+ .type bar, @function
+bar:
+.LFB1:
+ # tailcall-only.c:28
+ .loc 1 28 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:29
+ .loc 1 29 0
+ jmp bar_1
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL0:
+ .cfi_endproc
+.LFE1:
+ .size bar, .-bar
+ .p2align 4,,15
+ .type foo_1, @function
+foo_1:
+.LFB2:
+ # tailcall-only.c:34
+ .loc 1 34 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:35
+ .loc 1 35 0
+ jmp bar
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL1:
+ .cfi_endproc
+.LFE2:
+ .size foo_1, .-foo_1
+ .p2align 4,,15
+ .type foo, @function
+foo:
+.LFB3:
+ # tailcall-only.c:40
+ .loc 1 40 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:41
+ .loc 1 41 0
+ jmp foo_1
+# SUCC: EXIT [100.0%] (ABNORMAL,SIBCALL)
+.LVL2:
+ .cfi_endproc
+.LFE3:
+ .size foo, .-foo
+ .section .text.startup,"ax",@progbits
+ .p2align 4,,15
+ .globl main
+ .type main, @function
+main:
+.LFB4:
+ # tailcall-only.c:46
+ .loc 1 46 0
+ .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%] (FALLTHRU)
+ # tailcall-only.c:49
+ .loc 1 49 0
+ call foo
+.LVL3:
+ # tailcall-only.c:50
+ .loc 1 50 0
+ addl $1, %eax
+.LVL4:
+# SUCC: EXIT [100.0%]
+ # tailcall-only.c:53
+ .loc 1 53 0
+ ret
+ .cfi_endproc
+.LFE4:
+ .size main, .-main
+ .text
+.Letext0:
+ .section .debug_info,"",@progbits
+.Ldebug_info0:
+ .long 0x111 # Length of Compilation Unit Info
+ .value 0x4 # DWARF version number
+ .long .Ldebug_abbrev0 # Offset Into Abbrev. Section
+ .byte 0x8 # Pointer Size (in bytes)
+ .uleb128 0x1 # (DIE (0xb) DW_TAG_compile_unit)
+ .long .LASF1 # DW_AT_producer: "GNU C 4.8.3 20140911 (Red Hat 4.8.3-9) -mtune=generic -march=x86-64 -g -O2"
+ .byte 0x1 # DW_AT_language
+ .long .LASF2 # DW_AT_name: "tailcall-only.c"
+ .long .LASF3 # DW_AT_comp_dir: ""
+ .long .Ldebug_ranges0+0 # DW_AT_ranges
+ .quad 0 # DW_AT_low_pc
+ .long .Ldebug_line0 # DW_AT_stmt_list
+ .uleb128 0x2 # (DIE (0x29) DW_TAG_subprogram)
+ .long .LASF4 # DW_AT_name: "bar_1"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x15 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x46 # DW_AT_type
+ .quad .LFB0 # DW_AT_low_pc
+ .quad .LFE0-.LFB0 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .uleb128 0x3 # (DIE (0x46) DW_TAG_base_type)
+ .byte 0x4 # DW_AT_byte_size
+ .byte 0x5 # DW_AT_encoding
+ .ascii "int\0" # DW_AT_name
+ .uleb128 0x4 # (DIE (0x4d) DW_TAG_subprogram)
+ .ascii "bar\0" # DW_AT_name
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x1b # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x46 # DW_AT_type
+ .quad .LFB1 # DW_AT_low_pc
+ .quad .LFE1-.LFB1 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0x7c # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0x6e) DW_TAG_GNU_call_site)
+ .quad .LVL0 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x29 # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0x4d
+ .uleb128 0x6 # (DIE (0x7c) DW_TAG_subprogram)
+ .long .LASF0 # DW_AT_name: "foo_1"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x21 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x46 # DW_AT_type
+ .quad .LFB2 # DW_AT_low_pc
+ .quad .LFE2-.LFB2 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0xab # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0x9d) DW_TAG_GNU_call_site)
+ .quad .LVL1 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x4d # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0x7c
+ .uleb128 0x4 # (DIE (0xab) DW_TAG_subprogram)
+ .ascii "foo\0" # DW_AT_name
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x27 # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x46 # DW_AT_type
+ .quad .LFB3 # DW_AT_low_pc
+ .quad .LFE3-.LFB3 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .long 0xda # DW_AT_sibling
+ .uleb128 0x5 # (DIE (0xcc) DW_TAG_GNU_call_site)
+ .quad .LVL2 # DW_AT_low_pc
+ # DW_AT_GNU_tail_call
+ .long 0x7c # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0xab
+ .uleb128 0x7 # (DIE (0xda) DW_TAG_subprogram)
+ # DW_AT_external
+ .long .LASF5 # DW_AT_name: "main"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x2d # DW_AT_decl_line
+ # DW_AT_prototyped
+ .long 0x46 # DW_AT_type
+ .quad .LFB4 # DW_AT_low_pc
+ .quad .LFE4-.LFB4 # DW_AT_high_pc
+ .uleb128 0x1 # DW_AT_frame_base
+ .byte 0x9c # DW_OP_call_frame_cfa
+ # DW_AT_GNU_all_call_sites
+ .uleb128 0x8 # (DIE (0xf7) DW_TAG_variable)
+ .long .LASF6 # DW_AT_name: "answer"
+ .byte 0x1 # DW_AT_decl_file (tailcall-only.c)
+ .byte 0x2f # DW_AT_decl_line
+ .long 0x46 # DW_AT_type
+ .long .LLST0 # DW_AT_location
+ .uleb128 0x9 # (DIE (0x106) DW_TAG_GNU_call_site)
+ .quad .LVL3 # DW_AT_low_pc
+ .long 0xab # DW_AT_abstract_origin
+ .byte 0 # end of children of DIE 0xda
+ .byte 0 # end of children of DIE 0xb
+ .section .debug_abbrev,"",@progbits
+.Ldebug_abbrev0:
+ .uleb128 0x1 # (abbrev code)
+ .uleb128 0x11 # (TAG: DW_TAG_compile_unit)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x25 # (DW_AT_producer)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x13 # (DW_AT_language)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x1b # (DW_AT_comp_dir)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x55 # (DW_AT_ranges)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x10 # (DW_AT_stmt_list)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .byte 0
+ .byte 0
+ .uleb128 0x2 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0 # DW_children_no
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .byte 0
+ .byte 0
+ .uleb128 0x3 # (abbrev code)
+ .uleb128 0x24 # (TAG: DW_TAG_base_type)
+ .byte 0 # DW_children_no
+ .uleb128 0xb # (DW_AT_byte_size)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3e # (DW_AT_encoding)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0x8 # (DW_FORM_string)
+ .byte 0
+ .byte 0
+ .uleb128 0x4 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0x8 # (DW_FORM_string)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x1 # (DW_AT_sibling)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x5 # (abbrev code)
+ .uleb128 0x4109 # (TAG: DW_TAG_GNU_call_site)
+ .byte 0 # DW_children_no
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x2115 # (DW_AT_GNU_tail_call)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x31 # (DW_AT_abstract_origin)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x6 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x1 # (DW_AT_sibling)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .uleb128 0x7 # (abbrev code)
+ .uleb128 0x2e # (TAG: DW_TAG_subprogram)
+ .byte 0x1 # DW_children_yes
+ .uleb128 0x3f # (DW_AT_external)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x27 # (DW_AT_prototyped)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x12 # (DW_AT_high_pc)
+ .uleb128 0x7 # (DW_FORM_data8)
+ .uleb128 0x40 # (DW_AT_frame_base)
+ .uleb128 0x18 # (DW_FORM_exprloc)
+ .uleb128 0x2117 # (DW_AT_GNU_all_call_sites)
+ .uleb128 0x19 # (DW_FORM_flag_present)
+ .byte 0
+ .byte 0
+ .uleb128 0x8 # (abbrev code)
+ .uleb128 0x34 # (TAG: DW_TAG_variable)
+ .byte 0 # DW_children_no
+ .uleb128 0x3 # (DW_AT_name)
+ .uleb128 0xe # (DW_FORM_strp)
+ .uleb128 0x3a # (DW_AT_decl_file)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x3b # (DW_AT_decl_line)
+ .uleb128 0xb # (DW_FORM_data1)
+ .uleb128 0x49 # (DW_AT_type)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .uleb128 0x2 # (DW_AT_location)
+ .uleb128 0x17 # (DW_FORM_sec_offset)
+ .byte 0
+ .byte 0
+ .uleb128 0x9 # (abbrev code)
+ .uleb128 0x4109 # (TAG: DW_TAG_GNU_call_site)
+ .byte 0 # DW_children_no
+ .uleb128 0x11 # (DW_AT_low_pc)
+ .uleb128 0x1 # (DW_FORM_addr)
+ .uleb128 0x31 # (DW_AT_abstract_origin)
+ .uleb128 0x13 # (DW_FORM_ref4)
+ .byte 0
+ .byte 0
+ .byte 0
+ .section .debug_loc,"",@progbits
+.Ldebug_loc0:
+.LLST0:
+ .quad .LVL3 # Location list begin address (*.LLST0)
+ .quad .LVL4 # Location list end address (*.LLST0)
+ .value 0x3 # Location expression size
+ .byte 0x70 # DW_OP_breg0
+ .sleb128 1
+ .byte 0x9f # DW_OP_stack_value
+ .quad .LVL4 # Location list begin address (*.LLST0)
+ .quad .LFE4 # Location list end address (*.LLST0)
+ .value 0x1 # Location expression size
+ .byte 0x50 # DW_OP_reg0
+ .quad 0 # Location list terminator begin (*.LLST0)
+ .quad 0 # Location list terminator end (*.LLST0)
+ .section .debug_aranges,"",@progbits
+ .long 0x3c # Length of Address Ranges Info
+ .value 0x2 # DWARF Version
+ .long .Ldebug_info0 # Offset of Compilation Unit Info
+ .byte 0x8 # Size of Address
+ .byte 0 # Size of Segment Descriptor
+ .value 0 # Pad to 16 byte boundary
+ .value 0
+ .quad .Ltext0 # Address
+ .quad .Letext0-.Ltext0 # Length
+ .quad .LFB4 # Address
+ .quad .LFE4-.LFB4 # Length
+ .quad 0
+ .quad 0
+ .section .debug_ranges,"",@progbits
+.Ldebug_ranges0:
+ .quad .Ltext0 # Offset 0
+ .quad .Letext0
+ .quad .LFB4 # Offset 0x10
+ .quad .LFE4
+ .quad 0
+ .quad 0
+ .section .debug_line,"",@progbits
+.Ldebug_line0:
+ .section .debug_str,"MS",@progbits,1
+.LASF4:
+ .string "bar_1"
+.LASF2:
+ .string "tailcall-only.c"
+.LASF1:
+ .string "GNU C 4.8.3 20140911 (Red Hat 4.8.3-9) -mtune=generic -march=x86-64 -g -O2"
+.LASF6:
+ .string "answer"
+.LASF5:
+ .string "main"
+.LASF3:
+ .string ""
+.LASF0:
+ .string "foo_1"
+ .ident "GCC: (GNU) 4.8.3 20140911 (Red Hat 4.8.3-9)"
+ .section .note.GNU-stack,"",@progbits
--
1.8.3.1