PR symtab/18392

Initially there is some chain (let's say the longest one
but that doe snot matter).  Consequently its elements from the middle are
being removed and there remains only some few unambiguous top and bottom ones.

The original idea why the comparison should be sharp ("<") was that if there
are multiple chains like (0xaddr show jmp instruction address):
        main(0x100) -> a(0x200) -> d(0x400)
        main(0x100) -> a(0x200) -> c(0x300) -> d(0x400)
then - such situation cannot exist - if two jmp instructions in "a" have the
same address they must also jump to the same address (*).

(*) jump to a computed address would be never considered for the DWARF
    tail-call records.

So there could be:
        main(0x100) -> a(0x200) -> d(0x400)
        main(0x100) -> a(0x270) -> c(0x300) -> d(0x400)
But then "a" frame itself is ambiguous and it must not be displayed.

I did not realize that there can be self-tail-call:
        main(0x100) -> a(0x200) -> d(0x400)
        main(0x100) -> a(0x280) -> a(0x200) -> d(0x400)
which intersects to:
        main(0x100) -> <???>? -> a(0x200) -> d(0x400)
And so if the first chain was chosen the
        main(0x100) -> a(0x200) -> d(0x400)
then the final intersection has callers+callees==length.

> for example, if CALLERS is 3 and
> CALLEES is 2, what does the chain look like?

main(0x100) -> x(0x150) -> y(0x200) -> <???>? -> a(0x200) -> d(0x400)

And if LENGTH is 7 then:
        call_site[0] = main(0x100)
        call_site[1] = x(0x150)
        call_site[2] = y(0x200)
        call_site[3] = garbage
        call_site[4] = garbage
        call_site[5] = a(0x200)
        call_site[6] = d(0x400)

gdb/ChangeLog
2015-06-01  Andreas Schwab  <schwab@linux-m68k.org>
	    Jan Kratochvil  <jan.kratochvil@redhat.com>

	PR symtab/18392
	* dwarf2-frame-tailcall.c (pretended_chain_levels): Correct
	assertion.
	* dwarf2loc.c (chain_candidate): Likewise.

gdb/testsuite/ChangeLog
2015-06-01  Jan Kratochvil  <jan.kratochvil@redhat.com>

	PR symtab/18392
	* gdb.arch/amd64-tailcall-self.S: New file.
	* gdb.arch/amd64-tailcall-self.c: New file.
	* gdb.arch/amd64-tailcall-self.exp: New file.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0cfbd0d587b2c539a930779bb07b484c1f89bd88..5867465b196bcb548da4add94a18621531d54861 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,11 @@
+2015-06-01  Andreas Schwab  <schwab@linux-m68k.org>
+           Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+       PR symtab/18392
+       * dwarf2-frame-tailcall.c (pretended_chain_levels): Correct
+       assertion.
+       * dwarf2loc.c (chain_candidate): Likewise.
+
 2015-06-01  Yao Qi  <yao.qi@linaro.org>
 
        * arm-linux-nat.c (fetch_vfp_regs): Use PTRACE_GETREGSET.

diff --git a/gdb/dwarf2-frame-tailcall.c b/gdb/dwarf2-frame-tailcall.c
index b412a5b84b3e781596bb254a1322f78874230527..f964ab263d5966df409341afdcb82ff735e6f641 100644 (file)
--- a/gdb/dwarf2-frame-tailcall.c
+++ b/gdb/dwarf2-frame-tailcall.c
@@ -197,7 +197,7 @@ pretended_chain_levels (struct call_site_chain *chain)
     return chain->length;
 
   chain_levels = chain->callers + chain->callees;
-  gdb_assert (chain_levels < chain->length);
+  gdb_assert (chain_levels <= chain->length);
 
   return chain_levels;
 }

diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c
index 3aa8ddd5b8276a66e12e0958496b63356101767c..c75767ee09cb20edc6925f139294f702ae73de69 100644 (file)
--- a/gdb/dwarf2loc.c
+++ b/gdb/dwarf2loc.c
@@ -825,9 +825,8 @@ chain_candidate (struct gdbarch *gdbarch, struct call_site_chain **resultp,
 
   /* See call_site_find_chain_1 why there is no way to reach the bottom callee
      PC again.  In such case there must be two different code paths to reach
-     it, therefore some of the former determined intermediate PCs must differ
-     and the unambiguous chain gets shortened.  */
-  gdb_assert (result->callers + result->callees < result->length);
+     it.  CALLERS + CALLEES equal to LENGTH in the case of self tail-call.  */
+  gdb_assert (result->callers + result->callees <= result->length);
 }
 
 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC.  All the

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b08b59ddcb9d4c27c09aad6361fb41e8a6273869..5477f6c019c4cde72be8be9e08779ccf72712d32 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2015-06-01  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+       PR symtab/18392
+       * gdb.arch/amd64-tailcall-self.S: New file.
+       * gdb.arch/amd64-tailcall-self.c: New file.
+       * gdb.arch/amd64-tailcall-self.exp: New file.
+
 2015-05-28  Don Breazeal  <donb@codesourcery.com>
 
        * gdb.base/foll-vfork.exp (main): Disable exec-dependent

diff --git a/gdb/testsuite/gdb.arch/amd64-tailcall-self.S b/gdb/testsuite/gdb.arch/amd64-tailcall-self.S
new file mode 100644 (file)
index 0000000..b1ca7c8
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-tailcall-self.S
@@ -0,0 +1,614 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2015 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 source file was generated by:
+   gcc -o gdb.arch/amd64-tailcall-self.S -S gdb.arch/amd64-tailcall-self.c -Wall -g -dA -Os
+   */
+
+       .file   "amd64-tailcall-self.c"
+       .text
+.Ltext0:
+       .section        .text.unlikely,"ax",@progbits
+.LCOLDB0:
+       .text
+.LHOTB0:
+       .section        .text.unlikely
+.Ltext_cold0:
+       .text
+       .type   b, @function
+b:
+.LFB0:
+       .file 1 "amd64-tailcall-self.c"
+       # amd64-tailcall-self.c:1
+       .loc 1 1 0
+       .cfi_startproc
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%]  (FALLTHRU)
+       # amd64-tailcall-self.c:2
+       .loc 1 2 0
+# SUCC: EXIT [100.0%] 
+       ret
+       .cfi_endproc
+.LFE0:
+       .size   b, .-b
+       .section        .text.unlikely
+.LCOLDE0:
+       .text
+.LHOTE0:
+       .section        .text.unlikely
+.LCOLDB1:
+       .text
+.LHOTB1:
+       .globl  c
+       .type   c, @function
+c:
+.LFB1:
+       # amd64-tailcall-self.c:7
+       .loc 1 7 0
+       .cfi_startproc
+.LVL0:
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%]  (FALLTHRU)
+       # amd64-tailcall-self.c:8
+       .loc 1 8 0
+       leal    1(%rdi), %eax
+# SUCC: EXIT [100.0%] 
+       # amd64-tailcall-self.c:9
+       .loc 1 9 0
+       ret
+       .cfi_endproc
+.LFE1:
+       .size   c, .-c
+       .section        .text.unlikely
+.LCOLDE1:
+       .text
+.LHOTE1:
+       .section        .text.unlikely
+.LCOLDB2:
+       .text
+.LHOTB2:
+       .globl  a
+       .type   a, @function
+a:
+.LFB2:
+       # amd64-tailcall-self.c:11
+       .loc 1 11 0
+       .cfi_startproc
+.LVL1:
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%]  (FALLTHRU) 3 [100.0%]  (DFS_BACK,CAN_FALLTHRU)
+.L5:
+       # amd64-tailcall-self.c:12
+       .loc 1 12 0
+#APP
+# 12 "amd64-tailcall-self.c" 1
+       nop;nop;nop
+# 0 "" 2
+       # amd64-tailcall-self.c:13
+       .loc 1 13 0
+#NO_APP
+       movl    i(%rip), %edi
+       leal    -1(%rdi), %eax
+       cmpl    $9, %eax
+# SUCC: 3 [91.0%]  (FALLTHRU,CAN_FALLTHRU) 4 [9.0%]  (CAN_FALLTHRU,LOOP_EXIT)
+       ja      .L4
+# BLOCK 3 freq:9100 seq:1
+# PRED: 2 [91.0%]  (FALLTHRU,CAN_FALLTHRU)
+       # amd64-tailcall-self.c:14
+       .loc 1 14 0
+       orl     $1, %edi
+       movl    %edi, i(%rip)
+# SUCC: 2 [100.0%]  (DFS_BACK,CAN_FALLTHRU)
+       jmp     .L5
+.Lfirsttailcall:
+# BLOCK 4 freq:900 seq:2
+# PRED: 2 [9.0%]  (CAN_FALLTHRU,LOOP_EXIT)
+.L4:
+       # amd64-tailcall-self.c:16
+       .loc 1 16 0
+       cmpl    $0, %edi
+# SUCC: 5 [19.9%]  (FALLTHRU,CAN_FALLTHRU) 6 [80.1%]  (CAN_FALLTHRU)
+       jne     .L3
+# BLOCK 5 freq:179 seq:3
+# PRED: 4 [19.9%]  (FALLTHRU,CAN_FALLTHRU)
+# SUCC: EXIT [100.0%]  (ABNORMAL,SIBCALL)
+       # amd64-tailcall-self.c:17
+       .loc 1 17 0
+       jmp     b
+.LVL2:
+# BLOCK 6 freq:721 seq:4
+# PRED: 4 [80.1%]  (CAN_FALLTHRU)
+.L3:
+# SUCC: EXIT [100.0%] 
+       ret
+       .cfi_endproc
+.LFE2:
+       .size   a, .-a
+       .section        .text.unlikely
+.LCOLDE2:
+       .text
+.LHOTE2:
+       .section        .text.unlikely
+.LCOLDB3:
+       .section        .text.startup,"ax",@progbits
+.LHOTB3:
+       .globl  main
+       .type   main, @function
+main:
+.LFB3:
+       # amd64-tailcall-self.c:20
+       .loc 1 20 0
+       .cfi_startproc
+.LVL3:
+# BLOCK 2 freq:10000 seq:0
+# PRED: ENTRY [100.0%]  (FALLTHRU)
+       # amd64-tailcall-self.c:21
+       .loc 1 21 0
+       call    a
+.LVL4:
+       # amd64-tailcall-self.c:23
+       .loc 1 23 0
+       xorl    %eax, %eax
+# SUCC: EXIT [100.0%] 
+       ret
+       .cfi_endproc
+.LFE3:
+       .size   main, .-main
+       .section        .text.unlikely
+.LCOLDE3:
+       .section        .text.startup
+.LHOTE3:
+       .comm   i,4,4
+       .text
+.Letext0:
+       .section        .text.unlikely
+.Letext_cold0:
+       .section        .debug_info,"",@progbits
+.Ldebug_info0:
+       .long   2f-1f   # Length of Compilation Unit Info
+1:
+       .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   .LASF4  # DW_AT_producer: "GNU C 4.9.2 20150212 (Red Hat 4.9.2-6) -mtune=generic -march=x86-64 -g -Os"
+       .byte   0x1     # DW_AT_language
+       .long   .LASF5  # DW_AT_name: "amd64-tailcall-self.c"
+       .long   .LASF6  # DW_AT_comp_dir: "/home/jkratoch/t"
+       .long   .Ldebug_ranges0+0       # DW_AT_ranges
+       .quad   0       # DW_AT_low_pc
+       .long   .Ldebug_line0   # DW_AT_stmt_list
+die29:
+       .uleb128 0x2    # (DIE (0x29) DW_TAG_subprogram)
+       .ascii "b\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x1     # DW_AT_decl_line
+                       # DW_AT_prototyped
+       .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 (0x40) DW_TAG_subprogram)
+                       # DW_AT_external
+       .ascii "c\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x7     # DW_AT_decl_line
+                       # DW_AT_prototyped
+       .long   die6b   # 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
+       .uleb128 0x4    # (DIE (0x5f) DW_TAG_formal_parameter)
+       .ascii "q\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x7     # DW_AT_decl_line
+       .long   die6b   # DW_AT_type
+       .uleb128 0x1    # DW_AT_location
+       .byte   0x55    # DW_OP_reg5
+       .byte   0       # end of children of DIE 0x40
+die6b:
+       .uleb128 0x5    # (DIE (0x6b) DW_TAG_base_type)
+       .byte   0x4     # DW_AT_byte_size
+       .byte   0x5     # DW_AT_encoding
+       .ascii "int\0"  # DW_AT_name
+die72:
+       .uleb128 0x6    # (DIE (0x72) DW_TAG_subprogram)
+                       # DW_AT_external
+       .ascii "a\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0xb     # DW_AT_decl_line
+                       # DW_AT_prototyped
+       .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
+       .uleb128 0x4    # (DIE (0x8d) DW_TAG_formal_parameter)
+       .ascii "q\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0xb     # DW_AT_decl_line
+       .long   die6b   # DW_AT_type
+       .uleb128 0x4    # DW_AT_location
+       .byte   0xf3    # DW_OP_GNU_entry_value
+       .uleb128 0x1
+       .byte   0x55    # DW_OP_reg5
+       .byte   0x9f    # DW_OP_stack_value
+       .uleb128 0x7    # (DIE () DW_TAG_GNU_call_site)
+       .quad   .Lfirsttailcall # DW_AT_low_pc
+                       # DW_AT_GNU_tail_call
+       .long   die72   # DW_AT_abstract_origin
+       .uleb128 0x7    # (DIE (0x9b) DW_TAG_GNU_call_site)
+       .quad   .LVL2   # DW_AT_low_pc
+                       # DW_AT_GNU_tail_call
+       .long   die29   # DW_AT_abstract_origin
+       .byte   0       # end of children of DIE 0x72
+       .uleb128 0x8    # (DIE (0xa9) DW_TAG_subprogram)
+                       # DW_AT_external
+       .long   .LASF0  # DW_AT_name: "main"
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x14    # DW_AT_decl_line
+                       # DW_AT_prototyped
+       .long   die6b   # 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
+       .uleb128 0x9    # (DIE (0xca) DW_TAG_formal_parameter)
+       .long   .LASF1  # DW_AT_name: "argc"
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x14    # DW_AT_decl_line
+       .long   die6b   # DW_AT_type
+       .long   .LLST0  # DW_AT_location
+       .uleb128 0x9    # (DIE (0xd9) DW_TAG_formal_parameter)
+       .long   .LASF2  # DW_AT_name: "argv"
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x14    # DW_AT_decl_line
+       .long   diefe   # DW_AT_type
+       .long   .LLST1  # DW_AT_location
+       .uleb128 0xa    # (DIE (0xe8) DW_TAG_GNU_call_site)
+       .quad   .LVL4   # DW_AT_low_pc
+       .long   die72   # DW_AT_abstract_origin
+       .uleb128 0xb    # (DIE (0xf5) DW_TAG_GNU_call_site_parameter)
+       .uleb128 0x1    # DW_AT_location
+       .byte   0x55    # DW_OP_reg5
+       .uleb128 0x3    # DW_AT_GNU_call_site_value
+       .byte   0xf3    # DW_OP_GNU_entry_value
+       .uleb128 0x1
+       .byte   0x55    # DW_OP_reg5
+       .byte   0       # end of children of DIE 0xe8
+       .byte   0       # end of children of DIE 0xa9
+diefe:
+       .uleb128 0xc    # (DIE (0xfe) DW_TAG_pointer_type)
+       .byte   0x8     # DW_AT_byte_size
+       .long   die104  # DW_AT_type
+die104:
+       .uleb128 0xc    # (DIE (0x104) DW_TAG_pointer_type)
+       .byte   0x8     # DW_AT_byte_size
+       .long   die10a  # DW_AT_type
+die10a:
+       .uleb128 0xd    # (DIE (0x10a) DW_TAG_base_type)
+       .byte   0x1     # DW_AT_byte_size
+       .byte   0x6     # DW_AT_encoding
+       .long   .LASF3  # DW_AT_name: "char"
+       .uleb128 0xe    # (DIE (0x111) DW_TAG_variable)
+       .ascii "i\0"    # DW_AT_name
+       .byte   0x1     # DW_AT_decl_file (amd64-tailcall-self.c)
+       .byte   0x5     # DW_AT_decl_line
+       .long   die6b   # DW_AT_type
+                       # DW_AT_external
+       .uleb128 0x9    # DW_AT_location
+       .byte   0x3     # DW_OP_addr
+       .quad   i
+       .byte   0       # end of children of DIE 0xb
+2:
+       .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 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 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 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 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)
+       .byte   0
+       .byte   0
+       .uleb128 0x4    # (abbrev code)
+       .uleb128 0x5    # (TAG: DW_TAG_formal_parameter)
+       .byte   0       # DW_children_no
+       .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 0x49   # (DW_AT_type)
+       .uleb128 0x13   # (DW_FORM_ref4)
+       .uleb128 0x2    # (DW_AT_location)
+       .uleb128 0x18   # (DW_FORM_exprloc)
+       .byte   0
+       .byte   0
+       .uleb128 0x5    # (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 0x6    # (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 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 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 0x7    # (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 0x8    # (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 0x9    # (abbrev code)
+       .uleb128 0x5    # (TAG: DW_TAG_formal_parameter)
+       .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 0xa    # (abbrev code)
+       .uleb128 0x4109 # (TAG: DW_TAG_GNU_call_site)
+       .byte   0x1     # DW_children_yes
+       .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
+       .uleb128 0xb    # (abbrev code)
+       .uleb128 0x410a # (TAG: DW_TAG_GNU_call_site_parameter)
+       .byte   0       # DW_children_no
+       .uleb128 0x2    # (DW_AT_location)
+       .uleb128 0x18   # (DW_FORM_exprloc)
+       .uleb128 0x2111 # (DW_AT_GNU_call_site_value)
+       .uleb128 0x18   # (DW_FORM_exprloc)
+       .byte   0
+       .byte   0
+       .uleb128 0xc    # (abbrev code)
+       .uleb128 0xf    # (TAG: DW_TAG_pointer_type)
+       .byte   0       # DW_children_no
+       .uleb128 0xb    # (DW_AT_byte_size)
+       .uleb128 0xb    # (DW_FORM_data1)
+       .uleb128 0x49   # (DW_AT_type)
+       .uleb128 0x13   # (DW_FORM_ref4)
+       .byte   0
+       .byte   0
+       .uleb128 0xd    # (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 0xe    # (DW_FORM_strp)
+       .byte   0
+       .byte   0
+       .uleb128 0xe    # (abbrev code)
+       .uleb128 0x34   # (TAG: DW_TAG_variable)
+       .byte   0       # DW_children_no
+       .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 0x49   # (DW_AT_type)
+       .uleb128 0x13   # (DW_FORM_ref4)
+       .uleb128 0x3f   # (DW_AT_external)
+       .uleb128 0x19   # (DW_FORM_flag_present)
+       .uleb128 0x2    # (DW_AT_location)
+       .uleb128 0x18   # (DW_FORM_exprloc)
+       .byte   0
+       .byte   0
+       .byte   0
+       .section        .debug_loc,"",@progbits
+.Ldebug_loc0:
+.LLST0:
+       .quad   .LVL3   # Location list begin address (*.LLST0)
+       .quad   .LVL4-1 # Location list end address (*.LLST0)
+       .value  0x1     # Location expression size
+       .byte   0x55    # DW_OP_reg5
+       .quad   .LVL4-1 # Location list begin address (*.LLST0)
+       .quad   .LFE3   # Location list end address (*.LLST0)
+       .value  0x4     # Location expression size
+       .byte   0xf3    # DW_OP_GNU_entry_value
+       .uleb128 0x1
+       .byte   0x55    # DW_OP_reg5
+       .byte   0x9f    # DW_OP_stack_value
+       .quad   0       # Location list terminator begin (*.LLST0)
+       .quad   0       # Location list terminator end (*.LLST0)
+.LLST1:
+       .quad   .LVL3   # Location list begin address (*.LLST1)
+       .quad   .LVL4-1 # Location list end address (*.LLST1)
+       .value  0x1     # Location expression size
+       .byte   0x54    # DW_OP_reg4
+       .quad   .LVL4-1 # Location list begin address (*.LLST1)
+       .quad   .LFE3   # Location list end address (*.LLST1)
+       .value  0x4     # Location expression size
+       .byte   0xf3    # DW_OP_GNU_entry_value
+       .uleb128 0x1
+       .byte   0x54    # DW_OP_reg4
+       .byte   0x9f    # DW_OP_stack_value
+       .quad   0       # Location list terminator begin (*.LLST1)
+       .quad   0       # Location list terminator end (*.LLST1)
+       .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   .LFB3   # Address
+       .quad   .LFE3-.LFB3     # Length
+       .quad   0
+       .quad   0
+       .section        .debug_ranges,"",@progbits
+.Ldebug_ranges0:
+       .quad   .Ltext0 # Offset 0
+       .quad   .Letext0
+       .quad   .LFB3   # Offset 0x10
+       .quad   .LFE3
+       .quad   0
+       .quad   0
+       .section        .debug_line,"",@progbits
+.Ldebug_line0:
+       .section        .debug_str,"MS",@progbits,1
+.LASF1:
+       .string "argc"
+.LASF0:
+       .string "main"
+.LASF4:
+       .string "GNU C 4.9.2 20150212 (Red Hat 4.9.2-6) -mtune=generic -march=x86-64 -g -Os"
+.LASF5:
+       .string "amd64-tailcall-self.c"
+.LASF6:
+       .string ""
+.LASF3:
+       .string "char"
+.LASF2:
+       .string "argv"
+       .ident  "GCC: (GNU) 4.9.2 20150212 (Red Hat 4.9.2-6)"

diff --git a/gdb/testsuite/gdb.arch/amd64-tailcall-self.c b/gdb/testsuite/gdb.arch/amd64-tailcall-self.c
new file mode 100644 (file)
index 0000000..0b40dcb
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-tailcall-self.c
@@ -0,0 +1,40 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2015 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/>.  */
+
+__attribute__((noinline,noclone)) static void b(void) {
+  asm volatile("");
+}
+
+int i;
+
+__attribute__((noinline,noclone)) int c(int q) {
+  return q+1;
+}
+
+__attribute__((noinline,noclone)) void a(int q) {
+  asm volatile("nop;nop;nop"::"g"(q):"memory");
+  if (i>=1&&i<=10) {
+    i|=1;
+    a(i);
+  } else if (i==0)
+    b();
+}
+
+int main(int argc,char **argv) {
+  a(argc);
+  return 0;
+}

diff --git a/gdb/testsuite/gdb.arch/amd64-tailcall-self.exp b/gdb/testsuite/gdb.arch/amd64-tailcall-self.exp
new file mode 100644 (file)
index 0000000..0803ff2
--- /dev/null
+++ b/gdb/testsuite/gdb.arch/amd64-tailcall-self.exp
@@ -0,0 +1,31 @@
+# Copyright (C) 2015 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/>.
+
+standard_testfile .S
+
+if { ![istarget x86_64-*-* ] || ![is_lp64_target] } {
+    verbose "Skipping ${testfile}."
+    return
+}
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {}] } {
+    return -1
+}
+
+if ![runto b] {
+    return -1
+}
+
+gdb_test "bt" "#0 +b \\(\\) at \[^\r\n\]*\r\n#1 +0x\[0-9a-f\]+ in a \\(q=<optimized out>\\) at \[^\r\n\]*\r\n#2 +0x\[0-9a-f\]+ in main \\(\[^\r\n\]*\\) at .*"