[gdb/testsuite] Fix gdb.arch/amd64-entry-value-paramref.S

The file gdb.arch/amd64-entry-value-paramref.S contains a DIE for function
bar:
...
DIE29:  .uleb128 0x2    # (DIE (0x29) DW_TAG_subprogram)
        .ascii "bar\0"  # DW_AT_name
        .byte   0x1     # DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
        .byte   0x15    # DW_AT_decl_line
        .long   DIE45   # DW_AT_type
        .byte   0x1     # DW_AT_inline
...
which refers to DIE45:
...
DIE45:	.uleb128 0x4	# (DIE (0x45) DW_TAG_base_type)
	.byte	0x4	# DW_AT_byte_size
	.byte	0x5	# DW_AT_encoding
	.ascii "int\0"	# DW_AT_name
...
using a form DW_FORM_ref4:
...
	.uleb128 0x2	# (abbrev code)
	.uleb128 0x2e	# (TAG: DW_TAG_subprogram)
	.byte	0x1	# DW_children_yes
	...
	.uleb128 0x49	# (DW_AT_type)
	.uleb128 0x13	# (DW_FORM_ref4)
...

However, the DW_FORM_ref4 is a CU-relative reference, while using a label for
the value will result in a section-relative value.

So, if linked in object files contain dwarf info and are placed in the
.debug_info section before the compilation units generated from
amd64-entry-value-paramref.S, then the referenced type is at 0x108:
...
 <1><108>: Abbrev Number: 4 (DW_TAG_base_type)
    <109>   DW_AT_byte_size   : 4
    <10a>   DW_AT_encoding    : 5       (signed)
    <10b>   DW_AT_name        : int
...
but the reference will point to a non-existing DIE at 0x1cf:
...
 <1><f0>: Abbrev Number: 2 (DW_TAG_subprogram)
    <f1>   DW_AT_name        : bar
    <f5>   DW_AT_decl_file   : 1
    <f6>   DW_AT_decl_line   : 21
    <f7>   DW_AT_type        : <0x1cf>
    <fb>   DW_AT_inline      : 1        (inlined)
...
which happens to cause a GDB internal error described in PR23270 - "GDB
internal error: dwarf2read.c:18656: internal-error: could not find partial
DIE 0x1b7 in cache".

Fix the invalid DWARF by making the reference value CU-relative:
...
-       .long   DIE45   # DW_AT_type
+       .long   DIE45 - .Ldebug_info0   # DW_AT_type
...

Tested on x86_64-linux.

gdb/testsuite/ChangeLog:

2019-05-09  Tom de Vries  <tdevries@suse.de>

	* gdb.arch/amd64-entry-value-paramref.S: Make DW_FORM_ref4 references
	CU-relative.

2 files changed, 18 insertions, 13 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index a556eb3..47e82c4 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-05-09  Tom de Vries  <tdevries@suse.de>
+
+	* gdb.arch/amd64-entry-value-paramref.S: Make DW_FORM_ref4 references
+	CU-relative.
+
 2019-05-08  Joel Brobecker  <brobecker@adacore.com>
 
 	* gdb.ada/frame_arg_lang.exp: New testcase.
diff --git a/gdb/testsuite/gdb.arch/amd64-entry-value-paramref.S b/gdb/testsuite/gdb.arch/amd64-entry-value-paramref.S
index 7c12d13..2e59aae 100644
--- a/gdb/testsuite/gdb.arch/amd64-entry-value-paramref.S
+++ b/gdb/testsuite/gdb.arch/amd64-entry-value-paramref.S
@@ -121,32 +121,32 @@ DIE29:	.uleb128 0x2	# (DIE (0x29) DW_TAG_subprogram)
 	.ascii "bar\0"	# DW_AT_name
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x15	# DW_AT_decl_line
-	.long	DIE45	# DW_AT_type
+	.long	DIE45 - .Ldebug_info0	# DW_AT_type
 	.byte	0x1	# DW_AT_inline
 DIE39:	.uleb128 0x3	# (DIE (0x39) DW_TAG_formal_parameter)
 	.ascii "ref\0"	# DW_AT_name
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x15	# DW_AT_decl_line
-	.long	DIE4c	# DW_AT_type
+	.long	DIE4c - .Ldebug_info0	# DW_AT_type
 	.byte	0	# end of children of DIE 0x29
 DIE45:	.uleb128 0x4	# (DIE (0x45) DW_TAG_base_type)
 	.byte	0x4	# DW_AT_byte_size
 	.byte	0x5	# DW_AT_encoding
 	.ascii "int\0"	# DW_AT_name
 DIE4c:	.uleb128 0x5	# (DIE (0x4c) DW_TAG_const_type)
-	.long	DIE51	# DW_AT_type
+	.long	DIE51 - .Ldebug_info0	# DW_AT_type
 DIE51:	.uleb128 0x6	# (DIE (0x51) DW_TAG_reference_type)
 	.byte	0x8	# DW_AT_byte_size
-	.long	DIE45	# DW_AT_type
+	.long	DIE45 - .Ldebug_info0	# DW_AT_type
 DIE57:	.uleb128 0x7	# (DIE (0x57) DW_TAG_subprogram)
-	.long	DIE29	# DW_AT_abstract_origin
+	.long	DIE29 - .Ldebug_info0	# DW_AT_abstract_origin
 	.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
 DIE72:	.uleb128 0x8	# (DIE (0x72) DW_TAG_formal_parameter)
-	.long	DIE39	# DW_AT_abstract_origin
+	.long	DIE39 - .Ldebug_info0	# DW_AT_abstract_origin
 	.uleb128 0x1	# DW_AT_location
 	.byte	0x55	# DW_OP_reg5
 	.byte	0	# end of children of DIE 0x57
@@ -155,7 +155,7 @@ DIE7a:	.uleb128 0x9	# (DIE (0x7a) DW_TAG_subprogram)
 	.long	.LASF3	# DW_AT_name: "main"
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x1d	# DW_AT_decl_line
-	.long	DIE45	# DW_AT_type
+	.long	DIE45 - .Ldebug_info0	# DW_AT_type
 	.quad	.LFB1	# DW_AT_low_pc
 	.quad	.LFE1-.LFB1	# DW_AT_high_pc
 	.uleb128 0x1	# DW_AT_frame_base
@@ -168,13 +168,13 @@ DIEac:	.uleb128 0xb	# (DIE (0xac) DW_TAG_variable)
 	.ascii "var\0"	# DW_AT_name
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x1f	# DW_AT_decl_line
-	.long	DIE45	# DW_AT_type
+	.long	DIE45 - .Ldebug_info0	# DW_AT_type
 	.uleb128 0x2	# DW_AT_location
 	.byte	0x91	# DW_OP_fbreg
 	.sleb128 -12
 DIEba:	.uleb128 0xc	# (DIE (0xba) DW_TAG_GNU_call_site)
 	.quad	.LVL1	# DW_AT_low_pc
-	.long	DIE57	# DW_AT_abstract_origin
+	.long	DIE57 - .Ldebug_info0	# DW_AT_abstract_origin
 DIEc7:	.uleb128 0xd	# (DIE (0xc7) DW_TAG_GNU_call_site_parameter)
 	.uleb128 0x1	# DW_AT_location
 	.byte	0x55	# DW_OP_reg5
@@ -200,25 +200,25 @@ DIEd2:	.uleb128 0xe	# (DIE (0xd2) DW_TAG_variable)
 	.ascii "vv\0"	# DW_AT_name
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x12	# DW_AT_decl_line
-	.long	DIEe6	# DW_AT_type
+	.long	DIEe6 - .Ldebug_info0	# DW_AT_type
 			# DW_AT_external
 	.uleb128 0x9	# DW_AT_location
 	.byte	0x3	# DW_OP_addr
 	.quad	vv
 DIEe6:	.uleb128 0xf	# (DIE (0xe6) DW_TAG_volatile_type)
-	.long	DIE45	# DW_AT_type
+	.long	DIE45 - .Ldebug_info0	# DW_AT_type
 DIEeb:	.uleb128 0xe	# (DIE (0xeb) DW_TAG_variable)
 	.ascii "p\0"	# DW_AT_name
 	.byte	0x1	# DW_AT_decl_file (gdb.arch/amd64-entry-value-paramref.cc)
 	.byte	0x12	# DW_AT_decl_line
-	.long	DIEfe	# DW_AT_type
+	.long	DIEfe - .Ldebug_info0	# DW_AT_type
 			# DW_AT_external
 	.uleb128 0x9	# DW_AT_location
 	.byte	0x3	# DW_OP_addr
 	.quad	p
 DIEfe:	.uleb128 0x10	# (DIE (0xfe) DW_TAG_pointer_type)
 	.byte	0x8	# DW_AT_byte_size
-	.long	DIEe6	# DW_AT_type
+	.long	DIEe6 - .Ldebug_info0	# DW_AT_type
 	.byte	0	# end of children of DIE 0xb
 .Linfo_end:
 	.section	.debug_abbrev,"",@progbits