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From: Tom Tromey <tromey@sourceware.org>
To: gdb-cvs@sourceware.org
Subject: [binutils-gdb] Fix corrupt DWARF in dw2-double-set-die-type
Date: Sat, 25 Jun 2022 17:12:23 +0000 (GMT)	[thread overview]
Message-ID: <20220625171224.02FB438387BB@sourceware.org> (raw)

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1fa2e2287e8bcac6427f2495049e0ccfb3ee8514

commit 1fa2e2287e8bcac6427f2495049e0ccfb3ee8514
Author: Tom Tromey <tom@tromey.com>
Date:   Thu Jun 9 07:19:13 2022 -0600

    Fix corrupt DWARF in dw2-double-set-die-type
    
    The dw2-double-set-die-type.exp test case caused an AddressSanitizer
    failure in the new DWARF scanner.
    
    The immediate cause was bad DWARF in the test -- in particular, the
    the sibling attribute here:
    
         <2><181>: Abbrev Number: 33 (DW_TAG_subprogram)
            <182>   DW_AT_external    : 1
            <183>   DW_AT_name        : address
            <18b>   DW_AT_type        : <0x171>
            <18f>   DW_AT_declaration : 1
            <190>   DW_AT_sibling     : <0x1a1>
        ...
         <1><1a1>: Abbrev Number: 23 (DW_TAG_pointer_type)
            <1a2>   DW_AT_byte_size   : 4
            <1a3>   DW_AT_type        : <0x1a7>
    
    ...points to a "sibling" DIE that is at a different child depth.
    
    Because this test case doesn't really require sibling attributes, this
    patch fixes the problem by removing them from the test.
    
    Note that gdb is not generally robust against malformed DWARF.
    Detecting and compensating for this problem would probably be
    expensive and, IMO, is better left to some (still hypothetical) DWARF
    linter.

Diff:
---
 gdb/testsuite/gdb.dwarf2/dw2-double-set-die-type.S | 31 ----------------------
 1 file changed, 31 deletions(-)

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-double-set-die-type.S b/gdb/testsuite/gdb.dwarf2/dw2-double-set-die-type.S
index 6f0a0a80346..ab5a2f712aa 100644
--- a/gdb/testsuite/gdb.dwarf2/dw2-double-set-die-type.S
+++ b/gdb/testsuite/gdb.dwarf2/dw2-double-set-die-type.S
@@ -65,7 +65,6 @@
 .Ldie_4a:
 	.uleb128 0x4	/* (DIE (0x4a) DW_TAG_namespace) */
 	.ascii "std\0"	/* DW_AT_name */
-	.4byte	OFFSET (143)	/* DW_AT_sibling */
 
 .Ldie_70:
 	.uleb128 0x8	/* (DIE (0x70) DW_TAG_class_type) */
@@ -76,7 +75,6 @@
 	.uleb128 0x9	/* (DIE (0x76) DW_TAG_structure_type) */
 	.ascii	"_Vector_base<a::b, std::allocator<a::b> >\0"	/* DW_AT_name */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (f7)	/* DW_AT_sibling */
 
 .Ldie_80:
 	.uleb128 0xa	/* (DIE (0x80) DW_TAG_structure_type) */
@@ -131,13 +129,11 @@
 	.uleb128 0x1b	/* (DIE (0x221) DW_TAG_class_type) */
 	.ascii "a\0"	/* DW_AT_name */
 	.byte	0x18	/* DW_AT_byte_size */
-	.4byte	OFFSET (277)	/* DW_AT_sibling */
 
 .Ldie_22b:
 	.uleb128 0x1b	/* (DIE (0x22b) DW_TAG_class_type) */
 	.ascii "b\0"	/* DW_AT_name */
 	.byte	0x1	/* DW_AT_byte_size */
-	.4byte	OFFSET (244)	/* DW_AT_sibling */
 
 .Ldie_235:
 	.uleb128 0x1c	/* (DIE (0x235) DW_TAG_subprogram) */
@@ -165,7 +161,6 @@
 	.ascii "a\0"	/* DW_AT_name */
 	.byte	0x1	/* DW_AT_artificial */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (262)	/* DW_AT_sibling */
 
 .Ldie_25b:
 	.uleb128 0xe	/* (DIE (0x25b) DW_TAG_formal_parameter) */
@@ -201,7 +196,6 @@
 	.uleb128 0x20	/* (DIE (0x27d) DW_TAG_class_type) */
 	.4byte	OFFSET (162)	/* DW_AT_specification */
 	.byte	0x1	/* DW_AT_byte_size */
-	.4byte	OFFSET (3b2)	/* DW_AT_sibling */
 
 .Ldie_2d0:
 	.uleb128 0x21	/* (DIE (0x2d0) DW_TAG_subprogram) */
@@ -209,7 +203,6 @@
 	.ascii	"address\0"	/* DW_AT_name */
 	.4byte	OFFSET (277)	/* DW_AT_type */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (3b2)	/* DW_AT_sibling */
 
 .Ldie_2e5:
 	.uleb128 0xe	/* (DIE (0x2e5) DW_TAG_formal_parameter) */
@@ -249,7 +242,6 @@
 	.uleb128 0x20	/* (DIE (0x3e0) DW_TAG_class_type) */
 	.4byte	OFFSET (70)	/* DW_AT_specification */
 	.byte	0x1	/* DW_AT_byte_size */
-	.4byte	OFFSET (44e)	/* DW_AT_sibling */
 
 .Ldie_3ec:
 	.uleb128 0xb	/* (DIE (0x3ec) DW_TAG_inheritance) */
@@ -262,13 +254,11 @@
 	.uleb128 0x1a	/* (DIE (0x44e) DW_TAG_structure_type) */
 	.4byte	OFFSET (76)	/* DW_AT_specification */
 	.byte	0x18	/* DW_AT_byte_size */
-	.4byte	OFFSET (505)	/* DW_AT_sibling */
 
 .Ldie_505:
 	.uleb128 0x11	/* (DIE (0x505) DW_TAG_subprogram) */
 	.ascii	"~_Vector_base\0"	/* DW_AT_name */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (51f)	/* DW_AT_sibling */
 
 .Ldie_512:
 	.uleb128 0xe	/* (DIE (0x512) DW_TAG_formal_parameter) */
@@ -286,13 +276,11 @@
 	.ascii	"_M_allocate\0"	/* DW_AT_name */
 	.4byte	OFFSET (277)	/* DW_AT_type */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (540)	/* DW_AT_sibling */
 
 .Ldie_540:
 	.uleb128 0x11	/* (DIE (0x540) DW_TAG_subprogram) */
 	.ascii	"_M_deallocate\0"	/* DW_AT_name */
 	.byte	0x1	/* DW_AT_declaration */
-	.4byte	OFFSET (562)	/* DW_AT_sibling */
 
 .Ldie_551:
 	.uleb128 0xe	/* (DIE (0x551) DW_TAG_formal_parameter) */
@@ -327,7 +315,6 @@
 	.uleb128 0x20	/* (DIE (0x59d) DW_TAG_class_type) */
 	.4byte	OFFSET (f7)	/* DW_AT_specification */
 	.byte	0x18	/* DW_AT_byte_size */
-	.4byte	OFFSET (b44)	/* DW_AT_sibling */
 
 .Ldie_5a9:
 	.uleb128 0xb	/* (DIE (0x5a9) DW_TAG_inheritance) */
@@ -390,8 +377,6 @@
 	.byte	0x1	/* DW_children_yes */
 	.uleb128 0x3	/* (DW_AT_name) */
 	.uleb128 0x8	/* (DW_FORM_string) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -420,8 +405,6 @@
 	.uleb128 0x8	/* (DW_FORM_string) */
 	.uleb128 0x3c	/* (DW_AT_declaration) */
 	.uleb128 0xc	/* (DW_FORM_flag) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -472,8 +455,6 @@
 	.uleb128 0x8	/* (DW_FORM_string) */
 	.uleb128 0x3c	/* (DW_AT_declaration) */
 	.uleb128 0xc	/* (DW_FORM_flag) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -518,8 +499,6 @@
 	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.uleb128 0xb	/* (DW_AT_byte_size) */
 	.uleb128 0xb	/* (DW_FORM_data1) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -530,8 +509,6 @@
 	.uleb128 0x8	/* (DW_FORM_string) */
 	.uleb128 0xb	/* (DW_AT_byte_size) */
 	.uleb128 0xb	/* (DW_FORM_data1) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -572,8 +549,6 @@
 	.uleb128 0xc	/* (DW_FORM_flag) */
 	.uleb128 0x3c	/* (DW_AT_declaration) */
 	.uleb128 0xc	/* (DW_FORM_flag) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -598,8 +573,6 @@
 	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.uleb128 0xb	/* (DW_AT_byte_size) */
 	.uleb128 0xb	/* (DW_FORM_data1) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -614,8 +587,6 @@
 	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.uleb128 0x3c	/* (DW_AT_declaration) */
 	.uleb128 0xc	/* (DW_FORM_flag) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0
 
@@ -640,8 +611,6 @@
 	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.uleb128 0x3c	/* (DW_AT_declaration) */
 	.uleb128 0xc	/* (DW_FORM_flag) */
-	.uleb128 0x1	/* (DW_AT_sibling) */
-	.uleb128 0x13	/* (DW_FORM_ref4) */
 	.byte	0x0
 	.byte	0x0


                 reply	other threads:[~2022-06-25 17:12 UTC|newest]

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