fix dwarf2read.c offset-is-in-cu calculation
Doug Evans
dje@google.com
Sat Oct 4 20:55:00 GMT 2008
Some calculations for whether an offset is within a CU don't take into
account initial_length_size.
The error is innocuous because GDB will still lookup the correct CU,
but it didn't have to do the lookup. The error also causes the CU
to be made a dependency of itself which is unnecessary.
This also changes the name of a label in dw2-intercu.S to improve
readability.
Ok to check in?
2008-10-04 Doug Evans <dje@google.com>
* dwarf2read.c (offset_in_cu_p): New function.
(find_partial_die,follow_die_ref): Use it.
* gdb.dwarf2/dw2-cu-size.exp: New file.
* gdb.dwarf2/dw2-cu-size.S: New file.
* gdb.dwarf2/dw2-intercu.S (.Ltype_int_in_cu2): Renamed from
.Ltype_int for clarity.
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.285
diff -u -p -d -u -r1.285 dwarf2read.c
--- dwarf2read.c 30 Sep 2008 16:57:37 -0000 1.285
+++ dwarf2read.c 4 Oct 2008 20:41:13 -0000
@@ -360,7 +360,9 @@ struct dwarf2_per_cu_data
{
/* The start offset and length of this compilation unit. 2**30-1
bytes should suffice to store the length of any compilation unit
- - if it doesn't, GDB will fall over anyway. */
+ - if it doesn't, GDB will fall over anyway.
+ NOTE: Unlike comp_unit_head.length, this length includes
+ initial_length_size. */
unsigned long offset;
unsigned long length : 30;
@@ -1314,6 +1316,18 @@ dwarf2_build_psymtabs_easy (struct objfi
}
#endif
+/* Return TRUE if OFFSET is within CU. */
+
+static inline int
+offset_in_cu_p (const struct comp_unit_head *cu_header, unsigned int offset)
+{
+ unsigned int bottom = cu_header->offset;
+ unsigned int top = (cu_header->offset
+ + cu_header->length
+ + cu_header->initial_length_size);
+ return (offset >= bottom && offset < top);
+}
+
/* Read in the comp unit header information from the debug_info at
info_ptr. */
@@ -5990,8 +6004,7 @@ find_partial_die (unsigned long offset,
struct dwarf2_per_cu_data *per_cu = NULL;
struct partial_die_info *pd = NULL;
- if (offset >= cu->header.offset
- && offset < cu->header.offset + cu->header.length)
+ if (offset_in_cu_p (&cu->header, offset))
{
pd = find_partial_die_in_comp_unit (offset, cu);
if (pd != NULL)
@@ -9230,12 +9243,10 @@ follow_die_ref (struct die_info *src_die
offset = dwarf2_get_ref_die_offset (attr, cu);
- if (DW_ADDR (attr) < cu->header.offset
- || DW_ADDR (attr) >= cu->header.offset + cu->header.length)
+ if (! offset_in_cu_p (&cu->header, offset))
{
struct dwarf2_per_cu_data *per_cu;
- per_cu = dwarf2_find_containing_comp_unit (DW_ADDR (attr),
- cu->objfile);
+ per_cu = dwarf2_find_containing_comp_unit (offset, cu->objfile);
/* If necessary, add it to the queue and load its DIEs. */
maybe_queue_comp_unit (cu, per_cu);
Index: testsuite/gdb.dwarf2/dw2-cu-size.S
===================================================================
RCS file: testsuite/gdb.dwarf2/dw2-cu-size.S
diff -N testsuite/gdb.dwarf2/dw2-cu-size.S
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.dwarf2/dw2-cu-size.S 4 Oct 2008 20:41:13 -0000
@@ -0,0 +1,106 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2008 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/>. */
+
+/* Test inter-cu reference support where the referenced DIE is within
+ initial_length_size bytes of the end of the CU, but GDB doesn't take
+ into account initial_length_size.
+ GDB still gets the correct answer because it goes looking for the
+ correct CU, but the search is unnecessary. */
+
+/* Debug information */
+
+ .section .debug_info
+.Lcu1_begin:
+ /* CU header */
+ .4byte .Lcu1_end - .Lcu1_start /* Length of Compilation Unit */
+.Lcu1_start:
+ .2byte 2 /* DWARF Version */
+ .4byte .Labbrev1_begin /* Offset into abbrev section */
+ .byte 4 /* Pointer size */
+
+ /* CU die */
+ .uleb128 1 /* Abbrev: DW_TAG_compile_unit */
+ .ascii "file1.txt\0" /* DW_AT_name */
+ .ascii "GNU C 3.3.3\0" /* DW_AT_producer */
+ .byte 1 /* DW_AT_language (C) */
+
+ .uleb128 2 /* Abbrev: DW_TAG_variable */
+ .ascii "noloc\0" /* DW_AT_name */
+ .4byte .Ltype_const_int-.Lcu1_begin /* DW_AT_type */
+ .byte 1 /* DW_AT_external */
+
+.Ltype_int:
+ .uleb128 3 /* Abbrev: DW_TAG_base_type */
+ .ascii "int\0" /* DW_AT_name */
+ .byte 4 /* DW_AT_byte_size */
+ .byte 5 /* DW_AT_encoding */
+
+.Ltype_const_int:
+ .uleb128 4 /* Abbrev: DW_TAG_const_type */
+ .uleb128 .Ltype_int - .Lcu1_begin /* DW_AT_type */
+
+ .byte 0 /* End of children of CU */
+
+.Lcu1_end:
+
+/* Abbrev table */
+ .section .debug_abbrev
+.Labbrev1_begin:
+ .uleb128 1 /* Abbrev code */
+ .uleb128 0x11 /* DW_TAG_compile_unit */
+ .byte 1 /* has_children */
+ .uleb128 0x3 /* DW_AT_name */
+ .uleb128 0x8 /* DW_FORM_string */
+ .uleb128 0x25 /* DW_AT_producer */
+ .uleb128 0x8 /* DW_FORM_string */
+ .uleb128 0x13 /* DW_AT_language */
+ .uleb128 0xb /* DW_FORM_data1 */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+
+ .uleb128 2 /* Abbrev code */
+ .uleb128 0x34 /* DW_TAG_variable */
+ .byte 0 /* has_children */
+ .uleb128 0x3 /* DW_AT_name */
+ .uleb128 0x8 /* DW_FORM_string */
+ .uleb128 0x49 /* DW_AT_type */
+ .uleb128 0x13 /* DW_FORM_ref4 */
+ .uleb128 0x3f /* DW_AT_external */
+ .uleb128 0xc /* DW_FORM_flag */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+
+ .uleb128 3 /* Abbrev code */
+ .uleb128 0x24 /* DW_TAG_base_type */
+ .byte 0 /* has_children */
+ .uleb128 0x3 /* DW_AT_name */
+ .uleb128 0x8 /* DW_FORM_string */
+ .uleb128 0xb /* DW_AT_byte_size */
+ .uleb128 0xb /* DW_FORM_data1 */
+ .uleb128 0x3e /* DW_AT_encoding */
+ .uleb128 0xb /* DW_FORM_data1 */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+
+ .uleb128 4 /* Abbrev code */
+ .uleb128 0x26 /* DW_TAG_const_type */
+ .byte 0 /* has_children */
+ .uleb128 0x49 /* DW_AT_type */
+ .uleb128 0x15 /* DW_FORM_ref_udata */
+
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
Index: testsuite/gdb.dwarf2/dw2-cu-size.exp
===================================================================
RCS file: testsuite/gdb.dwarf2/dw2-cu-size.exp
diff -N testsuite/gdb.dwarf2/dw2-cu-size.exp
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.dwarf2/dw2-cu-size.exp 4 Oct 2008 20:41:13 -0000
@@ -0,0 +1,53 @@
+# Copyright 2004, 2005, 2007, 2008 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/>.
+
+# Test inter-cu references where the referenced DIE is within
+# initial_length_size bytes of the end of the CU.
+# This catches cases where the code doesn't include initial_length_size
+# in the length of the CU. */
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+# For now pick a sampling of likely targets.
+if {![istarget *-*-linux*]
+ && ![istarget *-*-gnu*]
+ && ![istarget *-*-elf*]
+ && ![istarget *-*-openbsd*]
+ && ![istarget arm-*-eabi*]
+ && ![istarget powerpc-*-eabi*]} {
+ return 0
+}
+
+set testfile "dw2-cu-size"
+set srcfile ${testfile}.S
+set binfile ${objdir}/${subdir}/${testfile}.x
+
+if { [gdb_compile "${srcdir}/${subdir}/main.c" "main.o" object {debug}] != "" } {
+ return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${testfile}.o" object {nodebug}] != "" } {
+ return -1
+}
+
+if { [gdb_compile "${testfile}.o main.o" "${binfile}" executable {debug}] != "" } {
+ return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+gdb_test "ptype noloc" "type = const int"
Index: testsuite/gdb.dwarf2/dw2-intercu.S
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.dwarf2/dw2-intercu.S,v
retrieving revision 1.5
diff -u -p -d -u -r1.5 dw2-intercu.S
--- testsuite/gdb.dwarf2/dw2-intercu.S 1 Jan 2008 22:53:19 -0000 1.5
+++ testsuite/gdb.dwarf2/dw2-intercu.S 4 Oct 2008 20:41:13 -0000
@@ -58,7 +58,7 @@ func_cu1:
.byte 1 /* DW_AT_decl_file */
.byte 2 /* DW_AT_decl_line */
.ascii "func_cu1\0" /* DW_AT_name */
- .4byte .Ltype_int /* DW_AT_type */
+ .4byte .Ltype_int_in_cu2 /* DW_AT_type */
.4byte .Lbegin_func_cu1 /* DW_AT_low_pc */
.4byte .Lend_func_cu1 /* DW_AT_high_pc */
.byte 1 /* DW_AT_frame_base: length */
@@ -83,7 +83,7 @@ func_cu1:
.ascii "GNU C 3.3.3\0" /* DW_AT_producer */
.byte 1 /* DW_AT_language (C) */
-.Ltype_int:
+.Ltype_int_in_cu2:
.uleb128 2 /* Abbrev: DW_TAG_base_type */
.ascii "int\0" /* DW_AT_name */
.byte 4 /* DW_AT_byte_size */
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