* [patch] Deal with full path in .file 0 directive
@ 2021-11-06 11:55 Eric Botcazou
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From: Eric Botcazou @ 2021-11-06 11:55 UTC (permalink / raw)
To: binutils
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Hi,
after https://sourceware.org/pipermail/binutils/2021-September/117880.html,
Gas uses the directory part, if present, of the .file 0 directive to set entry
0 of the directory table in DWARF 5, which represents the "current directory".
Now Gas also uses the file part of the same directive to set entry 0 of the
file table, which represents the "current compilation file". But the latter
need not be located in the former so GCC will use a full path in the file part
when it is passed a full path:
gcc -c /full/path/test.c -save-temps
yields:
.file 0 "/current/directory" "/full/path/test.c"
in the assembly file and:
The Directory Table (offset 0x22, lines 2, columns 1):
Entry Name
0 (indirect line string, offset: 0x25): /current/directory
1 (indirect line string, offset: 0x38): /full/path
The File Name Table (offset 0x30, lines 2, columns 2):
Entry Dir Name
0 0 (indirect line string, offset: 0x43): /full/path/test.c
in the object file. Note the full path and the questionable Dir value in the
0 entry of the file table.
The proposed change is to deal with a full path in the file part of the .file
0 directive, so as to yield:
The Directory Table (offset 0x22, lines 2, columns 1):
Entry Name
0 (indirect line string, offset: 0x25): /current/directory
1 (indirect line string, offset: 0x38): /full/path
The File Name Table (offset 0x30, lines 2, columns 2):
Entry Dir Name
0 1 (indirect line string, offset: 0x43): test.c
in the object file instead. Tested on x86-64/Linux, OK for the trunk?
2021-11-06 Eric Botcazou <ebotcazou@adacore.com>
gas/
* doc/as.texi (File): Update description of .file 0 directive.
* dwarf2dbg.c (get_directory_table_entry): Remove obsolete comment
and pass file0_dirname in recursive call.
(allocate_filename_to_slot): Deal with a full path in the file name
if the index number is 0.
* testsuite/gas/elf/dwarf-5-file0.d: Fix pasto.
* testsuite/gas/elf/dwarf-5-file0-2.d: Likewise.
* testsuite/gas/elf/dwarf-5-file0-3.d: New file.
* testsuite/gas/elf/dwarf-5-file0-3.s: Likewise.
* testsuite/gas/elf/elf.exp: Run dwarf-5-file0-3.
--
Eric Botcazou
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diff --git a/gas/doc/as.texi b/gas/doc/as.texi
index 0cc7455d3ae..9c1924d4bbd 100644
--- a/gas/doc/as.texi
+++ b/gas/doc/as.texi
@@ -5416,19 +5416,22 @@ table is shared with the @code{.debug_info} section of the DWARF2 debugging
information, and thus the user must know the exact indices that table
entries will have.
-If DWARF-5 support has been enabled via the @option{-gdwarf-5} option then
-an extended version of the @code{file} is also allowed:
+If DWARF5 support has been enabled via the @option{-gdwarf-5} option then
+an extended version of @code{.file} is also allowed:
@smallexample
.file @var{fileno} [@var{dirname}] @var{filename} [md5 @var{value}]
@end smallexample
With this version a separate directory name is allowed, although if this is
-used then @var{filename} should not contain any directory components. In
-addtion an md5 hash value of the contents of @var{filename} can be provided.
-This will be stored in the the file table as well, and can be used by tools
-reading the debug information to verify that the contents of the source file
-match the contents of the compiled file.
+used then @var{filename} should not contain any directory component, except
+for @var{fileno} equal to 0: in this case, @var{dirname} is expected to be
+the current directory and @var{filename} the currently processed file, and
+the latter need not be located in the former. In addtion an MD5 hash value
+of the contents of @var{filename} can be provided. This will be stored in
+the the file table as well, and can be used by tools reading the debug
+information to verify that the contents of the source file match the
+contents of the compiled file.
@node Fill
@section @code{.fill @var{repeat} , @var{size} , @var{value}}
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index c6e439aa862..256412f9c79 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -641,11 +641,9 @@ get_directory_table_entry (const char *dirname,
expected to be the same as the DW_AT_comp_dir (which
is set to the current build directory). Since we are
about to create a directory entry that is not the
- same, allocate the current directory first.
- FIXME: Alternatively we could generate an error
- message here. */
- (void) get_directory_table_entry (pwd, NULL, strlen (pwd),
- true);
+ same, allocate the current directory first. */
+ (void) get_directory_table_entry (pwd, file0_dirname,
+ strlen (pwd), true);
d = 1;
}
else
@@ -827,7 +825,7 @@ allocate_filename_to_slot (const char *dirname,
const char *file;
size_t dirlen;
unsigned int i, d;
- const char *file0_dirname = dirname;
+ const char *file0_dirname;
/* Short circuit the common case of adding the same pathname
as last time. */
@@ -906,20 +904,40 @@ allocate_filename_to_slot (const char *dirname,
return false;
}
- if (dirname == NULL)
+ /* For file .0, the directory name is the current directory and the file
+ may be in another directory contained in the file name. */
+ if (num == 0)
{
- dirname = filename;
+ file0_dirname = dirname;
+
file = get_basename (filename);
- dirlen = file - filename;
+
+ if (dirname && file == filename)
+ dirlen = strlen (dirname);
+ else
+ {
+ dirname = filename;
+ dirlen = file - filename;
+ }
}
else
{
- dirlen = strlen (dirname);
- file = filename;
+ file0_dirname = NULL;
+
+ if (dirname == NULL)
+ {
+ dirname = filename;
+ file = get_basename (filename);
+ dirlen = file - filename;
+ }
+ else
+ {
+ dirlen = strlen (dirname);
+ file = filename;
+ }
}
- d = get_directory_table_entry (dirname, file0_dirname, dirlen,
- num == 0);
+ d = get_directory_table_entry (dirname, file0_dirname, dirlen, num == 0);
i = num;
if (! assign_file_to_slot (i, file, d))
diff --git a/gas/testsuite/gas/elf/dwarf-5-file0-2.d b/gas/testsuite/gas/elf/dwarf-5-file0-2.d
index 4b3ed29f4c9..dfd8431a505 100644
--- a/gas/testsuite/gas/elf/dwarf-5-file0-2.d
+++ b/gas/testsuite/gas/elf/dwarf-5-file0-2.d
@@ -1,11 +1,10 @@
#as: --gdwarf-5
-#name: DWARF5 .file 0 dir file
+#name: DWARF5 .file 0 (directory and relative file)
#readelf: -wl
#...
The Directory Table \(offset 0x.*, lines 1, columns 1\):
Entry Name
-#...
0 \(indirect line string, offset: 0x.*\): /example
The File Name Table \(offset 0x.*, lines 2, columns 2\):
diff --git a/gas/testsuite/gas/elf/dwarf-5-file0-3.d b/gas/testsuite/gas/elf/dwarf-5-file0-3.d
new file mode 100644
index 00000000000..6c55d3266aa
--- /dev/null
+++ b/gas/testsuite/gas/elf/dwarf-5-file0-3.d
@@ -0,0 +1,15 @@
+#as: --gdwarf-5
+#name: DWARF5 .file 0 (directory and absolute file)
+#readelf: -wl
+
+#...
+ The Directory Table \(offset 0x.*, lines 2, columns 1\):
+ Entry Name
+ 0 \(indirect line string, offset: 0x.*\): /current/directory
+ 1 \(indirect line string, offset: 0x.*\): /full/path
+
+ The File Name Table \(offset 0x.*, lines 2, columns 2\):
+ Entry Dir Name
+ 0 1 \(indirect line string, offset: 0x.*\): test.c
+ 1 1 \(indirect line string, offset: 0x.*\): test.c
+#pass
diff --git a/gas/testsuite/gas/elf/dwarf-5-file0-3.s b/gas/testsuite/gas/elf/dwarf-5-file0-3.s
new file mode 100644
index 00000000000..b33c3645088
--- /dev/null
+++ b/gas/testsuite/gas/elf/dwarf-5-file0-3.s
@@ -0,0 +1,111 @@
+ .file "test.c"
+ .text
+.Ltext0:
+ .file 0 "/current/directory" "/full/path/test.c"
+ .globl x
+ .section .bss
+ .balign 4
+ .type x, %object
+ .size x, 4
+x:
+ .zero 4
+ .text
+.Letext0:
+ .file 1 "/full/path/test.c"
+ .section .debug_info,"",%progbits
+.Ldebug_info0:
+ .4byte 0x32
+ .2byte 0x5
+ .byte 0x1
+ .byte 0x4
+ .4byte .Ldebug_abbrev0
+ .uleb128 0x1
+ .4byte .LASF2
+ .byte 0x1d
+ .4byte .LASF0
+ .4byte .LASF1
+ .4byte .Ldebug_line0
+ .uleb128 0x2
+ .asciz "x"
+ .byte 0x1
+ .byte 0x1
+ .byte 0x5
+ .4byte 0x2e
+ .uleb128 0x5
+ .byte 0x3
+ .4byte x
+ .uleb128 0x3
+ .byte 0x4
+ .byte 0x5
+ .asciz "int"
+ .byte 0
+ .section .debug_abbrev,"",%progbits
+.Ldebug_abbrev0:
+ .uleb128 0x1
+ .uleb128 0x11
+ .byte 0x1
+ .uleb128 0x25
+ .uleb128 0xe
+ .uleb128 0x13
+ .uleb128 0xb
+ .uleb128 0x3
+ .uleb128 0x1f
+ .uleb128 0x1b
+ .uleb128 0x1f
+ .uleb128 0x10
+ .uleb128 0x17
+ .byte 0
+ .byte 0
+ .uleb128 0x2
+ .uleb128 0x34
+ .byte 0
+ .uleb128 0x3
+ .uleb128 0x8
+ .uleb128 0x3a
+ .uleb128 0xb
+ .uleb128 0x3b
+ .uleb128 0xb
+ .uleb128 0x39
+ .uleb128 0xb
+ .uleb128 0x49
+ .uleb128 0x13
+ .uleb128 0x3f
+ .uleb128 0x19
+ .uleb128 0x2
+ .uleb128 0x18
+ .byte 0
+ .byte 0
+ .uleb128 0x3
+ .uleb128 0x24
+ .byte 0
+ .uleb128 0xb
+ .uleb128 0xb
+ .uleb128 0x3e
+ .uleb128 0xb
+ .uleb128 0x3
+ .uleb128 0x8
+ .byte 0
+ .byte 0
+ .byte 0
+ .section .debug_aranges,"",%progbits
+ .4byte 0x14
+ .2byte 0x2
+ .4byte .Ldebug_info0
+ .byte 0x4
+ .byte 0
+ .2byte 0
+ .2byte 0
+ .4byte 0
+ .4byte 0
+ .section .debug_line,"",%progbits
+.Ldebug_line0:
+ .section .debug_str,"MS",%progbits,1
+.LASF2:
+ .asciz "GNU C17 11.2.1 -g"
+ .section .debug_line_str,"MS",%progbits,1
+.LASF1:
+ .asciz "/working/directory"
+.LASF0:
+ .asciz "/full/path/test.c"
+ .ident "GCC: (GNU) 11.2.1"
+ .section .note.GNU-stack,"",%progbits
diff --git a/gas/testsuite/gas/elf/dwarf-5-file0.d b/gas/testsuite/gas/elf/dwarf-5-file0.d
index f60411c8034..2502b80d1f9 100644
--- a/gas/testsuite/gas/elf/dwarf-5-file0.d
+++ b/gas/testsuite/gas/elf/dwarf-5-file0.d
@@ -1,5 +1,5 @@
-#as: --gdwarf-3
-#name: DWARF5 .line 0
+#as: --gdwarf-5
+#name: DWARF5 .file 0 (no directory)
#readelf: -wl
#...
diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index 16b9b565614..08105f88419 100644
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -300,6 +300,7 @@ if { [is_elf_format] } then {
run_dump_test "dwarf2-21" $dump_opts
run_dump_test "dwarf-5-file0" $dump_opts
run_dump_test "dwarf-5-file0-2" $dump_opts
+ run_dump_test "dwarf-5-file0-3" $dump_opts
run_dump_test "dwarf-5-dir0" $dump_opts
run_dump_test "dwarf-5-loc0" $dump_opts
run_dump_test "dwarf-4-cu" $dump_opts
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2021-11-06 11:55 [patch] Deal with full path in .file 0 directive Eric Botcazou
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