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[PATCH] gas: Add --gdwarf-cie-version command line flag
- From: Andrew Burgess <andrew dot burgess at embecosm dot com>
- To: binutils at sourceware dot org
- Cc: Andrew Burgess <andrew dot burgess at embecosm dot com>
- Date: Fri, 8 Nov 2019 00:19:03 +0000
- Subject: [PATCH] gas: Add --gdwarf-cie-version command line flag
Add a flag to control the version of CIE that is generated. By
default gas produces CIE version 1, and this continues to be the
default after this patch.
However, a user can now provide --gdwarf-cie-version=NUMBER to switch
to either version 3 or version 4 of CIE, version 2 was never released,
and so causes an error as does any number less than 1 or greater than
4.
Producing version 4 CIE requires two new fields to be added to the
CIE, an address size field, and an segment selector field. For a flat
address space the DWARF specification indicates that the segment
selector should be 0, and the address size fields just contains the
address size in bytes. For now we support 4 or 8 byte addresses, and
the segment selector is always produced as 0. At some future time we
might need to allow targets to override this.
gas/ChangeLog:
* as.c (parse_args): Parse --gdwarf-cie-version option.
(flag_dwarf_cie_version): New variable.
* as.h (flag_dwarf_cie_version): Declare.
* dw2gencfi.c (output_cie): Switch from DW_CIE_VERSION to
flag_dwarf_cie_version.
* doc/as.texi (Overview): Document --gdwarf-cie-version.
* NEWS: Likewise.
* testsuite/gas/cfi/cfi.exp: Add new tests.
* testsuite/gas/cfi/cie-version-0.d: New file.
* testsuite/gas/cfi/cie-version-1.d: New file.
* testsuite/gas/cfi/cie-version-2.d: New file.
* testsuite/gas/cfi/cie-version-3.d: New file.
* testsuite/gas/cfi/cie-version-4.d: New file.
* testsuite/gas/cfi/cie-version.s: New file.
include/ChangeLog:
* dwarf2.h (DW_CIE_VERSION): Delete.
Change-Id: I9de19461aeb8332b5a57bbfe802953d0725a7ae8
---
gas/ChangeLog | 17 +++++++++++++++++
gas/NEWS | 3 +++
gas/as.c | 17 +++++++++++++++++
gas/as.h | 1 +
gas/doc/as.texi | 6 ++++++
gas/dw2gencfi.c | 12 ++++++++++--
gas/testsuite/gas/cfi/cfi.exp | 6 ++++++
gas/testsuite/gas/cfi/cie-version-0.d | 5 +++++
gas/testsuite/gas/cfi/cie-version-1.d | 17 +++++++++++++++++
gas/testsuite/gas/cfi/cie-version-2.d | 5 +++++
gas/testsuite/gas/cfi/cie-version-3.d | 17 +++++++++++++++++
gas/testsuite/gas/cfi/cie-version-4.d | 19 +++++++++++++++++++
gas/testsuite/gas/cfi/cie-version.s | 2 ++
include/ChangeLog | 4 ++++
include/dwarf2.h | 1 -
15 files changed, 129 insertions(+), 3 deletions(-)
create mode 100644 gas/testsuite/gas/cfi/cie-version-0.d
create mode 100644 gas/testsuite/gas/cfi/cie-version-1.d
create mode 100644 gas/testsuite/gas/cfi/cie-version-2.d
create mode 100644 gas/testsuite/gas/cfi/cie-version-3.d
create mode 100644 gas/testsuite/gas/cfi/cie-version-4.d
create mode 100644 gas/testsuite/gas/cfi/cie-version.s
diff --git a/gas/NEWS b/gas/NEWS
index 1e7007428b5..aaf857292c3 100644
--- a/gas/NEWS
+++ b/gas/NEWS
@@ -27,6 +27,9 @@ Changes in 2.33:
-mfp16-format=[ieee|alternative] option for Arm to control the format of the
encoding.
+* Add --gdwarf-cie-version command line flag. This allows control over which
+ version of DWARF CIE the assembler creates.
+
Changes in 2.32:
* Add -mvexwig=[0|1] option to x86 assembler to control encoding of
diff --git a/gas/as.c b/gas/as.c
index d53db113e22..cc84725a421 100644
--- a/gas/as.c
+++ b/gas/as.c
@@ -95,6 +95,11 @@ int debug_memory = 0;
/* Enable verbose mode. */
int verbose = 0;
+/* Which version of DWARF CIE to produce. The default could be overridden
+ by a target during its initialisation, or by the --gdwarf-cie-version
+ command line flag. */
+int flag_dwarf_cie_version = 1;
+
#if defined OBJ_ELF || defined OBJ_MAYBE_ELF
int flag_use_elf_stt_common = DEFAULT_GENERATE_ELF_STT_COMMON;
bfd_boolean flag_generate_build_notes = DEFAULT_GENERATE_BUILD_NOTES;
@@ -479,6 +484,7 @@ parse_args (int * pargc, char *** pargv)
OPTION_GSTABS_PLUS,
OPTION_GDWARF2,
OPTION_GDWARF_SECTIONS,
+ OPTION_GDWARF_CIE_VERSION,
OPTION_STRIP_LOCAL_ABSOLUTE,
OPTION_TRADITIONAL_FORMAT,
OPTION_WARN,
@@ -534,6 +540,7 @@ parse_args (int * pargc, char *** pargv)
so we keep it here for backwards compatibility. */
,{"gdwarf2", no_argument, NULL, OPTION_GDWARF2}
,{"gdwarf-sections", no_argument, NULL, OPTION_GDWARF_SECTIONS}
+ ,{"gdwarf-cie-version", required_argument, NULL, OPTION_GDWARF_CIE_VERSION}
,{"gen-debug", no_argument, NULL, 'g'}
,{"gstabs", no_argument, NULL, OPTION_GSTABS}
,{"gstabs+", no_argument, NULL, OPTION_GSTABS_PLUS}
@@ -828,6 +835,16 @@ This program has absolutely no warranty.\n"));
flag_dwarf_sections = TRUE;
break;
+ case OPTION_GDWARF_CIE_VERSION:
+ flag_dwarf_cie_version = atoi (optarg);
+ /* The available CIE versions are 1 (DWARF 2), 3 (DWARF 3), and 4
+ (DWARF 4 and 5). */
+ if (flag_dwarf_cie_version < 1
+ || flag_dwarf_cie_version == 2
+ || flag_dwarf_cie_version > 4)
+ as_fatal (_("Invalid --gdwarf-cie-version `%s'"), optarg);
+ break;
+
case 'J':
flag_signed_overflow_ok = 1;
break;
diff --git a/gas/as.h b/gas/as.h
index d996697bed8..3c37519c1bf 100644
--- a/gas/as.h
+++ b/gas/as.h
@@ -412,6 +412,7 @@ enum debug_info_type
extern enum debug_info_type debug_type;
extern int use_gnu_debug_info_extensions;
COMMON bfd_boolean flag_dwarf_sections;
+extern int flag_dwarf_cie_version;
/* Maximum level of macro nesting. */
extern int max_macro_nest;
diff --git a/gas/doc/as.texi b/gas/doc/as.texi
index b54ab1eeccc..532ed7acfac 100644
--- a/gas/doc/as.texi
+++ b/gas/doc/as.texi
@@ -231,6 +231,7 @@
[@b{--debug-prefix-map} @var{old}=@var{new}]
[@b{--defsym} @var{sym}=@var{val}] [@b{-f}] [@b{-g}] [@b{--gstabs}]
[@b{--gstabs+}] [@b{--gdwarf-2}] [@b{--gdwarf-sections}]
+ [@b{--gdwarf-cie-version}=@var{VERSION}]
[@b{--help}] [@b{-I} @var{dir}] [@b{-J}]
[@b{-K}] [@b{-L}] [@b{--listing-lhs-width}=@var{NUM}]
[@b{--listing-lhs-width2}=@var{NUM}] [@b{--listing-rhs-width}=@var{NUM}]
@@ -772,6 +773,11 @@
then debug line section will still be called just @var{.debug_line} without any
suffix.
+@item --gdwarf-cie-version=@var{version}
+Control which version of DWARF Common Information Entries (CIEs) are produced.
+When this flag is not specificed the default is version 1, though some targets
+can modify this default. Other possible values for @var{version} are 3 or 4.
+
@ifset ELF
@item --size-check=error
@itemx --size-check=warning
diff --git a/gas/dw2gencfi.c b/gas/dw2gencfi.c
index 6c0478a7206..e27253db8ee 100644
--- a/gas/dw2gencfi.c
+++ b/gas/dw2gencfi.c
@@ -1860,7 +1860,7 @@ output_cie (struct cie_entry *cie, bfd_boolean eh_frame, int align)
if (fmt != dwarf2_format_32bit)
out_four (-1);
}
- out_one (DW_CIE_VERSION); /* Version. */
+ out_one (flag_dwarf_cie_version); /* Version. */
if (eh_frame)
{
out_one ('z'); /* Augmentation. */
@@ -1876,9 +1876,17 @@ output_cie (struct cie_entry *cie, bfd_boolean eh_frame, int align)
if (cie->signal_frame)
out_one ('S');
out_one (0);
+ if (flag_dwarf_cie_version >= 4)
+ {
+ /* For now we are assuming a flat address space with 4 or 8 byte
+ addresses. */
+ int address_size = dwarf2_format_32bit ? 4 : 8;
+ out_one (address_size); /* Address size. */
+ out_one (0); /* Segment size. */
+ }
out_uleb128 (DWARF2_LINE_MIN_INSN_LENGTH); /* Code alignment. */
out_sleb128 (DWARF2_CIE_DATA_ALIGNMENT); /* Data alignment. */
- if (DW_CIE_VERSION == 1) /* Return column. */
+ if (flag_dwarf_cie_version == 1) /* Return column. */
out_one (cie->return_column);
else
out_uleb128 (cie->return_column);
diff --git a/gas/testsuite/gas/cfi/cfi.exp b/gas/testsuite/gas/cfi/cfi.exp
index c55f069afb7..2d410545b29 100644
--- a/gas/testsuite/gas/cfi/cfi.exp
+++ b/gas/testsuite/gas/cfi/cfi.exp
@@ -133,4 +133,10 @@ if { ![istarget "hppa64*-*"] } then {
run_dump_test "cfi-common-7"
run_dump_test "cfi-common-8"
run_dump_test "cfi-common-9"
+
+ run_dump_test "cie-version-0"
+ run_dump_test "cie-version-1"
+ run_dump_test "cie-version-2"
+ run_dump_test "cie-version-3"
+ run_dump_test "cie-version-4"
}
diff --git a/gas/testsuite/gas/cfi/cie-version-0.d b/gas/testsuite/gas/cfi/cie-version-0.d
new file mode 100644
index 00000000000..d9f71c41834
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version-0.d
@@ -0,0 +1,5 @@
+#objdump: --dwarf=frames
+#name: CIE Version 0
+#as: --gdwarf-cie-version=0
+#source: cie-version.s
+#error: Invalid --gdwarf-cie-version `0'
diff --git a/gas/testsuite/gas/cfi/cie-version-1.d b/gas/testsuite/gas/cfi/cie-version-1.d
new file mode 100644
index 00000000000..2a9a8f1d386
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version-1.d
@@ -0,0 +1,17 @@
+#objdump: --dwarf=frames
+#name: CIE Version 1
+#as: --gdwarf-cie-version=1
+#source: cie-version.s
+#...
+.*: file format .*
+
+Contents of the .eh_frame section:
+
+00000000 0+[0-9a-f]+ 0+000 CIE
+ Version: 1
+ Augmentation: "zR"
+ Code alignment factor: .*
+ Data alignment factor: .*
+ Return address column: .*
+ Augmentation data: [01][abc]
+#...
\ No newline at end of file
diff --git a/gas/testsuite/gas/cfi/cie-version-2.d b/gas/testsuite/gas/cfi/cie-version-2.d
new file mode 100644
index 00000000000..5279489ae9c
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version-2.d
@@ -0,0 +1,5 @@
+#objdump: --dwarf=frames
+#name: CIE Version 2
+#as: --gdwarf-cie-version=2
+#source: cie-version.s
+#error: Invalid --gdwarf-cie-version `2'
diff --git a/gas/testsuite/gas/cfi/cie-version-3.d b/gas/testsuite/gas/cfi/cie-version-3.d
new file mode 100644
index 00000000000..68cb79d49e1
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version-3.d
@@ -0,0 +1,17 @@
+#objdump: --dwarf=frames
+#name: CIE Version 3
+#as: --gdwarf-cie-version=3
+#source: cie-version.s
+#...
+.*: file format .*
+
+Contents of the .eh_frame section:
+
+00000000 0+[0-9a-f]+ 0+000 CIE
+ Version: 3
+ Augmentation: "zR"
+ Code alignment factor: .*
+ Data alignment factor: .*
+ Return address column: .*
+ Augmentation data: [01][abc]
+#...
\ No newline at end of file
diff --git a/gas/testsuite/gas/cfi/cie-version-4.d b/gas/testsuite/gas/cfi/cie-version-4.d
new file mode 100644
index 00000000000..bdd19d994f5
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version-4.d
@@ -0,0 +1,19 @@
+#objdump: --dwarf=frames
+#name: CIE Version 4
+#as: --gdwarf-cie-version=4
+#source: cie-version.s
+#...
+.*: file format .*
+
+Contents of the .eh_frame section:
+
+00000000 0+[0-9a-f]+ 0+000 CIE
+ Version: 4
+ Augmentation: "zR"
+ Pointer Size: .*
+ Segment Size: .*
+ Code alignment factor: .*
+ Data alignment factor: .*
+ Return address column: .*
+ Augmentation data: [01][abc]
+#...
diff --git a/gas/testsuite/gas/cfi/cie-version.s b/gas/testsuite/gas/cfi/cie-version.s
new file mode 100644
index 00000000000..659b3b9d99b
--- /dev/null
+++ b/gas/testsuite/gas/cfi/cie-version.s
@@ -0,0 +1,2 @@
+ .cfi_startproc
+ .cfi_endproc
diff --git a/include/dwarf2.h b/include/dwarf2.h
index e03349da940..a4a18315535 100644
--- a/include/dwarf2.h
+++ b/include/dwarf2.h
@@ -316,7 +316,6 @@ enum dwarf_location_list_entry_type
#define DW_CIE_ID 0xffffffff
#define DW64_CIE_ID 0xffffffffffffffffULL
-#define DW_CIE_VERSION 1
#define DW_CFA_extended 0
--
2.14.5