Hello,
It was brought up when discussing PR debug/101283 (Several tests fail on
Darwin with -gctf/gbtf) that it will be good to provide means for targets to
opt out of CTF/BTF support.
By and large, it seems to me that CTF/BTF debug formats can be safely enabled
for all ELF-based targets by default in GCC.
So, at a high level:
- By default, CTF/BTF formats can be enabled for all ELF-based targets.
- By default, CTF/BTF formats can be disabled for all non ELF-based targets.
- If the user passed a -gctf but CTF is not enabled for the target, GCC
issues an error to the user (as is done currently with other debug formats) -
"target system does not support the 'ctf' debug format".
This is a makeshift patch which fulfills the above requirements and is based on
the approach taken for DWARF via DWARF2_DEBUGGING_INFO (I still have to see if
I need some specific handling in common_handle_option in opts.c). On minimal
testing, the patch works as desired on x86_64-pc-linux-gnu and a darwin-based
target.
My question is - Looking around in config.gcc etc., it seems defining in elfos.h
gives targets/platforms means to override it by virtue of the recommended order
of # includes in $tm_file. What I cannot say for certain is if this is true in
practice ? On first look, I believe this could work fine. What do you think ?
If you think this approach could work, I will continue on this track and
test/refine the patch.
Thanks
Indu
-------------
gcc/ChangeLog:
* config/elfos.h (CTF_DEBUGGING_INFO): New definition.
(BTF_DEBUGGING_INFO): Likewise.
* toplev.c: Guard initialization of debug hooks.
gcc/testsuite/ChangeLog:
* gcc.dg/debug/btf/btf.exp: Do not run BTF testsuite if target does not
support BTF format.
* gcc.dg/debug/ctf/ctf.exp: Do not run CTF testsuite if target does not
support CTF format.
---
gcc/config/elfos.h | 8 ++++++++
gcc/testsuite/gcc.dg/debug/btf/btf.exp | 11 +++++++++--
gcc/testsuite/gcc.dg/debug/ctf/ctf.exp | 11 +++++++++--
gcc/toplev.c | 11 +++++++++--
4 files changed, 35 insertions(+), 6 deletions(-)
diff --git a/gcc/config/elfos.h b/gcc/config/elfos.h
index 7a736cc..e5cb487 100644
--- a/gcc/config/elfos.h
+++ b/gcc/config/elfos.h
@@ -68,6 +68,14 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If
not, see
#define DWARF2_DEBUGGING_INFO 1
+/* All ELF targets can support CTF. */
+
+#define CTF_DEBUGGING_INFO 1
+
+/* All ELF targets can support BTF. */
+
+#define BTF_DEBUGGING_INFO 1
+
/* The GNU tools operate better with dwarf2, and it is required by some
psABI's. Since we don't have any native tools to be compatible with,
default to dwarf2. */
diff --git a/gcc/testsuite/gcc.dg/debug/btf/btf.exp
b/gcc/testsuite/gcc.dg/debug/btf/btf.exp
index e173515..a3e680c 100644
--- a/gcc/testsuite/gcc.dg/debug/btf/btf.exp
+++ b/gcc/testsuite/gcc.dg/debug/btf/btf.exp
@@ -39,8 +39,15 @@ if ![info exists DEFAULT_CFLAGS] then {
dg-init
# Main loop.
-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\] ]] \
- "" $DEFAULT_CFLAGS
+set comp_output [gcc_target_compile \
+ "$srcdir/$subdir/../trivial.c" "trivial.S" assembly \
+ "additional_flags=-gbtf"]
+if { ! [string match "*: target system does not support the * debug format*" \
+ $comp_output] } {
+ remove-build-file "trivial.S"
+ dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\] ]] \
+ "" $DEFAULT_CFLAGS
+}
# All done.
dg-finish
diff --git a/gcc/testsuite/gcc.dg/debug/ctf/ctf.exp
b/gcc/testsuite/gcc.dg/debug/ctf/ctf.exp
index 0b650ed..c53cd8b 100644
--- a/gcc/testsuite/gcc.dg/debug/ctf/ctf.exp
+++ b/gcc/testsuite/gcc.dg/debug/ctf/ctf.exp
@@ -39,8 +39,15 @@ if ![info exists DEFAULT_CFLAGS] then {
dg-init
# Main loop.
-dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\] ]] \
- "" $DEFAULT_CFLAGS
+set comp_output [gcc_target_compile \
+ "$srcdir/$subdir/../trivial.c" "trivial.S" assembly \
+ "additional_flags=-gctf"]
+if { ! [string match "*: target system does not support the * debug format*" \
+ $comp_output] } {
+ remove-build-file "trivial.S"
+ dg-runtest [lsort [glob -nocomplain $srcdir/$subdir/*.\[cS\] ]] \
+ "" $DEFAULT_CFLAGS
+}
# All done.
dg-finish
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 43f1f7d..8103812 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1463,8 +1463,15 @@ process_options (void)
debug_hooks = &xcoff_debug_hooks;
#endif
#ifdef DWARF2_DEBUGGING_INFO
- else if (dwarf_debuginfo_p ()
- || dwarf_based_debuginfo_p ())
+ else if (dwarf_debuginfo_p ())
+ debug_hooks = &dwarf2_debug_hooks;
+#endif
+#ifdef CTF_DEBUGGING_INFO
+ else if (write_symbols & CTF_DEBUG)
+ debug_hooks = &dwarf2_debug_hooks;
+#endif
+#ifdef BTF_DEBUGGING_INFO
+ else if (btf_debuginfo_p ())
debug_hooks = &dwarf2_debug_hooks;
#endif
#ifdef VMS_DEBUGGING_INFO
--
1.8.3.1
