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Re: PING: [RFA] Runtime Dwarf2 CFI engine cleanup
Michal Ludvig wrote:
Daniel Jacobowitz wrote:
In any case I am withdrawing my attempt to be helpful, since obviously
I'm being pushy again instead of helpful. Michal can go back to
waiting for someone else's response since my "help" has obviously
injured the entire process.
Thank you very much, anyway! You at least attempted to solve this issue.
Other "responsible" maintainers didn't bother to respond until you
approved my patch. Then Andrew felt he should step in, revert your
approval and say NO (why there doesn't come a *constructive* critique
along with your no, Andrew?). And Elena - apparently the only one who
could say yes - disappeared... Sigh.
I'm asking once again:
- Can I *at* *least* commit the dwarf2cfi.c part? Without the infcmd.c
hook? I know it duplicates the solib cleaner logic, but is that a
showstopper?
- Ad run_command() hook - would something like this be acceptable?
Index: config/i386/tm-x86-64linux.h
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/tm-x86-64linux.h,v
retrieving revision 1.1
diff -u -p -r1.1 tm-x86-64linux.h
--- config/i386/tm-x86-64linux.h 1 Jul 2002 22:09:52 -0000 1.1
+++ config/i386/tm-x86-64linux.h 27 Feb 2003 08:02:50 -0000
@@ -33,4 +33,6 @@
#define SVR4_SHARED_LIBS
#include "solib.h" /* Support for shared libraries. */
+#define DWARF2CFI_USED
+
#endif /* #ifndef TM_X86_64LINUX_H */
Index: infcmd.c
===================================================================
RCS file: /cvs/src/src/gdb/infcmd.c,v
retrieving revision 1.54.6.2
diff -u -p -r1.54.6.2 infcmd.c
--- infcmd.c 25 Sep 2002 20:43:21 -0000 1.54.6.2
+++ infcmd.c 27 Feb 2003 08:02:50 -0000
@@ -390,6 +390,10 @@ Start it from the beginning? "))
clear_breakpoint_hit_counts ();
+#if defined(DWARF2CFI_USED)
+ cleanup_cfi ();
+#endif
+
/* Purge old solib objfiles. */
objfile_purge_solibs ();
Every target that will use the CFI engine will just add one define to
their tm.h. No need to link dwarf2cfi.o to all targets.
I've extended this approach a little bit. Now it's enough to define
USED_DWARF2CFI=1 in config/arch/target.mh file and everything will be
configured automatically, ie. dwarf2cfi.o will be added to the list of
files to compile and -DUSED_DWARF2CFI=1 will be added to CFLAGS.
So only those targets that explicitly say "Yes, I want CFI engine" will
have it and the run_command cleanup hook will go in for them as well.
Is this a way to go?
Michal Ludvig
--
* SuSE CR, s.r.o * mludvig at suse dot cz
* (+420) 296.545.373 * http://www.suse.cz
2003-02-27 Michal Ludvig <mludvig at suse dot cz>
* config/i386/x86-64linux.mt (TDEPFILES): Remove dwarf2cfi.o
(USED_DWARF2CFI): New define.
* Makefile.in: Handle USED_DWARF2CFI define.
* infcmd.c (run_command): Add cleanup_cfi() if USED_DWARF2CFI
is defined.
* dwarf2cfi.c (struct cie_unit): New fields keep, refs.
(cleanup_cfi): New function.
Index: config/i386/x86-64linux.mt
===================================================================
RCS file: /cvs/src/src/gdb/config/i386/x86-64linux.mt,v
retrieving revision 1.5
diff -u -p -r1.5 x86-64linux.mt
--- config/i386/x86-64linux.mt 1 Jul 2002 22:09:52 -0000 1.5
+++ config/i386/x86-64linux.mt 27 Feb 2003 10:01:03 -0000
@@ -1,7 +1,9 @@
# Target: AMD x86-64 running GNU/Linux
-TDEPFILES= x86-64-tdep.o x86-64-linux-tdep.o dwarf2cfi.o \
+TDEPFILES= x86-64-tdep.o x86-64-linux-tdep.o \
solib.o solib-svr4.o solib-legacy.o
GDB_MULTI_ARCH=GDB_MULTI_ARCH_TM
TM_FILE=tm-x86-64linux.h
+
+USED_DWARF2CFI=1
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.257.2.5
diff -u -p -r1.257.2.5 Makefile.in
--- Makefile.in 25 Nov 2002 22:05:38 -0000 1.257.2.5
+++ Makefile.in 27 Feb 2003 10:01:03 -0000
@@ -414,6 +414,12 @@ ANNOTATE_OBS = annotate.o
@target_makefile_frag@
# End of host and target-dependent makefile fragments
+# Make a list of linked files depending on target's defines.
+ifeq ($(USED_DWARF2CFI), 1)
+ TDEPFILES+=dwarf2cfi.o
+ CFLAGS+=-DUSED_DWARF2CFI
+endif
+
# Possibly ignore the simulator. If the simulator is being ignored,
# these expand into SIM= and SIM_OBJ=, overriding the entries from
# target_makefile_frag
Index: infcmd.c
===================================================================
RCS file: /cvs/src/src/gdb/infcmd.c,v
retrieving revision 1.54.6.2
diff -u -p -r1.54.6.2 infcmd.c
--- infcmd.c 25 Sep 2002 20:43:21 -0000 1.54.6.2
+++ infcmd.c 27 Feb 2003 10:01:03 -0000
@@ -390,6 +390,10 @@ Start it from the beginning? "))
clear_breakpoint_hit_counts ();
+#if defined(USED_DWARF2CFI)
+ cleanup_cfi ();
+#endif
+
/* Purge old solib objfiles. */
objfile_purge_solibs ();
Index: dwarf2cfi.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2cfi.c,v
retrieving revision 1.16.6.1
diff -u -p -r1.16.6.1 dwarf2cfi.c
--- dwarf2cfi.c 3 Feb 2003 14:40:09 -0000 1.16.6.1
+++ dwarf2cfi.c 27 Feb 2003 10:01:04 -0000
@@ -54,6 +54,12 @@ struct cie_unit
/* Next in chain. */
struct cie_unit *next;
+
+ /* Keep or destroy this CIE on new run? */
+ int keep;
+
+ /* How many FDEs refer to this CIE? */
+ int refs;
};
/* Frame Description Entry. */
@@ -319,6 +260,90 @@ frame_state_alloc (void)
return fs;
}
+void
+cleanup_cfi (void *name)
+{
+ struct objfile *ofp;
+ struct cie_unit *cie, *cie_prev;
+ int fde_index = 0, fde_free = 0;
+
+ cie = cie_chunks;
+ while (cie)
+ {
+ cie->refs = 0;
+ cie->keep = 0;
+ cie = cie->next;
+ }
+
+ /* Mark all unwanted CIEs. */
+ ALL_OBJFILES (ofp)
+ {
+ if (!(ofp->flags & OBJF_USERLOADED) && (ofp->flags & OBJF_SHARED))
+ {
+ if (info_verbose)
+ printf_filtered ("\tRemoving %s...\n", ofp->name);
+ }
+ else
+ {
+ if (info_verbose)
+ printf_filtered ("\tKeeping %s...\n", ofp->name);
+
+ cie = cie_chunks;
+ while (cie)
+ {
+ if (cie->objfile == ofp)
+ cie->keep = 1;
+ cie = cie->next;
+ }
+ }
+ }
+
+ /* Remove all FDEs pointing to unwanted CIEs. */
+ for (fde_index = 0, fde_free = 0;
+ fde_index < fde_chunks.elems; fde_index++, fde_free++)
+ {
+ if (!fde_chunks.array[fde_index]->cie_ptr->keep)
+ {
+ fde_free--;
+ continue;
+ }
+ else if (fde_free < fde_index)
+ fde_chunks.array[fde_free] = fde_chunks.array[fde_index];
+ fde_chunks.array[fde_free]->cie_ptr->refs++;
+ }
+ fde_chunks.elems = fde_free;
+
+ /* Remove all unwanted CIEs. */
+ cie = cie_chunks;
+ cie_prev = NULL;
+ while (cie)
+ {
+ struct cie_unit *cie_tmp;
+
+ if (!cie->keep || !cie->refs)
+ {
+ cie_tmp = cie;
+ if (cie_prev == NULL)
+ {
+ cie_chunks = cie->next;
+ cie = cie_chunks;
+ }
+ else
+ {
+ cie_prev->next = cie->next;
+ cie = cie->next;
+ }
+ /* cie_prev must remain unchanged. */
+ xfree (cie_tmp);
+ }
+ else
+ {
+ cie_prev = cie;
+ cie = cie->next;
+ }
+ }
+}
+
static void
unwind_tmp_obstack_init (void)
{