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gdb-patches@sourceware.org
mailing list for the GDB project.
Re: JIT Reader
Hi,
New patches attached. Fixed the formatting errors, refactored
jit_reader_try_read_symtab to remove the label and the gotos
altogether, and fixed a small typo in the docs that I had overlooked.
Everything else is the same.
Thank you for your infinite patience! :)
--
Sanjoy Das
http://playingwithpointers.com
>From 9144218a00928583e4085f9d63f6413e73758218 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 1/7] Introduce jit-reader.in and modify build system.
jit-reader.in will host the interface to be implemented and the API to
be used by the reader. The file needs to be processed by ./configure
to produce `jit.reader.h'; so that GDB_CORE_ADDR is defined correctly.
This commit arranges for `jit-reader.h' to be installed in the global
include directory.
gdb/ChangeLog:
* gdb/Makefile.in: Add jit-reader.h as a header. Have it
installed in $(includedir)/gdb.
* gdb/configure.ac: Genereate a correct value for TARGET_PTR for
jit-reader.h. Tell configure to generate jit-reader.h from
jit-reader.in.
* gdb/configure: Re-generated by autoconf.
* gdb/jit-reader.in: New file.
* gdb/jit.c: Include jit-reader.h.
---
gdb/Makefile.in | 13 ++-
gdb/configure | 124 +++++++++++++++++++
gdb/configure.ac | 22 ++++
gdb/jit-reader.in | 344 +++++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/jit.c | 1 +
5 files changed, 500 insertions(+), 4 deletions(-)
create mode 100644 gdb/jit-reader.in
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 7a7ff9f..ff5f246 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -833,7 +833,7 @@ common/linux-osdata.h
# Header files that already have srcdir in them, or which are in objdir.
-HFILES_WITH_SRCDIR = ../bfd/bfd.h
+HFILES_WITH_SRCDIR = ../bfd/bfd.h jit-reader.h
# GDB "info" files, which should be included in their entirety
@@ -950,7 +950,7 @@ DISTSTUFF = $(YYFILES)
# All generated files which can be included by another file.
-generated_files = config.h observer.h observer.inc ada-lex.c \
+generated_files = config.h observer.h observer.inc ada-lex.c jit-reader.h \
$(GNULIB_H) $(NAT_GENERATED_FILES)
.c.o:
@@ -1035,7 +1035,9 @@ install-only: $(CONFIG_INSTALL)
$(SHELL) $(srcdir)/../mkinstalldirs \
$(DESTDIR)$(man1dir) ; \
$(INSTALL_DATA) $(srcdir)/gdb.1 \
- $(DESTDIR)$(man1dir)/$$transformed_name.1
+ $(DESTDIR)$(man1dir)/$$transformed_name.1 ; \
+ $(SHELL) $(srcdir)/../mkinstalldirs $(DESTDIR)$(includedir)/gdb ; \
+ $(INSTALL_DATA) jit-reader.h $(DESTDIR)$(includedir)/gdb/jit-reader.h
@$(MAKE) DO=install "DODIRS=$(SUBDIRS)" $(FLAGS_TO_PASS) subdir_do
.PHONY: install-tui
install-tui:
@@ -1263,7 +1265,7 @@ distclean: clean
rm -f gdbserver/config.status gdbserver/config.log
rm -f gdbserver/tm.h gdbserver/xm.h gdbserver/nm.h
rm -f gdbserver/Makefile gdbserver/config.cache
- rm -f nm.h config.status config.h stamp-h .gdbinit
+ rm -f nm.h config.status config.h stamp-h .gdbinit jit-reader.h
rm -f y.output yacc.acts yacc.tmp y.tab.h
rm -f config.log config.cache
rm -f Makefile
@@ -1329,6 +1331,9 @@ data-directory/Makefile: data-directory/Makefile.in config.status @frags@
CONFIG_LINKS= \
$(SHELL) config.status
+jit-reader.h: $(srcdir)/jit-reader.in
+ $(SHELL) config.status $@
+
config.h: stamp-h ; @true
stamp-h: $(srcdir)/config.in config.status
CONFIG_HEADERS=config.h:config.in \
diff --git a/gdb/configure b/gdb/configure
index aec9d43..a206ee0 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -666,6 +666,7 @@ python_prog_path
LTLIBEXPAT
LIBEXPAT
HAVE_LIBEXPAT
+TARGET_PTR
READLINE_TEXI_INCFLAG
READLINE_CFLAGS
READLINE_DEPS
@@ -9884,6 +9885,128 @@ fi
+# Generate jit-reader.h
+
+# This is typedeffed to GDB_CORE_ADDR in jit-reader.h
+TARGET_PTR=
+
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of unsigned long long" >&5
+$as_echo_n "checking size of unsigned long long... " >&6; }
+if test "${ac_cv_sizeof_unsigned_long_long+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (unsigned long long))" "ac_cv_sizeof_unsigned_long_long" "$ac_includes_default"; then :
+
+else
+ if test "$ac_cv_type_unsigned_long_long" = yes; then
+ { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (unsigned long long)
+See \`config.log' for more details." "$LINENO" 5; }; }
+ else
+ ac_cv_sizeof_unsigned_long_long=0
+ fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_unsigned_long_long" >&5
+$as_echo "$ac_cv_sizeof_unsigned_long_long" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_UNSIGNED_LONG_LONG $ac_cv_sizeof_unsigned_long_long
+_ACEOF
+
+
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of unsigned long" >&5
+$as_echo_n "checking size of unsigned long... " >&6; }
+if test "${ac_cv_sizeof_unsigned_long+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (unsigned long))" "ac_cv_sizeof_unsigned_long" "$ac_includes_default"; then :
+
+else
+ if test "$ac_cv_type_unsigned_long" = yes; then
+ { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (unsigned long)
+See \`config.log' for more details." "$LINENO" 5; }; }
+ else
+ ac_cv_sizeof_unsigned_long=0
+ fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_unsigned_long" >&5
+$as_echo "$ac_cv_sizeof_unsigned_long" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_UNSIGNED_LONG $ac_cv_sizeof_unsigned_long
+_ACEOF
+
+
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of unsigned __int128" >&5
+$as_echo_n "checking size of unsigned __int128... " >&6; }
+if test "${ac_cv_sizeof_unsigned___int128+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (unsigned __int128))" "ac_cv_sizeof_unsigned___int128" "$ac_includes_default"; then :
+
+else
+ if test "$ac_cv_type_unsigned___int128" = yes; then
+ { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (unsigned __int128)
+See \`config.log' for more details." "$LINENO" 5; }; }
+ else
+ ac_cv_sizeof_unsigned___int128=0
+ fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_unsigned___int128" >&5
+$as_echo "$ac_cv_sizeof_unsigned___int128" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_UNSIGNED___INT128 $ac_cv_sizeof_unsigned___int128
+_ACEOF
+
+
+
+if test "x${ac_cv_sizeof_unsigned_long}" = "x8"; then
+ TARGET_PTR="unsigned long"
+elif test "x${ac_cv_sizeof_unsigned_long_long}" = "x8"; then
+ TARGET_PTR="unsigned long long"
+elif test "x${ac_cv_sizeof_unsigned___int128}" = "x16"; then
+ TARGET_PTR="unsigned __int128"
+else
+ TARGET_PTR="unsigned long"
+fi
+
+
+ac_config_files="$ac_config_files jit-reader.h:jit-reader.in"
+
+
# Check whether --with-expat was given.
if test "${with_expat+set}" = set; then :
@@ -16794,6 +16917,7 @@ do
"config.h") CONFIG_HEADERS="$CONFIG_HEADERS config.h:config.in" ;;
"depdir") CONFIG_COMMANDS="$CONFIG_COMMANDS depdir" ;;
"depfiles") CONFIG_COMMANDS="$CONFIG_COMMANDS depfiles" ;;
+ "jit-reader.h") CONFIG_FILES="$CONFIG_FILES jit-reader.h:jit-reader.in" ;;
"$ac_config_links_1") CONFIG_LINKS="$CONFIG_LINKS $ac_config_links_1" ;;
"Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
".gdbinit") CONFIG_FILES="$CONFIG_FILES .gdbinit:gdbinit.in" ;;
diff --git a/gdb/configure.ac b/gdb/configure.ac
index fbbb2de..ac8707a 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -605,6 +605,28 @@ AC_SUBST(READLINE_DEPS)
AC_SUBST(READLINE_CFLAGS)
AC_SUBST(READLINE_TEXI_INCFLAG)
+# Generate jit-reader.h
+
+# This is typedeffed to GDB_CORE_ADDR in jit-reader.h
+TARGET_PTR=
+
+AC_CHECK_SIZEOF(unsigned long long)
+AC_CHECK_SIZEOF(unsigned long)
+AC_CHECK_SIZEOF(unsigned __int128)
+
+if test "x${ac_cv_sizeof_unsigned_long}" = "x8"; then
+ TARGET_PTR="unsigned long"
+elif test "x${ac_cv_sizeof_unsigned_long_long}" = "x8"; then
+ TARGET_PTR="unsigned long long"
+elif test "x${ac_cv_sizeof_unsigned___int128}" = "x16"; then
+ TARGET_PTR="unsigned __int128"
+else
+ TARGET_PTR="unsigned long"
+fi
+
+AC_SUBST(TARGET_PTR)
+AC_CONFIG_FILES([jit-reader.h:jit-reader.in])
+
AC_ARG_WITH(expat,
AS_HELP_STRING([--with-expat], [include expat support (auto/yes/no)]),
[], [with_expat=auto])
diff --git a/gdb/jit-reader.in b/gdb/jit-reader.in
new file mode 100644
index 0000000..3efe722
--- /dev/null
+++ b/gdb/jit-reader.in
@@ -0,0 +1,344 @@
+/* JIT declarations for GDB, the GNU Debugger.
+
+ Copyright (C) 2011 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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/>. */
+
+#ifndef GDB_JIT_READER_H
+#define GDB_JIT_READER_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Versioning information. See gdb_reader_funcs. */
+
+#define GDB_READER_INTERFACE_VERSION 1
+
+/* Readers must be released under a GPL compatible license. To
+ declare that the reader is indeed released under a GPL compatible
+ license, invoke the macro GDB_DECLARE_GPL_COMPATIBLE in a source
+ file. */
+
+#ifdef __cplusplus
+#define GDB_DECLARE_GPL_COMPATIBLE_READER \
+ extern "C" { \
+ extern int plugin_is_GPL_compatible (void) \
+ { \
+ return 0; \
+ } \
+ }
+
+#else
+
+#define GDB_DECLARE_GPL_COMPATIBLE_READER
+ extern int plugin_is_GPL_compatible (void) \
+ { \
+ return 0; \
+ }
+
+#endif
+
+/* Represents an address on the target system. */
+
+typedef @TARGET_PTR@ GDB_CORE_ADDR;
+
+/* Return status codes. */
+
+enum gdb_status {
+ GDB_FAIL = 0,
+ GDB_SUCCESS = 1
+};
+
+struct gdb_object;
+struct gdb_symtab;
+struct gdb_block;
+struct gdb_symbol_callbacks;
+
+/* An array of these are used to represent a map from code addresses to line
+ numbers in the source file. */
+
+struct gdb_line_mapping
+{
+ int line;
+ GDB_CORE_ADDR pc;
+};
+
+/* Create a new GDB code object. Each code object can have one or
+ more symbol tables, each representing a compiled source file. */
+
+typedef struct gdb_object *(gdb_object_open) (struct gdb_symbol_callbacks *cb);
+
+/* The callback used to create new symbol table. CB is the
+ gdb_symbol_callbacks which the structure is part of. FILE_NAME is
+ an (optionally NULL) file name to associate with this new symbol
+ table.
+
+ Returns a new instance to gdb_symtab that can later be passed to
+ gdb_block_new, gdb_symtab_add_line_mapping and gdb_symtab_close. */
+
+typedef struct gdb_symtab *(gdb_symtab_open) (struct gdb_symbol_callbacks *cb,
+ struct gdb_object *obj,
+ const char *file_name);
+
+/* Creates a new block in a given symbol table. A symbol table is a
+ forest of blocks, each block representing an code address range and
+ a corresponding (optionally NULL) NAME. In case the block
+ corresponds to a function, the NAME passed should be the name of
+ the function.
+
+ If the new block to be created is a child of (i.e. is nested in)
+ another block, the parent block can be passed in PARENT. SYMTAB is
+ the symbol table the new block is to belong in. BEGIN, END is the
+ code address range the block corresponds to.
+
+ Returns a new instance of gdb_block, which, as of now, has no use.
+ Note that the gdb_block returned must not be freed by the
+ caller. */
+
+typedef struct gdb_block *(gdb_block_open) (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *symtab,
+ struct gdb_block *parent,
+ GDB_CORE_ADDR begin,
+ GDB_CORE_ADDR end,
+ const char *name);
+
+/* Adds a PC to line number mapping for the symbol table SYMTAB.
+ NLINES is the number of elements in LINES, each element
+ corresponding to one (PC, line) pair. */
+
+typedef void (gdb_symtab_add_line_mapping) (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *symtab,
+ int nlines,
+ struct gdb_line_mapping *lines);
+
+/* Close the symtab SYMTAB. This signals to GDB that no more blocks
+ will be opened on this symtab. */
+
+typedef void (gdb_symtab_close) (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *symtab);
+
+
+/* Closes the gdb_object OBJ and adds the emitted information into
+ GDB's internal structures. Once this is done, the debug
+ information will be picked up and used; this will usually be the
+ last operation in gdb_read_debug_info. */
+
+typedef void (gdb_object_close) (struct gdb_symbol_callbacks *cb,
+ struct gdb_object *obj);
+
+/* Reads LEN bytes from TARGET_MEM in the target's virtual address
+ space into GDB_BUF.
+
+ Returns GDB_FAIL on failure, and GDB_SUCCESS on success. */
+
+typedef enum gdb_status (gdb_target_read) (GDB_CORE_ADDR target_mem,
+ void *gdb_buf, int len);
+
+/* The list of callbacks that are passed to read. These callbacks are
+ to be used to construct the symbol table. The functions have been
+ described above. */
+
+struct gdb_symbol_callbacks
+{
+ gdb_object_open *object_open;
+ gdb_symtab_open *symtab_open;
+ gdb_block_open *block_open;
+ gdb_symtab_close *symtab_close;
+ gdb_object_close *object_close;
+
+ gdb_symtab_add_line_mapping *line_mapping_add;
+ gdb_target_read *target_read;
+
+ /* For internal use by GDB. */
+ void *priv_data;
+};
+
+/* Forward declaration. */
+
+struct gdb_reg_value;
+
+/* A function of this type is used to free a gdb_reg_value. See the
+ comment on `free' in struct gdb_reg_value. */
+
+typedef void (gdb_reg_value_free) (struct gdb_reg_value *);
+
+/* Denotes the value of a register. */
+
+struct gdb_reg_value
+{
+ /* The size of the register in bytes. The reader need not set this
+ field. This will be set for (defined) register values being read
+ from GDB using reg_get. */
+ int size;
+
+ /* Set to non-zero if the value for the register is known. The
+ registers for which the reader does not call reg_set are also
+ assumed to be undefined */
+ int defined;
+
+ /* Since gdb_reg_value is a variable sized structure, it will
+ usually be allocated on the heap. This function is expected to
+ contain the corresponding "free" function.
+
+ When a pointer to gdb_reg_value is being sent from GDB to the
+ reader (via gdb_unwind_reg_get), the reader is expected to call
+ this function (with the same gdb_reg_value as argument) once it
+ is done with the value.
+
+ When the function sends the a gdb_reg_value to GDB (via
+ gdb_unwind_reg_set), it is expected to set this field to point to
+ an appropriate cleanup routine (or to NULL if no cleanup is
+ required). */
+ gdb_reg_value_free *free;
+
+ /* The value of the register. */
+ unsigned char value[1];
+};
+
+/* get_frame_id in gdb_reader_funcs is to return a gdb_frame_id
+ corresponding to the current frame. The registers corresponding to
+ the current frame can be read using reg_get. Calling get_frame_id
+ on a particular frame should return the same gdb_frame_id
+ throughout its lifetime (i.e. till before it gets unwound). One
+ way to do this is by having the CODE_ADDRESS point to the
+ function's first instruction and STACK_ADDRESS point to the value
+ of the stack pointer when entering the function. */
+
+struct gdb_frame_id
+{
+ GDB_CORE_ADDR code_address;
+ GDB_CORE_ADDR stack_address;
+};
+
+/* Forward declaration. */
+
+struct gdb_unwind_callbacks;
+
+/* Returns the value of a particular register in the current frame.
+ The current frame is the frame that needs to be unwound into the
+ outer (earlier) frame.
+
+ CB is the struct gdb_unwind_callbacks * the callback belongs to.
+ REGNUM is the DWARF register number of the register that needs to
+ be unwound.
+
+ Returns the gdb_reg_value corresponding to the register requested.
+ In case the value of the register has been optimized away or
+ otherwise unavailable, the defined flag in the returned
+ gdb_reg_value will be zero. */
+
+typedef struct gdb_reg_value *(gdb_unwind_reg_get)
+ (struct gdb_unwind_callbacks *cb, int regnum);
+
+/* Sets the previous value of a particular register. REGNUM is the
+ (DWARF) register number whose value is to be set. VAL is the value
+ the register is to be set to.
+
+ VAL is *not* copied, so the memory allocated to it cannot be
+ reused. Once GDB no longer needs the value, it is deallocated
+ using the FREE function (see gdb_reg_value).
+
+ A register can also be "set" to an undefined value by setting the
+ defined in VAL to zero. */
+
+typedef void (gdb_unwind_reg_set) (struct gdb_unwind_callbacks *cb, int regnum,
+ struct gdb_reg_value *val);
+
+/* This struct is passed to unwind in gdb_reader_funcs, and is to be
+ used to unwind the current frame (current being the frame whose
+ registers can be read using reg_get) into the earlier frame. The
+ functions have been described above. */
+
+struct gdb_unwind_callbacks
+{
+ gdb_unwind_reg_get *reg_get;
+ gdb_unwind_reg_set *reg_set;
+ gdb_target_read *target_read;
+
+ /* For internal use by GDB. */
+ void *priv_data;
+};
+
+/* Forward declaration. */
+
+struct gdb_reader_funcs;
+
+/* Parse the debug info off a block of memory, pointed to by MEMORY
+ (already copied to GDB's address space) and MEMORY_SZ bytes long.
+ The implementation has to use the functions in CB to actually emit
+ the parsed data into GDB. SELF is the same structure returned by
+ gdb_init_reader.
+
+ Return GDB_FAIL on failure and GDB_SUCCESS on success. */
+
+typedef enum gdb_status (gdb_read_debug_info) (struct gdb_reader_funcs *self,
+ struct gdb_symbol_callbacks *cb,
+ void *memory, long memory_sz);
+
+/* Unwind the current frame, CB is the set of unwind callbacks that
+ are to be used to do this.
+
+ Return GDB_FAIL on failure and GDB_SUCCESS on success. */
+
+typedef enum gdb_status (gdb_unwind_frame) (struct gdb_reader_funcs *self,
+ struct gdb_unwind_callbacks *cb);
+
+/* Return the frame ID corresponding to the current frame, using C to
+ read the current register values. See the comment on struct
+ gdb_frame_id. */
+
+typedef struct gdb_frame_id (gdb_get_frame_id) (struct gdb_reader_funcs *self,
+ struct gdb_unwind_callbacks *c);
+
+/* Called when a reader is being unloaded. This function should also
+ free SELF, if required. */
+
+typedef void (gdb_destroy_reader) (struct gdb_reader_funcs *self);
+
+/* Called when the reader is loaded. Must either return a properly
+ populated gdb_reader_funcs or NULL. The memory allocated for the
+ gdb_reader_funcs is to be managed by the reader itself (i.e. if it
+ is allocated from the heap, it must also be freed in
+ gdb_destroy_reader). */
+
+extern struct gdb_reader_funcs *gdb_init_reader (void);
+
+/* Pointer to the functions which implement the reader's
+ functionality. The individual functions have been documented
+ above.
+
+ None of the fields are optional. */
+
+struct gdb_reader_funcs
+{
+ /* Must be set to GDB_READER_INTERFACE_VERSION. */
+ int reader_version;
+
+ /* For use by the reader. */
+ void *priv_data;
+
+ gdb_read_debug_info *read;
+ gdb_unwind_frame *unwind;
+ gdb_get_frame_id *get_frame_id;
+ gdb_destroy_reader *destroy;
+};
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
diff --git a/gdb/jit.c b/gdb/jit.c
index 954d297..85e40ac 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -20,6 +20,7 @@
#include "defs.h"
#include "jit.h"
+#include "jit-reader.h"
#include "breakpoint.h"
#include "command.h"
#include "gdbcmd.h"
--
1.7.7
>From 42fd7d24efe4cc547cf4cdeac14eeed6ecab7df8 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 2/7] Relocatable directory for loading JIT readers.
Add a new directory `jit_reader_dir' to jit.c, which is relocated
during initialization. The value of the directory can be set by using
--with-jit-reader-dir on configure and defaults to `${libdir}/gdb'.
gdb/ChangeLog:
* gdb/config.in: Add new #defines: JIT_READER_DIR and
JIT_READER_DIR_RELOCATABLE.
* gdb/configure.ac: New GDB directory entry for jit-reader-dir.
* gdb/configure: Re-generated by autoconf.
* gdb/jit.c: New static variable: const char *jit_reader_dir.
(_initialize_jit): Relocate jit_reader_dir.
---
gdb/config.in | 6 ++++++
gdb/configure | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/configure.ac | 4 ++++
gdb/jit.c | 4 ++++
4 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/gdb/config.in b/gdb/config.in
index c1d7c68..27a4e2c 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -982,3 +982,9 @@
/* Define as `fork' if `vfork' does not work. */
#undef vfork
+
+/* The directory from which JIT readers should be loaded. */
+#undef JIT_READER_DIR
+
+/* Define if JIT_READER_DIR should be relocated when GDB is moved. */
+#undef JIT_READER_DIR_RELOCATABLE
diff --git a/gdb/configure b/gdb/configure
index a206ee0..78cd9e9 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -666,6 +666,7 @@ python_prog_path
LTLIBEXPAT
LIBEXPAT
HAVE_LIBEXPAT
+JIT_READER_DIR
TARGET_PTR
READLINE_TEXI_INCFLAG
READLINE_CFLAGS
@@ -966,6 +967,7 @@ with_zlib
with_libiconv_prefix
with_iconv_bin
with_system_readline
+with_jit_reader_dir
with_expat
with_gnu_ld
enable_rpath
@@ -1666,6 +1668,8 @@ Optional Packages:
search for libiconv in DIR/include and DIR/lib
--with-iconv-bin=PATH specify where to find the iconv program
--with-system-readline use installed readline library
+ --with-jit-reader-dir=PATH
+ directory to load the JIT readers from
--with-expat include expat support (auto/yes/no)
--with-gnu-ld assume the C compiler uses GNU ld default=no
--with-libexpat-prefix[=DIR] search for libexpat in DIR/include and DIR/lib
@@ -10008,6 +10012,53 @@ ac_config_files="$ac_config_files jit-reader.h:jit-reader.in"
+
+# Check whether --with-jit-reader-dir was given.
+if test "${with_jit_reader_dir+set}" = set; then :
+ withval=$with_jit_reader_dir;
+ JIT_READER_DIR=$withval
+else
+ JIT_READER_DIR=${libdir}/gdb
+fi
+
+
+ test "x$prefix" = xNONE && prefix="$ac_default_prefix"
+ test "x$exec_prefix" = xNONE && exec_prefix='${prefix}'
+ ac_define_dir=`eval echo $JIT_READER_DIR`
+ ac_define_dir=`eval echo $ac_define_dir`
+
+cat >>confdefs.h <<_ACEOF
+#define JIT_READER_DIR "$ac_define_dir"
+_ACEOF
+
+
+
+
+ if test "x$exec_prefix" = xNONE || test "x$exec_prefix" = 'x${prefix}'; then
+ if test "x$prefix" = xNONE; then
+ test_prefix=/usr/local
+ else
+ test_prefix=$prefix
+ fi
+ else
+ test_prefix=$exec_prefix
+ fi
+ value=0
+ case ${ac_define_dir} in
+ "${test_prefix}"|"${test_prefix}/"*|\
+ '${exec_prefix}'|'${exec_prefix}/'*)
+ value=1
+ ;;
+ esac
+
+cat >>confdefs.h <<_ACEOF
+#define JIT_READER_DIR_RELOCATABLE $value
+_ACEOF
+
+
+
+
+
# Check whether --with-expat was given.
if test "${with_expat+set}" = set; then :
withval=$with_expat;
diff --git a/gdb/configure.ac b/gdb/configure.ac
index ac8707a..4ecb5c9 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -627,6 +627,10 @@ fi
AC_SUBST(TARGET_PTR)
AC_CONFIG_FILES([jit-reader.h:jit-reader.in])
+GDB_AC_WITH_DIR([JIT_READER_DIR], [jit-reader-dir],
+ [directory to load the JIT readers from],
+ [${libdir}/gdb])
+
AC_ARG_WITH(expat,
AS_HELP_STRING([--with-expat], [include expat support (auto/yes/no)]),
[], [with_expat=auto])
diff --git a/gdb/jit.c b/gdb/jit.c
index 85e40ac..af33a91 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -33,6 +33,8 @@
#include "target.h"
#include "gdb_stat.h"
+static const char *jit_reader_dir = NULL;
+
static const struct objfile_data *jit_objfile_data;
static const char *const jit_break_name = "__jit_debug_register_code";
@@ -558,6 +560,8 @@ extern void _initialize_jit (void);
void
_initialize_jit (void)
{
+ jit_reader_dir = relocate_gdb_directory (JIT_READER_DIR,
+ JIT_READER_DIR_RELOCATABLE);
add_setshow_zinteger_cmd ("jit", class_maintenance, &jit_debug,
_("Set JIT debugging."),
_("Show JIT debugging."),
--
1.7.7
>From 889e0bad82e809f9bae87f518f4178f4d1a7c660 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 3/7] Platform agnostic dynamic loading code.
gdb-dlfcn.h and gdb-dlfcn.c are added, which implement the (cross
platform) functions is_dl_available, gdb_dlopen, gdb_dlsym and
gdb_dlclose. They should work correctly on POSIX and windows systems.
gdb/ChangeLog:
* gdb/Makefile.in: Add gdb-dlfcn.c and gdb-dlfcn.h to build
system.
* gdb/config.in: Add new #define HAVE_DLFCN_H.
* gdb/configure.ac: Add check for dlopen and for dlfcn.h
* gdb/configure: Re-generated by autoconf.
---
gdb/Makefile.in | 6 +-
gdb/config.in | 3 +
gdb/configure | 60 ++++++++++++++++++++++-
gdb/configure.ac | 5 ++-
gdb/gdb-dlfcn.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/gdb-dlfcn.h | 51 +++++++++++++++++++
6 files changed, 263 insertions(+), 5 deletions(-)
create mode 100644 gdb/gdb-dlfcn.c
create mode 100644 gdb/gdb-dlfcn.h
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index ff5f246..48221f2 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -748,7 +748,7 @@ SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c ada-tasks.c \
annotate.c common/signals.c copying.c dfp.c gdb.c inf-child.c \
regset.c sol-thread.c windows-termcap.c \
common/common-utils.c common/xml-utils.c \
- common/ptid.c common/buffer.c
+ common/ptid.c common/buffer.c gdb-dlfcn.c
LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c
@@ -829,7 +829,7 @@ solib-darwin.h solib-ia64-hpux.h solib-spu.h windows-nat.h xcoffread.h \
gnulib/extra/arg-nonnull.h gnulib/extra/c++defs.h gnulib/extra/warn-on-use.h \
gnulib/stddef.in.h inline-frame.h skip.h \
common/common-utils.h common/xml-utils.h common/buffer.h common/ptid.h \
-common/linux-osdata.h
+common/linux-osdata.h gdb-dlfcn.h
# Header files that already have srcdir in them, or which are in objdir.
@@ -916,7 +916,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
target-descriptions.o target-memory.o xml-tdesc.o xml-builtin.o \
inferior.o osdata.o gdb_usleep.o record.o gcore.o \
jit.o progspace.o skip.o \
- common-utils.o buffer.o ptid.o
+ common-utils.o buffer.o ptid.o gdb-dlfcn.o
TSOBS = inflow.o
diff --git a/gdb/config.in b/gdb/config.in
index 27a4e2c..4af4e69 100644
--- a/gdb/config.in
+++ b/gdb/config.in
@@ -988,3 +988,6 @@
/* Define if JIT_READER_DIR should be relocated when GDB is moved. */
#undef JIT_READER_DIR_RELOCATABLE
+
+/* Define if the platform has dlfcn.h. */
+#undef HAVE_DLFCN_H
diff --git a/gdb/configure b/gdb/configure
index 78cd9e9..f8d038c 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -10011,6 +10011,63 @@ fi
ac_config_files="$ac_config_files jit-reader.h:jit-reader.in"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
+$as_echo_n "checking for library containing dlopen... " >&6; }
+if test "${ac_cv_search_dlopen+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+/* Override any GCC internal prototype to avoid an error.
+ Use char because int might match the return type of a GCC
+ builtin and then its argument prototype would still apply. */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dlopen ();
+int
+main ()
+{
+return dlopen ();
+ ;
+ return 0;
+}
+_ACEOF
+for ac_lib in '' dl; do
+ if test -z "$ac_lib"; then
+ ac_res="none required"
+ else
+ ac_res=-l$ac_lib
+ LIBS="-l$ac_lib $ac_func_search_save_LIBS"
+ fi
+ if ac_fn_c_try_link "$LINENO"; then :
+ ac_cv_search_dlopen=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext
+ if test "${ac_cv_search_dlopen+set}" = set; then :
+ break
+fi
+done
+if test "${ac_cv_search_dlopen+set}" = set; then :
+
+else
+ ac_cv_search_dlopen=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
+$as_echo "$ac_cv_search_dlopen" >&6; }
+ac_res=$ac_cv_search_dlopen
+if test "$ac_res" != no; then :
+ test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+
# Check whether --with-jit-reader-dir was given.
@@ -11607,7 +11664,8 @@ for ac_header in nlist.h machine/reg.h poll.h sys/poll.h proc_service.h \
sys/resource.h sys/procfs.h sys/ptrace.h ptrace.h \
sys/reg.h sys/debugreg.h sys/select.h sys/syscall.h \
sys/types.h sys/wait.h wait.h termios.h termio.h \
- sgtty.h unistd.h elf_hp.h ctype.h time.h locale.h
+ sgtty.h unistd.h elf_hp.h ctype.h time.h locale.h \
+ dlfcn.h
do :
as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 4ecb5c9..cbbf647 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -627,6 +627,8 @@ fi
AC_SUBST(TARGET_PTR)
AC_CONFIG_FILES([jit-reader.h:jit-reader.in])
+AC_SEARCH_LIBS(dlopen, dl)
+
GDB_AC_WITH_DIR([JIT_READER_DIR], [jit-reader-dir],
[directory to load the JIT readers from],
[${libdir}/gdb])
@@ -981,7 +983,8 @@ AC_CHECK_HEADERS([nlist.h machine/reg.h poll.h sys/poll.h proc_service.h \
sys/resource.h sys/procfs.h sys/ptrace.h ptrace.h \
sys/reg.h sys/debugreg.h sys/select.h sys/syscall.h \
sys/types.h sys/wait.h wait.h termios.h termio.h \
- sgtty.h unistd.h elf_hp.h ctype.h time.h locale.h])
+ sgtty.h unistd.h elf_hp.h ctype.h time.h locale.h \
+ dlfcn.h])
AC_CHECK_HEADERS(link.h, [], [],
[#if HAVE_SYS_TYPES_H
# include <sys/types.h>
diff --git a/gdb/gdb-dlfcn.c b/gdb/gdb-dlfcn.c
new file mode 100644
index 0000000..604876e
--- /dev/null
+++ b/gdb/gdb-dlfcn.c
@@ -0,0 +1,143 @@
+/* Platform independent shared object routines for GDB.
+
+ Copyright (C) 2011 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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/>. */
+
+#include "defs.h"
+#include "gdb_assert.h"
+
+#include "gdb-dlfcn.h"
+
+#ifdef HAVE_DLFCN_H
+#include <dlfcn.h>
+#elif __MINGW32__
+#include <windows.h>
+#else
+/* Unsupported configuration. */
+#define NO_SHARED_LIB
+#endif
+
+#ifdef NO_SHARED_LIB
+
+void *
+gdb_dlopen (const char *filename)
+{
+ gdb_assert_not_reached ("gdb_dlopen should not be called on this platform.");
+ return NULL;
+}
+
+void *
+gdb_dlsym (void *handle, const char *symbol)
+{
+ gdb_assert_not_reached ("gdb_dlsym should not be called on this platform.");
+ return NULL;
+}
+
+struct cleanup *
+make_cleanup_dlclose (void *handle)
+{
+ gdb_assert_not_reached ("make_cleanup_dlclose should not be called on this "
+ "platform.");
+ return NULL;
+}
+
+int
+gdb_dlclose (void *handle)
+{
+ gdb_assert_not_reached ("gdb_dlclose should not be called on this platform.");
+ return 0;
+}
+
+int
+is_dl_available (void)
+{
+ return 0;
+}
+
+#else /* NO_SHARED_LIB */
+
+void *
+gdb_dlopen (const char *filename)
+{
+ void *result;
+#ifdef HAVE_DLFCN_H
+ result = dlopen (filename, RTLD_NOW);
+#elif __MINGW32__
+ result = (void *) LoadLibrary (filename);
+#endif
+ if (result != NULL)
+ return result;
+
+#ifdef HAVE_DLFCN_H
+ error (_("Could not load %s: %s"), filename, dlerror());
+#else
+ {
+ LPVOID buffer;
+ DWORD dw;
+
+ dw = GetLastError();
+
+ FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+ FORMAT_MESSAGE_IGNORE_INSERTS,
+ NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+ (LPTSTR) &buffer
+ 0, NULL);
+
+ error (_("Could not load %s: %s"), filename, (char *) buffer);
+ }
+#endif
+}
+
+void *
+gdb_dlsym (void *handle, const char *symbol)
+{
+#ifdef HAVE_DLFCN_H
+ return dlsym (handle, symbol);
+#elif __MINGW32__
+ return (void *) GetProcAddress (handle, symbol);
+#endif
+}
+
+int
+gdb_dlclose (void *handle)
+{
+#ifdef HAVE_DLFCN_H
+ return dlclose (handle);
+#elif __MINGW32__
+ return !((int) FreeLibrary (handle));
+#endif
+}
+
+static void
+do_dlclose_cleanup (void *handle)
+{
+ gdb_dlclose (handle);
+}
+
+struct cleanup *
+make_cleanup_dlclose (void *handle)
+{
+ return make_cleanup (do_dlclose_cleanup, handle);
+}
+
+int
+is_dl_available (void)
+{
+ return 1;
+}
+
+#endif /* NO_SHARED_LIB */
diff --git a/gdb/gdb-dlfcn.h b/gdb/gdb-dlfcn.h
new file mode 100644
index 0000000..0a9d1eb
--- /dev/null
+++ b/gdb/gdb-dlfcn.h
@@ -0,0 +1,51 @@
+/* Platform independent shared object routines for GDB.
+
+ Copyright (C) 2011 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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/>. */
+
+#ifndef GDB_DLFCN_H
+#define GDB_DLFCN_H
+
+#include "defs.h"
+
+/* Load the dynamic library file named FILENAME, and return a handle
+ for that dynamic library. Return NULL if the loading fails for any
+ reason. */
+
+void *gdb_dlopen (const char *filename);
+
+/* Return the address of the symbol named SYMBOL inside the shared
+ library whose handle is HANDLE. Return NULL when the symbol could
+ not be found. */
+
+void *gdb_dlsym (void *handle, const char *symbol);
+
+/* Install a cleanup routine which closes the handle HANDLE. */
+
+struct cleanup *make_cleanup_dlclose (void *handle);
+
+/* Cleanup the shared object pointed to by HANDLE. Return 0 on success
+ and nonzero on failure. */
+
+int gdb_dlclose (void *handle);
+
+/* Return non-zero if the dynamic library functions are available on
+ this platform. */
+
+int is_dl_available(void);
+
+#endif /* GDB_DLFCN_H */
--
1.7.7
>From 37080394ab35ec20f24fb7b7b294630090642562 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 4/7] New commands for loading and unloading a reader.
Introduces two new GDB commands - `load-jit-reader' and
`unload-jit-reader'. The commands are not added if the platform does
not support loading dynamic libraries.
gdb/ChangeLog:
* gdb/jit.c: Include gdb-dlfcn.h.
(loaded_jit_reader, reader_init_fn_sym): New static variables.
(jit_reader_load, jit_reader_load_command)
(jit_reader_unload_command): New functions.
(_initialize_jit): Add commands "jit-reader-load" and
"jit-reader-unload".
---
gdb/jit.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 100 insertions(+), 0 deletions(-)
diff --git a/gdb/jit.c b/gdb/jit.c
index af33a91..7cd70d0 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -31,6 +31,7 @@
#include "symfile.h"
#include "symtab.h"
#include "target.h"
+#include "gdb-dlfcn.h"
#include "gdb_stat.h"
static const char *jit_reader_dir = NULL;
@@ -115,6 +116,92 @@ mem_bfd_iovec_stat (struct bfd *abfd, void *stream, struct stat *sb)
return 0;
}
+/* One reader that has been loaded successfully, and can potentially be used to
+ parse debug info. */
+
+static struct jit_reader
+{
+ struct gdb_reader_funcs *functions;
+ void *handle;
+} *loaded_jit_reader = NULL;
+
+typedef struct gdb_reader_funcs * (reader_init_fn_type) (void);
+static const char *reader_init_fn_sym = "gdb_init_reader";
+
+/* Try to load FILE_NAME as a JIT debug info reader. */
+
+static struct jit_reader *
+jit_reader_load (const char *file_name)
+{
+ void *so;
+ reader_init_fn_type *init_fn;
+ struct jit_reader *new_reader = NULL;
+ struct gdb_reader_funcs *funcs = NULL;
+ struct cleanup *old_cleanups;
+
+ if (jit_debug)
+ fprintf_unfiltered (gdb_stdlog, _("Opening shared object %s.\n"),
+ file_name);
+ so = gdb_dlopen (file_name);
+ old_cleanups = make_cleanup_dlclose (so);
+
+ init_fn = gdb_dlsym (so, reader_init_fn_sym);
+ if (!init_fn)
+ error (_("Could not locate initialization function: %s."),
+ reader_init_fn_sym);
+
+ if (gdb_dlsym (so, "plugin_is_GPL_compatible") == NULL)
+ error (_("Reader not GPL compatible."));
+
+ funcs = init_fn ();
+ if (funcs->reader_version != GDB_READER_INTERFACE_VERSION)
+ error (_("Reader version does not match GDB version."));
+
+ new_reader = XZALLOC (struct jit_reader);
+ new_reader->functions = funcs;
+ new_reader->handle = so;
+
+ discard_cleanups (old_cleanups);
+ return new_reader;
+}
+
+/* Provides the jit-reader-load command. */
+
+static void
+jit_reader_load_command (char *args, int from_tty)
+{
+ char *so_name;
+ int len;
+ struct cleanup *prev_cleanup;
+
+ if (args == NULL)
+ error (_("No reader name provided."));
+
+ if (loaded_jit_reader != NULL)
+ error (_("JIT reader already loaded. Run jit-reader-unload first."));
+
+ so_name = xstrprintf ("%s/%s", jit_reader_dir, args);
+ prev_cleanup = make_cleanup (xfree, so_name);
+
+ loaded_jit_reader = jit_reader_load (so_name);
+ do_cleanups (prev_cleanup);
+}
+
+/* Provides the jit-reader-unload command. */
+
+static void
+jit_reader_unload_command (char *args, int from_tty)
+{
+ if (!loaded_jit_reader)
+ error (_("No JIT reader loaded."));
+
+ loaded_jit_reader->functions->destroy (loaded_jit_reader->functions);
+
+ gdb_dlclose (loaded_jit_reader->handle);
+ xfree (loaded_jit_reader);
+ loaded_jit_reader = NULL;
+}
+
/* Open a BFD from the target's memory. */
static struct bfd *
@@ -576,4 +663,17 @@ _initialize_jit (void)
jit_objfile_data = register_objfile_data ();
jit_inferior_data =
register_inferior_data_with_cleanup (jit_inferior_data_cleanup);
+ if (is_dl_available ())
+ {
+ add_com ("jit-reader-load", no_class, jit_reader_load_command, _("\
+Load FILE as debug info reader and unwinder for JIT compiled code.\n\
+Usage: jit-reader-load FILE\n\
+Try to load file FILE as a debug info reader (and unwinder) for\n\
+JIT compiled code. The file is loaded from " JIT_READER_DIR ",\n\
+relocated relative to the GDB executable if required."));
+ add_com ("jit-reader-unload", no_class, jit_reader_unload_command, _("\
+Unload the currently loaded JIT debug info reader.\n\
+Usage: jit-reader-unload FILE\n\n\
+Do \"help jit-reader-load\" for info on loading debug info readers."));
+ }
}
--
1.7.7
>From d53e49d4ed80d9abb35752a92a628cb422b0b8a3 Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 5/7] Use the loaded reader.
Invoke the loaded JIT debug info reader to parse the registered symbol
files.
gdb/ChangeLog:
* gdb/jit.c: Include block.h, dictionary.h and frame-unwind.h.
(add_objfile_entry, jit_target_read_impl, jit_object_open_impl)
(jit_symtab_open_impl, compare_block, jit_block_open_impl)
(jit_symtab_line_mapping_add_impl, jit_symtab_close_impl)
(finalize_symtab, jit_object_close_impl)
(jit_reader_try_read_symtab, jit_bfd_try_read_symtab)
(free_objfile_data): New functions.
(_initialize_jit): Register jit_objfile_data with a proper cleanup
function.
---
gdb/jit.c | 481 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 468 insertions(+), 13 deletions(-)
diff --git a/gdb/jit.c b/gdb/jit.c
index 7cd70d0..6010a36 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -21,8 +21,11 @@
#include "jit.h"
#include "jit-reader.h"
+#include "block.h"
#include "breakpoint.h"
#include "command.h"
+#include "dictionary.h"
+#include "frame-unwind.h"
#include "gdbcmd.h"
#include "gdbcore.h"
#include "inferior.h"
@@ -33,6 +36,7 @@
#include "target.h"
#include "gdb-dlfcn.h"
#include "gdb_stat.h"
+#include "exceptions.h"
static const char *jit_reader_dir = NULL;
@@ -228,6 +232,18 @@ struct jit_inferior_data
CORE_ADDR descriptor_addr; /* &__jit_debug_descriptor */
};
+/* Remember a mapping from entry_addr to objfile. */
+
+static void
+add_objfile_entry (struct objfile *objfile, CORE_ADDR entry)
+{
+ CORE_ADDR *entry_addr_ptr;
+
+ entry_addr_ptr = xmalloc (sizeof (CORE_ADDR));
+ *entry_addr_ptr = entry;
+ set_objfile_data (objfile, jit_objfile_data, entry_addr_ptr);
+}
+
/* Return jit_inferior_data for current inferior. Allocate if not already
present. */
@@ -330,14 +346,423 @@ jit_read_code_entry (struct gdbarch *gdbarch,
extract_unsigned_integer (&entry_buf[off], 8, byte_order);
}
-/* This function registers code associated with a JIT code entry. It uses the
- pointer and size pair in the entry to read the symbol file from the remote
- and then calls symbol_file_add_from_local_memory to add it as though it were
- a symbol file added by the user. */
+/* Proxy object for building a block. */
+
+struct gdb_block
+{
+ /* gdb_blocks are linked into a tree structure. Next points to the
+ next node at the same depth as this block and parent to the
+ parent gdb_block. */
+ struct gdb_block *next, *parent;
+
+ /* Points to the "real" block that is being built out of this
+ instance. This block will be added to a blockvector, which will
+ then be added to a symtab. */
+ struct block *real_block;
+
+ /* The first and last code address corresponding to this block. */
+ CORE_ADDR begin, end;
+
+ /* The name of this block (if any). If this is non-NULL, the
+ FUNCTION symbol symbol is set to this value. */
+ const char *name;
+};
+
+/* Proxy object for building a symtab. */
+
+struct gdb_symtab
+{
+ /* The list of blocks in this symtab. These will eventually be
+ converted to real blocks. */
+ struct gdb_block *blocks;
+
+ /* The number of blocks inserted. */
+ int nblocks;
+
+ /* A mapping between line numbers to PC. */
+ struct linetable *linetable;
+
+ /* The source file for this symtab. */
+ const char *file_name;
+ struct gdb_symtab *next;
+};
+
+/* Proxy object for building an object. */
+
+struct gdb_object
+{
+ struct gdb_symtab *symtabs;
+};
+
+/* The type of the `private' data passed around by the callback
+ functions. */
+
+typedef CORE_ADDR jit_dbg_reader_data;
+
+/* The reader calls into this function to read data off the targets
+ address space. */
+
+static enum gdb_status
+jit_target_read_impl (GDB_CORE_ADDR target_mem, void *gdb_buf, int len)
+{
+ int result = target_read_memory ((CORE_ADDR) target_mem, gdb_buf, len);
+ if (result == 0)
+ return GDB_SUCCESS;
+ else
+ return GDB_FAIL;
+}
+
+/* The reader calls into this function to create a new gdb_object
+ which it can then pass around to the other callbacks. Right now,
+ all that is required is allocating the memory. */
+
+static struct gdb_object *
+jit_object_open_impl (struct gdb_symbol_callbacks *cb)
+{
+ /* CB is not required right now, but sometime in the future we might
+ need a handle to it, and we'd like to do that without breaking
+ the ABI. */
+ return XZALLOC (struct gdb_object);
+}
+
+/* Readers call into this function to open a new gdb_symtab, which,
+ again, is passed around to other callbacks. */
+
+static struct gdb_symtab *
+jit_symtab_open_impl (struct gdb_symbol_callbacks *cb,
+ struct gdb_object *object,
+ const char *file_name)
+{
+ struct gdb_symtab *ret;
+
+ /* CB stays unused. See comment in jit_object_open_impl. */
+
+ ret = XZALLOC (struct gdb_symtab);
+ ret->file_name = file_name ? xstrdup (file_name) : xstrdup ("");
+ ret->next = object->symtabs;
+ object->symtabs = ret;
+ return ret;
+}
+
+/* Returns true if the block corresponding to old should be placed
+ before the block corresponding to new in the final blockvector. */
+
+static int
+compare_block (const struct gdb_block *const old,
+ const struct gdb_block *const new)
+{
+ if (old == NULL)
+ return 1;
+ if (old->begin < new->begin)
+ return 1;
+ else if (old->begin == new->begin)
+ {
+ if (old->end > new->end)
+ return 1;
+ else
+ return 0;
+ }
+ else
+ return 0;
+}
+
+/* Called by readers to open a new gdb_block. This function also
+ inserts the new gdb_block in the correct place in the corresponding
+ gdb_symtab. */
+
+static struct gdb_block *
+jit_block_open_impl (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *symtab, struct gdb_block *parent,
+ GDB_CORE_ADDR begin, GDB_CORE_ADDR end, const char *name)
+{
+ struct gdb_block *block = XZALLOC (struct gdb_block);
+
+ block->next = symtab->blocks;
+ block->begin = (CORE_ADDR) begin;
+ block->end = (CORE_ADDR) end;
+ block->name = name ? xstrdup (name) : NULL;
+ block->parent = parent;
+
+ /* Ensure that the blocks are inserted in the correct (reverse of
+ the order expected by blockvector). */
+ if (compare_block (symtab->blocks, block))
+ {
+ symtab->blocks = block;
+ }
+ else
+ {
+ struct gdb_block *i = symtab->blocks;
+
+ for (;; i = i->next)
+ {
+ /* Guaranteed to terminate, since compare_block (NULL, _)
+ returns 1. */
+ if (compare_block (i->next, block))
+ {
+ block->next = i->next;
+ i->next = block;
+ break;
+ }
+ }
+ }
+ symtab->nblocks++;
+
+ return block;
+}
+
+/* Readers call this to add a line mapping (from PC to line number) to
+ a gdb_symtab. */
static void
-jit_register_code (struct gdbarch *gdbarch,
- CORE_ADDR entry_addr, struct jit_code_entry *code_entry)
+jit_symtab_line_mapping_add_impl (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *stab, int nlines,
+ struct gdb_line_mapping *map)
+{
+ int i;
+
+ if (nlines < 1)
+ return;
+
+ stab->linetable = xmalloc (sizeof (struct linetable)
+ + (nlines - 1) * sizeof (struct linetable_entry));
+ stab->linetable->nitems = nlines;
+ for (i = 0; i < nlines; i++)
+ {
+ stab->linetable->item[i].pc = (CORE_ADDR) map[i].pc;
+ stab->linetable->item[i].line = map[i].line;
+ }
+}
+
+/* Called by readers to close a gdb_symtab. Does not need to do
+ anything as of now. */
+
+static void
+jit_symtab_close_impl (struct gdb_symbol_callbacks *cb,
+ struct gdb_symtab *stab)
+{
+ /* Right now nothing needs to be done here. We may need to do some
+ cleanup here in the future (again, without breaking the plugin
+ ABI). */
+}
+
+/* Transform STAB to a proper symtab, and add it it OBJFILE. */
+
+static void
+finalize_symtab (struct gdb_symtab *stab, struct objfile *objfile)
+{
+ struct symtab *symtab;
+ struct gdb_block *gdb_block_iter, *gdb_block_iter_tmp;
+ struct block *block_iter;
+ int actual_nblocks, i, blockvector_size;
+ CORE_ADDR begin, end;
+
+ actual_nblocks = FIRST_LOCAL_BLOCK + stab->nblocks;
+
+ symtab = allocate_symtab (stab->file_name, objfile);
+ /* JIT compilers compile in memory. */
+ symtab->dirname = NULL;
+
+ /* Copy over the linetable entry if one was provided. */
+ if (stab->linetable)
+ {
+ int size = ((stab->linetable->nitems - 1)
+ * sizeof (struct linetable_entry)
+ + sizeof (struct linetable));
+ LINETABLE (symtab) = obstack_alloc (&objfile->objfile_obstack, size);
+ memcpy (LINETABLE (symtab), stab->linetable, size);
+ }
+ else
+ {
+ LINETABLE (symtab) = NULL;
+ }
+
+ blockvector_size = (sizeof (struct blockvector)
+ + (actual_nblocks - 1) * sizeof (struct block *));
+ symtab->blockvector = obstack_alloc (&objfile->objfile_obstack,
+ blockvector_size);
+
+ /* (begin, end) will contain the PC range this entire blockvector
+ spans. */
+ symtab->primary = 1;
+ BLOCKVECTOR_MAP (symtab->blockvector) = NULL;
+ begin = stab->blocks->begin;
+ end = stab->blocks->end;
+ BLOCKVECTOR_NBLOCKS (symtab->blockvector) = actual_nblocks;
+
+ /* First run over all the gdb_block objects, creating a real block
+ object for each. Simultaneously, keep setting the real_block
+ fields. */
+ for (i = (actual_nblocks - 1), gdb_block_iter = stab->blocks;
+ i >= FIRST_LOCAL_BLOCK;
+ i--, gdb_block_iter = gdb_block_iter->next)
+ {
+ struct block *new_block = allocate_block (&objfile->objfile_obstack);
+ struct symbol *block_name = obstack_alloc (&objfile->objfile_obstack,
+ sizeof (struct symbol));
+
+ BLOCK_DICT (new_block) = dict_create_linear (&objfile->objfile_obstack,
+ NULL);
+ /* The address range. */
+ BLOCK_START (new_block) = (CORE_ADDR) gdb_block_iter->begin;
+ BLOCK_END (new_block) = (CORE_ADDR) gdb_block_iter->end;
+
+ /* The name. */
+ memset (block_name, 0, sizeof (struct symbol));
+ SYMBOL_DOMAIN (block_name) = VAR_DOMAIN;
+ SYMBOL_CLASS (block_name) = LOC_BLOCK;
+ SYMBOL_SYMTAB (block_name) = symtab;
+ SYMBOL_BLOCK_VALUE (block_name) = new_block;
+
+ block_name->ginfo.name = obsavestring (gdb_block_iter->name,
+ strlen (gdb_block_iter->name),
+ &objfile->objfile_obstack);
+
+ BLOCK_FUNCTION (new_block) = block_name;
+
+ BLOCKVECTOR_BLOCK (symtab->blockvector, i) = new_block;
+ if (begin > BLOCK_START (new_block))
+ begin = BLOCK_START (new_block);
+ if (end < BLOCK_END (new_block))
+ end = BLOCK_END (new_block);
+
+ gdb_block_iter->real_block = new_block;
+ }
+
+ /* Now add the special blocks. */
+ block_iter = NULL;
+ for (i = 0; i < FIRST_LOCAL_BLOCK; i++)
+ {
+ struct block *new_block = allocate_block (&objfile->objfile_obstack);
+ BLOCK_DICT (new_block) = dict_create_linear (&objfile->objfile_obstack,
+ NULL);
+ BLOCK_SUPERBLOCK (new_block) = block_iter;
+ block_iter = new_block;
+
+ BLOCK_START (new_block) = (CORE_ADDR) begin;
+ BLOCK_END (new_block) = (CORE_ADDR) end;
+
+ BLOCKVECTOR_BLOCK (symtab->blockvector, i) = new_block;
+ }
+
+ /* Fill up the superblock fields for the real blocks, using the
+ real_block fields populated earlier. */
+ for (gdb_block_iter = stab->blocks;
+ gdb_block_iter;
+ gdb_block_iter = gdb_block_iter->next)
+ {
+ if (gdb_block_iter->parent != NULL)
+ BLOCK_SUPERBLOCK (gdb_block_iter->real_block) =
+ gdb_block_iter->parent->real_block;
+ }
+
+ /* Free memory. */
+ gdb_block_iter = stab->blocks;
+
+ for (gdb_block_iter = stab->blocks, gdb_block_iter_tmp = gdb_block_iter->next;
+ gdb_block_iter;
+ gdb_block_iter = gdb_block_iter_tmp)
+ {
+ xfree ((void *) gdb_block_iter->name);
+ xfree (gdb_block_iter);
+ }
+ xfree (stab->linetable);
+ xfree ((char *) stab->file_name);
+ xfree (stab);
+}
+
+/* Called when closing a gdb_objfile. Converts OBJ to a proper
+ objfile. */
+
+static void
+jit_object_close_impl (struct gdb_symbol_callbacks *cb,
+ struct gdb_object *obj)
+{
+ struct gdb_symtab *i, *j;
+ struct objfile *objfile;
+ jit_dbg_reader_data *priv_data;
+
+ priv_data = cb->priv_data;
+
+ objfile = allocate_objfile (NULL, 0);
+ objfile->gdbarch = target_gdbarch;
+
+ objfile->msymbols = obstack_alloc (&objfile->objfile_obstack,
+ sizeof (struct minimal_symbol));
+ memset (objfile->msymbols, 0, sizeof (struct minimal_symbol));
+
+ xfree (objfile->name);
+ objfile->name = xstrdup ("<< JIT compiled code >>");
+
+ j = NULL;
+ for (i = obj->symtabs; i; i = j)
+ {
+ j = i->next;
+ finalize_symtab (i, objfile);
+ }
+ add_objfile_entry (objfile, *priv_data);
+ xfree (obj);
+}
+
+/* Try to read CODE_ENTRY using the loaded jit reader (if any). */
+
+static int
+jit_reader_try_read_symtab (struct jit_code_entry *code_entry)
+{
+ void *gdb_mem;
+ int status;
+ struct jit_dbg_reader *i;
+ jit_dbg_reader_data priv_data;
+ struct gdb_reader_funcs *funcs;
+ volatile struct gdb_exception e;
+ struct gdb_symbol_callbacks callbacks =
+ {
+ jit_object_open_impl,
+ jit_symtab_open_impl,
+ jit_block_open_impl,
+ jit_symtab_close_impl,
+ jit_object_close_impl,
+
+ jit_symtab_line_mapping_add_impl,
+ jit_target_read_impl,
+
+ &priv_data
+ };
+
+ priv_data = code_entry->symfile_addr;
+
+ if (!loaded_jit_reader)
+ return 0;
+
+ gdb_mem = xmalloc (code_entry->symfile_size);
+
+ status = 1;
+ TRY_CATCH (e, RETURN_MASK_ALL)
+ if (target_read_memory (code_entry->symfile_addr, gdb_mem,
+ code_entry->symfile_size))
+ status = 0;
+ if (e.reason < 0)
+ status = 0;
+
+ if (status)
+ {
+ funcs = loaded_jit_reader->functions;
+ if (funcs->read (funcs, &callbacks, gdb_mem, code_entry->symfile_size)
+ != GDB_SUCCESS)
+ status = 0;
+ }
+
+ xfree (gdb_mem);
+ if (jit_debug && status == 0)
+ fprintf_unfiltered (gdb_stdlog,
+ "Could not read symtab using the loaded JIT reader.\n");
+ return status;
+}
+
+/* Try to read CODE_ENTRY using BFD. */
+
+static void
+jit_bfd_try_read_symtab (struct jit_code_entry *code_entry,
+ struct gdbarch *gdbarch)
{
bfd *nbfd;
struct section_addr_info *sai;
@@ -346,7 +771,6 @@ jit_register_code (struct gdbarch *gdbarch,
struct cleanup *old_cleanups;
int i;
const struct bfd_arch_info *b;
- CORE_ADDR *entry_addr_ptr;
if (jit_debug)
fprintf_unfiltered (gdb_stdlog,
@@ -400,12 +824,34 @@ JITed symbol file is not an object file, ignoring it.\n"));
/* This call takes ownership of NBFD. It does not take ownership of SAI. */
objfile = symbol_file_add_from_bfd (nbfd, 0, sai, OBJF_SHARED, NULL);
- /* Remember a mapping from entry_addr to objfile. */
- entry_addr_ptr = xmalloc (sizeof (CORE_ADDR));
- *entry_addr_ptr = entry_addr;
- set_objfile_data (objfile, jit_objfile_data, entry_addr_ptr);
-
do_cleanups (old_cleanups);
+ add_objfile_entry (objfile, code_entry->symfile_addr);
+}
+
+/* This function registers code associated with a JIT code entry. It uses the
+ pointer and size pair in the entry to read the symbol file from the remote
+ and then calls symbol_file_add_from_local_memory to add it as though it were
+ a symbol file added by the user. */
+
+static void
+jit_register_code (struct gdbarch *gdbarch,
+ CORE_ADDR entry_addr, struct jit_code_entry *code_entry)
+{
+ int i, success;
+ const struct bfd_arch_info *b;
+ struct jit_inferior_data *inf_data = get_jit_inferior_data ();
+
+ if (jit_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ "jit_register_code, symfile_addr = %s, "
+ "symfile_size = %s\n",
+ paddress (gdbarch, code_entry->symfile_addr),
+ pulongest (code_entry->symfile_size));
+
+ success = jit_reader_try_read_symtab (code_entry);
+
+ if (!success)
+ jit_bfd_try_read_symtab (code_entry, gdbarch);
}
/* This function unregisters JITed code and frees the corresponding
@@ -640,6 +1086,14 @@ jit_event_handler (struct gdbarch *gdbarch)
}
}
+/* Called to free the data allocated to the jit_inferior_data slot. */
+
+static void
+free_objfile_data (struct objfile *objfile, void *data)
+{
+ xfree (data);
+}
+
/* Provide a prototype to silence -Wmissing-prototypes. */
extern void _initialize_jit (void);
@@ -660,7 +1114,8 @@ _initialize_jit (void)
observer_attach_inferior_created (jit_inferior_created_observer);
observer_attach_inferior_exit (jit_inferior_exit_hook);
observer_attach_executable_changed (jit_executable_changed_observer);
- jit_objfile_data = register_objfile_data ();
+ jit_objfile_data =
+ register_objfile_data_with_cleanup (NULL, free_objfile_data);
jit_inferior_data =
register_inferior_data_with_cleanup (jit_inferior_data_cleanup);
if (is_dl_available ())
--
1.7.7
>From 0fc08965906571f94372b55e58e49da572d8e21e Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Thu, 3 Nov 2011 12:22:32 +0530
Subject: [PATCH 6/7] New JIT unwinder.
Introduce a "proxy unwinder", whcih will pass down all calls to the
functions the JIT reader provides.
gdb/ChangeLog:
* gdb/jit.c: Include regcache.h.
(jit_gdbarch_data, jit_frame_unwind): New static variables.
(jit_unwind_reg_set_impl, free_reg_value_impl)
(jit_unwind_reg_get_impl, jit_frame_sniffer)
(jit_frame_unwind_stop_reason, jit_frame_this_id)
(jit_frame_prev_register, jit_dealloc_cache)
(jit_prepend_unwinder, jit_gdbarch_data_init): New functions.
(jit_inferior_init): Prepend (new) pseudo unwinder by calling
jit_prepend_unwinder.
(_initialize_jit): Register new gdbarch data jit_gdbarch_data.
Conflicts:
gdb/jit.c
---
gdb/jit.c | 259 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 259 insertions(+), 0 deletions(-)
diff --git a/gdb/jit.c b/gdb/jit.c
index 6010a36..7bd6b36 100644
--- a/gdb/jit.c
+++ b/gdb/jit.c
@@ -31,6 +31,7 @@
#include "inferior.h"
#include "observer.h"
#include "objfiles.h"
+#include "regcache.h"
#include "symfile.h"
#include "symtab.h"
#include "target.h"
@@ -50,6 +51,12 @@ static const struct inferior_data *jit_inferior_data = NULL;
static void jit_inferior_init (struct gdbarch *gdbarch);
+/* An unwinder is registered for every gdbarch. This key is used to
+ remember if the unwinder has been registered for a particular
+ gdbarch. */
+
+static struct gdbarch_data *jit_gdbarch_data;
+
/* Non-zero if we want to see trace of jit level stuff. */
static int jit_debug = 0;
@@ -920,6 +927,242 @@ jit_breakpoint_re_set_internal (struct gdbarch *gdbarch,
return 0;
}
+/* The private data passed around in the frame unwind callback
+ functions. */
+
+struct jit_unwind_private
+{
+ /* Cached register values. See jit_frame_sniffer to see how this
+ works. */
+ struct gdb_reg_value **registers;
+
+ /* The frame being unwound. */
+ struct frame_info *this_frame;
+};
+
+/* Sets the value of a particular register in this frame. */
+
+static void
+jit_unwind_reg_set_impl (struct gdb_unwind_callbacks *cb, int dwarf_regnum,
+ struct gdb_reg_value *value)
+{
+ struct jit_unwind_private *priv;
+ int gdb_reg;
+
+ priv = cb->priv_data;
+
+ gdb_reg = gdbarch_dwarf2_reg_to_regnum (get_frame_arch (priv->this_frame),
+ dwarf_regnum);
+ if (gdb_reg == -1)
+ {
+ if (jit_debug)
+ fprintf_unfiltered (gdb_stdlog,
+ _("Could not recognize DWARF regnum %d"),
+ dwarf_regnum);
+ return;
+ }
+
+ gdb_assert (priv->registers);
+ priv->registers[gdb_reg] = value;
+}
+
+static void
+reg_value_free_impl (struct gdb_reg_value *value)
+{
+ xfree (value);
+}
+
+/* Get the value of register REGNUM in the previous frame. */
+
+static struct gdb_reg_value *
+jit_unwind_reg_get_impl (struct gdb_unwind_callbacks *cb, int regnum)
+{
+ struct jit_unwind_private *priv;
+ struct gdb_reg_value *value;
+ int gdb_reg, size;
+ struct gdbarch *frame_arch;
+
+ priv = cb->priv_data;
+ frame_arch = get_frame_arch (priv->this_frame);
+
+ gdb_reg = gdbarch_dwarf2_reg_to_regnum (frame_arch, regnum);
+ size = register_size (frame_arch, gdb_reg);
+ value = xmalloc (sizeof (struct gdb_reg_value) + size - 1);
+ value->defined = frame_register_read (priv->this_frame, gdb_reg,
+ value->value);
+ value->size = size;
+ value->free = reg_value_free_impl;
+ return value;
+}
+
+/* gdb_reg_value has a free function, which must be called on each
+ saved register value. */
+
+static void
+jit_dealloc_cache (struct frame_info *this_frame, void *cache)
+{
+ struct jit_unwind_private *priv_data = cache;
+ struct gdbarch *frame_arch;
+ int i;
+
+ gdb_assert (priv_data->registers);
+ frame_arch = get_frame_arch (priv_data->this_frame);
+
+ for (i = 0; i < gdbarch_num_regs (frame_arch); i++)
+ if (priv_data->registers[i] && priv_data->registers[i]->free)
+ priv_data->registers[i]->free (priv_data->registers[i]);
+
+ xfree (priv_data->registers);
+ xfree (priv_data);
+}
+
+/* The frame sniffer for the pseudo unwinder.
+
+ While this is nominally a frame sniffer, in the case where the JIT
+ reader actually recognizes the frame, it does a lot more work -- it
+ unwinds the frame and saves the corresponding register values in
+ the cache. jit_frame_prev_register simply returns the saved
+ register values. */
+
+static int
+jit_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame, void **cache)
+{
+ struct jit_inferior_data *inf_data;
+ struct jit_unwind_private *priv_data;
+ struct jit_dbg_reader *iter;
+ struct gdb_unwind_callbacks callbacks;
+ struct gdb_reader_funcs *funcs;
+
+ inf_data = get_jit_inferior_data ();
+
+ callbacks.reg_get = jit_unwind_reg_get_impl;
+ callbacks.reg_set = jit_unwind_reg_set_impl;
+ callbacks.target_read = jit_target_read_impl;
+
+ if (loaded_jit_reader == NULL)
+ return 0;
+
+ funcs = loaded_jit_reader->functions;
+
+ gdb_assert (!*cache);
+
+ *cache = XZALLOC (struct jit_unwind_private);
+ priv_data = *cache;
+ priv_data->registers =
+ XCALLOC (gdbarch_num_regs (get_frame_arch (this_frame)),
+ struct gdb_reg_value *);
+ priv_data->this_frame = this_frame;
+
+ callbacks.priv_data = priv_data;
+
+ /* Try to coax the provided unwinder to unwind the stack */
+ if (funcs->unwind (funcs, &callbacks) == GDB_SUCCESS)
+ {
+ if (jit_debug)
+ fprintf_unfiltered (gdb_stdlog, _("Successfully unwound frame using "
+ "JIT reader.\n"));
+ return 1;
+ }
+ if (jit_debug)
+ fprintf_unfiltered (gdb_stdlog, _("Could not unwind frame using "
+ "JIT reader.\n"));
+
+ jit_dealloc_cache (this_frame, *cache);
+ *cache = NULL;
+
+ return 0;
+}
+
+
+/* The frame_id function for the pseudo unwinder. Relays the call to
+ the loaded plugin. */
+
+static void
+jit_frame_this_id (struct frame_info *this_frame, void **cache,
+ struct frame_id *this_id)
+{
+ struct jit_unwind_private private;
+ struct gdb_frame_id frame_id;
+ struct gdb_reader_funcs *funcs;
+ struct gdb_unwind_callbacks callbacks;
+
+ private.registers = NULL;
+ private.this_frame = this_frame;
+
+ /* We don't expect the frame_id function to set any registers, so we
+ set reg_set to NULL. */
+ callbacks.reg_get = jit_unwind_reg_get_impl;
+ callbacks.reg_set = NULL;
+ callbacks.target_read = jit_target_read_impl;
+ callbacks.priv_data = &private;
+
+ gdb_assert (loaded_jit_reader);
+ funcs = loaded_jit_reader->functions;
+
+ frame_id = funcs->get_frame_id (funcs, &callbacks);
+ *this_id = frame_id_build (frame_id.stack_address, frame_id.code_address);
+}
+
+/* Pseudo unwinder function. Reads the previously fetched value for
+ the register from the cache. */
+
+static struct value *
+jit_frame_prev_register (struct frame_info *this_frame, void **cache, int reg)
+{
+ struct jit_unwind_private *priv = *cache;
+ struct gdb_reg_value *value;
+
+ if (priv == NULL)
+ return frame_unwind_got_optimized (this_frame, reg);
+
+ gdb_assert (priv->registers);
+ value = priv->registers[reg];
+ if (value && value->defined)
+ return frame_unwind_got_bytes (this_frame, reg, value->value);
+ else
+ return frame_unwind_got_optimized (this_frame, reg);
+}
+
+/* Relay everything back to the unwinder registered by the JIT debug
+ info reader.*/
+
+static const struct frame_unwind jit_frame_unwind =
+{
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ jit_frame_this_id,
+ jit_frame_prev_register,
+ NULL,
+ jit_frame_sniffer,
+ jit_dealloc_cache
+};
+
+
+/* This is the information that is stored at jit_gdbarch_data for each
+ architecture. */
+
+struct jit_gdbarch_data_type
+{
+ /* Has the (pseudo) unwinder been prepended? */
+ int unwinder_registered;
+};
+
+/* Check GDBARCH and prepend the pseudo JIT unwinder if needed. */
+
+static void
+jit_prepend_unwinder (struct gdbarch *gdbarch)
+{
+ struct jit_gdbarch_data_type *data;
+
+ data = gdbarch_data (gdbarch, jit_gdbarch_data);
+ if (!data->unwinder_registered)
+ {
+ frame_unwind_prepend_unwinder (gdbarch, &jit_frame_unwind);
+ data->unwinder_registered = 1;
+ }
+}
+
/* Register any already created translations. */
static void
@@ -933,6 +1176,8 @@ jit_inferior_init (struct gdbarch *gdbarch)
if (jit_debug)
fprintf_unfiltered (gdb_stdlog, "jit_inferior_init\n");
+ jit_prepend_unwinder (gdbarch);
+
inf_data = get_jit_inferior_data ();
if (jit_breakpoint_re_set_internal (gdbarch, inf_data) != 0)
return;
@@ -1094,6 +1339,19 @@ free_objfile_data (struct objfile *objfile, void *data)
xfree (data);
}
+/* Initialize the jit_gdbarch_data slot with an instance of struct
+ jit_gdbarch_data_type */
+
+static void *
+jit_gdbarch_data_init (struct obstack *obstack)
+{
+ struct jit_gdbarch_data_type *data;
+
+ data = obstack_alloc (obstack, sizeof (struct jit_gdbarch_data_type));
+ data->unwinder_registered = 0;
+ return data;
+}
+
/* Provide a prototype to silence -Wmissing-prototypes. */
extern void _initialize_jit (void);
@@ -1118,6 +1376,7 @@ _initialize_jit (void)
register_objfile_data_with_cleanup (NULL, free_objfile_data);
jit_inferior_data =
register_inferior_data_with_cleanup (jit_inferior_data_cleanup);
+ jit_gdbarch_data = gdbarch_data_register_pre_init (jit_gdbarch_data_init);
if (is_dl_available ())
{
add_com ("jit-reader-load", no_class, jit_reader_load_command, _("\
--
1.7.7
>From 1b6d99afa919713457ab0e3b3f72086da68f0bda Mon Sep 17 00:00:00 2001
From: Sanjoy Das <sanjoy@playingwithpointers.com>
Date: Tue, 25 Oct 2011 18:50:53 +0530
Subject: [PATCH 7/7] Documentation.
Add some basic documentation to gdb.texinfo about the new JIT reader
functionality. Most of the actual documentation is still in
jit-reader.h.
gdb/doc/ChangeLog:
* gdb.texinfo (JIT Interface): Add documentation on writing and
usind JIT debug info readers.
(Custom Debug Info, Using JIT Debug Info Readers, Writing JIT
Debug Info Readers): New nodes.
---
gdb/doc/gdb.texinfo | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 117 insertions(+), 0 deletions(-)
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 25942b3..a53d8be 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -31709,6 +31709,7 @@ out about additional code.
* Declarations:: Relevant C struct declarations
* Registering Code:: Steps to register code
* Unregistering Code:: Steps to unregister code
+* Custom Debug Info:: Emit debug information in a custom format
@end menu
@node Declarations
@@ -31805,6 +31806,122 @@ Set @code{action_flag} to @code{JIT_UNREGISTER} and call
If the JIT frees or recompiles code without unregistering it, then @value{GDBN}
and the JIT will leak the memory used for the associated symbol files.
+@node Custom Debug Info
+@section Custom Debug Info
+@cindex custom JIT debug info
+@cindex JIT debug info reader
+
+Generating debug information in platform-native file formats (like ELF
+or COFF) may be an overkill for JIT compilers; especially if all the
+debug info is used for is displaying a meaningful backtrace. The
+issue can be resolved by having the JIT writers decide on a debug info
+format and also provide a reader that parses the debug info generated
+by the JIT compiler. This section gives a brief overview on writing
+such a parser. More specific details can be found in the source file
+@file{gdb/jit-reader.in}, which is also installed as a header at
+@file{@var{includedir}/gdb/jit-reader.h} for easy inclusion.
+
+The reader is implemented as a shared object (so this functionality is
+not available on platforms which don't allow loading shared objects at
+runtime). Two new @value{GDBN} commands, @code{jit-reader-load} and
+@code{jit-reader-unload} are provided, to be used to load and unload
+the readers from a preconfigured directory. Once loaded, the shared
+object is used the parse the debug information emitted by the JIT
+compiler.
+
+@menu
+* Using JIT Debug Info Readers:: How to use supplied readers correctly
+* Writing JIT Debug Info Readers:: Creating a debug-info reader
+@end menu
+
+@node Using JIT Debug Info Readers
+@subsection Using JIT Debug Info Readers
+@kindex jit-reader-load
+@kindex jit-reader-unload
+
+Readers can be loaded and unloaded using the @code{jit-reader-load}
+and @code{jit-reader-unload} commands.
+
+@table @code
+@item jit-reader-load @var{reader-name}
+
+Load the JIT reader named @var{reader-name}. On a UNIX system, this
+will usually result load @file{@var{libdir}/gdb/@var{reader-name}},
+where @var{libdir} is the system library directory, usually
+@file{/usr/local/lib}. Only one reader can be active at a time;
+trying to load a second reader when one is already loaded will result
+in @value{GDBN} reporting an error. A new JIT reader can be loaded by
+first unloading the current one using @code{jit-reader-load} and
+then invoking @code{jit-reader-load}.
+
+@item jit-reader-unload
+
+Unload the currently loaded JIT reader.
+
+@end table
+
+@node Writing JIT Debug Info Readers
+@subsection Writing JIT Debug Info Readers
+
+As mentioned, a reader is essentially a shared object conforming to a
+certain ABI. This ABI is described in @file{jit-reader.h}.
+
+@file{jit-reader.h} defines the structures, macros and functions
+required to write a reader. It is installed (along with
+@value{GDBN}), in @file{@var{includedir}/gdb} where @var{includedir} is
+the system include directory.
+
+Readers need to be released under a GPL compatible license. A reader
+can be declared as released under such a license by placing the macro
+@code{GDB_DECLARE_GPL_COMPATIBLE_READER} in a source file.
+
+The entry point for readers is the symbol @code{gdb_init_reader},
+which is expected to be a function with the prototype
+
+@findex gdb_init_reader
+@smallexample
+extern struct gdb_reader_funcs *gdb_init_reader (void);
+@end smallexample
+
+@cindex @code{struct gdb_reader_funcs}
+
+@code{struct gdb_reader_funcs} contains a set of pointers to callback
+functions. These functions are executed to read the debug info
+generated by the JIT compiler (@code{read}), to unwind stack frames
+(@code{unwind}) and to create canonical frame IDs
+(@code{get_Frame_id}). It also has a callback that is called when the
+reader is being unloaded (@code{destroy}). The struct looks like this
+
+@smallexample
+struct gdb_reader_funcs
+@{
+ /* Must be set to GDB_READER_INTERFACE_VERSION. */
+ int reader_version;
+
+ /* For use by the reader. */
+ void *priv_data;
+
+ gdb_read_debug_info *read;
+ gdb_unwind_frame *unwind;
+ gdb_get_frame_id *get_frame_id;
+ gdb_destroy_reader *destroy;
+@};
+@end smallexample
+
+@cindex @code{struct gdb_symbol_callbacks}
+@cindex @code{struct gdb_unwind_callbacks}
+
+The callbacks are provided with another set of callbacks by
+@value{GDBN} to do their job. For @code{read}, these callbacks are
+passed in a @code{struct gdb_symbol_callbacks} and for @code{unwind}
+and @code{get_frame_id}, in a @code{struct gdb_unwind_callbacks}.
+@code{struct gdb_symbol_callbacks} has callbacks to create new object
+files and new symbol tables inside those object files. @code{struct
+gdb_unwind_callbacks} has callbacks to read registers off the current
+frame and to write out the values of the registers in the previous
+frame. Both have a callback (@code{target_read}) to read bytes off the
+target's address space.
+
@node GDB Bugs
@chapter Reporting Bugs in @value{GDBN}
@cindex bugs in @value{GDBN}
--
1.7.7