[PATCH v4 06/14] add infcall_mmap and gcc_target_options gdbarch methods

Jan Kratochvil
2014-11-23T19:28:10Z

The compiler needed two new gdbarch methods.

The infcall_mmap method allocates memory in the inferior.
This is used when inserting the object code.

The gcc_target_options method computes some arch-specific gcc options
to pass to the compiler. This is used to ensure that gcc generates
object code for the correct architecture.

2014-10-07 Jan Kratochvil <jan.kratochvil@redhat.com>

* arch-utils.c (default_infcall_mmap)
(default_gcc_target_options): New functions.
* arch-utils.h (GDB_MMAP_PROT_READ, GDB_MMAP_PROT_WRITE)
(GDB_MMAP_PROT_EXEC): Define.
(default_infcall_mmap, default_gcc_target_options): Declare.
* gdbarch.h: Rebuild.
* gdbarch.c: Rebuild.
* gdbarch.sh (infcall_mmap, gcc_target_options): New methods.
---
gdb/ChangeLog | 11 +++++++++++
gdb/arch-utils.c | 16 ++++++++++++++++
gdb/arch-utils.h | 9 +++++++++
gdb/gdbarch.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
gdb/gdbarch.h | 17 +++++++++++++++++
gdb/gdbarch.sh | 11 +++++++++++
6 files changed, 110 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 951b7b5..d62748a 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,16 @@
2014-10-07 Jan Kratochvil <jan.kratochvil@redhat.com>

+ * arch-utils.c (default_infcall_mmap)
+ (default_gcc_target_options): New functions.
+ * arch-utils.h (GDB_MMAP_PROT_READ, GDB_MMAP_PROT_WRITE)
+ (GDB_MMAP_PROT_EXEC): Define.
+ (default_infcall_mmap, default_gcc_target_options): Declare.
+ * gdbarch.h: Rebuild.
+ * gdbarch.c: Rebuild.
+ * gdbarch.sh (infcall_mmap, gcc_target_options): New methods.
+
+2014-10-07 Jan Kratochvil <jan.kratochvil@redhat.com>
+
* dummy-frame.c (struct dummy_frame) <dtor, dtor_data>: New
fields.
(pop_dummy_frame): Call the destructor if it exists.
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index a2e76de..950912d 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -839,6 +839,22 @@ default_skip_permanent_breakpoint (struct regcache *regcache)
regcache_write_pc (regcache, current_pc);
}

+CORE_ADDR
+default_infcall_mmap (CORE_ADDR size, unsigned prot)
+{
+ error (_("This target does not support inferior memory allocation by mmap."));
+}
+
+/* -mcmodel=large is used so that no GOT (Global Offset Table) is needed to be
+ created in inferior memory by GDB (normally it is set by ld.so). */
+
+char *
+default_gcc_target_options (struct gdbarch *gdbarch)
+{
+ return xstrprintf ("-m%d%s", gdbarch_ptr_bit (gdbarch),
+ gdbarch_ptr_bit (gdbarch) == 64 ? " -mcmodel=large" : "");
+}
+
/* -Wmissing-prototypes */
extern initialize_file_ftype _initialize_gdbarch_utils;

diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index 1f5dd55..1ccb56a 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -186,4 +186,13 @@ extern int default_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *ra
module determines whether a breakpoint is permanent. */
extern void default_skip_permanent_breakpoint (struct regcache *regcache);

+/* Symbols for gdbarch_infcall_mmap; their Linux PROT_* system
+ definitions would be dependent on compilation host. */
+#define GDB_MMAP_PROT_READ 0x1 /* Page can be read. */
+#define GDB_MMAP_PROT_WRITE 0x2 /* Page can be written. */
+#define GDB_MMAP_PROT_EXEC 0x4 /* Page can be executed. */
+
+extern CORE_ADDR default_infcall_mmap (CORE_ADDR size, unsigned prot);
+extern char *default_gcc_target_options (struct gdbarch *gdbarch);
+
#endif
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index f89a6d2..7eb1e6b 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -318,6 +318,8 @@ struct gdbarch
gdbarch_insn_is_jump_ftype *insn_is_jump;
gdbarch_auxv_parse_ftype *auxv_parse;
gdbarch_vsyscall_range_ftype *vsyscall_range;
+ gdbarch_infcall_mmap_ftype *infcall_mmap;
+ gdbarch_gcc_target_options_ftype *gcc_target_options;
};

/* Create a new ``struct gdbarch'' based on information provided by
@@ -412,6 +414,8 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->insn_is_ret = default_insn_is_ret;
gdbarch->insn_is_jump = default_insn_is_jump;
gdbarch->vsyscall_range = default_vsyscall_range;
+ gdbarch->infcall_mmap = default_infcall_mmap;
+ gdbarch->gcc_target_options = default_gcc_target_options;
/* gdbarch_alloc() */

return gdbarch;
@@ -634,6 +638,8 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of insn_is_jump, invalid_p == 0 */
/* Skip verify of auxv_parse, has predicate. */
/* Skip verify of vsyscall_range, invalid_p == 0 */
+ /* Skip verify of infcall_mmap, invalid_p == 0 */
+ /* Skip verify of gcc_target_options, invalid_p == 0 */
buf = ui_file_xstrdup (log, &length);
make_cleanup (xfree, buf);
if (length > 0)
@@ -895,6 +901,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: frame_red_zone_size = %s\n",
plongest (gdbarch->frame_red_zone_size));
fprintf_unfiltered (file,
+ "gdbarch_dump: gcc_target_options = <%s>\n",
+ host_address_to_string (gdbarch->gcc_target_options));
+ fprintf_unfiltered (file,
"gdbarch_dump: gdbarch_gcore_bfd_target_p() = %d\n",
gdbarch_gcore_bfd_target_p (gdbarch));
fprintf_unfiltered (file,
@@ -961,6 +970,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: in_solib_return_trampoline = <%s>\n",
host_address_to_string (gdbarch->in_solib_return_trampoline));
fprintf_unfiltered (file,
+ "gdbarch_dump: infcall_mmap = <%s>\n",
+ host_address_to_string (gdbarch->infcall_mmap));
+ fprintf_unfiltered (file,
"gdbarch_dump: gdbarch_info_proc_p() = %d\n",
gdbarch_info_proc_p (gdbarch));
fprintf_unfiltered (file,
@@ -4441,6 +4453,40 @@ set_gdbarch_vsyscall_range (struct gdbarch *gdbarch,
gdbarch->vsyscall_range = vsyscall_range;
}

+CORE_ADDR
+gdbarch_infcall_mmap (struct gdbarch *gdbarch, CORE_ADDR size, unsigned prot)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->infcall_mmap != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_infcall_mmap called\n");
+ return gdbarch->infcall_mmap (size, prot);
+}
+
+void
+set_gdbarch_infcall_mmap (struct gdbarch *gdbarch,
+ gdbarch_infcall_mmap_ftype infcall_mmap)
+{
+ gdbarch->infcall_mmap = infcall_mmap;
+}
+
+char *
+gdbarch_gcc_target_options (struct gdbarch *gdbarch)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->gcc_target_options != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_gcc_target_options called\n");
+ return gdbarch->gcc_target_options (gdbarch);
+}
+
+void
+set_gdbarch_gcc_target_options (struct gdbarch *gdbarch,
+ gdbarch_gcc_target_options_ftype gcc_target_options)
+{
+ gdbarch->gcc_target_options = gcc_target_options;
+}
+

/* Keep a registry of per-architecture data-pointers required by GDB
modules. */
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 0bd1d56..304d136 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -1339,6 +1339,23 @@ typedef int (gdbarch_vsyscall_range_ftype) (struct gdbarch *gdbarch, struct mem_
extern int gdbarch_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range);
extern void set_gdbarch_vsyscall_range (struct gdbarch *gdbarch, gdbarch_vsyscall_range_ftype *vsyscall_range);

+/* Allocate SIZE bytes of PROT protected page aligned memory in inferior.
+ PROT has GDB_MMAP_PROT_* bitmask format.
+ Throw an error if it is not possible. Returned address is always valid. */
+
+typedef CORE_ADDR (gdbarch_infcall_mmap_ftype) (CORE_ADDR size, unsigned prot);
+extern CORE_ADDR gdbarch_infcall_mmap (struct gdbarch *gdbarch, CORE_ADDR size, unsigned prot);
+extern void set_gdbarch_infcall_mmap (struct gdbarch *gdbarch, gdbarch_infcall_mmap_ftype *infcall_mmap);
+
+/* Return string (caller has to use xfree for it) with options for GCC
+ to produce code for this target, typically "-m64", "-m32" or "-m31".
+ These options are put before CU's DW_AT_producer compilation options so that
+ they can override it. Method may also return NULL. */
+
+typedef char * (gdbarch_gcc_target_options_ftype) (struct gdbarch *gdbarch);
+extern char * gdbarch_gcc_target_options (struct gdbarch *gdbarch);
+extern void set_gdbarch_gcc_target_options (struct gdbarch *gdbarch, gdbarch_gcc_target_options_ftype *gcc_target_options);
+
/* Definition for an unknown syscall, used basically in error-cases. */
#define UNKNOWN_SYSCALL (-1)

diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 8aeb394..d3d4e57 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -1042,6 +1042,17 @@ M:int:auxv_parse:gdb_byte **readptr, gdb_byte *endptr, CORE_ADDR *typep, CORE_AD
# range with zero length is returned. Returns true if the vsyscall is
# found, false otherwise.
m:int:vsyscall_range:struct mem_range *range:range::default_vsyscall_range::0
+
+# Allocate SIZE bytes of PROT protected page aligned memory in inferior.
+# PROT has GDB_MMAP_PROT_* bitmask format.
+# Throw an error if it is not possible. Returned address is always valid.
+f:CORE_ADDR:infcall_mmap:CORE_ADDR size, unsigned prot:size, prot::default_infcall_mmap::0
+
+# Return string (caller has to use xfree for it) with options for GCC
+# to produce code for this target, typically "-m64", "-m32" or "-m31".
+# These options are put before CU's DW_AT_producer compilation options so that
+# they can override it. Method may also return NULL.
+m:char *:gcc_target_options:void:::default_gcc_target_options::0
EOF
}