#include "annotate.h"
#include "valprint.h"
#include "source.h"
+#include "observer.h"
#ifndef ADA_RETAIN_DOTS
#define ADA_RETAIN_DOTS 0
static const char ADA_MAIN_PROGRAM_SYMBOL_NAME[]
= "__gnat_ada_main_program_name";
-/* The name of the runtime function called when an exception is raised. */
-static const char raise_sym_name[] = "__gnat_raise_nodefer_with_msg";
-
-/* The name of the runtime function called when an unhandled exception
- is raised. */
-static const char raise_unhandled_sym_name[] = "__gnat_unhandled_exception";
-
-/* The name of the runtime function called when an assert failure is
- raised. */
-static const char raise_assert_sym_name[] =
- "system__assertions__raise_assert_failure";
-
-/* A string that reflects the longest exception expression rewrite,
- aside from the exception name. */
-static const char longest_exception_template[] =
- "'__gnat_raise_nodefer_with_msg' if long_integer(e) = long_integer(&)";
-
/* Limit on the number of warnings to raise per expression evaluation. */
static int warning_limit = 2;
breakpoint structure of the BP_BREAKPOINT type, but with its own set
of breakpoint_ops.
+ Support in the runtime for exception catchpoints have been changed
+ a few times already, and these changes affect the implementation
+ of these catchpoints. In order to be able to support several
+ variants of the runtime, we use a sniffer that will determine
+ the runtime variant used by the program being debugged.
+
At this time, we do not support the use of conditions on Ada exception
catchpoints. The COND and COND_STRING fields are therefore set
to NULL (most of the time, see below).
ex_catch_assert
};
+typedef CORE_ADDR (ada_unhandled_exception_name_addr_ftype) (void);
+
+/* A structure that describes how to support exception catchpoints
+ for a given executable. */
+
+struct exception_support_info
+{
+ /* The name of the symbol to break on in order to insert
+ a catchpoint on exceptions. */
+ const char *catch_exception_sym;
+
+ /* The name of the symbol to break on in order to insert
+ a catchpoint on unhandled exceptions. */
+ const char *catch_exception_unhandled_sym;
+
+ /* The name of the symbol to break on in order to insert
+ a catchpoint on failed assertions. */
+ const char *catch_assert_sym;
+
+ /* Assuming that the inferior just triggered an unhandled exception
+ catchpoint, this function is responsible for returning the address
+ in inferior memory where the name of that exception is stored.
+ Return zero if the address could not be computed. */
+ ada_unhandled_exception_name_addr_ftype *unhandled_exception_name_addr;
+};
+
+static CORE_ADDR ada_unhandled_exception_name_addr (void);
+static CORE_ADDR ada_unhandled_exception_name_addr_from_raise (void);
+
+/* The following exception support info structure describes how to
+ implement exception catchpoints with the latest version of the
+ Ada runtime (as of 2007-03-06). */
+
+static const struct exception_support_info default_exception_support_info =
+{
+ "__gnat_debug_raise_exception", /* catch_exception_sym */
+ "__gnat_unhandled_exception", /* catch_exception_unhandled_sym */
+ "__gnat_debug_raise_assert_failure", /* catch_assert_sym */
+ ada_unhandled_exception_name_addr
+};
+
+/* The following exception support info structure describes how to
+ implement exception catchpoints with a slightly older version
+ of the Ada runtime. */
+
+static const struct exception_support_info exception_support_info_fallback =
+{
+ "__gnat_raise_nodefer_with_msg", /* catch_exception_sym */
+ "__gnat_unhandled_exception", /* catch_exception_unhandled_sym */
+ "system__assertions__raise_assert_failure", /* catch_assert_sym */
+ ada_unhandled_exception_name_addr_from_raise
+};
+
+/* For each executable, we sniff which exception info structure to use
+ and cache it in the following global variable. */
+
+static const struct exception_support_info *exception_info = NULL;
+
+/* Inspect the Ada runtime and determine which exception info structure
+ should be used to provide support for exception catchpoints.
+
+ This function will always set exception_info, or raise an error. */
+
+static void
+ada_exception_support_info_sniffer (void)
+{
+ struct symbol *sym;
+
+ /* If the exception info is already known, then no need to recompute it. */
+ if (exception_info != NULL)
+ return;
+
+ /* Check the latest (default) exception support info. */
+ sym = standard_lookup (default_exception_support_info.catch_exception_sym,
+ NULL, VAR_DOMAIN);
+ if (sym != NULL)
+ {
+ exception_info = &default_exception_support_info;
+ return;
+ }
+
+ /* Try our fallback exception suport info. */
+ sym = standard_lookup (exception_support_info_fallback.catch_exception_sym,
+ NULL, VAR_DOMAIN);
+ if (sym != NULL)
+ {
+ exception_info = &exception_support_info_fallback;
+ return;
+ }
+
+ /* Sometimes, it is normal for us to not be able to find the routine
+ we are looking for. This happens when the program is linked with
+ the shared version of the GNAT runtime, and the program has not been
+ started yet. Inform the user of these two possible causes if
+ applicable. */
+
+ if (ada_update_initial_language (language_unknown, NULL) != language_ada)
+ error (_("Unable to insert catchpoint. Is this an Ada main program?"));
+
+ /* If the symbol does not exist, then check that the program is
+ already started, to make sure that shared libraries have been
+ loaded. If it is not started, this may mean that the symbol is
+ in a shared library. */
+
+ if (ptid_get_pid (inferior_ptid) == 0)
+ error (_("Unable to insert catchpoint. Try to start the program first."));
+
+ /* At this point, we know that we are debugging an Ada program and
+ that the inferior has been started, but we still are not able to
+ find the run-time symbols. That can mean that we are in
+ configurable run time mode, or that a-except as been optimized
+ out by the linker... In any case, at this point it is not worth
+ supporting this feature. */
+
+ error (_("Cannot insert catchpoints in this configuration."));
+}
+
+/* An observer of "executable_changed" events.
+ Its role is to clear certain cached values that need to be recomputed
+ each time a new executable is loaded by GDB. */
+
+static void
+ada_executable_changed_observer (void *unused)
+{
+ /* If the executable changed, then it is possible that the Ada runtime
+ is different. So we need to invalidate the exception support info
+ cache. */
+ exception_info = NULL;
+}
+
/* Return the name of the function at PC, NULL if could not find it.
This function only checks the debugging information, not the symbol
table. */
static CORE_ADDR
ada_unhandled_exception_name_addr (void)
+{
+ return parse_and_eval_address ("e.full_name");
+}
+
+/* Same as ada_unhandled_exception_name_addr, except that this function
+ should be used when the inferior uses an older version of the runtime,
+ where the exception name needs to be extracted from a specific frame
+ several frames up in the callstack. */
+
+static CORE_ADDR
+ada_unhandled_exception_name_addr_from_raise (void)
{
int frame_level;
struct frame_info *fi;
const char *func_name =
function_name_from_pc (get_frame_address_in_block (fi));
if (func_name != NULL
- && strcmp (func_name, raise_sym_name) == 0)
+ && strcmp (func_name, exception_info->catch_exception_sym) == 0)
break; /* We found the frame we were looking for... */
fi = get_prev_frame (fi);
}
break;
case ex_catch_exception_unhandled:
- return ada_unhandled_exception_name_addr ();
+ return exception_info->unhandled_exception_name_addr ();
break;
case ex_catch_assert:
|| b->ops == &catch_assert_breakpoint_ops);
}
-/* Cause the appropriate error if no appropriate runtime symbol is
- found to set a breakpoint, using ERR_DESC to describe the
- breakpoint. */
-
-static void
-error_breakpoint_runtime_sym_not_found (const char *err_desc)
-{
- /* If we are not debugging an Ada program, we cannot put exception
- catchpoints! */
-
- if (ada_update_initial_language (language_unknown, NULL) != language_ada)
- error (_("Unable to break on %s. Is this an Ada main program?"),
- err_desc);
-
- /* If the symbol does not exist, then check that the program is
- already started, to make sure that shared libraries have been
- loaded. If it is not started, this may mean that the symbol is
- in a shared library. */
-
- if (ptid_get_pid (inferior_ptid) == 0)
- error (_("Unable to break on %s. Try to start the program first."),
- err_desc);
-
- /* At this point, we know that we are debugging an Ada program and
- that the inferior has been started, but we still are not able to
- find the run-time symbols. That can mean that we are in
- configurable run time mode, or that a-except as been optimized
- out by the linker... In any case, at this point it is not worth
- supporting this feature. */
-
- error (_("Cannot break on %s in this configuration."), err_desc);
-}
-
/* Return a newly allocated copy of the first space-separated token
in ARGSP, and then adjust ARGSP to point immediately after that
token.
static const char *
ada_exception_sym_name (enum exception_catchpoint_kind ex)
{
+ gdb_assert (exception_info != NULL);
+
switch (ex)
{
case ex_catch_exception:
- return (raise_sym_name);
+ return (exception_info->catch_exception_sym);
break;
case ex_catch_exception_unhandled:
- return (raise_unhandled_sym_name);
+ return (exception_info->catch_exception_unhandled_sym);
break;
case ex_catch_assert:
- return (raise_assert_sym_name);
+ return (exception_info->catch_assert_sym);
break;
default:
internal_error (__FILE__, __LINE__,
struct symbol *sym;
struct symtab_and_line sal;
- /* First lookup the function on which we will break in order to catch
+ /* First, find out which exception support info to use. */
+ ada_exception_support_info_sniffer ();
+
+ /* Then lookup the function on which we will break in order to catch
the Ada exceptions requested by the user. */
sym_name = ada_exception_sym_name (ex);
this case for now. */
if (sym == NULL)
- error_breakpoint_runtime_sym_not_found (sym_name);
+ error (_("Unable to break on '%s' in this configuration."), sym_name);
/* Make sure that the symbol we found corresponds to a function. */
if (SYMBOL_CLASS (sym) != LOC_BLOCK)
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