ocaml/runtime/caml/backtrace_prim.h

119 lines
4.8 KiB
C

/**************************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 2001 Institut National de Recherche en Informatique et */
/* en Automatique. */
/* */
/* All rights reserved. This file is distributed under the terms of */
/* the GNU Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
#ifndef CAML_BACKTRACE_PRIM_H
#define CAML_BACKTRACE_PRIM_H
#ifdef CAML_INTERNALS
#include "backtrace.h"
/* Backtrace generation is split in [backtrace.c] and [backtrace_prim].
*
* [backtrace_prim] contains all backend-specific
* code, and has two different
* implementations in [runtime/backtrace_byt.c] and [runtime/backtrace_nat.c].
*
* [backtrace.c] has a unique implementation, and exposes a uniform
* higher level API above [backtrace_{byt,nat}.c].
*/
/* Extract location information for the given raw_backtrace_slot */
struct caml_loc_info {
int loc_valid;
int loc_is_raise;
char * loc_filename;
char * loc_defname;
int loc_lnum;
int loc_startchr;
int loc_endchr;
int loc_is_inlined;
};
/* When compiling with -g, backtrace slots have debug info associated.
* When a call is inlined in native mode, debuginfos form a sequence.
*/
typedef void * debuginfo;
/* Check availability of debug information before extracting a trace.
* Relevant for bytecode, always true for native code. */
int caml_debug_info_available(void);
/* Check load status of debug information for the main program. This is always 1
* for native code. For bytecode, it is 1 if the debug information has been
* loaded, 0 if it has not been loaded or one of the error constants in
* startup.h if something went wrong loading the debug information. */
int caml_debug_info_status(void);
/* Return debuginfo associated to a slot or NULL. */
debuginfo caml_debuginfo_extract(backtrace_slot slot);
/* In case of an inlined call return next debuginfo or NULL otherwise. */
debuginfo caml_debuginfo_next(debuginfo dbg);
/* Extract locations from backtrace_slot */
void caml_debuginfo_location(debuginfo dbg, /*out*/ struct caml_loc_info * li);
/* In order to prevent the GC from walking through the debug
information (which have no headers), we transform slots to 31/63 bits
ocaml integers by shifting them by 1 to the right. We do not lose
information as slots are aligned.
In particular, we do not need to use [caml_modify] when setting
an array element with such a value.
*/
#define Val_backtrace_slot(bslot) (Val_long(((uintnat)(bslot))>>1))
#define Backtrace_slot_val(vslot) ((backtrace_slot)(Long_val(vslot) << 1))
/* Allocate Caml_state->backtrace_buffer. Returns 0 on success, -1 otherwise */
int caml_alloc_backtrace_buffer(void);
#ifndef NATIVE_CODE
/* These two functions are used by the bytecode runtime when loading
and unloading bytecode */
value caml_add_debug_info(code_t code_start, value code_size,
value events_heap);
value caml_remove_debug_info(code_t start);
#endif
#define BACKTRACE_BUFFER_SIZE 1024
/* Besides decoding backtrace info, [backtrace_prim] has two other
* responsibilities:
*
* It defines the [caml_stash_backtrace] function, which is called to quickly
* fill the backtrace buffer by walking the stack when an exception is raised.
*
* It also defines [caml_collect_current_callstack], which stores up
* to [max_frames] frames of the current call stack into the
* statically allocated buffer [*pbuffer] of length [*plen]. If the
* buffer is not long enough, it will be reallocated. The number of
* frames collected is returned.
*
* The alloc_idx parameter is used to select between the backtraces of
* different allocation sites which were combined by Comballoc.
* Passing -1 here means the caller doesn't care which is chosen.
*
* We use `intnat` for max_frames because, were it only `int`, passing
* `max_int` from the OCaml side would overflow on 64bits machines. */
intnat caml_collect_current_callstack(value** pbuffer, intnat* plen,
intnat max_frames, int alloc_idx);
#endif /* CAML_INTERNALS */
#endif /* CAML_BACKTRACE_PRIM_H */