diff options
Diffstat (limited to 'contrib/gcc/frame.c')
| -rw-r--r-- | contrib/gcc/frame.c | 53 |
1 files changed, 51 insertions, 2 deletions
diff --git a/contrib/gcc/frame.c b/contrib/gcc/frame.c index 4b62759..b5f643e 100644 --- a/contrib/gcc/frame.c +++ b/contrib/gcc/frame.c @@ -1,6 +1,6 @@ /* Subroutines needed for unwinding stack frames for exception handling. */ /* Compile this one with gcc. */ -/* Copyright (C) 1997 Free Software Foundation, Inc. +/* Copyright (C) 1997, 1998 Free Software Foundation, Inc. Contributed by Jason Merrill <jason@cygnus.com>. This file is part of GNU CC. @@ -46,7 +46,6 @@ Boston, MA 02111-1307, USA. */ #include "defaults.h" #ifdef DWARF2_UNWIND_INFO -#include "gansidecl.h" #include "dwarf2.h" #include <stddef.h> #include "frame.h" @@ -71,6 +70,25 @@ typedef unsigned int uaddr __attribute__ ((mode (pointer))); typedef int saddr __attribute__ ((mode (pointer))); typedef unsigned char ubyte; +/* Terminology: + CIE - Common Information Element + FDE - Frame Descriptor Element + + There is one per function, and it describes where the function code + is located, and what the register lifetimes and stack layout are + within the function. + + The data structures are defined in the DWARF specfication, although + not in a very readable way (see LITERATURE). + + Every time an exception is thrown, the code needs to locate the FDE + for the current function, and starts to look for exception regions + from that FDE. This works in a two-level search: + a) in a linear search, find the shared image (i.e. DLL) containing + the PC + b) using the FDE table for that shared object, locate the FDE using + binary search (which requires the sorting). */ + /* The first few fields of a CIE. The CIE_id field is 0 for a CIE, to distinguish it from a valid FDE. FDEs are aligned to an addressing unit boundary, but the fields within are unaligned. */ @@ -114,6 +132,33 @@ struct frame_state_internal struct frame_state s; struct frame_state_internal *saved_state; }; + +/* This is undefined below if we need it to be an actual function. */ +#define init_object_mutex_once() + +#if __GTHREADS +#ifdef __GTHREAD_MUTEX_INIT_FUNCTION + +/* Helper for init_object_mutex_once. */ + +static void +init_object_mutex (void) +{ + __GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex); +} + +/* Call this to arrange to initialize the object mutex. */ + +#undef init_object_mutex_once +static void +init_object_mutex_once (void) +{ + static __gthread_once_t once = __GTHREAD_ONCE_INIT; + __gthread_once (&once, init_object_mutex); +} + +#endif /* __GTHREAD_MUTEX_INIT_FUNCTION */ +#endif /* __GTHREADS */ /* Decode the unsigned LEB128 constant at BUF into the variable pointed to by R, and return the new value of BUF. */ @@ -468,6 +513,7 @@ find_fde (void *pc) struct object *ob; size_t lo, hi; + init_object_mutex_once (); __gthread_mutex_lock (&object_mutex); for (ob = objects; ob; ob = ob->next) @@ -685,6 +731,7 @@ __register_frame_info (void *begin, struct object *ob) ob->fde_array = 0; ob->count = 0; + init_object_mutex_once (); __gthread_mutex_lock (&object_mutex); ob->next = objects; @@ -713,6 +760,7 @@ __register_frame_info_table (void *begin, struct object *ob) ob->pc_begin = ob->pc_end = 0; ob->count = 0; + init_object_mutex_once (); __gthread_mutex_lock (&object_mutex); ob->next = objects; @@ -735,6 +783,7 @@ __deregister_frame_info (void *begin) { struct object **p; + init_object_mutex_once (); __gthread_mutex_lock (&object_mutex); p = &objects; |
