| /* Memory mamagement routines. |
| Copyright 2002 Free Software Foundation, Inc. |
| Contributed by Paul Brook <paul@nowt.org> |
| |
| This file is part of the GNU Fortran 95 runtime library (libgfortran). |
| |
| Libgfortran 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 2 of the License, or (at your option) any later version. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combine |
| executable.) |
| |
| Libgfortran 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 libgfortran; see the file COPYING. If not, |
| write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "config.h" |
| #include <stdlib.h> |
| #include "libgfortran.h" |
| |
| /* If GFC_CLEAR_MEMORY is defined, the memory allocation routines will |
| return memory that is guaranteed to be set to zero. This can have |
| a severe efficiency penalty, so it should never be set if good |
| performance is desired, but it can help when you're debugging code. */ |
| /* #define GFC_CLEAR_MEMORY */ |
| |
| /* If GFC_CHECK_MEMORY is defined, we do some sanity checks at runtime. |
| This causes small overhead, but again, it also helps debugging. */ |
| #define GFC_CHECK_MEMORY |
| |
| /* We use a double linked list of these structures to keep track of |
| the memory we allocate internally. We could also use this for user |
| allocated memory (ALLOCATE/DEALLOCATE). This should be stored in a |
| seperate list. */ |
| typedef struct malloc_t |
| { |
| int magic; |
| int marker; |
| struct malloc_t *prev, *next; |
| |
| /* The start of the block. */ |
| void *data; |
| } |
| malloc_t; |
| |
| /* We try to make sure we don't get memory corruption by checking for |
| a magic number. */ |
| #define GFC_MALLOC_MAGIC 0x4d353941 /* "G95M" */ |
| |
| #define HEADER_SIZE offsetof (malloc_t, data) |
| #define DATA_POINTER(pheader) (&((pheader)->data)) |
| #define DATA_HEADER(pdata) ((malloc_t *)((char *) (pdata) - HEADER_SIZE)) |
| |
| /* The root of the circular double linked list for compiler generated |
| malloc calls. */ |
| static malloc_t mem_root = { |
| .next = &mem_root, |
| .prev = &mem_root |
| }; |
| |
| #if 0 |
| /* ??? Disabled because, well, it wasn't being called before transforming |
| it to a destructor, and turning it on causes testsuite failures. */ |
| /* Doesn't actually do any cleaning up, just throws an error if something |
| has got out of sync somewhere. */ |
| |
| static void __attribute__((destructor)) |
| runtime_cleanup (void) |
| { |
| /* Make sure all memory we've allocated is freed on exit. */ |
| if (mem_root.next != &mem_root) |
| runtime_error ("Unfreed memory on program termination"); |
| } |
| #endif |
| |
| |
| void * |
| get_mem (size_t n) |
| { |
| void *p; |
| |
| #ifdef GFC_CLEAR_MEMORY |
| p = (void *) calloc (1, n); |
| #else |
| p = (void *) malloc (n); |
| #endif |
| if (p == NULL) |
| os_error ("Memory allocation failed"); |
| |
| return p; |
| } |
| |
| |
| void |
| free_mem (void *p) |
| { |
| free (p); |
| } |
| |
| |
| /* Allocates a block of memory with a size of N bytes. N does not |
| include the size of the header. */ |
| |
| static malloc_t * |
| malloc_with_header (size_t n) |
| { |
| malloc_t *newmem; |
| |
| n = n + HEADER_SIZE; |
| |
| newmem = (malloc_t *) get_mem (n); |
| |
| if (newmem) |
| { |
| newmem->magic = GFC_MALLOC_MAGIC; |
| newmem->marker = 0; |
| } |
| |
| return newmem; |
| } |
| |
| |
| /* Allocate memory for internal (compiler generated) use. */ |
| |
| void * |
| internal_malloc_size (size_t size) |
| { |
| malloc_t *newmem; |
| |
| newmem = malloc_with_header (size); |
| |
| if (!newmem) |
| os_error ("Out of memory."); |
| |
| /* Add to end of list. */ |
| newmem->next = &mem_root; |
| newmem->prev = mem_root.prev; |
| mem_root.prev->next = newmem; |
| mem_root.prev = newmem; |
| |
| return DATA_POINTER (newmem); |
| } |
| |
| extern void *internal_malloc (GFC_INTEGER_4); |
| export_proto(internal_malloc); |
| |
| void * |
| internal_malloc (GFC_INTEGER_4 size) |
| { |
| #ifdef GFC_CHECK_MEMORY |
| /* Under normal circumstances, this is _never_ going to happen! */ |
| if (size < 0) |
| runtime_error ("Attempt to allocate a negative amount of memory."); |
| |
| #endif |
| return internal_malloc_size ((size_t) size); |
| } |
| |
| extern void *internal_malloc64 (GFC_INTEGER_8); |
| export_proto(internal_malloc64); |
| |
| void * |
| internal_malloc64 (GFC_INTEGER_8 size) |
| { |
| #ifdef GFC_CHECK_MEMORY |
| /* Under normal circumstances, this is _never_ going to happen! */ |
| if (size < 0) |
| runtime_error ("Attempt to allocate a negative amount of memory."); |
| #endif |
| return internal_malloc_size ((size_t) size); |
| } |
| |
| |
| /* Free internally allocated memory. Pointer is NULLified. Also used to |
| free user allocated memory. */ |
| /* TODO: keep a list of previously allocated blocks and reuse them. */ |
| |
| void |
| internal_free (void *mem) |
| { |
| malloc_t *m; |
| |
| if (!mem) |
| runtime_error ("Internal: Possible double free of temporary."); |
| |
| m = DATA_HEADER (mem); |
| |
| if (m->magic != GFC_MALLOC_MAGIC) |
| runtime_error ("Internal: No magic memblock marker. " |
| "Possible memory corruption"); |
| |
| /* Move markers up the chain, so they don't get lost. */ |
| m->prev->marker += m->marker; |
| /* Remove from list. */ |
| m->prev->next = m->next; |
| m->next->prev = m->prev; |
| |
| free (m); |
| } |
| iexport(internal_free); |
| |
| |
| /* User-allocate, one call for each member of the alloc-list of an |
| ALLOCATE statement. */ |
| |
| static void |
| allocate_size (void **mem, size_t size, GFC_INTEGER_4 * stat) |
| { |
| malloc_t *newmem; |
| |
| if (!mem) |
| runtime_error ("Internal: NULL mem pointer in ALLOCATE."); |
| |
| newmem = malloc_with_header (size); |
| if (!newmem) |
| { |
| if (stat) |
| { |
| *stat = 1; |
| return; |
| } |
| else |
| runtime_error ("ALLOCATE: Out of memory."); |
| } |
| |
| /* We don't keep a list of these at the moment, so just link to itself. */ |
| newmem->next = newmem; |
| newmem->prev = newmem; |
| |
| (*mem) = DATA_POINTER (newmem); |
| |
| if (stat) |
| *stat = 0; |
| } |
| |
| extern void allocate (void **, GFC_INTEGER_4, GFC_INTEGER_4 *); |
| export_proto(allocate); |
| |
| void |
| allocate (void **mem, GFC_INTEGER_4 size, GFC_INTEGER_4 * stat) |
| { |
| if (size < 0) |
| { |
| runtime_error ("Attempt to allocate negative amount of memory. " |
| "Possible integer overflow"); |
| abort (); |
| } |
| |
| allocate_size (mem, (size_t) size, stat); |
| } |
| |
| extern void allocate64 (void **, GFC_INTEGER_8, GFC_INTEGER_4 *); |
| export_proto(allocate64); |
| |
| void |
| allocate64 (void **mem, GFC_INTEGER_8 size, GFC_INTEGER_4 * stat) |
| { |
| if (size < 0) |
| { |
| runtime_error |
| ("ALLOCATE64: Attempt to allocate negative amount of memory. " |
| "Possible integer overflow"); |
| abort (); |
| } |
| |
| allocate_size (mem, (size_t) size, stat); |
| } |
| |
| |
| /* User-deallocate; pointer is NULLified. */ |
| |
| extern void deallocate (void **, GFC_INTEGER_4 *); |
| export_proto(deallocate); |
| |
| void |
| deallocate (void **mem, GFC_INTEGER_4 * stat) |
| { |
| if (!mem) |
| runtime_error ("Internal: NULL mem pointer in ALLOCATE."); |
| |
| if (!*mem) |
| { |
| if (stat) |
| { |
| *stat = 1; |
| return; |
| } |
| else |
| { |
| runtime_error |
| ("Internal: Attempt to DEALLOCATE unallocated memory."); |
| abort (); |
| } |
| } |
| |
| /* Just use the internal routine. */ |
| internal_free (*mem); |
| *mem = NULL; |
| |
| if (stat) |
| *stat = 0; |
| } |