/* alloca.c -- allocate automatically reclaimed memory
- (Mostly) portable public-domain implementation -- D A Gwyn
+ This file is in the public domain. */
+
+/* (Mostly) portable implementation -- D A Gwyn
This implementation of the PWB library alloca function,
which is used to allocate space off the run-time stack so
#include <string.h>
#include <stdlib.h>
-#ifdef emacs
-# include "lisp.h"
-# include "blockinput.h"
-# ifdef EMACS_FREE
-# undef free
-# define free EMACS_FREE
-# endif
-#else
-# define memory_full() abort ()
-#endif
-
-/* If compiling with GCC 2, this file's not needed. */
-#if !defined (__GNUC__) || __GNUC__ < 2
+/* If compiling with GCC or clang, this file is not needed. */
+#if !(defined __GNUC__ || defined __clang__)
/* If someone has defined alloca as a macro,
there must be some other way alloca is supposed to work. */
# ifndef alloca
-# ifdef emacs
-# ifdef static
-/* actually, only want this if static is defined as ""
- -- this is for usg, in which emacs must undefine static
- in order to make unexec workable
- */
-# ifndef STACK_DIRECTION
-you
-lose
--- must know STACK_DIRECTION at compile-time
-/* Using #error here is not wise since this file should work for
- old and obscure compilers. */
-# endif /* STACK_DIRECTION undefined */
-# endif /* static */
-# endif /* emacs */
-
-/* If your stack is a linked list of frames, you have to
- provide an "address metric" ADDRESS_FUNCTION macro. */
-
-# if defined (CRAY) && defined (CRAY_STACKSEG_END)
-long i00afunc ();
-# define ADDRESS_FUNCTION(arg) (char *) i00afunc (&(arg))
-# else
-# define ADDRESS_FUNCTION(arg) &(arg)
-# endif
-
/* Define STACK_DIRECTION if you know the direction of stack
growth for your system; otherwise it will be automatically
deduced at run-time.
alloca (size_t size)
{
auto char probe; /* Probes stack depth: */
- register char *depth = ADDRESS_FUNCTION (probe);
+ register char *depth = &probe;
# if STACK_DIRECTION == 0
if (STACK_DIR == 0) /* Unknown growth direction. */
{
register header *hp; /* Traverses linked list. */
-# ifdef emacs
- BLOCK_INPUT;
-# endif
-
for (hp = last_alloca_header; hp != NULL;)
if ((STACK_DIR > 0 && hp->h.deep > depth)
|| (STACK_DIR < 0 && hp->h.deep < depth))
break; /* Rest are not deeper. */
last_alloca_header = hp; /* -> last valid storage. */
-
-# ifdef emacs
- UNBLOCK_INPUT;
-# endif
}
if (size == 0)
}
}
-# if defined (CRAY) && defined (CRAY_STACKSEG_END)
-
-# ifdef DEBUG_I00AFUNC
-# include <stdio.h>
-# endif
-
-# ifndef CRAY_STACK
-# define CRAY_STACK
-# ifndef CRAY2
-/* Stack structures for CRAY-1, CRAY X-MP, and CRAY Y-MP */
-struct stack_control_header
- {
- long shgrow:32; /* Number of times stack has grown. */
- long shaseg:32; /* Size of increments to stack. */
- long shhwm:32; /* High water mark of stack. */
- long shsize:32; /* Current size of stack (all segments). */
- };
-
-/* The stack segment linkage control information occurs at
- the high-address end of a stack segment. (The stack
- grows from low addresses to high addresses.) The initial
- part of the stack segment linkage control information is
- 0200 (octal) words. This provides for register storage
- for the routine which overflows the stack. */
-
-struct stack_segment_linkage
- {
- long ss[0200]; /* 0200 overflow words. */
- long sssize:32; /* Number of words in this segment. */
- long ssbase:32; /* Offset to stack base. */
- long:32;
- long sspseg:32; /* Offset to linkage control of previous
- segment of stack. */
- long:32;
- long sstcpt:32; /* Pointer to task common address block. */
- long sscsnm; /* Private control structure number for
- microtasking. */
- long ssusr1; /* Reserved for user. */
- long ssusr2; /* Reserved for user. */
- long sstpid; /* Process ID for pid based multi-tasking. */
- long ssgvup; /* Pointer to multitasking thread giveup. */
- long sscray[7]; /* Reserved for Cray Research. */
- long ssa0;
- long ssa1;
- long ssa2;
- long ssa3;
- long ssa4;
- long ssa5;
- long ssa6;
- long ssa7;
- long sss0;
- long sss1;
- long sss2;
- long sss3;
- long sss4;
- long sss5;
- long sss6;
- long sss7;
- };
-
-# else /* CRAY2 */
-/* The following structure defines the vector of words
- returned by the STKSTAT library routine. */
-struct stk_stat
- {
- long now; /* Current total stack size. */
- long maxc; /* Amount of contiguous space which would
- be required to satisfy the maximum
- stack demand to date. */
- long high_water; /* Stack high-water mark. */
- long overflows; /* Number of stack overflow ($STKOFEN) calls. */
- long hits; /* Number of internal buffer hits. */
- long extends; /* Number of block extensions. */
- long stko_mallocs; /* Block allocations by $STKOFEN. */
- long underflows; /* Number of stack underflow calls ($STKRETN). */
- long stko_free; /* Number of deallocations by $STKRETN. */
- long stkm_free; /* Number of deallocations by $STKMRET. */
- long segments; /* Current number of stack segments. */
- long maxs; /* Maximum number of stack segments so far. */
- long pad_size; /* Stack pad size. */
- long current_address; /* Current stack segment address. */
- long current_size; /* Current stack segment size. This
- number is actually corrupted by STKSTAT to
- include the fifteen word trailer area. */
- long initial_address; /* Address of initial segment. */
- long initial_size; /* Size of initial segment. */
- };
-
-/* The following structure describes the data structure which trails
- any stack segment. I think that the description in 'asdef' is
- out of date. I only describe the parts that I am sure about. */
-
-struct stk_trailer
- {
- long this_address; /* Address of this block. */
- long this_size; /* Size of this block (does not include
- this trailer). */
- long unknown2;
- long unknown3;
- long link; /* Address of trailer block of previous
- segment. */
- long unknown5;
- long unknown6;
- long unknown7;
- long unknown8;
- long unknown9;
- long unknown10;
- long unknown11;
- long unknown12;
- long unknown13;
- long unknown14;
- };
-
-# endif /* CRAY2 */
-# endif /* not CRAY_STACK */
-
-# ifdef CRAY2
-/* Determine a "stack measure" for an arbitrary ADDRESS.
- I doubt that "lint" will like this much. */
-
-static long
-i00afunc (long *address)
-{
- struct stk_stat status;
- struct stk_trailer *trailer;
- long *block, size;
- long result = 0;
-
- /* We want to iterate through all of the segments. The first
- step is to get the stack status structure. We could do this
- more quickly and more directly, perhaps, by referencing the
- $LM00 common block, but I know that this works. */
-
- STKSTAT (&status);
-
- /* Set up the iteration. */
-
- trailer = (struct stk_trailer *) (status.current_address
- + status.current_size
- - 15);
-
- /* There must be at least one stack segment. Therefore it is
- a fatal error if "trailer" is null. */
-
- if (trailer == NULL)
- abort ();
-
- /* Discard segments that do not contain our argument address. */
-
- while (trailer != NULL)
- {
- block = (long *) trailer->this_address;
- size = trailer->this_size;
- if (block == NULL || size == 0)
- abort ();
- trailer = (struct stk_trailer *) trailer->link;
- if ((block <= address) && (address < (block + size)))
- break;
- }
-
- /* Set the result to the offset in this segment and add the sizes
- of all predecessor segments. */
-
- result = address - block;
-
- if (trailer == NULL)
- {
- return result;
- }
-
- do
- {
- if (trailer->this_size <= 0)
- abort ();
- result += trailer->this_size;
- trailer = (struct stk_trailer *) trailer->link;
- }
- while (trailer != NULL);
-
- /* We are done. Note that if you present a bogus address (one
- not in any segment), you will get a different number back, formed
- from subtracting the address of the first block. This is probably
- not what you want. */
-
- return (result);
-}
-
-# else /* not CRAY2 */
-/* Stack address function for a CRAY-1, CRAY X-MP, or CRAY Y-MP.
- Determine the number of the cell within the stack,
- given the address of the cell. The purpose of this
- routine is to linearize, in some sense, stack addresses
- for alloca. */
-
-static long
-i00afunc (long address)
-{
- long stkl = 0;
-
- long size, pseg, this_segment, stack;
- long result = 0;
-
- struct stack_segment_linkage *ssptr;
-
- /* Register B67 contains the address of the end of the
- current stack segment. If you (as a subprogram) store
- your registers on the stack and find that you are past
- the contents of B67, you have overflowed the segment.
-
- B67 also points to the stack segment linkage control
- area, which is what we are really interested in. */
-
- stkl = CRAY_STACKSEG_END ();
- ssptr = (struct stack_segment_linkage *) stkl;
-
- /* If one subtracts 'size' from the end of the segment,
- one has the address of the first word of the segment.
-
- If this is not the first segment, 'pseg' will be
- nonzero. */
-
- pseg = ssptr->sspseg;
- size = ssptr->sssize;
-
- this_segment = stkl - size;
-
- /* It is possible that calling this routine itself caused
- a stack overflow. Discard stack segments which do not
- contain the target address. */
-
- while (!(this_segment <= address && address <= stkl))
- {
-# ifdef DEBUG_I00AFUNC
- fprintf (stderr, "%011o %011o %011o\n", this_segment, address, stkl);
-# endif
- if (pseg == 0)
- break;
- stkl = stkl - pseg;
- ssptr = (struct stack_segment_linkage *) stkl;
- size = ssptr->sssize;
- pseg = ssptr->sspseg;
- this_segment = stkl - size;
- }
-
- result = address - this_segment;
-
- /* If you subtract pseg from the current end of the stack,
- you get the address of the previous stack segment's end.
- This seems a little convoluted to me, but I'll bet you save
- a cycle somewhere. */
-
- while (pseg != 0)
- {
-# ifdef DEBUG_I00AFUNC
- fprintf (stderr, "%011o %011o\n", pseg, size);
-# endif
- stkl = stkl - pseg;
- ssptr = (struct stack_segment_linkage *) stkl;
- size = ssptr->sssize;
- pseg = ssptr->sspseg;
- result += size;
- }
- return (result);
-}
-
-# endif /* not CRAY2 */
-# endif /* CRAY */
-
# endif /* no alloca */
-#endif /* not GCC 2 */
+#endif /* not GCC || clang */
projects / platform / upstream / make.git / blobdiff