compiler/purify/src/stack.c

   1 #include <stdio.h>
   2 #include <assert.h>
   3 #include "debug.h"
   4 #include "hash.h"
   5
   6 static MemHash * Purify_CurrentStackNode;
   7
   8 void Purify_InitStack (char * stackBase, long stackSize)
   9 {
  10     MemHash * node;
  11     char ** argv;
  12     int argc, t;
  13     long offset;
  14
  15     stackBase +=
  16         4 /* two arguments */
  17         +4 /* return address for main() */
  18         +8 /* two arguments for main() */
  19     ;
  20
  21 #if DEBUG
  22     printf ("Stack goes from %p to %p\n", stackBase - stackSize, stackBase);
  23 #endif
  24
  25     node = Purify_AddMemory (stackBase - stackSize
  26         , stackSize
  27         , PURIFY_MemFlag_Empty
  28         , PURIFY_MemType_Stack
  29     );
  30
  31     node->data = "Stack";
  32
  33     Purify_CurrentStackNode = node;
  34
  35     /* Major hack :-/ */
  36     argv = ((char ***)stackBase)[-1];
  37     argc = ((int *)stackBase)[-2];
  38
  39 #if 0
  40     printf ("&argc=%p\n", &((int *)stackBase)[-2]);
  41     printf ("argc=%d argv=%p\n", argc, argv);
  42 #endif
  43
  44     offset = (long)(&((int *)stackBase)[-2]) - (long)(node->mem);
  45
  46     Purify_SetMemoryFlags (node, offset, 8,
  47         PURIFY_MemFlag_Readable|PURIFY_MemFlag_Writable
  48     );
  49
  50     node = Purify_AddMemory (argv
  51         , (argc+1) * sizeof (char *)
  52         , PURIFY_MemFlag_Readable|PURIFY_MemFlag_Writable
  53         , PURIFY_MemType_Stack
  54     );
  55
  56     node->data = "argv[] array";
  57
  58     for (t=0; t<argc; t++)
  59     {
  60         node = Purify_AddMemory (argv[t]
  61             , strlen (argv[t]) + 1
  62             , PURIFY_MemFlag_Readable|PURIFY_MemFlag_Writable
  63             , PURIFY_MemType_Stack
  64         );
  65
  66         node->data = "argument string";
  67     }
  68
  69 #if DEBUG
  70     Purify_PrintMemory ();
  71 #endif
  72 }
  73
  74 void Purify_Push (char * stackBase, long pushSize)
  75 {
  76     long offset;
  77
  78     passert (Purify_CurrentStackNode);
  79     passert (Purify_CurrentStackNode->mem);
  80
  81 #if 0
  82     printf ("Push(): sp=%p, size=%ld fp=%p  stackBase=%p\n",
  83         stackBase, pushSize, (&offset)-1, Purify_CurrentStackNode->mem);
  84 #endif
  85
  86     stackBase += 4;
  87     stackBase -= pushSize;
  88
  89     offset = (long)stackBase - (long)(Purify_CurrentStackNode->mem);
  90
  91 #if 0
  92     printf ("offset=%d\n", offset);
  93 #endif
  94
  95     passert (offset >= 0);
  96
  97     Purify_SetMemoryFlags (Purify_CurrentStackNode, offset, pushSize,
  98         PURIFY_MemFlag_Readable|PURIFY_MemFlag_Writable
  99     );
 100 }
 101
 102 void Purify_Pop (char * stackBase, long popSize)
 103 {
 104     long offset;
 105
 106     passert (Purify_CurrentStackNode);
 107     passert (Purify_CurrentStackNode->mem);
 108
 109     stackBase += 4;
 110
 111     offset = (long)stackBase - (long)(Purify_CurrentStackNode->mem);
 112
 113     passert (offset >= 0);
 114
 115     Purify_SetMemoryFlags (Purify_CurrentStackNode, offset, popSize,
 116         PURIFY_MemFlag_Free
 117     );
 118 }
 119
 120 void Purify_Alloca (char * stackBase, long allocSize)
 121 {
 122     long offset;
 123
 124     passert (Purify_CurrentStackNode);
 125     passert (Purify_CurrentStackNode->mem);
 126
 127 #if 0
 128     printf ("alloca(): sp=%p, size=%ld fp=%p  stackBase=%p\n",
 129         stackBase, allocSize, (&offset)-1, Purify_CurrentStackNode->mem);
 130 #endif
 131
 132     stackBase += 4;
 133     stackBase -= allocSize;
 134
 135     offset = (long)stackBase - (long)(Purify_CurrentStackNode->mem);
 136
 137 #if 0
 138     printf ("offset=%ld\n", offset);
 139 #endif
 140
 141     passert (offset >= 0);
 142
 143     Purify_SetMemoryFlags (Purify_CurrentStackNode, offset, allocSize,
 144         PURIFY_MemFlag_Empty|PURIFY_MemFlag_Writable
 145     );
 146 }
 147
 148 void Purify_MoveSP (char * SP, char * newSP)
 149 {
 150     long dist;
 151
 152     dist = (long)newSP - (long)SP;
 153
 154     if (dist > 0)
 155         Purify_Pop (SP, dist);
 156     else if (dist < 0)
 157         Purify_Alloca (SP, -dist);
 158 }