*/
#include "Rts.h"
#include "RtsUtils.h"
+#include "RtsFlags.h"
/* Heavily arch-specific, I'm afraid.. */
#if defined(i386_TARGET_ARCH)
-char*
+void*
createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
{
- void *adjustor,*adj;
+ void *adjustor;
unsigned char* adj_code;
- int i;
size_t sizeof_adjustor;
if (cconv == 0) { /* the adjustor will be _stdcall'ed */
(offset and machine code prefixed):
<0>: 58 popl %eax # temp. remove ret addr..
- <1>: 68 63 fd fc fe fa pushl 0xfafefcfd # constant is large enough to
+ <1>: 68 fd fc fe fa pushl 0xfafefcfd # constant is large enough to
# hold a StgStablePtr
<6>: 50 pushl %eax # put back ret. addr
<7>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr
<c>: ff e0 jmp %eax # and jump to it.
- # the callee cleans up the it will then clean up the stack
+ # the callee cleans up the stack
*/
- sizeof_adjustor = 15*sizeof(char);
+ sizeof_adjustor = 14*sizeof(char);
if ((adjustor = stgMallocBytes(sizeof_adjustor,"createAdjustor")) == NULL) {
return NULL;
}
- adj_code = (unsigned char*)adjustor;
- adj_code[0] = (unsigned char)0x58; /* popl %eax */
- adj_code[1] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
+ adj_code = (unsigned char*)adjustor;
+ adj_code[0x00] = (unsigned char)0x58; /* popl %eax */
- adj = (StgStablePtr*)(adj_code+2);
- *((StgStablePtr*)adj) = (StgStablePtr)hptr;
+ adj_code[0x01] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
+ *((StgStablePtr*)(adj_code + 0x02)) = (StgStablePtr)hptr;
- i = 2 + sizeof(StgStablePtr);
- adj_code[i] = (unsigned char)0x50; /* pushl %eax */
- adj_code[i+1] = (unsigned char)0xb8; /* movl $wptr, %eax */
- adj = (char*)(adj_code+i+2);
- *((StgFunPtr*)adj) = (StgFunPtr)wptr;
+ adj_code[0x06] = (unsigned char)0x50; /* pushl %eax */
+
+ adj_code[0x07] = (unsigned char)0xb8; /* movl $wptr, %eax */
+ *((StgFunPtr*)(adj_code + 0x08)) = (StgFunPtr)wptr;
+
+ adj_code[0x0c] = (unsigned char)0xff; /* jmp %eax */
+ adj_code[0x0d] = (unsigned char)0xe0;
- i = i+2+sizeof(StgFunPtr);
- adj_code[i] = (unsigned char)0xff; /* jmp %eax */
- adj_code[i+1] = (unsigned char)0xe0;
} else { /* the adjustor will be _ccall'ed */
the following assembly language snippet
(offset and machine code prefixed):
- <0>: 58 popl %eax # temp. remove ret addr..
- <1>: 68 63 fd fc fe fa pushl 0xfafefcfd # constant is large enough to
+ <00>: 68 ef be ad de pushl $0xdeadbeef # constant is large enough to
# hold a StgStablePtr
- <6>: 50 pushl %eax # put back ret. addr
- <7>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr
- <c>: ff d0 call %eax # and call it.
- <e>: 58 popl %eax # store away return address.
- <f>: 83 c4 04 addl $0x4,%esp # remove stable pointer
- <12>: 50 pushl %eax # put back return address.
- <13>: c3 ret # return to where you came from.
-
+ <05>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr
+ <0a>: ff d0 call %eax # and call it.
+ <0c>: 83 c4 04 addl $0x4,%esp # remove stable pointer.
+ <0f>: c3 ret # return to where you came from.
+
+ The ccall'ing version is a tad different, passing in the return
+ address of the caller to the auto-generated C stub (which enters
+ via the stable pointer.) (The auto-generated C stub is on this
+ game, don't worry :-)
+
+ The adjustor makes the assumption that any return value
+ coming back from the C stub is not stored on the stack.
+ That's (thankfully) the case here with the restricted set of
+ return types that we support.
*/
- sizeof_adjustor = 20*sizeof(char);
+ sizeof_adjustor = 16*sizeof(char);
if ((adjustor = stgMallocBytes(sizeof_adjustor,"createAdjustor")) == NULL) {
return NULL;
}
- adj_code = (unsigned char*)adjustor;
- adj_code[0] = (unsigned char)0x58; /* popl %eax */
- adj_code[1] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
-
- adj = (StgStablePtr*)(adj_code+2);
- *((StgStablePtr*)adj) = (StgStablePtr)hptr;
-
- i = 2 + sizeof(StgStablePtr);
- adj_code[i] = (unsigned char)0x50; /* pushl %eax */
- adj_code[i+1] = (unsigned char)0xb8; /* movl $wptr, %eax */
- adj = (char*)(adj_code+i+2);
- *((StgFunPtr*)adj) = (StgFunPtr)wptr;
-
- i = i+2+sizeof(StgFunPtr);
- adj_code[i] = (unsigned char)0xff; /* call %eax */
- adj_code[i+1] = (unsigned char)0xd0;
- adj_code[i+2] = (unsigned char)0x58; /* popl %eax */
- adj_code[i+3] = (unsigned char)0x83; /* addl $0x4, %esp */
- adj_code[i+4] = (unsigned char)0xc4;
- adj_code[i+5] = (unsigned char)0x04;
- adj_code[i+6] = (unsigned char)0x50; /* pushl %eax */
- adj_code[i+7] = (unsigned char)0xc3; /* ret */
+ adj_code = (unsigned char*)adjustor;
+
+ adj_code[0x00] = (unsigned char)0x68; /* pushl hptr (which is a dword immediate ) */
+ *((StgStablePtr*)(adj_code+0x01)) = (StgStablePtr)hptr;
+
+ adj_code[0x05] = (unsigned char)0xb8; /* movl $wptr, %eax */
+ *((StgFunPtr*)(adj_code + 0x06)) = (StgFunPtr)wptr;
+
+ adj_code[0x0a] = (unsigned char)0xff; /* call %eax */
+ adj_code[0x0b] = (unsigned char)0xd0;
+
+ adj_code[0x0c] = (unsigned char)0x83; /* addl $0x4, %esp */
+ adj_code[0x0d] = (unsigned char)0xc4;
+ adj_code[0x0e] = (unsigned char)0x04;
+
+ adj_code[0x0f] = (unsigned char)0xc3; /* ret */
+
}
/* Have fun! */
- return (adjustor);
+ return ((void*)adjustor);
}
void
freeHaskellFunctionPtr(void* ptr)
{
- char* tmp;
-
+ if ( *(unsigned char*)ptr != 0x68 &&
+ *(unsigned char*)ptr != 0x58 ) {
+ fprintf(stderr, "freeHaskellFunctionPtr: not for me, guv! %p\n", ptr);
+ return;
+ }
+
/* Free the stable pointer first..*/
- tmp=(char*)ptr+2;
- freeStablePointer(*((StgStablePtr*)tmp));
+ if (*(unsigned char*)ptr == 0x68) { /* Aha, a ccall adjustor! */
+ freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x01)));
+ } else {
+ freeStablePtr(*((StgStablePtr*)((unsigned char*)ptr + 0x02)));
+ }
+ *((unsigned char*)ptr) = '\0';
free(ptr);
}
projects / ghc-hetmet.git / blobdiff