From 0926a3ca0b5caabc00b8dad7912495a25f63d099 Mon Sep 17 00:00:00 2001
From: sof <unknown>
Date: Mon, 18 Jan 1999 14:35:21 +0000
Subject: [PATCH] [project @ 1999-01-18 14:35:20 by sof] Fixed a couple of bad
bugs in the implementation of 'foreign export ccall dynamic'.
---
ghc/compiler/deSugar/DsForeign.lhs | 32 ++++++--
ghc/rts/Adjustor.c | 120 +++++++++++++++--------------
2 files changed, 89 insertions(+), 63 deletions(-)
diff --git a/ghc/compiler/deSugar/DsForeign.lhs b/ghc/compiler/deSugar/DsForeign.lhs
index a151d44bb7f0..84ccaf4f8ae2 100644
--- a/ghc/compiler/deSugar/DsForeign.lhs
+++ b/ghc/compiler/deSugar/DsForeign.lhs
@@ -269,7 +269,7 @@ dsFExport i ty ext_name cconv isDyn =
Dynamic -> panic "dsFExport: Dynamic - shouldn't ever happen."
f_helper_glob = mkIdVisible mod uniq f_helper
- (h_stub, c_stub) = fexportEntry c_nm f_helper_glob wrapper_arg_tys the_result_ty cconv
+ (h_stub, c_stub) = fexportEntry c_nm f_helper_glob wrapper_arg_tys the_result_ty cconv isDyn
in
returnDs (NonRec f_helper_glob the_body, h_stub, c_stub)
@@ -430,8 +430,14 @@ The C stub constructs the application of the exported Haskell function
using the hugs/ghc rts invocation API.
\begin{code}
-fexportEntry :: FAST_STRING -> Id -> [Type] -> Maybe Type -> CallConv -> (SDoc, SDoc)
-fexportEntry c_nm helper args res cc = (header_bits, c_bits)
+fexportEntry :: FAST_STRING
+ -> Id
+ -> [Type]
+ -> Maybe Type
+ -> CallConv
+ -> Bool
+ -> (SDoc, SDoc)
+fexportEntry c_nm helper args res cc isDyn = (header_bits, c_bits)
where
-- name of the (Haskell) helper function generated by the desugarer.
h_nm = ppr helper <> text "_closure"
@@ -439,7 +445,7 @@ fexportEntry c_nm helper args res cc = (header_bits, c_bits)
header_bits = ptext SLIT("extern") <+> fun_proto <> semi
fun_proto = cResType <+> pprCconv <+> ptext c_nm <>
- parens (hsep (punctuate comma (zipWith (<+>) cParamTypes c_args)))
+ parens (hsep (punctuate comma (zipWith (<+>) cParamTypes proto_args)))
c_bits =
externDecl $$
@@ -458,7 +464,7 @@ fexportEntry c_nm helper args res cc = (header_bits, c_bits)
appArg acc (a,c_a) =
text "rts_apply" <> parens (acc <> comma <> mkHObj a <> parens c_a)
- cParamTypes = map showStgType args
+ cParamTypes = map showStgType real_args
cResType =
case res of
@@ -487,7 +493,21 @@ fexportEntry c_nm helper args res cc = (header_bits, c_bits)
Nothing -> empty
Just t -> unpackHObj t <> parens (text "ret")
- c_args = zipWith (\ _ n -> text ('a':show n)) args [0..]
+ c_args = mkCArgNames 0 args
+
+ {-
+ If we're generating an entry point for a 'foreign export ccall dynamic',
+ then we receive the return address of the C function that wants to
+ invoke a Haskell function as any other C function, as second arg.
+ This arg is unused within the body of the generated C stub, but
+ needed by the Adjustor.c code to get the stack cleanup right.
+ -}
+ (proto_args, real_args)
+ | cc == cCallConv && isDyn = ( text "a0" : text "a_" : mkCArgNames 1 (tail args)
+ , head args : addrTy : tail args)
+ | otherwise = (mkCArgNames 0 args, args)
+
+ mkCArgNames n as = zipWith (\ _ n -> text ('a':show n)) as [n..]
mkHObj :: Type -> SDoc
mkHObj t = text "rts_mk" <> showFFIType t
diff --git a/ghc/rts/Adjustor.c b/ghc/rts/Adjustor.c
index 11354c5ca52a..b976f38b2589 100644
--- a/ghc/rts/Adjustor.c
+++ b/ghc/rts/Adjustor.c
@@ -38,15 +38,15 @@ Haskell side.
*/
#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 */
@@ -56,35 +56,33 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
(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 */
@@ -92,60 +90,68 @@ createAdjustor(int cconv, StgStablePtr hptr, StgFunPtr wptr)
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! */
+ freeStablePointer(*((StgStablePtr*)((unsigned char*)ptr + 0x01)));
+ } else {
+ freeStablePointer(*((StgStablePtr*)((unsigned char*)ptr + 0x02)));
+ }
+ *((unsigned char*)ptr) = '\0';
free(ptr);
}
--
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