diff options
Diffstat (limited to 'rts/Adjustor.c')
| -rw-r--r-- | rts/Adjustor.c | 58 |
1 files changed, 9 insertions, 49 deletions
diff --git a/rts/Adjustor.c b/rts/Adjustor.c index 607c0b8abe..0d5829368f 100644 --- a/rts/Adjustor.c +++ b/rts/Adjustor.c @@ -47,7 +47,7 @@ Haskell side. #include <string.h> #endif -#if defined(i386_HOST_ARCH) && defined(darwin_HOST_OS) +#if defined(i386_HOST_ARCH) extern void adjustorCode(void); #elif defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH) // from AdjustorAsm.s @@ -288,7 +288,7 @@ typedef struct AdjustorStub { #endif #endif -#if defined(i386_HOST_ARCH) && defined(darwin_HOST_OS) +#if defined(i386_HOST_ARCH) /* !!! !!! WARNING: !!! !!! * This structure is accessed from AdjustorAsm.s @@ -304,7 +304,7 @@ typedef struct AdjustorStub { } AdjustorStub; #endif -#if (defined(i386_HOST_ARCH) && defined(darwin_HOST_OS)) || defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH) +#if defined(i386_HOST_ARCH) || defined(powerpc_HOST_ARCH) || defined(powerpc64_HOST_ARCH) static int totalArgumentSize(char *typeString) { int sz = 0; @@ -380,54 +380,14 @@ createAdjustor(int cconv, StgStablePtr hptr, break; case 1: /* _ccall */ -#if defined(i386_HOST_ARCH) && !defined(darwin_HOST_OS) - /* Magic constant computed by inspecting the code length of - the following assembly language snippet - (offset and machine code prefixed): - - <00>: 68 ef be ad de pushl $0xdeadbeef # constant is large enough to - # hold a StgStablePtr - <05>: b8 fa ef ff 00 movl $0x00ffeffa, %eax # load up wptr - <0a>: 68 ef be ad de pushl $obscure_ccall_ret_code # push the return address - <0f>: ff e0 jmp *%eax # jump to wptr - - 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 in on this - game, don't worry :-) - - See the comment next to obscure_ccall_ret_code why we need to - perform a tail jump instead of a call, followed by some C stack - fixup. - - Note: 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. - */ - adjustor = allocateExec(17,&code); - { - unsigned char *const 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)0x68; /* pushl obscure_ccall_ret_code */ - *((StgFunPtr*)(adj_code + 0x0b)) = - (StgFunPtr)obscure_ccall_ret_code; - - adj_code[0x0f] = (unsigned char)0xff; /* jmp *%eax */ - adj_code[0x10] = (unsigned char)0xe0; - } -#elif defined(i386_HOST_ARCH) && defined(darwin_HOST_OS) +#if defined(i386_HOST_ARCH) { /* - What's special about Darwin/Mac OS X on i386? - It wants the stack to stay 16-byte aligned. - + Most of the trickiness here is due to the need to keep the + stack pointer 16-byte aligned (see #5250). That means we + can't just push another argument on the stack and call the + wrapper, we may have to shuffle the whole argument block. + We offload most of the work to AdjustorAsm.S. */ AdjustorStub *adjustorStub = allocateExec(sizeof(AdjustorStub),&code); |