Aegisub/vendor/luajit/src/lj_ccall.c

901 lines
27 KiB
C
Raw Normal View History

2014-04-28 04:45:14 +02:00
/*
** FFI C call handling.
2015-09-12 12:38:01 +02:00
** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
2014-04-28 04:45:14 +02:00
*/
#include "lj_obj.h"
#if LJ_HASFFI
#include "lj_gc.h"
#include "lj_err.h"
#include "lj_str.h"
#include "lj_tab.h"
#include "lj_ctype.h"
#include "lj_cconv.h"
#include "lj_cdata.h"
#include "lj_ccall.h"
#include "lj_trace.h"
/* Target-specific handling of register arguments. */
#if LJ_TARGET_X86
/* -- x86 calling conventions --------------------------------------------- */
#if LJ_ABI_WIN
#define CCALL_HANDLE_STRUCTRET \
/* Return structs bigger than 8 by reference (on stack only). */ \
cc->retref = (sz > 8); \
if (cc->retref) cc->stack[nsp++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET CCALL_HANDLE_STRUCTRET
#else
#if LJ_TARGET_OSX
#define CCALL_HANDLE_STRUCTRET \
/* Return structs of size 1, 2, 4 or 8 in registers. */ \
cc->retref = !(sz == 1 || sz == 2 || sz == 4 || sz == 8); \
if (cc->retref) { \
if (ngpr < maxgpr) \
cc->gpr[ngpr++] = (GPRArg)dp; \
else \
cc->stack[nsp++] = (GPRArg)dp; \
} else { /* Struct with single FP field ends up in FPR. */ \
cc->resx87 = ccall_classify_struct(cts, ctr); \
}
#define CCALL_HANDLE_STRUCTRET2 \
if (cc->resx87) sp = (uint8_t *)&cc->fpr[0]; \
memcpy(dp, sp, ctr->size);
#else
#define CCALL_HANDLE_STRUCTRET \
cc->retref = 1; /* Return all structs by reference (in reg or on stack). */ \
if (ngpr < maxgpr) \
cc->gpr[ngpr++] = (GPRArg)dp; \
else \
cc->stack[nsp++] = (GPRArg)dp;
#endif
#define CCALL_HANDLE_COMPLEXRET \
/* Return complex float in GPRs and complex double by reference. */ \
cc->retref = (sz > 8); \
if (cc->retref) { \
if (ngpr < maxgpr) \
cc->gpr[ngpr++] = (GPRArg)dp; \
else \
cc->stack[nsp++] = (GPRArg)dp; \
}
#endif
#define CCALL_HANDLE_COMPLEXRET2 \
if (!cc->retref) \
*(int64_t *)dp = *(int64_t *)sp; /* Copy complex float from GPRs. */
#define CCALL_HANDLE_STRUCTARG \
ngpr = maxgpr; /* Pass all structs by value on the stack. */
#define CCALL_HANDLE_COMPLEXARG \
isfp = 1; /* Pass complex by value on stack. */
#define CCALL_HANDLE_REGARG \
if (!isfp) { /* Only non-FP values may be passed in registers. */ \
if (n > 1) { /* Anything > 32 bit is passed on the stack. */ \
if (!LJ_ABI_WIN) ngpr = maxgpr; /* Prevent reordering. */ \
} else if (ngpr + 1 <= maxgpr) { \
dp = &cc->gpr[ngpr]; \
ngpr += n; \
goto done; \
} \
}
#elif LJ_TARGET_X64 && LJ_ABI_WIN
/* -- Windows/x64 calling conventions ------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
/* Return structs of size 1, 2, 4 or 8 in a GPR. */ \
cc->retref = !(sz == 1 || sz == 2 || sz == 4 || sz == 8); \
if (cc->retref) cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET CCALL_HANDLE_STRUCTRET
#define CCALL_HANDLE_COMPLEXRET2 \
if (!cc->retref) \
*(int64_t *)dp = *(int64_t *)sp; /* Copy complex float from GPRs. */
#define CCALL_HANDLE_STRUCTARG \
/* Pass structs of size 1, 2, 4 or 8 in a GPR by value. */ \
if (!(sz == 1 || sz == 2 || sz == 4 || sz == 8)) { \
rp = cdataptr(lj_cdata_new(cts, did, sz)); \
sz = CTSIZE_PTR; /* Pass all other structs by reference. */ \
}
#define CCALL_HANDLE_COMPLEXARG \
/* Pass complex float in a GPR and complex double by reference. */ \
if (sz != 2*sizeof(float)) { \
rp = cdataptr(lj_cdata_new(cts, did, sz)); \
sz = CTSIZE_PTR; \
}
/* Windows/x64 argument registers are strictly positional (use ngpr). */
#define CCALL_HANDLE_REGARG \
if (isfp) { \
if (ngpr < maxgpr) { dp = &cc->fpr[ngpr++]; nfpr = ngpr; goto done; } \
} else { \
if (ngpr < maxgpr) { dp = &cc->gpr[ngpr++]; goto done; } \
}
#elif LJ_TARGET_X64
/* -- POSIX/x64 calling conventions --------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
int rcl[2]; rcl[0] = rcl[1] = 0; \
if (ccall_classify_struct(cts, ctr, rcl, 0)) { \
cc->retref = 1; /* Return struct by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp; \
} else { \
cc->retref = 0; /* Return small structs in registers. */ \
}
#define CCALL_HANDLE_STRUCTRET2 \
int rcl[2]; rcl[0] = rcl[1] = 0; \
ccall_classify_struct(cts, ctr, rcl, 0); \
ccall_struct_ret(cc, rcl, dp, ctr->size);
#define CCALL_HANDLE_COMPLEXRET \
/* Complex values are returned in one or two FPRs. */ \
cc->retref = 0;
#define CCALL_HANDLE_COMPLEXRET2 \
if (ctr->size == 2*sizeof(float)) { /* Copy complex float from FPR. */ \
*(int64_t *)dp = cc->fpr[0].l[0]; \
} else { /* Copy non-contiguous complex double from FPRs. */ \
((int64_t *)dp)[0] = cc->fpr[0].l[0]; \
((int64_t *)dp)[1] = cc->fpr[1].l[0]; \
}
#define CCALL_HANDLE_STRUCTARG \
int rcl[2]; rcl[0] = rcl[1] = 0; \
if (!ccall_classify_struct(cts, d, rcl, 0)) { \
cc->nsp = nsp; cc->ngpr = ngpr; cc->nfpr = nfpr; \
if (ccall_struct_arg(cc, cts, d, rcl, o, narg)) goto err_nyi; \
nsp = cc->nsp; ngpr = cc->ngpr; nfpr = cc->nfpr; \
continue; \
} /* Pass all other structs by value on stack. */
#define CCALL_HANDLE_COMPLEXARG \
isfp = 2; /* Pass complex in FPRs or on stack. Needs postprocessing. */
#define CCALL_HANDLE_REGARG \
if (isfp) { /* Try to pass argument in FPRs. */ \
int n2 = ctype_isvector(d->info) ? 1 : n; \
if (nfpr + n2 <= CCALL_NARG_FPR) { \
dp = &cc->fpr[nfpr]; \
nfpr += n2; \
goto done; \
} \
} else { /* Try to pass argument in GPRs. */ \
/* Note that reordering is explicitly allowed in the x64 ABI. */ \
if (n <= 2 && ngpr + n <= maxgpr) { \
dp = &cc->gpr[ngpr]; \
ngpr += n; \
goto done; \
} \
}
#elif LJ_TARGET_ARM
/* -- ARM calling conventions --------------------------------------------- */
#if LJ_ABI_SOFTFP
#define CCALL_HANDLE_STRUCTRET \
/* Return structs of size <= 4 in a GPR. */ \
cc->retref = !(sz <= 4); \
if (cc->retref) cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET \
cc->retref = 1; /* Return all complex values by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET2 \
UNUSED(dp); /* Nothing to do. */
#define CCALL_HANDLE_STRUCTARG \
/* Pass all structs by value in registers and/or on the stack. */
#define CCALL_HANDLE_COMPLEXARG \
/* Pass complex by value in 2 or 4 GPRs. */
#define CCALL_HANDLE_REGARG_FP1
#define CCALL_HANDLE_REGARG_FP2
#else
#define CCALL_HANDLE_STRUCTRET \
cc->retref = !ccall_classify_struct(cts, ctr, ct); \
if (cc->retref) cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_STRUCTRET2 \
if (ccall_classify_struct(cts, ctr, ct) > 1) sp = (uint8_t *)&cc->fpr[0]; \
memcpy(dp, sp, ctr->size);
#define CCALL_HANDLE_COMPLEXRET \
if (!(ct->info & CTF_VARARG)) cc->retref = 0; /* Return complex in FPRs. */
#define CCALL_HANDLE_COMPLEXRET2 \
if (!(ct->info & CTF_VARARG)) memcpy(dp, &cc->fpr[0], ctr->size);
#define CCALL_HANDLE_STRUCTARG \
isfp = (ccall_classify_struct(cts, d, ct) > 1);
/* Pass all structs by value in registers and/or on the stack. */
#define CCALL_HANDLE_COMPLEXARG \
isfp = 1; /* Pass complex by value in FPRs or on stack. */
#define CCALL_HANDLE_REGARG_FP1 \
if (isfp && !(ct->info & CTF_VARARG)) { \
if ((d->info & CTF_ALIGN) > CTALIGN_PTR) { \
if (nfpr + (n >> 1) <= CCALL_NARG_FPR) { \
dp = &cc->fpr[nfpr]; \
nfpr += (n >> 1); \
goto done; \
} \
} else { \
if (sz > 1 && fprodd != nfpr) fprodd = 0; \
if (fprodd) { \
if (2*nfpr+n <= 2*CCALL_NARG_FPR+1) { \
dp = (void *)&cc->fpr[fprodd-1].f[1]; \
nfpr += (n >> 1); \
if ((n & 1)) fprodd = 0; else fprodd = nfpr-1; \
goto done; \
} \
} else { \
if (2*nfpr+n <= 2*CCALL_NARG_FPR) { \
dp = (void *)&cc->fpr[nfpr]; \
nfpr += (n >> 1); \
if ((n & 1)) fprodd = ++nfpr; else fprodd = 0; \
goto done; \
} \
} \
} \
fprodd = 0; /* No reordering after the first FP value is on stack. */ \
} else {
#define CCALL_HANDLE_REGARG_FP2 }
#endif
#define CCALL_HANDLE_REGARG \
CCALL_HANDLE_REGARG_FP1 \
if ((d->info & CTF_ALIGN) > CTALIGN_PTR) { \
if (ngpr < maxgpr) \
ngpr = (ngpr + 1u) & ~1u; /* Align to regpair. */ \
} \
if (ngpr < maxgpr) { \
dp = &cc->gpr[ngpr]; \
if (ngpr + n > maxgpr) { \
nsp += ngpr + n - maxgpr; /* Assumes contiguous gpr/stack fields. */ \
if (nsp > CCALL_MAXSTACK) goto err_nyi; /* Too many arguments. */ \
ngpr = maxgpr; \
} else { \
ngpr += n; \
} \
goto done; \
} CCALL_HANDLE_REGARG_FP2
#define CCALL_HANDLE_RET \
if ((ct->info & CTF_VARARG)) sp = (uint8_t *)&cc->gpr[0];
#elif LJ_TARGET_PPC
/* -- PPC calling conventions --------------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
cc->retref = 1; /* Return all structs by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET \
/* Complex values are returned in 2 or 4 GPRs. */ \
cc->retref = 0;
#define CCALL_HANDLE_COMPLEXRET2 \
memcpy(dp, sp, ctr->size); /* Copy complex from GPRs. */
#define CCALL_HANDLE_STRUCTARG \
rp = cdataptr(lj_cdata_new(cts, did, sz)); \
sz = CTSIZE_PTR; /* Pass all structs by reference. */
#define CCALL_HANDLE_COMPLEXARG \
/* Pass complex by value in 2 or 4 GPRs. */
#define CCALL_HANDLE_REGARG \
if (isfp) { /* Try to pass argument in FPRs. */ \
if (nfpr + 1 <= CCALL_NARG_FPR) { \
dp = &cc->fpr[nfpr]; \
nfpr += 1; \
d = ctype_get(cts, CTID_DOUBLE); /* FPRs always hold doubles. */ \
goto done; \
} \
} else { /* Try to pass argument in GPRs. */ \
if (n > 1) { \
lua_assert(n == 2 || n == 4); /* int64_t or complex (float). */ \
if (ctype_isinteger(d->info)) \
ngpr = (ngpr + 1u) & ~1u; /* Align int64_t to regpair. */ \
else if (ngpr + n > maxgpr) \
ngpr = maxgpr; /* Prevent reordering. */ \
} \
if (ngpr + n <= maxgpr) { \
dp = &cc->gpr[ngpr]; \
ngpr += n; \
goto done; \
} \
}
#define CCALL_HANDLE_RET \
if (ctype_isfp(ctr->info) && ctr->size == sizeof(float)) \
ctr = ctype_get(cts, CTID_DOUBLE); /* FPRs always hold doubles. */
#elif LJ_TARGET_PPCSPE
/* -- PPC/SPE calling conventions ----------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
cc->retref = 1; /* Return all structs by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET \
/* Complex values are returned in 2 or 4 GPRs. */ \
cc->retref = 0;
#define CCALL_HANDLE_COMPLEXRET2 \
memcpy(dp, sp, ctr->size); /* Copy complex from GPRs. */
#define CCALL_HANDLE_STRUCTARG \
rp = cdataptr(lj_cdata_new(cts, did, sz)); \
sz = CTSIZE_PTR; /* Pass all structs by reference. */
#define CCALL_HANDLE_COMPLEXARG \
/* Pass complex by value in 2 or 4 GPRs. */
/* PPC/SPE has a softfp ABI. */
#define CCALL_HANDLE_REGARG \
if (n > 1) { /* Doesn't fit in a single GPR? */ \
lua_assert(n == 2 || n == 4); /* int64_t, double or complex (float). */ \
if (n == 2) \
ngpr = (ngpr + 1u) & ~1u; /* Only align 64 bit value to regpair. */ \
else if (ngpr + n > maxgpr) \
ngpr = maxgpr; /* Prevent reordering. */ \
} \
if (ngpr + n <= maxgpr) { \
dp = &cc->gpr[ngpr]; \
ngpr += n; \
goto done; \
}
#elif LJ_TARGET_MIPS
/* -- MIPS calling conventions -------------------------------------------- */
#define CCALL_HANDLE_STRUCTRET \
cc->retref = 1; /* Return all structs by reference. */ \
cc->gpr[ngpr++] = (GPRArg)dp;
#define CCALL_HANDLE_COMPLEXRET \
/* Complex values are returned in 1 or 2 FPRs. */ \
cc->retref = 0;
#define CCALL_HANDLE_COMPLEXRET2 \
if (ctr->size == 2*sizeof(float)) { /* Copy complex float from FPRs. */ \
((float *)dp)[0] = cc->fpr[0].f; \
((float *)dp)[1] = cc->fpr[1].f; \
} else { /* Copy complex double from FPRs. */ \
((double *)dp)[0] = cc->fpr[0].d; \
((double *)dp)[1] = cc->fpr[1].d; \
}
#define CCALL_HANDLE_STRUCTARG \
/* Pass all structs by value in registers and/or on the stack. */
#define CCALL_HANDLE_COMPLEXARG \
/* Pass complex by value in 2 or 4 GPRs. */
#define CCALL_HANDLE_REGARG \
if (isfp && nfpr < CCALL_NARG_FPR && !(ct->info & CTF_VARARG)) { \
/* Try to pass argument in FPRs. */ \
dp = n == 1 ? (void *)&cc->fpr[nfpr].f : (void *)&cc->fpr[nfpr].d; \
nfpr++; ngpr += n; \
goto done; \
} else { /* Try to pass argument in GPRs. */ \
nfpr = CCALL_NARG_FPR; \
if ((d->info & CTF_ALIGN) > CTALIGN_PTR) \
ngpr = (ngpr + 1u) & ~1u; /* Align to regpair. */ \
if (ngpr < maxgpr) { \
dp = &cc->gpr[ngpr]; \
if (ngpr + n > maxgpr) { \
nsp += ngpr + n - maxgpr; /* Assumes contiguous gpr/stack fields. */ \
if (nsp > CCALL_MAXSTACK) goto err_nyi; /* Too many arguments. */ \
ngpr = maxgpr; \
} else { \
ngpr += n; \
} \
goto done; \
} \
}
#define CCALL_HANDLE_RET \
if (ctype_isfp(ctr->info) && ctr->size == sizeof(float)) \
sp = (uint8_t *)&cc->fpr[0].f;
#else
#error "Missing calling convention definitions for this architecture"
#endif
#ifndef CCALL_HANDLE_STRUCTRET2
#define CCALL_HANDLE_STRUCTRET2 \
memcpy(dp, sp, ctr->size); /* Copy struct return value from GPRs. */
#endif
/* -- x86 OSX ABI struct classification ----------------------------------- */
#if LJ_TARGET_X86 && LJ_TARGET_OSX
/* Check for struct with single FP field. */
static int ccall_classify_struct(CTState *cts, CType *ct)
{
CTSize sz = ct->size;
if (!(sz == sizeof(float) || sz == sizeof(double))) return 0;
if ((ct->info & CTF_UNION)) return 0;
while (ct->sib) {
ct = ctype_get(cts, ct->sib);
if (ctype_isfield(ct->info)) {
CType *sct = ctype_rawchild(cts, ct);
if (ctype_isfp(sct->info)) {
if (sct->size == sz)
return (sz >> 2); /* Return 1 for float or 2 for double. */
} else if (ctype_isstruct(sct->info)) {
if (sct->size)
return ccall_classify_struct(cts, sct);
} else {
break;
}
} else if (ctype_isbitfield(ct->info)) {
break;
} else if (ctype_isxattrib(ct->info, CTA_SUBTYPE)) {
CType *sct = ctype_rawchild(cts, ct);
if (sct->size)
return ccall_classify_struct(cts, sct);
}
}
return 0;
}
#endif
/* -- x64 struct classification ------------------------------------------- */
#if LJ_TARGET_X64 && !LJ_ABI_WIN
/* Register classes for x64 struct classification. */
#define CCALL_RCL_INT 1
#define CCALL_RCL_SSE 2
#define CCALL_RCL_MEM 4
/* NYI: classify vectors. */
static int ccall_classify_struct(CTState *cts, CType *ct, int *rcl, CTSize ofs);
/* Classify a C type. */
static void ccall_classify_ct(CTState *cts, CType *ct, int *rcl, CTSize ofs)
{
if (ctype_isarray(ct->info)) {
CType *cct = ctype_rawchild(cts, ct);
CTSize eofs, esz = cct->size, asz = ct->size;
for (eofs = 0; eofs < asz; eofs += esz)
ccall_classify_ct(cts, cct, rcl, ofs+eofs);
} else if (ctype_isstruct(ct->info)) {
ccall_classify_struct(cts, ct, rcl, ofs);
} else {
int cl = ctype_isfp(ct->info) ? CCALL_RCL_SSE : CCALL_RCL_INT;
lua_assert(ctype_hassize(ct->info));
if ((ofs & (ct->size-1))) cl = CCALL_RCL_MEM; /* Unaligned. */
rcl[(ofs >= 8)] |= cl;
}
}
/* Recursively classify a struct based on its fields. */
static int ccall_classify_struct(CTState *cts, CType *ct, int *rcl, CTSize ofs)
{
if (ct->size > 16) return CCALL_RCL_MEM; /* Too big, gets memory class. */
while (ct->sib) {
CTSize fofs;
ct = ctype_get(cts, ct->sib);
fofs = ofs+ct->size;
if (ctype_isfield(ct->info))
ccall_classify_ct(cts, ctype_rawchild(cts, ct), rcl, fofs);
else if (ctype_isbitfield(ct->info))
rcl[(fofs >= 8)] |= CCALL_RCL_INT; /* NYI: unaligned bitfields? */
else if (ctype_isxattrib(ct->info, CTA_SUBTYPE))
ccall_classify_struct(cts, ctype_rawchild(cts, ct), rcl, fofs);
}
return ((rcl[0]|rcl[1]) & CCALL_RCL_MEM); /* Memory class? */
}
/* Try to split up a small struct into registers. */
static int ccall_struct_reg(CCallState *cc, GPRArg *dp, int *rcl)
{
MSize ngpr = cc->ngpr, nfpr = cc->nfpr;
uint32_t i;
for (i = 0; i < 2; i++) {
lua_assert(!(rcl[i] & CCALL_RCL_MEM));
if ((rcl[i] & CCALL_RCL_INT)) { /* Integer class takes precedence. */
if (ngpr >= CCALL_NARG_GPR) return 1; /* Register overflow. */
cc->gpr[ngpr++] = dp[i];
} else if ((rcl[i] & CCALL_RCL_SSE)) {
if (nfpr >= CCALL_NARG_FPR) return 1; /* Register overflow. */
cc->fpr[nfpr++].l[0] = dp[i];
}
}
cc->ngpr = ngpr; cc->nfpr = nfpr;
return 0; /* Ok. */
}
/* Pass a small struct argument. */
static int ccall_struct_arg(CCallState *cc, CTState *cts, CType *d, int *rcl,
TValue *o, int narg)
{
GPRArg dp[2];
dp[0] = dp[1] = 0;
/* Convert to temp. struct. */
lj_cconv_ct_tv(cts, d, (uint8_t *)dp, o, CCF_ARG(narg));
if (ccall_struct_reg(cc, dp, rcl)) { /* Register overflow? Pass on stack. */
MSize nsp = cc->nsp, n = rcl[1] ? 2 : 1;
if (nsp + n > CCALL_MAXSTACK) return 1; /* Too many arguments. */
cc->nsp = nsp + n;
memcpy(&cc->stack[nsp], dp, n*CTSIZE_PTR);
}
return 0; /* Ok. */
}
/* Combine returned small struct. */
static void ccall_struct_ret(CCallState *cc, int *rcl, uint8_t *dp, CTSize sz)
{
GPRArg sp[2];
MSize ngpr = 0, nfpr = 0;
uint32_t i;
for (i = 0; i < 2; i++) {
if ((rcl[i] & CCALL_RCL_INT)) { /* Integer class takes precedence. */
sp[i] = cc->gpr[ngpr++];
} else if ((rcl[i] & CCALL_RCL_SSE)) {
sp[i] = cc->fpr[nfpr++].l[0];
}
}
memcpy(dp, sp, sz);
}
#endif
/* -- ARM hard-float ABI struct classification ---------------------------- */
#if LJ_TARGET_ARM && !LJ_ABI_SOFTFP
/* Classify a struct based on its fields. */
static unsigned int ccall_classify_struct(CTState *cts, CType *ct, CType *ctf)
{
CTSize sz = ct->size;
unsigned int r = 0, n = 0, isu = (ct->info & CTF_UNION);
if ((ctf->info & CTF_VARARG)) goto noth;
while (ct->sib) {
CType *sct;
ct = ctype_get(cts, ct->sib);
if (ctype_isfield(ct->info)) {
sct = ctype_rawchild(cts, ct);
if (ctype_isfp(sct->info)) {
r |= sct->size;
if (!isu) n++; else if (n == 0) n = 1;
} else if (ctype_iscomplex(sct->info)) {
r |= (sct->size >> 1);
if (!isu) n += 2; else if (n < 2) n = 2;
} else if (ctype_isstruct(sct->info)) {
goto substruct;
} else {
goto noth;
}
} else if (ctype_isbitfield(ct->info)) {
goto noth;
} else if (ctype_isxattrib(ct->info, CTA_SUBTYPE)) {
sct = ctype_rawchild(cts, ct);
substruct:
if (sct->size > 0) {
unsigned int s = ccall_classify_struct(cts, sct, ctf);
if (s <= 1) goto noth;
r |= (s & 255);
if (!isu) n += (s >> 8); else if (n < (s >>8)) n = (s >> 8);
}
}
}
if ((r == 4 || r == 8) && n <= 4)
return r + (n << 8);
noth: /* Not a homogeneous float/double aggregate. */
return (sz <= 4); /* Return structs of size <= 4 in a GPR. */
}
#endif
/* -- Common C call handling ---------------------------------------------- */
/* Infer the destination CTypeID for a vararg argument. */
CTypeID lj_ccall_ctid_vararg(CTState *cts, cTValue *o)
{
if (tvisnumber(o)) {
return CTID_DOUBLE;
} else if (tviscdata(o)) {
CTypeID id = cdataV(o)->ctypeid;
CType *s = ctype_get(cts, id);
if (ctype_isrefarray(s->info)) {
return lj_ctype_intern(cts,
CTINFO(CT_PTR, CTALIGN_PTR|ctype_cid(s->info)), CTSIZE_PTR);
} else if (ctype_isstruct(s->info) || ctype_isfunc(s->info)) {
/* NYI: how to pass a struct by value in a vararg argument? */
return lj_ctype_intern(cts, CTINFO(CT_PTR, CTALIGN_PTR|id), CTSIZE_PTR);
} else if (ctype_isfp(s->info) && s->size == sizeof(float)) {
return CTID_DOUBLE;
} else {
return id;
}
} else if (tvisstr(o)) {
return CTID_P_CCHAR;
} else if (tvisbool(o)) {
return CTID_BOOL;
} else {
return CTID_P_VOID;
}
}
/* Setup arguments for C call. */
static int ccall_set_args(lua_State *L, CTState *cts, CType *ct,
CCallState *cc)
{
int gcsteps = 0;
TValue *o, *top = L->top;
CTypeID fid;
CType *ctr;
MSize maxgpr, ngpr = 0, nsp = 0, narg;
#if CCALL_NARG_FPR
MSize nfpr = 0;
#if LJ_TARGET_ARM
MSize fprodd = 0;
#endif
#endif
/* Clear unused regs to get some determinism in case of misdeclaration. */
memset(cc->gpr, 0, sizeof(cc->gpr));
#if CCALL_NUM_FPR
memset(cc->fpr, 0, sizeof(cc->fpr));
#endif
#if LJ_TARGET_X86
/* x86 has several different calling conventions. */
cc->resx87 = 0;
switch (ctype_cconv(ct->info)) {
case CTCC_FASTCALL: maxgpr = 2; break;
case CTCC_THISCALL: maxgpr = 1; break;
default: maxgpr = 0; break;
}
#else
maxgpr = CCALL_NARG_GPR;
#endif
/* Perform required setup for some result types. */
ctr = ctype_rawchild(cts, ct);
if (ctype_isvector(ctr->info)) {
if (!(CCALL_VECTOR_REG && (ctr->size == 8 || ctr->size == 16)))
goto err_nyi;
} else if (ctype_iscomplex(ctr->info) || ctype_isstruct(ctr->info)) {
/* Preallocate cdata object and anchor it after arguments. */
CTSize sz = ctr->size;
GCcdata *cd = lj_cdata_new(cts, ctype_cid(ct->info), sz);
void *dp = cdataptr(cd);
setcdataV(L, L->top++, cd);
if (ctype_isstruct(ctr->info)) {
CCALL_HANDLE_STRUCTRET
} else {
CCALL_HANDLE_COMPLEXRET
}
#if LJ_TARGET_X86
} else if (ctype_isfp(ctr->info)) {
cc->resx87 = ctr->size == sizeof(float) ? 1 : 2;
#endif
}
/* Skip initial attributes. */
fid = ct->sib;
while (fid) {
CType *ctf = ctype_get(cts, fid);
if (!ctype_isattrib(ctf->info)) break;
fid = ctf->sib;
}
/* Walk through all passed arguments. */
for (o = L->base+1, narg = 1; o < top; o++, narg++) {
CTypeID did;
CType *d;
CTSize sz;
MSize n, isfp = 0, isva = 0;
void *dp, *rp = NULL;
if (fid) { /* Get argument type from field. */
CType *ctf = ctype_get(cts, fid);
fid = ctf->sib;
lua_assert(ctype_isfield(ctf->info));
did = ctype_cid(ctf->info);
} else {
if (!(ct->info & CTF_VARARG))
lj_err_caller(L, LJ_ERR_FFI_NUMARG); /* Too many arguments. */
did = lj_ccall_ctid_vararg(cts, o); /* Infer vararg type. */
isva = 1;
}
d = ctype_raw(cts, did);
sz = d->size;
/* Find out how (by value/ref) and where (GPR/FPR) to pass an argument. */
if (ctype_isnum(d->info)) {
if (sz > 8) goto err_nyi;
if ((d->info & CTF_FP))
isfp = 1;
} else if (ctype_isvector(d->info)) {
if (CCALL_VECTOR_REG && (sz == 8 || sz == 16))
isfp = 1;
else
goto err_nyi;
} else if (ctype_isstruct(d->info)) {
CCALL_HANDLE_STRUCTARG
} else if (ctype_iscomplex(d->info)) {
CCALL_HANDLE_COMPLEXARG
} else {
sz = CTSIZE_PTR;
}
sz = (sz + CTSIZE_PTR-1) & ~(CTSIZE_PTR-1);
n = sz / CTSIZE_PTR; /* Number of GPRs or stack slots needed. */
CCALL_HANDLE_REGARG /* Handle register arguments. */
/* Otherwise pass argument on stack. */
if (CCALL_ALIGN_STACKARG && !rp && (d->info & CTF_ALIGN) > CTALIGN_PTR) {
MSize align = (1u << ctype_align(d->info-CTALIGN_PTR)) -1;
nsp = (nsp + align) & ~align; /* Align argument on stack. */
}
if (nsp + n > CCALL_MAXSTACK) { /* Too many arguments. */
err_nyi:
lj_err_caller(L, LJ_ERR_FFI_NYICALL);
}
dp = &cc->stack[nsp];
nsp += n;
isva = 0;
done:
if (rp) { /* Pass by reference. */
gcsteps++;
*(void **)dp = rp;
dp = rp;
}
lj_cconv_ct_tv(cts, d, (uint8_t *)dp, o, CCF_ARG(narg));
/* Extend passed integers to 32 bits at least. */
if (ctype_isinteger_or_bool(d->info) && d->size < 4) {
if (d->info & CTF_UNSIGNED)
*(uint32_t *)dp = d->size == 1 ? (uint32_t)*(uint8_t *)dp :
(uint32_t)*(uint16_t *)dp;
else
*(int32_t *)dp = d->size == 1 ? (int32_t)*(int8_t *)dp :
(int32_t)*(int16_t *)dp;
}
#if LJ_TARGET_X64 && LJ_ABI_WIN
if (isva) { /* Windows/x64 mirrors varargs in both register sets. */
if (nfpr == ngpr)
cc->gpr[ngpr-1] = cc->fpr[ngpr-1].l[0];
else
cc->fpr[ngpr-1].l[0] = cc->gpr[ngpr-1];
}
#else
UNUSED(isva);
#endif
#if LJ_TARGET_X64 && !LJ_ABI_WIN
if (isfp == 2 && n == 2 && (uint8_t *)dp == (uint8_t *)&cc->fpr[nfpr-2]) {
cc->fpr[nfpr-1].d[0] = cc->fpr[nfpr-2].d[1]; /* Split complex double. */
cc->fpr[nfpr-2].d[1] = 0;
}
#else
UNUSED(isfp);
#endif
}
if (fid) lj_err_caller(L, LJ_ERR_FFI_NUMARG); /* Too few arguments. */
#if LJ_TARGET_X64 || LJ_TARGET_PPC
cc->nfpr = nfpr; /* Required for vararg functions. */
#endif
cc->nsp = nsp;
cc->spadj = (CCALL_SPS_FREE + CCALL_SPS_EXTRA)*CTSIZE_PTR;
if (nsp > CCALL_SPS_FREE)
cc->spadj += (((nsp-CCALL_SPS_FREE)*CTSIZE_PTR + 15u) & ~15u);
return gcsteps;
}
/* Get results from C call. */
static int ccall_get_results(lua_State *L, CTState *cts, CType *ct,
CCallState *cc, int *ret)
{
CType *ctr = ctype_rawchild(cts, ct);
uint8_t *sp = (uint8_t *)&cc->gpr[0];
if (ctype_isvoid(ctr->info)) {
*ret = 0; /* Zero results. */
return 0; /* No additional GC step. */
}
*ret = 1; /* One result. */
if (ctype_isstruct(ctr->info)) {
/* Return cdata object which is already on top of stack. */
if (!cc->retref) {
void *dp = cdataptr(cdataV(L->top-1)); /* Use preallocated object. */
CCALL_HANDLE_STRUCTRET2
}
return 1; /* One GC step. */
}
if (ctype_iscomplex(ctr->info)) {
/* Return cdata object which is already on top of stack. */
void *dp = cdataptr(cdataV(L->top-1)); /* Use preallocated object. */
CCALL_HANDLE_COMPLEXRET2
return 1; /* One GC step. */
}
if (LJ_BE && ctype_isinteger_or_bool(ctr->info) && ctr->size < CTSIZE_PTR)
sp += (CTSIZE_PTR - ctr->size);
#if CCALL_NUM_FPR
if (ctype_isfp(ctr->info) || ctype_isvector(ctr->info))
sp = (uint8_t *)&cc->fpr[0];
#endif
#ifdef CCALL_HANDLE_RET
CCALL_HANDLE_RET
#endif
/* No reference types end up here, so there's no need for the CTypeID. */
lua_assert(!(ctype_isrefarray(ctr->info) || ctype_isstruct(ctr->info)));
return lj_cconv_tv_ct(cts, ctr, 0, L->top-1, sp);
}
/* Call C function. */
int lj_ccall_func(lua_State *L, GCcdata *cd)
{
CTState *cts = ctype_cts(L);
CType *ct = ctype_raw(cts, cd->ctypeid);
CTSize sz = CTSIZE_PTR;
if (ctype_isptr(ct->info)) {
sz = ct->size;
ct = ctype_rawchild(cts, ct);
}
if (ctype_isfunc(ct->info)) {
CCallState cc;
int gcsteps, ret;
cc.func = (void (*)(void))cdata_getptr(cdataptr(cd), sz);
gcsteps = ccall_set_args(L, cts, ct, &cc);
ct = (CType *)((intptr_t)ct-(intptr_t)cts->tab);
cts->cb.slot = ~0u;
lj_vm_ffi_call(&cc);
if (cts->cb.slot != ~0u) { /* Blacklist function that called a callback. */
TValue tv;
setlightudV(&tv, (void *)cc.func);
setboolV(lj_tab_set(L, cts->miscmap, &tv), 1);
}
ct = (CType *)((intptr_t)ct+(intptr_t)cts->tab); /* May be reallocated. */
gcsteps += ccall_get_results(L, cts, ct, &cc, &ret);
#if LJ_TARGET_X86 && LJ_ABI_WIN
/* Automatically detect __stdcall and fix up C function declaration. */
if (cc.spadj && ctype_cconv(ct->info) == CTCC_CDECL) {
CTF_INSERT(ct->info, CCONV, CTCC_STDCALL);
lj_trace_abort(G(L));
}
#endif
while (gcsteps-- > 0)
lj_gc_check(L);
return ret;
}
return -1; /* Not a function. */
}
#endif