From b354ead7efbaba80569e3a6f80865b715aaa6315 Mon Sep 17 00:00:00 2001 From: Josh Haberman Date: Tue, 7 Jul 2015 11:47:45 -0700 Subject: Moved DynASM to third_party to comply with Google policy. --- third_party/dynasm/dasm_x86.h | 470 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 470 insertions(+) create mode 100644 third_party/dynasm/dasm_x86.h (limited to 'third_party/dynasm/dasm_x86.h') diff --git a/third_party/dynasm/dasm_x86.h b/third_party/dynasm/dasm_x86.h new file mode 100644 index 0000000..7c6dcd3 --- /dev/null +++ b/third_party/dynasm/dasm_x86.h @@ -0,0 +1,470 @@ +/* +** DynASM x86 encoding engine. +** Copyright (C) 2005-2012 Mike Pall. All rights reserved. +** Released under the MIT license. See dynasm.lua for full copyright notice. +*/ + +#include +#include +#include +#include + +#define DASM_ARCH "x86" + +#ifndef DASM_EXTERN +#define DASM_EXTERN(a,b,c,d) 0 +#endif + +/* Action definitions. DASM_STOP must be 255. */ +enum { + DASM_DISP = 233, + DASM_IMM_S, DASM_IMM_B, DASM_IMM_W, DASM_IMM_D, DASM_IMM_WB, DASM_IMM_DB, + DASM_VREG, DASM_SPACE, DASM_SETLABEL, DASM_REL_A, DASM_REL_LG, DASM_REL_PC, + DASM_IMM_LG, DASM_IMM_PC, DASM_LABEL_LG, DASM_LABEL_PC, DASM_ALIGN, + DASM_EXTERN, DASM_ESC, DASM_MARK, DASM_SECTION, DASM_STOP +}; + +/* Maximum number of section buffer positions for a single dasm_put() call. */ +#define DASM_MAXSECPOS 25 + +/* DynASM encoder status codes. Action list offset or number are or'ed in. */ +#define DASM_S_OK 0x00000000 +#define DASM_S_NOMEM 0x01000000 +#define DASM_S_PHASE 0x02000000 +#define DASM_S_MATCH_SEC 0x03000000 +#define DASM_S_RANGE_I 0x11000000 +#define DASM_S_RANGE_SEC 0x12000000 +#define DASM_S_RANGE_LG 0x13000000 +#define DASM_S_RANGE_PC 0x14000000 +#define DASM_S_RANGE_VREG 0x15000000 +#define DASM_S_UNDEF_L 0x21000000 +#define DASM_S_UNDEF_PC 0x22000000 + +/* Macros to convert positions (8 bit section + 24 bit index). */ +#define DASM_POS2IDX(pos) ((pos)&0x00ffffff) +#define DASM_POS2BIAS(pos) ((pos)&0xff000000) +#define DASM_SEC2POS(sec) ((sec)<<24) +#define DASM_POS2SEC(pos) ((pos)>>24) +#define DASM_POS2PTR(D, pos) (D->sections[DASM_POS2SEC(pos)].rbuf + (pos)) + +/* Action list type. */ +typedef const unsigned char *dasm_ActList; + +/* Per-section structure. */ +typedef struct dasm_Section { + int *rbuf; /* Biased buffer pointer (negative section bias). */ + int *buf; /* True buffer pointer. */ + size_t bsize; /* Buffer size in bytes. */ + int pos; /* Biased buffer position. */ + int epos; /* End of biased buffer position - max single put. */ + int ofs; /* Byte offset into section. */ +} dasm_Section; + +/* Core structure holding the DynASM encoding state. */ +struct dasm_State { + size_t psize; /* Allocated size of this structure. */ + dasm_ActList actionlist; /* Current actionlist pointer. */ + int *lglabels; /* Local/global chain/pos ptrs. */ + size_t lgsize; + int *pclabels; /* PC label chains/pos ptrs. */ + size_t pcsize; + void **globals; /* Array of globals (bias -10). */ + dasm_Section *section; /* Pointer to active section. */ + size_t codesize; /* Total size of all code sections. */ + int maxsection; /* 0 <= sectionidx < maxsection. */ + int status; /* Status code. */ + dasm_Section sections[1]; /* All sections. Alloc-extended. */ +}; + +/* The size of the core structure depends on the max. number of sections. */ +#define DASM_PSZ(ms) (sizeof(dasm_State)+(ms-1)*sizeof(dasm_Section)) + + +/* Initialize DynASM state. */ +void dasm_init(Dst_DECL, int maxsection) +{ + dasm_State *D; + size_t psz = 0; + int i; + Dst_REF = NULL; + DASM_M_GROW(Dst, struct dasm_State, Dst_REF, psz, DASM_PSZ(maxsection)); + D = Dst_REF; + D->psize = psz; + D->lglabels = NULL; + D->lgsize = 0; + D->pclabels = NULL; + D->pcsize = 0; + D->globals = NULL; + D->maxsection = maxsection; + for (i = 0; i < maxsection; i++) { + D->sections[i].buf = NULL; /* Need this for pass3. */ + D->sections[i].rbuf = D->sections[i].buf - DASM_SEC2POS(i); + D->sections[i].bsize = 0; + D->sections[i].epos = 0; /* Wrong, but is recalculated after resize. */ + } +} + +/* Free DynASM state. */ +void dasm_free(Dst_DECL) +{ + dasm_State *D = Dst_REF; + int i; + for (i = 0; i < D->maxsection; i++) + if (D->sections[i].buf) + DASM_M_FREE(Dst, D->sections[i].buf, D->sections[i].bsize); + if (D->pclabels) DASM_M_FREE(Dst, D->pclabels, D->pcsize); + if (D->lglabels) DASM_M_FREE(Dst, D->lglabels, D->lgsize); + DASM_M_FREE(Dst, D, D->psize); +} + +/* Setup global label array. Must be called before dasm_setup(). */ +void dasm_setupglobal(Dst_DECL, void **gl, unsigned int maxgl) +{ + dasm_State *D = Dst_REF; + D->globals = gl - 10; /* Negative bias to compensate for locals. */ + DASM_M_GROW(Dst, int, D->lglabels, D->lgsize, (10+maxgl)*sizeof(int)); +} + +/* Grow PC label array. Can be called after dasm_setup(), too. */ +void dasm_growpc(Dst_DECL, unsigned int maxpc) +{ + dasm_State *D = Dst_REF; + size_t osz = D->pcsize; + DASM_M_GROW(Dst, int, D->pclabels, D->pcsize, maxpc*sizeof(int)); + memset((void *)(((unsigned char *)D->pclabels)+osz), 0, D->pcsize-osz); +} + +/* Setup encoder. */ +void dasm_setup(Dst_DECL, const void *actionlist) +{ + dasm_State *D = Dst_REF; + int i; + D->actionlist = (dasm_ActList)actionlist; + D->status = DASM_S_OK; + D->section = &D->sections[0]; + memset((void *)D->lglabels, 0, D->lgsize); + if (D->pclabels) memset((void *)D->pclabels, 0, D->pcsize); + for (i = 0; i < D->maxsection; i++) { + D->sections[i].pos = DASM_SEC2POS(i); + D->sections[i].ofs = 0; + } +} + + +#ifdef DASM_CHECKS +#define CK(x, st) \ + do { if (!(x)) { \ + D->status = DASM_S_##st|(int)(p-D->actionlist-1); return; } } while (0) +#define CKPL(kind, st) \ + do { if ((size_t)((char *)pl-(char *)D->kind##labels) >= D->kind##size) { \ + D->status=DASM_S_RANGE_##st|(int)(p-D->actionlist-1); return; } } while (0) +#else +#define CK(x, st) ((void)0) +#define CKPL(kind, st) ((void)0) +#endif + +/* Pass 1: Store actions and args, link branches/labels, estimate offsets. */ +void dasm_put(Dst_DECL, int start, ...) +{ + va_list ap; + dasm_State *D = Dst_REF; + dasm_ActList p = D->actionlist + start; + dasm_Section *sec = D->section; + int pos = sec->pos, ofs = sec->ofs, mrm = 4; + int *b; + + if (pos >= sec->epos) { + DASM_M_GROW(Dst, int, sec->buf, sec->bsize, + sec->bsize + 2*DASM_MAXSECPOS*sizeof(int)); + sec->rbuf = sec->buf - DASM_POS2BIAS(pos); + sec->epos = (int)sec->bsize/sizeof(int) - DASM_MAXSECPOS+DASM_POS2BIAS(pos); + } + + b = sec->rbuf; + b[pos++] = start; + + va_start(ap, start); + while (1) { + int action = *p++; + if (action < DASM_DISP) { + ofs++; + } else if (action <= DASM_REL_A) { + int n = va_arg(ap, int); + b[pos++] = n; + switch (action) { + case DASM_DISP: + if (n == 0) { if ((mrm&7) == 4) mrm = p[-2]; if ((mrm&7) != 5) break; } + case DASM_IMM_DB: if (((n+128)&-256) == 0) goto ob; + case DASM_REL_A: /* Assumes ptrdiff_t is int. !x64 */ + case DASM_IMM_D: ofs += 4; break; + case DASM_IMM_S: CK(((n+128)&-256) == 0, RANGE_I); goto ob; + case DASM_IMM_B: CK((n&-256) == 0, RANGE_I); ob: ofs++; break; + case DASM_IMM_WB: if (((n+128)&-256) == 0) goto ob; + case DASM_IMM_W: CK((n&-65536) == 0, RANGE_I); ofs += 2; break; + case DASM_SPACE: p++; ofs += n; break; + case DASM_SETLABEL: b[pos-2] = -0x40000000; break; /* Neg. label ofs. */ + case DASM_VREG: CK((n&-8) == 0 && (n != 4 || (*p&1) == 0), RANGE_VREG); + if (*p++ == 1 && *p == DASM_DISP) mrm = n; continue; + } + mrm = 4; + } else { + int *pl, n; + switch (action) { + case DASM_REL_LG: + case DASM_IMM_LG: + n = *p++; pl = D->lglabels + n; + if (n <= 246) { CKPL(lg, LG); goto putrel; } /* Bkwd rel or global. */ + pl -= 246; n = *pl; + if (n < 0) n = 0; /* Start new chain for fwd rel if label exists. */ + goto linkrel; + case DASM_REL_PC: + case DASM_IMM_PC: pl = D->pclabels + va_arg(ap, int); CKPL(pc, PC); + putrel: + n = *pl; + if (n < 0) { /* Label exists. Get label pos and store it. */ + b[pos] = -n; + } else { + linkrel: + b[pos] = n; /* Else link to rel chain, anchored at label. */ + *pl = pos; + } + pos++; + ofs += 4; /* Maximum offset needed. */ + if (action == DASM_REL_LG || action == DASM_REL_PC) + b[pos++] = ofs; /* Store pass1 offset estimate. */ + break; + case DASM_LABEL_LG: pl = D->lglabels + *p++; CKPL(lg, LG); goto putlabel; + case DASM_LABEL_PC: pl = D->pclabels + va_arg(ap, int); CKPL(pc, PC); + putlabel: + n = *pl; /* n > 0: Collapse rel chain and replace with label pos. */ + while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = pos; } + *pl = -pos; /* Label exists now. */ + b[pos++] = ofs; /* Store pass1 offset estimate. */ + break; + case DASM_ALIGN: + ofs += *p++; /* Maximum alignment needed (arg is 2**n-1). */ + b[pos++] = ofs; /* Store pass1 offset estimate. */ + break; + case DASM_EXTERN: p += 2; ofs += 4; break; + case DASM_ESC: p++; ofs++; break; + case DASM_MARK: mrm = p[-2]; break; + case DASM_SECTION: + n = *p; CK(n < D->maxsection, RANGE_SEC); D->section = &D->sections[n]; + case DASM_STOP: goto stop; + } + } + } +stop: + va_end(ap); + sec->pos = pos; + sec->ofs = ofs; +} +#undef CK + +/* Pass 2: Link sections, shrink branches/aligns, fix label offsets. */ +int dasm_link(Dst_DECL, size_t *szp) +{ + dasm_State *D = Dst_REF; + int secnum; + int ofs = 0; + +#ifdef DASM_CHECKS + *szp = 0; + if (D->status != DASM_S_OK) return D->status; + { + int pc; + for (pc = 0; pc*sizeof(int) < D->pcsize; pc++) + if (D->pclabels[pc] > 0) return DASM_S_UNDEF_PC|pc; + } +#endif + + { /* Handle globals not defined in this translation unit. */ + int idx; + for (idx = 10; idx*sizeof(int) < D->lgsize; idx++) { + int n = D->lglabels[idx]; + /* Undefined label: Collapse rel chain and replace with marker (< 0). */ + while (n > 0) { int *pb = DASM_POS2PTR(D, n); n = *pb; *pb = -idx; } + } + } + + /* Combine all code sections. No support for data sections (yet). */ + for (secnum = 0; secnum < D->maxsection; secnum++) { + dasm_Section *sec = D->sections + secnum; + int *b = sec->rbuf; + int pos = DASM_SEC2POS(secnum); + int lastpos = sec->pos; + + while (pos != lastpos) { + dasm_ActList p = D->actionlist + b[pos++]; + while (1) { + int op, action = *p++; + switch (action) { + case DASM_REL_LG: p++; op = p[-3]; goto rel_pc; + case DASM_REL_PC: op = p[-2]; rel_pc: { + int shrink = op == 0xe9 ? 3 : ((op&0xf0) == 0x80 ? 4 : 0); + if (shrink) { /* Shrinkable branch opcode? */ + int lofs, lpos = b[pos]; + if (lpos < 0) goto noshrink; /* Ext global? */ + lofs = *DASM_POS2PTR(D, lpos); + if (lpos > pos) { /* Fwd label: add cumulative section offsets. */ + int i; + for (i = secnum; i < DASM_POS2SEC(lpos); i++) + lofs += D->sections[i].ofs; + } else { + lofs -= ofs; /* Bkwd label: unfix offset. */ + } + lofs -= b[pos+1]; /* Short branch ok? */ + if (lofs >= -128-shrink && lofs <= 127) ofs -= shrink; /* Yes. */ + else { noshrink: shrink = 0; } /* No, cannot shrink op. */ + } + b[pos+1] = shrink; + pos += 2; + break; + } + case DASM_SPACE: case DASM_IMM_LG: case DASM_VREG: p++; + case DASM_DISP: case DASM_IMM_S: case DASM_IMM_B: case DASM_IMM_W: + case DASM_IMM_D: case DASM_IMM_WB: case DASM_IMM_DB: + case DASM_SETLABEL: case DASM_REL_A: case DASM_IMM_PC: pos++; break; + case DASM_LABEL_LG: p++; + case DASM_LABEL_PC: b[pos++] += ofs; break; /* Fix label offset. */ + case DASM_ALIGN: ofs -= (b[pos++]+ofs)&*p++; break; /* Adjust ofs. */ + case DASM_EXTERN: p += 2; break; + case DASM_ESC: p++; break; + case DASM_MARK: break; + case DASM_SECTION: case DASM_STOP: goto stop; + } + } + stop: (void)0; + } + ofs += sec->ofs; /* Next section starts right after current section. */ + } + + D->codesize = ofs; /* Total size of all code sections */ + *szp = ofs; + return DASM_S_OK; +} + +#define dasmb(x) *cp++ = (unsigned char)(x) +#ifndef DASM_ALIGNED_WRITES +#define dasmw(x) \ + do { *((unsigned short *)cp) = (unsigned short)(x); cp+=2; } while (0) +#define dasmd(x) \ + do { *((unsigned int *)cp) = (unsigned int)(x); cp+=4; } while (0) +#else +#define dasmw(x) do { dasmb(x); dasmb((x)>>8); } while (0) +#define dasmd(x) do { dasmw(x); dasmw((x)>>16); } while (0) +#endif + +/* Pass 3: Encode sections. */ +int dasm_encode(Dst_DECL, void *buffer) +{ + dasm_State *D = Dst_REF; + unsigned char *base = (unsigned char *)buffer; + unsigned char *cp = base; + int secnum; + + /* Encode all code sections. No support for data sections (yet). */ + for (secnum = 0; secnum < D->maxsection; secnum++) { + dasm_Section *sec = D->sections + secnum; + int *b = sec->buf; + int *endb = sec->rbuf + sec->pos; + + while (b != endb) { + dasm_ActList p = D->actionlist + *b++; + unsigned char *mark = NULL; + while (1) { + int action = *p++; + int n = (action >= DASM_DISP && action <= DASM_ALIGN) ? *b++ : 0; + switch (action) { + case DASM_DISP: if (!mark) mark = cp; { + unsigned char *mm = mark; + if (*p != DASM_IMM_DB && *p != DASM_IMM_WB) mark = NULL; + if (n == 0) { int mrm = mm[-1]&7; if (mrm == 4) mrm = mm[0]&7; + if (mrm != 5) { mm[-1] -= 0x80; break; } } + if (((n+128) & -256) != 0) goto wd; else mm[-1] -= 0x40; + } + case DASM_IMM_S: case DASM_IMM_B: wb: dasmb(n); break; + case DASM_IMM_DB: if (((n+128)&-256) == 0) { + db: if (!mark) mark = cp; mark[-2] += 2; mark = NULL; goto wb; + } else mark = NULL; + case DASM_IMM_D: wd: dasmd(n); break; + case DASM_IMM_WB: if (((n+128)&-256) == 0) goto db; else mark = NULL; + case DASM_IMM_W: dasmw(n); break; + case DASM_VREG: { int t = *p++; if (t >= 2) n<<=3; cp[-1] |= n; break; } + case DASM_REL_LG: p++; if (n >= 0) goto rel_pc; + b++; n = (int)(ptrdiff_t)D->globals[-n]; + case DASM_REL_A: rel_a: n -= (int)(ptrdiff_t)(cp+4); goto wd; /* !x64 */ + case DASM_REL_PC: rel_pc: { + int shrink = *b++; + int *pb = DASM_POS2PTR(D, n); if (*pb < 0) { n = pb[1]; goto rel_a; } + n = *pb - ((int)(cp-base) + 4-shrink); + if (shrink == 0) goto wd; + if (shrink == 4) { cp--; cp[-1] = *cp-0x10; } else cp[-1] = 0xeb; + goto wb; + } + case DASM_IMM_LG: + p++; if (n < 0) { n = (int)(ptrdiff_t)D->globals[-n]; goto wd; } + case DASM_IMM_PC: { + int *pb = DASM_POS2PTR(D, n); + n = *pb < 0 ? pb[1] : (*pb + (int)(ptrdiff_t)base); + goto wd; + } + case DASM_LABEL_LG: { + int idx = *p++; + if (idx >= 10) + D->globals[idx] = (void *)(base + (*p == DASM_SETLABEL ? *b : n)); + break; + } + case DASM_LABEL_PC: case DASM_SETLABEL: break; + case DASM_SPACE: { int fill = *p++; while (n--) *cp++ = fill; break; } + case DASM_ALIGN: + n = *p++; + while (((cp-base) & n)) *cp++ = 0x90; /* nop */ + break; + case DASM_EXTERN: n = DASM_EXTERN(Dst, cp, p[1], *p); p += 2; goto wd; + case DASM_MARK: mark = cp; break; + case DASM_ESC: action = *p++; + default: *cp++ = action; break; + case DASM_SECTION: case DASM_STOP: goto stop; + } + } + stop: (void)0; + } + } + + if (base + D->codesize != cp) /* Check for phase errors. */ + return DASM_S_PHASE; + return DASM_S_OK; +} + +/* Get PC label offset. */ +int dasm_getpclabel(Dst_DECL, unsigned int pc) +{ + dasm_State *D = Dst_REF; + if (pc*sizeof(int) < D->pcsize) { + int pos = D->pclabels[pc]; + if (pos < 0) return *DASM_POS2PTR(D, -pos); + if (pos > 0) return -1; /* Undefined. */ + } + return -2; /* Unused or out of range. */ +} + +#ifdef DASM_CHECKS +/* Optional sanity checker to call between isolated encoding steps. */ +int dasm_checkstep(Dst_DECL, int secmatch) +{ + dasm_State *D = Dst_REF; + if (D->status == DASM_S_OK) { + int i; + for (i = 1; i <= 9; i++) { + if (D->lglabels[i] > 0) { D->status = DASM_S_UNDEF_L|i; break; } + D->lglabels[i] = 0; + } + } + if (D->status == DASM_S_OK && secmatch >= 0 && + D->section != &D->sections[secmatch]) + D->status = DASM_S_MATCH_SEC|(int)(D->section-D->sections); + return D->status; +} +#endif + -- cgit v1.2.3