cosmopolitan/tool/build/lib/disinst.c
Justine Tunney 23d333c090 Make more improvements
This change includes many bug fixes, for the NT polyfills, strings,
memory, boot, and math libraries which were discovered by adding more
tools for recreational programming, such as PC emulation. Lemon has also
been vendored because it works so well at parsing languages.
2020-09-28 01:20:34 -07:00

217 lines
7.5 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/log/check.h"
#include "libc/nexgen32e/tinystrcmp.h"
#include "libc/str/str.h"
#include "tool/build/lib/dis.h"
#include "tool/build/lib/high.h"
#include "tool/build/lib/modrm.h"
static const char kJcxz[3][6] = {"jcxz", "jecxz", "jrcxz"};
static const char kAluOp[8][4] = {"add", "or", "adc", "sbb",
"and", "sub", "xor", "cmp"};
static const char kBitOp[8][4] = {"rol", "ror", "rcl", "rcr",
"shl", "shr", "sal", "sar"};
static const char kCc[16][3] = {"o", "no", "b", "ae", "e", "ne", "be", "a",
"s", "ns", "p", "np", "l", "ge", "le", "g"};
static bool IsProbablyByteOp(struct XedDecodedInst *x) {
return !(x->op.opcode & 1);
}
static int IsRepOpcode(struct Dis *d) {
switch (d->xedd->op.opcode & ~1) {
case 0x6C: // INS
return 1;
case 0x6E: // OUTS
return 1;
case 0xA4: // MOVS
return 1;
case 0xAA: // STOS
return 1;
case 0xAC: // LODS
return 1;
case 0xA6: // CMPS
return 2;
case 0xAE: // SCAS
return 2;
default:
return 0;
}
}
static char *DisRepPrefix(struct Dis *d, char *p) {
const char *s;
if (Rep(d->xedd->op.rde) && d->xedd->op.map == XED_ILD_MAP0) {
switch (IsRepOpcode(d)) {
case 0:
break;
case 1:
p = stpcpy(p, "rep ");
break;
case 2:
p = stpcpy(p, Rep(d->xedd->op.rde) == 2 ? "repnz " : "repz ");
break;
default:
break;
}
}
return p;
}
static char *DisBranchTaken(struct Dis *d, char *p) {
switch (d->xedd->op.hint) {
case XED_HINT_NTAKEN:
return stpcpy(p, ",pn");
case XED_HINT_TAKEN:
return stpcpy(p, ",pt");
default:
return p;
}
}
static char *DisName(struct Dis *d, char *bp, const char *name,
bool ambiguous) {
char *p, *np;
uint32_t rde;
bool notbyte, notlong, wantsuffix, wantsuffixsd;
p = bp;
rde = d->xedd->op.rde;
if (d->xedd->op.lock) p = stpcpy(p, "lock ");
p = DisRepPrefix(d, p);
if (tinystrcmp(name, "BIT") == 0) {
p = stpcpy(p, kBitOp[ModrmReg(rde)]);
} else if (tinystrcmp(name, "nop") == 0 && d->xedd->op.rep) {
p = stpcpy(p, "pause");
} else if (tinystrcmp(name, "CALL") == 0) {
p = stpcpy(p, "call");
} else if (tinystrcmp(name, "JMP") == 0) {
p = stpcpy(p, "jmp");
} else if (tinystrcmp(name, "jcxz") == 0) {
p = stpcpy(p, kJcxz[Eamode(rde)]);
p = DisBranchTaken(d, p);
} else if (tinystrcmp(name, "loop") == 0 || tinystrcmp(name, "loope") == 0 ||
tinystrcmp(name, "loopne") == 0) {
p = stpcpy(p, name);
if (Eamode(rde) != Mode(rde)) {
*p++ = "wl"[Eamode(rde)];
*p = '\0';
}
p = DisBranchTaken(d, p);
} else if (tinystrcmp(name, "cwtl") == 0) {
if (Osz(rde)) name = "cbtw";
if (Rexw(rde)) name = "cltq";
p = stpcpy(p, name);
} else if (tinystrcmp(name, "cltd") == 0) {
if (Osz(rde)) name = "cwtd";
if (Rexw(rde)) name = "cqto";
p = stpcpy(p, name);
} else {
notbyte = false;
notlong = false;
wantsuffix = false;
wantsuffixsd = false;
for (np = name; *np && (islower(*np) || isdigit(*np)); ++np) {
*p++ = *np;
}
if (tinystrcmp(name, "ALU") == 0) {
p = stpcpy(p, kAluOp[(d->xedd->op.opcode & 070) >> 3]);
} else if (tinystrcmp(name, "ALU2") == 0) {
p = stpcpy(p, kAluOp[ModrmReg(rde)]);
} else if (tinystrcmp(np, "WLQ") == 0) {
notbyte = true;
wantsuffix = true;
} else if (tinystrcmp(np, "CC") == 0) {
p = stpcpy(p, kCc[d->xedd->op.opcode & 15]);
p = DisBranchTaken(d, p);
} else if (tinystrcmp(np, "WQ") == 0) {
notbyte = true;
notlong = Eamode(rde) != XED_MODE_REAL;
wantsuffix = true;
} else if (tinystrcmp(np, "LQ") == 0 || tinystrcmp(np, "WL") == 0) {
notbyte = true;
wantsuffix = true;
} else if (tinystrcmp(np, "SD") == 0) {
notbyte = true;
wantsuffixsd = true;
} else if (tinystrcmp(np, "ABS") == 0) {
if (Rexw(rde)) p = stpcpy(p, "abs");
}
if (wantsuffixsd) {
if (Osz(rde)) {
*p++ = 'd';
} else {
*p++ = 's';
}
} else if (wantsuffix || (ambiguous && !startswith(name, "f") &&
!startswith(name, "set"))) {
if (Osz(rde)) {
if (Mode(rde) != XED_MODE_REAL) {
*p++ = 'w';
}
} else if (Rexw(rde)) {
*p++ = 'q';
} else if (ambiguous && !notbyte && IsProbablyByteOp(d->xedd)) {
*p++ = 'b';
} else if (!notlong) {
*p++ = 'l';
}
}
}
*p++ = ' ';
while (p - bp < 8) *p++ = ' ';
*p = '\0';
return p;
}
/**
* Disassembles instruction based on string spec.
* @see DisSpec()
*/
char *DisInst(struct Dis *d, char *p, const char *spec) {
long i, n;
char sbuf[300];
char args[4][300];
char *s, *name, *state;
bool hasarg, hasmodrm, hasregister, hasmemory;
CHECK_EQ(0, (int)d->xedd->op.error);
DCHECK_LT(strlen(spec), 128);
hasarg = false;
hasmodrm = d->xedd->op.has_modrm;
hasmemory = hasmodrm && !IsModrmRegister(d->xedd->op.rde);
hasregister = hasmodrm && IsModrmRegister(d->xedd->op.rde);
name = strtok_r(strcpy(sbuf, spec), " ", &state);
for (n = 0; (s = strtok_r(NULL, " ", &state)); ++n) {
hasarg = true;
hasregister |= *s == '%';
hasmemory |= *s == 'O';
CHECK_LT(DisArg(d, args[n], s) - args[n], sizeof(args[n]));
}
p = HighStart(p, g_high.keyword);
p = DisName(d, p, name, hasarg && !hasregister && hasmemory);
p = HighEnd(p);
for (i = 0; i < n; ++i) {
if (i && args[n - i][0]) {
*p++ = ',';
}
p = stpcpy(p, args[n - i - 1]);
}
return p;
}