diff options
Diffstat (limited to 'bin/jrp.c')
| -rw-r--r-- | bin/jrp.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/bin/jrp.c b/bin/jrp.c new file mode 100644 index 00000000..9fa3dcc1 --- /dev/null +++ b/bin/jrp.c @@ -0,0 +1,285 @@ +/* JIT RPN calculator. + * + * Copyright (c) 2017, June McEnroe <programble@gmail.com> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * 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 Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <err.h> +#include <histedit.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/mman.h> +#include <sysexits.h> +#include <unistd.h> + +typedef unsigned long qop; +typedef unsigned int dop; + +typedef long qvalue; +typedef int dvalue; +typedef unsigned long uvalue; + +typedef qvalue *(*jitFn)(qvalue *); +typedef void (*rtFn)(qvalue); + +static char *formatBin(qvalue val) { + static char buf[sizeof(qvalue) * 8 + 1]; + uvalue uval = val; + size_t i = sizeof(buf); + do { + buf[--i] = '0' + (uval & 1); + } while (uval >>= 1); + return &buf[i]; +} + +static void rtPrintAscii(qvalue val) { + printf("%c\n", (char)val); +} +static void rtPrintBin(qvalue val) { + printf("%s\n", formatBin(val)); +} +static void rtPrintOct(qvalue val) { + printf("%lo\n", val); +} +static void rtPrintDec(qvalue val) { + printf("%ld\n", val); +} +static void rtPrintHex(qvalue val) { + printf("%lx\n", val); +} + +static const dop DOP_NOP = 0x90666666; // nop +static const dop DOP_PUSH = 0xc7c74857; // push rdi; mov rdi, strict dword 0 +static const dop DOP_DROP = 0x9066665f; // pop rdi +static const dop DOP_DUP = 0x90666657; // push rdi +static const dop DOP_SWAP = 0x243c8748; // xchg rdi, [rsp] +static const dop DOP_NEG = 0x90dff748; // neg rdi +static const dop DOP_ADD = 0xc7014858; // pop rax; add rdi, rax +static const dop DOP_QUO = 0x90c78948; // mov rdi, rax +static const dop DOP_REM = 0x90d78948; // mov rdi, rdx +static const dop DOP_NOT = 0x90d7f748; // not rdi +static const dop DOP_AND = 0xc7214858; // pop rax; and rdi, rax +static const dop DOP_OR = 0xc7094858; // pop rax; or rdi, rax +static const dop DOP_XOR = 0xc7314858; // pop rax; xor rdi, rax + +static const qop QOP_PROL = 0x5ffc8948e5894855; // push rbp; mov rbp, rsp; mov rsp, rdi; pop rdi +static const qop QOP_EPIL = 0x5dec8948e0894857; // push rdi; mov rax, rsp; mov rsp, rbp; pop rbp +static const qop QOP_RET = 0x90666666906666c3; // ret +static const qop QOP_CRT = 0xb848906690e58748; // xchg rsp, rbp; mov rax, strict qword 0 +static const qop QOP_CALL = 0x90665fe58748d0ff; // call rax; xchg rsp, rbp; pop rdi +static const qop QOP_PUSH = 0xbf48906690666657; // push rdi; mov rdi, strict qword 0 +static const qop QOP_SUB = 0x9066665f243c2948; // sub [rsp], rdi; pop rdi +static const qop QOP_MUL = 0x906666f8af0f4858; // pop rax; imul rdi, rax +static const qop QOP_DIV = 0x9066fff748994858; // pop rax; cqo; idiv rdi +static const qop QOP_SHL = 0x5f2424d348f98948; // mov rcx, rdi; shl qword [rsp], cl; pop rdi +static const qop QOP_SHR = 0x5f242cd348f98948; // mov rcx, rdi; shr qword [rsp], cl; pop rdi + +static int radix = 10; + +static struct { + qop *base; + qop *ptr; + dop dop; +} code; + +static struct { + qvalue *base; + qvalue *limit; + qvalue *ptr; +} stack; + +static void jitDop(dop op) { + if (code.dop) { + *code.ptr++ = (qop)op << 32 | code.dop; + code.dop = 0; + } else { + code.dop = op; + } +} + +static void jitQop(qop op) { + if (code.dop) jitDop(DOP_NOP); + *code.ptr++ = op; +} + +static void jitPush(qvalue imm) { + if ((dvalue)imm == imm) { + jitQop(DOP_PUSH | (qop)imm << 32); + } else { + jitQop(QOP_PUSH); + jitQop((qop)imm); + } +} + +static void jitCall(rtFn fn) { + jitQop(QOP_CRT); + jitQop((qop)fn); + jitQop(QOP_CALL); +} + +static void jitBegin(void) { + code.ptr = code.base; + jitQop(QOP_PROL); +} + +static void jitEnd(void) { + jitQop(QOP_EPIL); + jitQop(QOP_RET); +} + +static void jitInit(void) { + code.base = mmap(0, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); + if (code.base == MAP_FAILED) err(EX_OSERR, "mmap"); +} + +static void stackInit(void) { + stack.base = mmap(0, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); + if (stack.base == MAP_FAILED) err(EX_OSERR, "mmap"); + stack.limit = stack.base + getpagesize() / sizeof(qvalue); + stack.ptr = stack.limit; +} + +static void jitExec(void) { + int error; + error = mprotect(code.base, getpagesize(), PROT_READ | PROT_EXEC); + if (error) err(EX_OSERR, "mprotect"); + stack.ptr = ((jitFn)code.base)(stack.ptr); + if (stack.ptr > stack.limit) stack.ptr = stack.limit; + error = mprotect(code.base, getpagesize(), PROT_READ | PROT_WRITE); + if (error) err(EX_OSERR, "mprotect"); +} + +static void jitSrc(const char *src) { + bool quote = false; + while (*src) { + if (quote) { + jitPush(*src++); + quote = false; + continue; + } + + switch (*src) { + case ' ': break; + case 39: quote = true; break; + case 'B': radix = 2; break; + case 'O': radix = 8; break; + case 'D': radix = 10; break; + case 'X': radix = 16; break; + case ';': jitDop(DOP_DROP); break; + case ':': jitDop(DOP_DUP); break; + case 92: jitDop(DOP_SWAP); break; + case '_': jitDop(DOP_NEG); break; + case '+': jitDop(DOP_ADD); break; + case '-': jitQop(QOP_SUB); break; + case '*': jitQop(QOP_MUL); break; + case '/': jitQop(QOP_DIV); jitDop(DOP_QUO); break; + case '%': jitQop(QOP_DIV); jitDop(DOP_REM); break; + case '~': jitDop(DOP_NOT); break; + case '&': jitDop(DOP_AND); break; + case '|': jitDop(DOP_OR); break; + case '^': jitDop(DOP_XOR); break; + case '<': jitQop(QOP_SHL); break; + case '>': jitQop(QOP_SHR); break; + case ',': jitCall(rtPrintAscii); break; + case '.': switch (radix) { + case 2: jitCall(rtPrintBin); break; + case 8: jitCall(rtPrintOct); break; + case 10: jitCall(rtPrintDec); break; + case 16: jitCall(rtPrintHex); break; + } break; + + default: { + char *rest; + qvalue val = strtol(src, &rest, radix); + if (rest != src) { + src = rest; + jitPush(val); + continue; + } + } + } + + src++; + } +} + +static void jitDump(const char *path, FILE *file) { + size_t nitems = code.ptr - code.base; + size_t written = fwrite(code.base, sizeof(qop), nitems, file); + if (written < nitems) err(EX_IOERR, "%s", path); +} + +static char *prompt(EditLine *el __attribute((unused))) { + static char buf[4096]; + char *bufPtr = buf; + for (qvalue *stackPtr = stack.limit - 1; stackPtr >= stack.ptr; --stackPtr) { + size_t bufLen = sizeof(buf) - (bufPtr - buf) - 2; + switch (radix) { + case 2: bufPtr += snprintf(bufPtr, bufLen, " %s", formatBin(*stackPtr)); break; + case 8: bufPtr += snprintf(bufPtr, bufLen, " %lo", *stackPtr); break; + case 10: bufPtr += snprintf(bufPtr, bufLen, " %ld", *stackPtr); break; + case 16: bufPtr += snprintf(bufPtr, bufLen, " %lx", *stackPtr); break; + } + } + buf[0] = '['; + if (bufPtr == buf) bufPtr++; + *bufPtr++ = ']'; + *bufPtr++ = ' '; + *bufPtr = 0; + return buf; +} + +int main(int argc, char *argv[]) { + FILE *file = NULL; + char *path = getenv("JRP_DUMP"); + if (path) { + file = fopen(path, "w"); + if (!file) err(EX_CANTCREAT, "%s", path); + } + + jitInit(); + stackInit(); + + if (argc > 1) { + jitBegin(); + for (int i = 1; i < argc; ++i) + jitSrc(argv[i]); + jitEnd(); + if (file) jitDump(path, file); + jitExec(); + return EX_OK; + } + + EditLine *el = el_init(argv[0], stdin, stdout, stderr); + el_set(el, EL_PROMPT, prompt); + el_set(el, EL_SIGNAL, true); + + for (;;) { + int count; + const char *line = el_gets(el, &count); + if (count < 0) err(EX_IOERR, "el_gets"); + if (!line) break; + + jitBegin(); + jitSrc(line); + jitEnd(); + if (file) jitDump(path, file); + jitExec(); + } + + el_end(el); + return EX_OK; +} |