ref: e1bc6c3a19ded30fb1affa8dceaeec7d5c0a0951
dir: /src/cmd/as/symbol.c/
#include <ctype.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <scc/scc.h> #include "as.h" #define HASHSIZ 64 #define NALLOC 10 Section *cursec, *seclist; Section *sabs, *sbss, *sdata, *stext; Symbol *linesym, *symlist; int pass; static Symbol *hashtbl[HASHSIZ], *symlast; static Alloc *tmpalloc; #ifndef NDEBUG void dumpstab(char *msg) { Symbol **bp, *sym; fprintf(stderr, "%s\n", msg); for (bp = hashtbl; bp < &hashtbl[HASHSIZ]; ++bp) { if (*bp == NULL) continue; fprintf(stderr, "[%d]", (int) (bp - hashtbl)); for (sym = *bp; sym; sym = sym->hash) { fprintf(stderr, " -> %s:%0X:%0X", sym->name.buf, sym->flags, sym->value); } putc('\n', stderr); } } #endif Symbol * lookup(char *name) { unsigned h; Symbol *sym, **list; int c, symtype; char *t; h = genhash(name) & HASHSIZ-1; c = toupper(*name); list = &hashtbl[h]; for (sym = *list; sym; sym = sym->hash) { t = sym->name.buf; if (c == toupper(*t) && !casecmp(t, name)) return sym; } sym = xmalloc(sizeof(*sym)); sym->name = newstring(name); sym->flags = 0; sym->size = sym->value = 0; sym->section = cursec; sym->hash = *list; sym->next = NULL; *list = sym; if (symlast) symlast->next = sym; symlast = sym; if (!symlist) symlist = sym; return sym; } Symbol * deflabel(char *name) { static Symbol *cursym; Symbol *sym; char label[MAXSYM+1]; if (*name == '.') { int r; if (!cursym) { error("local label '%s' without global label", name); return NULL; } r = snprintf(label, sizeof(label), "%s%s", cursym->name.buf, name); if (r == sizeof(label)) { error("local label '%s' in '%s' produces too long symbol", name, cursym->name.buf); return NULL; } name = label; } sym = lookup(name); if (pass == 1 && (sym->flags & FDEF)) error("redefinition of label '%s'", name); if (cursec->flags & SABS) sym->flags |= FABS; sym->flags |= FDEF; sym->value = cursec->curpc; sym->section = cursec; if (*name != '.') cursym = sym; return sym; } int toobig(Node *np, int type) { unsigned long long val = np->sym->value; switch (type) { case AIMM2: return val > 3; case AIMM3: return val > 7; case AIMM5: return val > 0x1F; case AIMM8: return val > 0xFF; case AIMM16: return val > 0xFFFF; case AIMM32: return val > 0xFFFFFFFF; case AIMM64: return 1; default: abort(); } } static void incpc(int siz) { TUINT pc, curpc; pc = cursec->pc; curpc = cursec->curpc; cursec->curpc += siz; cursec->pc += siz; if (pass == 2) return; if (cursec->pc > cursec->max) cursec->max = cursec->pc; if (pc > cursec->pc || curpc > cursec->curpc || cursec->curpc > maxaddr || cursec->pc > maxaddr) { die("as: address overflow in section '%s'"); } } static int secflags(char *attr) { int c, flags; if (!attr) return 0; for (flags = 0; c = *attr++; ) { switch (c) { case 'w': flags |= SWRITE; break; case 'r': flags |= SREAD; break; case 'x': flags |= SEXEC; break; case 'f': flags |= SFILE; break; case 'l': flags |= SLOAD; break; case 'a': flags |= SABS; break; } } return flags; } Section * setsec(char *name, char *attr) { Section *sec; Symbol *sym; cursec = NULL; sym = lookup(name); if (sym->flags & ~FSECT) error("invalid section name '%s'", name); if ((sec = sym->section) == NULL) { sec = xmalloc(sizeof(*sec)); sec->mem = NULL; sec->sym = sym; sec->base = sec->max = sec->pc = sec->curpc = 0; sec->next = seclist; sec->flags = 0; sec->fill = 0; sec->aligment = 0; sec->next = seclist; seclist = sec; sym->section = sec; sym->flags = FSECT; } sec->flags |= secflags(attr); return cursec = sec; } void isecs(void) { sabs = setsec(".abs", "rwx"); sbss = setsec(".bss", "rwf"); sdata = setsec(".data", "rw"); stext = setsec(".text", "rx"); } void cleansecs(void) { Section *sec; TUINT siz; for (sec = seclist; sec; sec = sec->next) { sec->curpc = sec->pc = sec->base; if (pass == 1 || sec->flags & SFILE) continue; siz = sec->max - sec->base; if (siz > SIZE_MAX) die("as: out of memory"); sec->mem = xmalloc(sec->max - sec->base); } cursec = stext; } void emit(char *bytes, int n) { if (cursec->mem) { size_t len = cursec->pc - cursec->base; memcpy(&cursec->mem[len], bytes, n); } incpc(n); } Symbol * tmpsym(TUINT val) { Symbol *sym; if (!tmpalloc) tmpalloc = alloc(sizeof(*sym), NALLOC); sym = new(tmpalloc); sym->value = val; sym->section = NULL; sym->flags = FABS; return sym; } void killtmp(void) { if (!tmpalloc) return; dealloc(tmpalloc); tmpalloc = NULL; } String newstring(char *s) { size_t len = strlen(s) + 1; String str; str.offset = 0; str.buf = xmalloc(len); memcpy(str.buf, s, len); return str; }