ref: 75d44bc306ffcbaadaa18c161bf54071304510b0
dir: /sys/src/cmd/7l/dyn.c/
#include "l.h" enum{ ABSD = 0, ABSU = 1, RELD = 2, RELU = 3, }; int modemap[4] = { 0, 1, -1, 2, }; typedef struct Reloc Reloc; struct Reloc { int n; int t; uchar *m; ulong *a; }; Reloc rels; static void grow(Reloc *r) { int t; uchar *m, *nm; ulong *a, *na; t = r->t; r->t += 64; m = r->m; a = r->a; r->m = nm = malloc(r->t*sizeof(uchar)); r->a = na = malloc(r->t*sizeof(ulong)); memmove(nm, m, t*sizeof(uchar)); memmove(na, a, t*sizeof(ulong)); free(m); free(a); } void dynreloc(Sym *s, long v, int abs) { int i, k, n; uchar *m; ulong *a; Reloc *r; if(v&3) diag("bad relocation address"); v >>= 2; if(s != S && s->type == SUNDEF) k = abs ? ABSU : RELU; else k = abs ? ABSD : RELD; /* Bprint(&bso, "R %s a=%ld(%lx) %d\n", s->name, a, a, k); */ k = modemap[k]; r = &rels; n = r->n; if(n >= r->t) grow(r); m = r->m; a = r->a; for(i = n; i > 0; i--){ if(v < a[i-1]){ /* happens occasionally for data */ m[i] = m[i-1]; a[i] = a[i-1]; } else break; } m[i] = k; a[i] = v; r->n++; } static int sput(char *s) { char *p; p = s; while(*s) cput(*s++); cput(0); return s-p+1; } void asmdyn(void) { int i, n, t, c; Sym *s; ulong la, ra, *a; vlong off; uchar *m; Reloc *r; cflush(); off = seek(cout, 0, 1); lput(0); t = 0; lput(imports); t += 4; for(i = 0; i < NHASH; i++) for(s = hash[i]; s != S; s = s->link) if(s->type == SUNDEF){ lput(s->sig); t += 4; t += sput(s->name); } la = 0; r = &rels; n = r->n; m = r->m; a = r->a; lput(n); t += 4; for(i = 0; i < n; i++){ ra = *a-la; if(*a < la) diag("bad relocation order"); if(ra < 256) c = 0; else if(ra < 65536) c = 1; else c = 2; cput((c<<6)|*m++); t++; if(c == 0){ cput(ra); t++; } else if(c == 1){ wput(ra); t += 2; } else{ lput(ra); t += 4; } la = *a++; } cflush(); seek(cout, off, 0); lput(t); if(debug['v']){ Bprint(&bso, "import table entries = %d\n", imports); Bprint(&bso, "export table entries = %d\n", exports); } }