ref: faa625a1d5ab47ac0438b2cea5b2bde1ea747b8b
dir: /sys/src/cmd/patch.c/
#include <u.h> #include <libc.h> #include <ctype.h> #include <bio.h> typedef struct Patch Patch; typedef struct Hunk Hunk; typedef struct Fbuf Fbuf; typedef struct Fchg Fchg; struct Patch { char *name; Hunk *hunk; usize nhunk; }; struct Hunk { int lnum; char *oldpath; int oldln; int oldcnt; int oldlen; int oldsz; char *old; char *newpath; int newln; int newcnt; int newlen; int newsz; char *new; }; struct Fbuf { int *lines; int nlines; int lastln; int lastfuzz; char *buf; int len; int mode; }; struct Fchg { char *tmp; char *old; char *new; }; int strip; int reverse; void (*addnew)(Hunk*, char*); void (*addold)(Hunk*, char*); Fchg *changed; int nchanged; int dryrun; char* readline(Biobuf *f, int *lnum) { char *ln; if((ln = Brdstr(f, '\n', 0)) == nil) return nil; *lnum += 1; return ln; } void * emalloc(ulong n) { void *v; v = mallocz(n, 1); if(v == nil) sysfatal("malloc: %r"); setmalloctag(v, getcallerpc(&n)); return v; } void * erealloc(void *v, ulong n) { if(n == 0) n++; v = realloc(v, n); if(v == nil) sysfatal("malloc: %r"); setmalloctag(v, getcallerpc(&n)); return v; } int fileheader(char *s, char *pfx, char **name) { int len, n, nnull; char *e; if((strncmp(s, pfx, strlen(pfx))) != 0) return -1; for(s += strlen(pfx); *s; s++) if(!isspace(*s)) break; for(e = s; *e; e++) if(isspace(*e)) break; if(s == e) return -1; nnull = strlen("/dev/null"); if((e - s) != nnull || strncmp(s, "/dev/null", nnull) != 0){ n = strip; while(s != e && n > 0){ while(s != e && *s == '/') s++; while(s != e && *s != '/') s++; n--; } while(*s == '/') s++; if(*s == '\0') sysfatal("too many components stripped"); } len = (e - s) + 1; *name = emalloc(len); strecpy(*name, *name + len, s); return 0; } int hunkheader(Hunk *h, char *s, char *oldpath, char *newpath, int lnum) { char *e; memset(h, 0, sizeof(*h)); h->lnum = lnum; h->oldpath = strdup(oldpath); h->newpath = strdup(newpath); h->oldlen = 0; h->oldsz = 32; h->old = emalloc(h->oldsz); h->newlen = 0; h->newsz = 32; h->new = emalloc(h->newsz); if(strncmp(s, "@@ -", 4) != 0) return -1; e = s + 4; h->oldln = strtol(e, &e, 10); h->oldcnt = 1; if(*e == ','){ e++; h->oldcnt = strtol(e, &e, 10); } while(*e == ' ' || *e == '\t') e++; if(*e != '+') return -1; e++; h->newln = strtol(e, &e, 10); if(e == s) return -1; h->newcnt = 1; if(*e == ','){ e++; h->newcnt = strtol(e, &e, 10); } if(e == s || *e != ' ') return -1; if(strncmp(e, " @@", 3) != 0) return -1; /* * empty files have line number 0: keep that, * otherwise adjust down. */ if(h->oldln > 0) h->oldln--; if(h->newln > 0) h->newln--; if(h->oldln < 0 || h->newln < 0 || h->oldcnt < 0 || h->newcnt < 0) sysfatal("malformed hunk %s", s); return 0; } void addnewfn(Hunk *h, char *ln) { int n; ln++; n = strlen(ln); while(h->newlen + n >= h->newsz){ h->newsz *= 2; h->new = erealloc(h->new, h->newsz); } memcpy(h->new + h->newlen, ln, n); h->newlen += n; } void addoldfn(Hunk *h, char *ln) { int n; ln++; n = strlen(ln); while(h->oldlen + n >= h->oldsz){ h->oldsz *= 2; h->old = erealloc(h->old, h->oldsz); } memcpy(h->old + h->oldlen, ln, n); h->oldlen += n; } int addmiss(Hunk *h, char *ln, int *nold, int *nnew) { if(ln == nil) return 1; else if(ln[0] != '-' && ln[0] != '+') return 0; if(ln[0] == '-'){ addold(h, ln); *nold += 1; }else{ addnew(h, ln); *nnew += 1; } return 1; } void addhunk(Patch *p, Hunk *h) { p->hunk = erealloc(p->hunk, ++p->nhunk*sizeof(Hunk)); p->hunk[p->nhunk-1] = *h; } int hunkcmp(void *a, void *b) { int c; c = strcmp(((Hunk*)a)->oldpath, ((Hunk*)b)->oldpath); if(c != 0) return c; return ((Hunk*)a)->oldln - ((Hunk*)b)->oldln; } Patch* parse(Biobuf *f, char *name) { char *ln, *old, *new, **oldp, **newp; int oldcnt, newcnt, lnum; Patch *p; Hunk h; ln = nil; lnum = 0; p = emalloc(sizeof(Patch)); if(!reverse){ oldp = &old; newp = &new; }else{ oldp = &new; newp = &old; } comment: free(ln); while((ln = readline(f, &lnum)) != nil){ if(strncmp(ln, "--- ", 4) == 0) goto patch; free(ln); } if(p->nhunk == 0) sysfatal("%s: could not find start of patch", name); goto out; patch: if(fileheader(ln, "--- ", oldp) == -1) goto comment; free(ln); if((ln = readline(f, &lnum)) == nil) goto out; if(fileheader(ln, "+++ ", newp) == -1) goto comment; free(ln); if((ln = readline(f, &lnum)) == nil) goto out; hunk: oldcnt = 0; newcnt = 0; if(hunkheader(&h, ln, old, new, lnum) == -1) goto comment; free(ln); while(1){ if((ln = readline(f, &lnum)) == nil){ if(oldcnt != h.oldcnt || newcnt != h.newcnt) sysfatal("%s:%d: malformed hunk: mismatched counts", name, lnum); addhunk(p, &h); break; } switch(ln[0]){ default: sysfatal("%s:%d: malformed hunk: leading junk", name, lnum); goto out; case '-': addold(&h, ln); oldcnt++; break; case '+': addnew(&h, ln); newcnt++; break; case '\n': addold(&h, " \n"); addnew(&h, " \n"); oldcnt++; newcnt++; break; case ' ': addold(&h, ln); addnew(&h, ln); oldcnt++; newcnt++; break; } free(ln); if(oldcnt > h.oldcnt || newcnt > h.newcnt) sysfatal("%s:%d: malformed hunk: oversized hunk", name, lnum); if(oldcnt < h.oldcnt || newcnt < h.newcnt) continue; addhunk(p, &h); if((ln = readline(f, &lnum)) == nil) goto out; if(strncmp(ln, "--- ", 4) == 0) goto patch; if(strncmp(ln, "@@ ", 3) == 0) goto hunk; goto comment; } out: qsort(p->hunk, p->nhunk, sizeof(Hunk), hunkcmp); free(old); free(new); free(ln); return p; } int rename(int fd, char *name) { Dir st; char *p; nulldir(&st); if((p = strrchr(name, '/')) == nil) st.name = name; else st.name = p + 1; return dirfwstat(fd, &st); } int mkpath(char *path) { char *p, buf[ERRMAX]; int f; if(*path == '\0') return 0; for(p = strchr(path+1, '/'); p != nil; p = strchr(p+1, '/')){ *p = '\0'; if(access(path, AEXIST) != 0){ if((f = create(path, OREAD, DMDIR | 0777)) == -1){ rerrstr(buf, sizeof(buf)); if(strstr(buf, "exist") == nil) return -1; } close(f); } *p = '/'; } return 0; } void blat(char *old, char *new, char *o, usize len, int mode) { char *tmp; int fd; tmp = nil; if(strcmp(new, "/dev/null") == 0){ if(len != 0) sysfatal("diff modifies removed file"); }else if(!dryrun){ if(mkpath(new) == -1) sysfatal("mkpath %s: %r", new); if((tmp = smprint("%s.tmp%d", new, getpid())) == nil) sysfatal("smprint: %r"); if((fd = create(tmp, OWRITE, mode|0200)) == -1) sysfatal("open %s: %r", tmp); if(write(fd, o, len) != len) sysfatal("write %s: %r", tmp); close(fd); } if((changed = realloc(changed, (nchanged+1)*sizeof(Fchg))) == nil) sysfatal("realloc: %r"); if((changed[nchanged].new = strdup(new)) == nil) sysfatal("strdup: %r"); if((changed[nchanged].old = strdup(old)) == nil) sysfatal("strdup: %r"); changed[nchanged].tmp = tmp; nchanged++; } void finish(int ok) { Fchg *c; int i, fd; for(i = 0; i < nchanged; i++){ c = &changed[i]; if(!ok){ if(c->tmp != nil && remove(c->tmp) == -1) fprint(2, "remove %s: %r\n", c->tmp); goto Free; } if(!dryrun){ if(strcmp(c->new, "/dev/null") == 0){ if(remove(c->old) == -1) sysfatal("remove %s: %r", c->old); goto Print; } if((fd = open(c->tmp, ORDWR)) == -1) sysfatal("open %s: %r", c->tmp); if(strcmp(c->old, c->new) == 0 && remove(c->old) == -1) sysfatal("remove %s: %r", c->old); if(rename(fd, c->new) == -1) sysfatal("create %s: %r", c->new); if(close(fd) == -1) sysfatal("close %s: %r", c->tmp); } Print: if(strcmp(c->new, "/dev/null") == 0) print("%s\n", c->old); else print("%s\n", c->new); Free: free(c->tmp); free(c->old); free(c->new); } free(changed); } void slurp(Fbuf *f, char *path) { int n, i, fd, sz, len, nlines, linesz; char *buf; int *lines; Dir *d; if((fd = open(path, OREAD)) == -1) sysfatal("open %s: %r", path); if((d = dirfstat(fd)) == nil) sysfatal("stat %s: %r", path); sz = 8192; len = 0; buf = emalloc(sz); while(1){ if(len == sz){ sz *= 2; buf = erealloc(buf, sz); } n = read(fd, buf + len, sz - len); if(n == 0) break; if(n == -1) sysfatal("read %s: %r", path); len += n; } nlines = 0; linesz = 32; lines = emalloc(linesz*sizeof(int)); lines[nlines++] = 0; for(i = 0; i < len; i++){ if(buf[i] != '\n') continue; if(nlines+2 == linesz){ linesz *= 2; lines = erealloc(lines, linesz*sizeof(int)); } lines[nlines++] = i+1; } lines[nlines] = len; f->len = len; f->buf = buf; f->lines = lines; f->nlines = nlines; f->lastln = 0; f->lastfuzz = 0; f->mode = d->mode; free(d); close(fd); } char* searchln(Fbuf *f, Hunk *h, int ln) { int off; off = f->lines[ln]; if(off + h->oldlen > f->len) return nil; if(memcmp(f->buf + off, h->old, h->oldlen) != 0) return nil; f->lastln = ln + h->oldcnt; f->lastfuzz = ln - h->oldln; return f->buf + off; } char* search(Fbuf *f, Hunk *h, char *fname) { int ln, oldln, fuzz, scanning; char *p; oldln = h->oldln + f->lastfuzz; if(oldln + h->oldcnt > f->nlines) oldln = f->nlines - h->oldcnt; scanning = oldln >= f->lastln; for(fuzz = 0; scanning && fuzz < 250; fuzz++){ scanning = 0; ln = oldln - fuzz; if(ln >= f->lastln){ scanning = 1; if((p = searchln(f, h, ln)) != nil) return p; } ln = oldln + fuzz + 1; if(ln + h->oldcnt <= f->nlines){ scanning = 1; if((p = searchln(f, h, ln)) != nil) return p; } } sysfatal("%s:%d: unable to find hunk offset in %s", fname, h->lnum, h->oldpath); return nil; } char* append(char *o, int *sz, char *s, char *e) { int n; n = (e - s); o = erealloc(o, *sz + n); memcpy(o + *sz, s, n); *sz += n; return o; } int apply(Patch *p, char *fname) { char *o, *s, *e, *curfile, *nextfile; int i, osz; Hunk *h, *prevh; Fbuf f; e = nil; o = nil; osz = 0; curfile = nil; h = nil; prevh = nil; for(i = 0; i < p->nhunk; i++){ h = &p->hunk[i]; if(strcmp(h->newpath, "/dev/null") == 0) nextfile = h->oldpath; else nextfile = h->newpath; if(curfile == nil || strcmp(curfile, nextfile) != 0){ if(curfile != nil){ if(!dryrun) o = append(o, &osz, e, f.buf + f.len); blat(prevh->oldpath, prevh->newpath, o, osz, f.mode); osz = 0; } if(!dryrun){ slurp(&f, h->oldpath); e = f.buf; } curfile = nextfile; } if(!dryrun){ s = e; e = search(&f, h, fname); o = append(o, &osz, s, e); o = append(o, &osz, h->new, h->new + h->newlen); e += h->oldlen; } prevh = h; } if(curfile != nil){ if(!dryrun) o = append(o, &osz, e, f.buf + f.len); blat(h->oldpath, h->newpath, o, osz, f.mode); } free(o); return 0; } void freepatch(Patch *p) { Hunk *h; int i; for(i = 0; i < p->nhunk; i++){ h = &p->hunk[i]; free(h->oldpath); free(h->newpath); free(h->old); free(h->new); } free(p->hunk); free(p->name); free(p); } void usage(void) { fprint(2, "usage: %s [-nR] [-p nstrip] [patch...]\n", argv0); exits("usage"); } void main(int argc, char **argv) { Biobuf *f; Patch *p; int i, ok; ARGBEGIN{ case 'p': strip = atoi(EARGF(usage())); break; case 'n': dryrun++; break; case 'R': reverse++; break; default: usage(); break; }ARGEND; if(reverse){ addnew = addoldfn; addold = addnewfn; }else{ addnew = addnewfn; addold = addoldfn; } ok = 1; if(argc == 0){ if((f = Bfdopen(0, OREAD)) == nil) sysfatal("open stdin: %r"); if((p = parse(f, "stdin")) == nil) sysfatal("parse patch: %r"); if(apply(p, "stdin") == -1){ fprint(2, "apply stdin: %r\n"); ok = 0; } freepatch(p); Bterm(f); }else{ for(i = 0; i < argc; i++){ if((f = Bopen(argv[i], OREAD)) == nil) sysfatal("open %s: %r", argv[i]); if((p = parse(f, argv[i])) == nil) sysfatal("parse patch: %r"); if(apply(p, argv[i]) == -1){ fprint(2, "apply %s: %r\n", argv[i]); ok = 0; } freepatch(p); Bterm(f); } } finish(ok); exits(nil); }