Merge branch 'jc/grep'
authorJunio C Hamano <junkio@cox.net>
Mon, 10 Jul 2006 06:49:03 +0000 (23:49 -0700)
committerJunio C Hamano <junkio@cox.net>
Mon, 10 Jul 2006 06:49:03 +0000 (23:49 -0700)
* jc/grep:
  git-grep: boolean expression on pattern matching.

builtin-grep.c

index 6973c66..743ca8c 100644 (file)
@@ -82,17 +82,47 @@ static int pathspec_matches(const char **paths, const char *name)
        return 0;
 }
 
+enum grep_pat_token {
+       GREP_PATTERN,
+       GREP_AND,
+       GREP_OPEN_PAREN,
+       GREP_CLOSE_PAREN,
+       GREP_NOT,
+       GREP_OR,
+};
+
 struct grep_pat {
        struct grep_pat *next;
        const char *origin;
        int no;
+       enum grep_pat_token token;
        const char *pattern;
        regex_t regexp;
 };
 
+enum grep_expr_node {
+       GREP_NODE_ATOM,
+       GREP_NODE_NOT,
+       GREP_NODE_AND,
+       GREP_NODE_OR,
+};
+
+struct grep_expr {
+       enum grep_expr_node node;
+       union {
+               struct grep_pat *atom;
+               struct grep_expr *unary;
+               struct {
+                       struct grep_expr *left;
+                       struct grep_expr *right;
+               } binary;
+       } u;
+};
+
 struct grep_opt {
        struct grep_pat *pattern_list;
        struct grep_pat **pattern_tail;
+       struct grep_expr *pattern_expression;
        regex_t regexp;
        unsigned linenum:1;
        unsigned invert:1;
@@ -105,43 +135,224 @@ struct grep_opt {
 #define GREP_BINARY_NOMATCH    1
 #define GREP_BINARY_TEXT       2
        unsigned binary:2;
+       unsigned extended:1;
        int regflags;
        unsigned pre_context;
        unsigned post_context;
 };
 
 static void add_pattern(struct grep_opt *opt, const char *pat,
-                       const char *origin, int no)
+                       const char *origin, int no, enum grep_pat_token t)
 {
        struct grep_pat *p = xcalloc(1, sizeof(*p));
        p->pattern = pat;
        p->origin = origin;
        p->no = no;
+       p->token = t;
        *opt->pattern_tail = p;
        opt->pattern_tail = &p->next;
        p->next = NULL;
 }
 
+static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
+{
+       int err = regcomp(&p->regexp, p->pattern, opt->regflags);
+       if (err) {
+               char errbuf[1024];
+               char where[1024];
+               if (p->no)
+                       sprintf(where, "In '%s' at %d, ",
+                               p->origin, p->no);
+               else if (p->origin)
+                       sprintf(where, "%s, ", p->origin);
+               else
+                       where[0] = 0;
+               regerror(err, &p->regexp, errbuf, 1024);
+               regfree(&p->regexp);
+               die("%s'%s': %s", where, p->pattern, errbuf);
+       }
+}
+
+#if DEBUG
+static inline void indent(int in)
+{
+       int i;
+       for (i = 0; i < in; i++) putchar(' ');
+}
+
+static void dump_pattern_exp(struct grep_expr *x, int in)
+{
+       switch (x->node) {
+       case GREP_NODE_ATOM:
+               indent(in);
+               puts(x->u.atom->pattern);
+               break;
+       case GREP_NODE_NOT:
+               indent(in);
+               puts("--not");
+               dump_pattern_exp(x->u.unary, in+1);
+               break;
+       case GREP_NODE_AND:
+               dump_pattern_exp(x->u.binary.left, in+1);
+               indent(in);
+               puts("--and");
+               dump_pattern_exp(x->u.binary.right, in+1);
+               break;
+       case GREP_NODE_OR:
+               dump_pattern_exp(x->u.binary.left, in+1);
+               indent(in);
+               puts("--or");
+               dump_pattern_exp(x->u.binary.right, in+1);
+               break;
+       }
+}
+
+static void looking_at(const char *msg, struct grep_pat **list)
+{
+       struct grep_pat *p = *list;
+       fprintf(stderr, "%s: looking at ", msg);
+       if (!p)
+               fprintf(stderr, "empty\n");
+       else
+               fprintf(stderr, "<%s>\n", p->pattern);
+}
+#else
+#define looking_at(a,b) do {} while(0)
+#endif
+
+static struct grep_expr *compile_pattern_expr(struct grep_pat **);
+static struct grep_expr *compile_pattern_atom(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x;
+
+       looking_at("atom", list);
+
+       p = *list;
+       switch (p->token) {
+       case GREP_PATTERN: /* atom */
+               x = xcalloc(1, sizeof (struct grep_expr));
+               x->node = GREP_NODE_ATOM;
+               x->u.atom = p;
+               *list = p->next;
+               return x;
+       case GREP_OPEN_PAREN:
+               *list = p->next;
+               x = compile_pattern_expr(list);
+               if (!x)
+                       return NULL;
+               if (!*list || (*list)->token != GREP_CLOSE_PAREN)
+                       die("unmatched parenthesis");
+               *list = (*list)->next;
+               return x;
+       default:
+               return NULL;
+       }
+}
+
+static struct grep_expr *compile_pattern_not(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x;
+
+       looking_at("not", list);
+
+       p = *list;
+       switch (p->token) {
+       case GREP_NOT:
+               if (!p->next)
+                       die("--not not followed by pattern expression");
+               *list = p->next;
+               x = xcalloc(1, sizeof (struct grep_expr));
+               x->node = GREP_NODE_NOT;
+               x->u.unary = compile_pattern_not(list);
+               if (!x->u.unary)
+                       die("--not followed by non pattern expression");
+               return x;
+       default:
+               return compile_pattern_atom(list);
+       }
+}
+
+static struct grep_expr *compile_pattern_and(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x, *y, *z;
+
+       looking_at("and", list);
+
+       x = compile_pattern_not(list);
+       p = *list;
+       if (p && p->token == GREP_AND) {
+               if (!p->next)
+                       die("--and not followed by pattern expression");
+               *list = p->next;
+               y = compile_pattern_and(list);
+               if (!y)
+                       die("--and not followed by pattern expression");
+               z = xcalloc(1, sizeof (struct grep_expr));
+               z->node = GREP_NODE_AND;
+               z->u.binary.left = x;
+               z->u.binary.right = y;
+               return z;
+       }
+       return x;
+}
+
+static struct grep_expr *compile_pattern_or(struct grep_pat **list)
+{
+       struct grep_pat *p;
+       struct grep_expr *x, *y, *z;
+
+       looking_at("or", list);
+
+       x = compile_pattern_and(list);
+       p = *list;
+       if (x && p && p->token != GREP_CLOSE_PAREN) {
+               y = compile_pattern_or(list);
+               if (!y)
+                       die("not a pattern expression %s", p->pattern);
+               z = xcalloc(1, sizeof (struct grep_expr));
+               z->node = GREP_NODE_OR;
+               z->u.binary.left = x;
+               z->u.binary.right = y;
+               return z;
+       }
+       return x;
+}
+
+static struct grep_expr *compile_pattern_expr(struct grep_pat **list)
+{
+       looking_at("expr", list);
+
+       return compile_pattern_or(list);
+}
+
 static void compile_patterns(struct grep_opt *opt)
 {
        struct grep_pat *p;
+
+       /* First compile regexps */
        for (p = opt->pattern_list; p; p = p->next) {
-               int err = regcomp(&p->regexp, p->pattern, opt->regflags);
-               if (err) {
-                       char errbuf[1024];
-                       char where[1024];
-                       if (p->no)
-                               sprintf(where, "In '%s' at %d, ",
-                                       p->origin, p->no);
-                       else if (p->origin)
-                               sprintf(where, "%s, ", p->origin);
-                       else
-                               where[0] = 0;
-                       regerror(err, &p->regexp, errbuf, 1024);
-                       regfree(&p->regexp);
-                       die("%s'%s': %s", where, p->pattern, errbuf);
-               }
+               if (p->token == GREP_PATTERN)
+                       compile_regexp(p, opt);
+               else
+                       opt->extended = 1;
        }
+
+       if (!opt->extended)
+               return;
+
+       /* Then bundle them up in an expression.
+        * A classic recursive descent parser would do.
+        */
+       p = opt->pattern_list;
+       opt->pattern_expression = compile_pattern_expr(&p);
+#if DEBUG
+       dump_pattern_exp(opt->pattern_expression, 0);
+#endif
+       if (p)
+               die("incomplete pattern expression: %s", p->pattern);
 }
 
 static char *end_of_line(char *cp, unsigned long *left)
@@ -196,6 +407,79 @@ static int fixmatch(const char *pattern, char *line, regmatch_t *match)
        }
 }
 
+static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol, char *eol)
+{
+       int hit = 0;
+       regmatch_t pmatch[10];
+
+       if (!opt->fixed) {
+               regex_t *exp = &p->regexp;
+               hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
+                              pmatch, 0);
+       }
+       else {
+               hit = !fixmatch(p->pattern, bol, pmatch);
+       }
+
+       if (hit && opt->word_regexp) {
+               /* Match beginning must be either
+                * beginning of the line, or at word
+                * boundary (i.e. the last char must
+                * not be alnum or underscore).
+                */
+               if ((pmatch[0].rm_so < 0) ||
+                   (eol - bol) <= pmatch[0].rm_so ||
+                   (pmatch[0].rm_eo < 0) ||
+                   (eol - bol) < pmatch[0].rm_eo)
+                       die("regexp returned nonsense");
+               if (pmatch[0].rm_so != 0 &&
+                   word_char(bol[pmatch[0].rm_so-1]))
+                       hit = 0;
+               if (pmatch[0].rm_eo != (eol-bol) &&
+                   word_char(bol[pmatch[0].rm_eo]))
+                       hit = 0;
+       }
+       return hit;
+}
+
+static int match_expr_eval(struct grep_opt *opt,
+                          struct grep_expr *x,
+                          char *bol, char *eol)
+{
+       switch (x->node) {
+       case GREP_NODE_ATOM:
+               return match_one_pattern(opt, x->u.atom, bol, eol);
+               break;
+       case GREP_NODE_NOT:
+               return !match_expr_eval(opt, x->u.unary, bol, eol);
+       case GREP_NODE_AND:
+               return (match_expr_eval(opt, x->u.binary.left, bol, eol) &&
+                       match_expr_eval(opt, x->u.binary.right, bol, eol));
+       case GREP_NODE_OR:
+               return (match_expr_eval(opt, x->u.binary.left, bol, eol) ||
+                       match_expr_eval(opt, x->u.binary.right, bol, eol));
+       }
+       die("Unexpected node type (internal error) %d\n", x->node);
+}
+
+static int match_expr(struct grep_opt *opt, char *bol, char *eol)
+{
+       struct grep_expr *x = opt->pattern_expression;
+       return match_expr_eval(opt, x, bol, eol);
+}
+
+static int match_line(struct grep_opt *opt, char *bol, char *eol)
+{
+       struct grep_pat *p;
+       if (opt->extended)
+               return match_expr(opt, bol, eol);
+       for (p = opt->pattern_list; p; p = p->next) {
+               if (match_one_pattern(opt, p, bol, eol))
+                       return 1;
+       }
+       return 0;
+}
+
 static int grep_buffer(struct grep_opt *opt, const char *name,
                       char *buf, unsigned long size)
 {
@@ -231,46 +515,15 @@ static int grep_buffer(struct grep_opt *opt, const char *name,
                hunk_mark = "--\n";
 
        while (left) {
-               regmatch_t pmatch[10];
                char *eol, ch;
                int hit = 0;
-               struct grep_pat *p;
 
                eol = end_of_line(bol, &left);
                ch = *eol;
                *eol = 0;
 
-               for (p = opt->pattern_list; p; p = p->next) {
-                       if (!opt->fixed) {
-                               regex_t *exp = &p->regexp;
-                               hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
-                                              pmatch, 0);
-                       }
-                       else {
-                               hit = !fixmatch(p->pattern, bol, pmatch);
-                       }
+               hit = match_line(opt, bol, eol);
 
-                       if (hit && opt->word_regexp) {
-                               /* Match beginning must be either
-                                * beginning of the line, or at word
-                                * boundary (i.e. the last char must
-                                * not be alnum or underscore).
-                                */
-                               if ((pmatch[0].rm_so < 0) ||
-                                   (eol - bol) <= pmatch[0].rm_so ||
-                                   (pmatch[0].rm_eo < 0) ||
-                                   (eol - bol) < pmatch[0].rm_eo)
-                                       die("regexp returned nonsense");
-                               if (pmatch[0].rm_so != 0 &&
-                                   word_char(bol[pmatch[0].rm_so-1]))
-                                       hit = 0;
-                               if (pmatch[0].rm_eo != (eol-bol) &&
-                                   word_char(bol[pmatch[0].rm_eo]))
-                                       hit = 0;
-                       }
-                       if (hit)
-                               break;
-               }
                /* "grep -v -e foo -e bla" should list lines
                 * that do not have either, so inversion should
                 * be done outside.
@@ -452,6 +705,8 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
        char *argptr = randarg;
        struct grep_pat *p;
 
+       if (opt->extended)
+               return -1;
        len = nr = 0;
        push_arg("grep");
        if (opt->fixed)
@@ -813,16 +1068,36 @@ int cmd_grep(int argc, const char **argv, char **envp)
                                /* ignore empty line like grep does */
                                if (!buf[0])
                                        continue;
-                               add_pattern(&opt, strdup(buf), argv[1], ++lno);
+                               add_pattern(&opt, strdup(buf), argv[1], ++lno,
+                                           GREP_PATTERN);
                        }
                        fclose(patterns);
                        argv++;
                        argc--;
                        continue;
                }
+               if (!strcmp("--not", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_NOT);
+                       continue;
+               }
+               if (!strcmp("--and", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_AND);
+                       continue;
+               }
+               if (!strcmp("--or", arg))
+                       continue; /* no-op */
+               if (!strcmp("(", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_OPEN_PAREN);
+                       continue;
+               }
+               if (!strcmp(")", arg)) {
+                       add_pattern(&opt, arg, "command line", 0, GREP_CLOSE_PAREN);
+                       continue;
+               }
                if (!strcmp("-e", arg)) {
                        if (1 < argc) {
-                               add_pattern(&opt, argv[1], "-e option", 0);
+                               add_pattern(&opt, argv[1], "-e option", 0,
+                                           GREP_PATTERN);
                                argv++;
                                argc--;
                                continue;
@@ -840,7 +1115,8 @@ int cmd_grep(int argc, const char **argv, char **envp)
 
                /* First unrecognized non-option token */
                if (!opt.pattern_list) {
-                       add_pattern(&opt, arg, "command line", 0);
+                       add_pattern(&opt, arg, "command line", 0,
+                                   GREP_PATTERN);
                        break;
                }
                else {