Change while loop into for loop

[git.git] / attr.c

diff --git a/attr.c b/attr.c
index f6b3f7e850f9fcf5672031049ef1d6f43e619f63..b56542e7234161518a131d3e3edbb8c20c50fbab 100644 (file)
--- a/attr.c
+++ b/attr.c
@@ -1,3 +1,12 @@
+/*
+ * Handle git attributes.  See gitattributes(5) for a description of
+ * the file syntax, and Documentation/technical/api-gitattributes.txt
+ * for a description of the API.
+ *
+ * One basic design decision here is that we are not going to support
+ * an insanely large number of attributes.
+ */
+
 #define NO_THE_INDEX_COMPATIBILITY_MACROS
 #include "cache.h"
 #include "exec_cmd.h"
@@ -13,12 +22,7 @@ static const char git_attr__unknown[] = "(builtin)unknown";
 
 static const char *attributes_file;
 
-/*
- * The basic design decision here is that we are not going to have
- * insanely large number of attributes.
- *
- * This is a randomly chosen prime.
- */
+/* This is a randomly chosen prime. */
 #define HASHSIZE 257
 
 #ifndef DEBUG_ATTR
@@ -103,22 +107,26 @@ struct git_attr *git_attr(const char *name)
        return git_attr_internal(name, strlen(name));
 }
 
-/*
- * .gitattributes file is one line per record, each of which is
- *
- * (1) glob pattern.
- * (2) whitespace
- * (3) whitespace separated list of attribute names, each of which
- *     could be prefixed with '-' to mean "set to false", '!' to mean
- *     "unset".
- */
-
 /* What does a matched pattern decide? */
 struct attr_state {
        struct git_attr *attr;
        const char *setto;
 };
 
+/*
+ * One rule, as from a .gitattributes file.
+ *
+ * If is_macro is true, then u.attr is a pointer to the git_attr being
+ * defined.
+ *
+ * If is_macro is false, then u.pattern points at the filename pattern
+ * to which the rule applies.  (The memory pointed to is part of the
+ * memory block allocated for the match_attr instance.)
+ *
+ * In either case, num_attr is the number of attributes affected by
+ * this rule, and state is an array listing them.  The attributes are
+ * listed as they appear in the file (macros unexpanded).
+ */
 struct match_attr {
        union {
                char *pattern;
@@ -131,8 +139,15 @@ struct match_attr {
 
 static const char blank[] = " \t\r\n";
 
+/*
+ * Parse a whitespace-delimited attribute state (i.e., "attr",
+ * "-attr", "!attr", or "attr=value") from the string starting at src.
+ * If e is not NULL, write the results to *e.  Return a pointer to the
+ * remainder of the string (with leading whitespace removed), or NULL
+ * if there was an error.
+ */
 static const char *parse_attr(const char *src, int lineno, const char *cp,
-                             int *num_attr, struct match_attr *res)
+                             struct attr_state *e)
 {
        const char *ep, *equals;
        int len;
@@ -145,7 +160,7 @@ static const char *parse_attr(const char *src, int lineno, const char *cp,
                len = equals - cp;
        else
                len = ep - cp;
-       if (!res) {
+       if (!e) {
                if (*cp == '-' || *cp == '!') {
                        cp++;
                        len--;
@@ -157,9 +172,6 @@ static const char *parse_attr(const char *src, int lineno, const char *cp,
                        return NULL;
                }
        } else {
-               struct attr_state *e;
-
-               e = &(res->state[*num_attr]);
                if (*cp == '-' || *cp == '!') {
                        e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
                        cp++;
@@ -172,7 +184,6 @@ static const char *parse_attr(const char *src, int lineno, const char *cp,
                }
                e->attr = git_attr_internal(cp, len);
        }
-       (*num_attr)++;
        return ep + strspn(ep, blank);
 }
 
@@ -181,7 +192,7 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
 {
        int namelen;
        int num_attr;
-       const char *cp, *name;
+       const char *cp, *name, *states;
        struct match_attr *res = NULL;
        int pass;
        int is_macro;
@@ -212,13 +223,14 @@ static struct match_attr *parse_attr_line(const char *line, const char *src,
        else
                is_macro = 0;
 
+       states = name + namelen;
+       states += strspn(states, blank);
+
        for (pass = 0; pass < 2; pass++) {
                /* pass 0 counts and allocates, pass 1 fills */
-               num_attr = 0;
-               cp = name + namelen;
-               cp = cp + strspn(cp, blank);
-               while (*cp) {
-                       cp = parse_attr(src, lineno, cp, &num_attr, res);
+               for (cp = states, num_attr = 0; *cp; num_attr++) {
+                       cp = parse_attr(src, lineno, cp,
+                               pass ? &(res->state[num_attr]) : NULL);
                        if (!cp)
                                return NULL;
                }