Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 383 insertions, 0 deletions

diff --git a/ws.c b/ws.c
new file mode 100644
index 0000000000..6e69877f25
--- /dev/null
+++ b/ws.c
@@ -0,0 +1,383 @@
+/*
+ * Whitespace rules
+ *
+ * Copyright (c) 2007 Junio C Hamano
+ */
+#include "cache.h"
+#include "attr.h"
+
+static struct whitespace_rule {
+	const char *rule_name;
+	unsigned rule_bits;
+	unsigned loosens_error:1,
+		exclude_default:1;
+} whitespace_rule_names[] = {
+	{ "trailing-space", WS_TRAILING_SPACE, 0 },
+	{ "space-before-tab", WS_SPACE_BEFORE_TAB, 0 },
+	{ "indent-with-non-tab", WS_INDENT_WITH_NON_TAB, 0 },
+	{ "cr-at-eol", WS_CR_AT_EOL, 1 },
+	{ "blank-at-eol", WS_BLANK_AT_EOL, 0 },
+	{ "blank-at-eof", WS_BLANK_AT_EOF, 0 },
+	{ "tab-in-indent", WS_TAB_IN_INDENT, 0, 1 },
+};
+
+unsigned parse_whitespace_rule(const char *string)
+{
+	unsigned rule = WS_DEFAULT_RULE;
+
+	while (string) {
+		int i;
+		size_t len;
+		const char *ep;
+		int negated = 0;
+
+		string = string + strspn(string, ", \t\n\r");
+		ep = strchrnul(string, ',');
+		len = ep - string;
+
+		if (*string == '-') {
+			negated = 1;
+			string++;
+			len--;
+		}
+		if (!len)
+			break;
+		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++) {
+			if (strncmp(whitespace_rule_names[i].rule_name,
+				    string, len))
+				continue;
+			if (negated)
+				rule &= ~whitespace_rule_names[i].rule_bits;
+			else
+				rule |= whitespace_rule_names[i].rule_bits;
+			break;
+		}
+		if (strncmp(string, "tabwidth=", 9) == 0) {
+			unsigned tabwidth = atoi(string + 9);
+			if (0 < tabwidth && tabwidth < 0100) {
+				rule &= ~WS_TAB_WIDTH_MASK;
+				rule |= tabwidth;
+			}
+			else
+				warning("tabwidth %.*s out of range",
+					(int)(len - 9), string + 9);
+		}
+		string = ep;
+	}
+
+	if (rule & WS_TAB_IN_INDENT && rule & WS_INDENT_WITH_NON_TAB)
+		die("cannot enforce both tab-in-indent and indent-with-non-tab");
+	return rule;
+}
+
+unsigned whitespace_rule(struct index_state *istate, const char *pathname)
+{
+	static struct attr_check *attr_whitespace_rule;
+	const char *value;
+
+	if (!attr_whitespace_rule)
+		attr_whitespace_rule = attr_check_initl("whitespace", NULL);
+
+	git_check_attr(istate, pathname, attr_whitespace_rule);
+	value = attr_whitespace_rule->items[0].value;
+	if (ATTR_TRUE(value)) {
+		/* true (whitespace) */
+		unsigned all_rule = ws_tab_width(whitespace_rule_cfg);
+		int i;
+		for (i = 0; i < ARRAY_SIZE(whitespace_rule_names); i++)
+			if (!whitespace_rule_names[i].loosens_error &&
+			    !whitespace_rule_names[i].exclude_default)
+				all_rule |= whitespace_rule_names[i].rule_bits;
+		return all_rule;
+	} else if (ATTR_FALSE(value)) {
+		/* false (-whitespace) */
+		return ws_tab_width(whitespace_rule_cfg);
+	} else if (ATTR_UNSET(value)) {
+		/* reset to default (!whitespace) */
+		return whitespace_rule_cfg;
+	} else {
+		/* string */
+		return parse_whitespace_rule(value);
+	}
+}
+
+/* The returned string should be freed by the caller. */
+char *whitespace_error_string(unsigned ws)
+{
+	struct strbuf err = STRBUF_INIT;
+	if ((ws & WS_TRAILING_SPACE) == WS_TRAILING_SPACE)
+		strbuf_addstr(&err, "trailing whitespace");
+	else {
+		if (ws & WS_BLANK_AT_EOL)
+			strbuf_addstr(&err, "trailing whitespace");
+		if (ws & WS_BLANK_AT_EOF) {
+			if (err.len)
+				strbuf_addstr(&err, ", ");
+			strbuf_addstr(&err, "new blank line at EOF");
+		}
+	}
+	if (ws & WS_SPACE_BEFORE_TAB) {
+		if (err.len)
+			strbuf_addstr(&err, ", ");
+		strbuf_addstr(&err, "space before tab in indent");
+	}
+	if (ws & WS_INDENT_WITH_NON_TAB) {
+		if (err.len)
+			strbuf_addstr(&err, ", ");
+		strbuf_addstr(&err, "indent with spaces");
+	}
+	if (ws & WS_TAB_IN_INDENT) {
+		if (err.len)
+			strbuf_addstr(&err, ", ");
+		strbuf_addstr(&err, "tab in indent");
+	}
+	return strbuf_detach(&err, NULL);
+}
+
+/* If stream is non-NULL, emits the line after checking. */
+static unsigned ws_check_emit_1(const char *line, int len, unsigned ws_rule,
+				FILE *stream, const char *set,
+				const char *reset, const char *ws)
+{
+	unsigned result = 0;
+	int written = 0;
+	int trailing_whitespace = -1;
+	int trailing_newline = 0;
+	int trailing_carriage_return = 0;
+	int i;
+
+	/* Logic is simpler if we temporarily ignore the trailing newline. */
+	if (len > 0 && line[len - 1] == '\n') {
+		trailing_newline = 1;
+		len--;
+	}
+	if ((ws_rule & WS_CR_AT_EOL) &&
+	    len > 0 && line[len - 1] == '\r') {
+		trailing_carriage_return = 1;
+		len--;
+	}
+
+	/* Check for trailing whitespace. */
+	if (ws_rule & WS_BLANK_AT_EOL) {
+		for (i = len - 1; i >= 0; i--) {
+			if (isspace(line[i])) {
+				trailing_whitespace = i;
+				result |= WS_BLANK_AT_EOL;
+			}
+			else
+				break;
+		}
+	}
+
+	if (trailing_whitespace == -1)
+		trailing_whitespace = len;
+
+	/* Check indentation */
+	for (i = 0; i < trailing_whitespace; i++) {
+		if (line[i] == ' ')
+			continue;
+		if (line[i] != '\t')
+			break;
+		if ((ws_rule & WS_SPACE_BEFORE_TAB) && written < i) {
+			result |= WS_SPACE_BEFORE_TAB;
+			if (stream) {
+				fputs(ws, stream);
+				fwrite(line + written, i - written, 1, stream);
+				fputs(reset, stream);
+				fwrite(line + i, 1, 1, stream);
+			}
+		} else if (ws_rule & WS_TAB_IN_INDENT) {
+			result |= WS_TAB_IN_INDENT;
+			if (stream) {
+				fwrite(line + written, i - written, 1, stream);
+				fputs(ws, stream);
+				fwrite(line + i, 1, 1, stream);
+				fputs(reset, stream);
+			}
+		} else if (stream) {
+			fwrite(line + written, i - written + 1, 1, stream);
+		}
+		written = i + 1;
+	}
+
+	/* Check for indent using non-tab. */
+	if ((ws_rule & WS_INDENT_WITH_NON_TAB) && i - written >= ws_tab_width(ws_rule)) {
+		result |= WS_INDENT_WITH_NON_TAB;
+		if (stream) {
+			fputs(ws, stream);
+			fwrite(line + written, i - written, 1, stream);
+			fputs(reset, stream);
+		}
+		written = i;
+	}
+
+	if (stream) {
+		/*
+		 * Now the rest of the line starts at "written".
+		 * The non-highlighted part ends at "trailing_whitespace".
+		 */
+
+		/* Emit non-highlighted (middle) segment. */
+		if (trailing_whitespace - written > 0) {
+			fputs(set, stream);
+			fwrite(line + written,
+			    trailing_whitespace - written, 1, stream);
+			fputs(reset, stream);
+		}
+
+		/* Highlight errors in trailing whitespace. */
+		if (trailing_whitespace != len) {
+			fputs(ws, stream);
+			fwrite(line + trailing_whitespace,
+			    len - trailing_whitespace, 1, stream);
+			fputs(reset, stream);
+		}
+		if (trailing_carriage_return)
+			fputc('\r', stream);
+		if (trailing_newline)
+			fputc('\n', stream);
+	}
+	return result;
+}
+
+void ws_check_emit(const char *line, int len, unsigned ws_rule,
+		   FILE *stream, const char *set,
+		   const char *reset, const char *ws)
+{
+	(void)ws_check_emit_1(line, len, ws_rule, stream, set, reset, ws);
+}
+
+unsigned ws_check(const char *line, int len, unsigned ws_rule)
+{
+	return ws_check_emit_1(line, len, ws_rule, NULL, NULL, NULL, NULL);
+}
+
+int ws_blank_line(const char *line, int len, unsigned ws_rule)
+{
+	/*
+	 * We _might_ want to treat CR differently from other
+	 * whitespace characters when ws_rule has WS_CR_AT_EOL, but
+	 * for now we just use this stupid definition.
+	 */
+	while (len-- > 0) {
+		if (!isspace(*line))
+			return 0;
+		line++;
+	}
+	return 1;
+}
+
+/* Copy the line onto the end of the strbuf while fixing whitespaces */
+void ws_fix_copy(struct strbuf *dst, const char *src, int len, unsigned ws_rule, int *error_count)
+{
+	/*
+	 * len is number of bytes to be copied from src, starting
+	 * at src.  Typically src[len-1] is '\n', unless this is
+	 * the incomplete last line.
+	 */
+	int i;
+	int add_nl_to_tail = 0;
+	int add_cr_to_tail = 0;
+	int fixed = 0;
+	int last_tab_in_indent = -1;
+	int last_space_in_indent = -1;
+	int need_fix_leading_space = 0;
+
+	/*
+	 * Strip trailing whitespace
+	 */
+	if (ws_rule & WS_BLANK_AT_EOL) {
+		if (0 < len && src[len - 1] == '\n') {
+			add_nl_to_tail = 1;
+			len--;
+			if (0 < len && src[len - 1] == '\r') {
+				add_cr_to_tail = !!(ws_rule & WS_CR_AT_EOL);
+				len--;
+			}
+		}
+		if (0 < len && isspace(src[len - 1])) {
+			while (0 < len && isspace(src[len-1]))
+				len--;
+			fixed = 1;
+		}
+	}
+
+	/*
+	 * Check leading whitespaces (indent)
+	 */
+	for (i = 0; i < len; i++) {
+		char ch = src[i];
+		if (ch == '\t') {
+			last_tab_in_indent = i;
+			if ((ws_rule & WS_SPACE_BEFORE_TAB) &&
+			    0 <= last_space_in_indent)
+			    need_fix_leading_space = 1;
+		} else if (ch == ' ') {
+			last_space_in_indent = i;
+			if ((ws_rule & WS_INDENT_WITH_NON_TAB) &&
+			    ws_tab_width(ws_rule) <= i - last_tab_in_indent)
+				need_fix_leading_space = 1;
+		} else
+			break;
+	}
+
+	if (need_fix_leading_space) {
+		/* Process indent ourselves */
+		int consecutive_spaces = 0;
+		int last = last_tab_in_indent + 1;
+
+		if (ws_rule & WS_INDENT_WITH_NON_TAB) {
+			/* have "last" point at one past the indent */
+			if (last_tab_in_indent < last_space_in_indent)
+				last = last_space_in_indent + 1;
+			else
+				last = last_tab_in_indent + 1;
+		}
+
+		/*
+		 * between src[0..last-1], strip the funny spaces,
+		 * updating them to tab as needed.
+		 */
+		for (i = 0; i < last; i++) {
+			char ch = src[i];
+			if (ch != ' ') {
+				consecutive_spaces = 0;
+				strbuf_addch(dst, ch);
+			} else {
+				consecutive_spaces++;
+				if (consecutive_spaces == ws_tab_width(ws_rule)) {
+					strbuf_addch(dst, '\t');
+					consecutive_spaces = 0;
+				}
+			}
+		}
+		while (0 < consecutive_spaces--)
+			strbuf_addch(dst, ' ');
+		len -= last;
+		src += last;
+		fixed = 1;
+	} else if ((ws_rule & WS_TAB_IN_INDENT) && last_tab_in_indent >= 0) {
+		/* Expand tabs into spaces */
+		int start = dst->len;
+		int last = last_tab_in_indent + 1;
+		for (i = 0; i < last; i++) {
+			if (src[i] == '\t')
+				do {
+					strbuf_addch(dst, ' ');
+				} while ((dst->len - start) % ws_tab_width(ws_rule));
+			else
+				strbuf_addch(dst, src[i]);
+		}
+		len -= last;
+		src += last;
+		fixed = 1;
+	}
+
+	strbuf_add(dst, src, len);
+	if (add_cr_to_tail)
+		strbuf_addch(dst, '\r');
+	if (add_nl_to_tail)
+		strbuf_addch(dst, '\n');
+	if (fixed && error_count)
+		(*error_count)++;
+}