parse: separate out parsing functions from config.h

The files config.{h,c} contain functions that have to do with parsing,
but not config.

In order to further reduce all-in-one headers, separate out functions in
config.c that do not operate on config into its own file, parse.h,
and update the include directives in the .c files that need only such
functions accordingly.

Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 182 insertions, 0 deletions

diff --git a/parse.c b/parse.c
new file mode 100644
index 0000000000..42d691a0fb
--- /dev/null
+++ b/parse.c
@@ -0,0 +1,182 @@
+#include "git-compat-util.h"
+#include "gettext.h"
+#include "parse.h"
+
+static uintmax_t get_unit_factor(const char *end)
+{
+	if (!*end)
+		return 1;
+	else if (!strcasecmp(end, "k"))
+		return 1024;
+	else if (!strcasecmp(end, "m"))
+		return 1024 * 1024;
+	else if (!strcasecmp(end, "g"))
+		return 1024 * 1024 * 1024;
+	return 0;
+}
+
+int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		intmax_t val;
+		intmax_t factor;
+
+		if (max < 0)
+			BUG("max must be a positive integer");
+
+		errno = 0;
+		val = strtoimax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if ((val < 0 && -max / factor > val) ||
+		    (val > 0 && max / factor < val)) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+static int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
+{
+	if (value && *value) {
+		char *end;
+		uintmax_t val;
+		uintmax_t factor;
+
+		/* negative values would be accepted by strtoumax */
+		if (strchr(value, '-')) {
+			errno = EINVAL;
+			return 0;
+		}
+		errno = 0;
+		val = strtoumax(value, &end, 0);
+		if (errno == ERANGE)
+			return 0;
+		if (end == value) {
+			errno = EINVAL;
+			return 0;
+		}
+		factor = get_unit_factor(end);
+		if (!factor) {
+			errno = EINVAL;
+			return 0;
+		}
+		if (unsigned_mult_overflows(factor, val) ||
+		    factor * val > max) {
+			errno = ERANGE;
+			return 0;
+		}
+		val *= factor;
+		*ret = val;
+		return 1;
+	}
+	errno = EINVAL;
+	return 0;
+}
+
+int git_parse_int(const char *value, int *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_int64(const char *value, int64_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ulong(const char *value, unsigned long *ret)
+{
+	uintmax_t tmp;
+	if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ssize_t(const char *value, ssize_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(ssize_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_maybe_bool_text(const char *value)
+{
+	if (!value)
+		return 1;
+	if (!*value)
+		return 0;
+	if (!strcasecmp(value, "true")
+	    || !strcasecmp(value, "yes")
+	    || !strcasecmp(value, "on"))
+		return 1;
+	if (!strcasecmp(value, "false")
+	    || !strcasecmp(value, "no")
+	    || !strcasecmp(value, "off"))
+		return 0;
+	return -1;
+}
+
+int git_parse_maybe_bool(const char *value)
+{
+	int v = git_parse_maybe_bool_text(value);
+	if (0 <= v)
+		return v;
+	if (git_parse_int(value, &v))
+		return !!v;
+	return -1;
+}
+
+/*
+ * Parse environment variable 'k' as a boolean (in various
+ * possible spellings); if missing, use the default value 'def'.
+ */
+int git_env_bool(const char *k, int def)
+{
+	const char *v = getenv(k);
+	int val;
+	if (!v)
+		return def;
+	val = git_parse_maybe_bool(v);
+	if (val < 0)
+		die(_("bad boolean environment value '%s' for '%s'"),
+		    v, k);
+	return val;
+}
+
+/*
+ * Parse environment variable 'k' as ulong with possibly a unit
+ * suffix; if missing, use the default value 'val'.
+ */
+unsigned long git_env_ulong(const char *k, unsigned long val)
+{
+	const char *v = getenv(k);
+	if (v && !git_parse_ulong(v, &val))
+		die(_("failed to parse %s"), k);
+	return val;
+}