diff --git a/Makefile b/Makefile
index 4eb4637..c79eced 100644
--- a/Makefile
+++ b/Makefile
@@ -135,7 +135,7 @@ uname_P := $(shell sh -c 'uname -p 2>/dev/null || echo not')
 
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
-CFLAGS = -g -O2 -Wall
+CFLAGS = -g -Wall
 LDFLAGS =
 ALL_CFLAGS = $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)
@@ -283,7 +283,7 @@ XDIFF_LIB=xdiff/lib.a
 LIB_H = \
 	archive.h blob.h cache.h commit.h csum-file.h delta.h grep.h \
 	diff.h object.h pack.h pkt-line.h quote.h refs.h list-objects.h sideband.h \
-	run-command.h strbuf.h tag.h tree.h git-compat-util.h revision.h \
+	run-command.h strbuf.h str.h str-static.h tag.h tree.h git-compat-util.h revision.h \
 	tree-walk.h log-tree.h dir.h path-list.h unpack-trees.h builtin.h \
 	utf8.h reflog-walk.h patch-ids.h attr.h decorate.h progress.h \
 	mailmap.h remote.h
@@ -302,7 +302,7 @@ LIB_OBJS = \
 	object.o pack-check.o pack-write.o patch-delta.o path.o pkt-line.o \
 	sideband.o reachable.o reflog-walk.o \
 	quote.o read-cache.o refs.o run-command.o dir.o object-refs.o \
-	server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
+	server-info.o setup.o sha1_file.o sha1_name.o strbuf.o str.o str-static.o \
 	tag.o tree.o usage.o config.o environment.o ctype.o copy.o \
 	revision.o pager.o tree-walk.o xdiff-interface.o \
 	write_or_die.o trace.o list-objects.o grep.o match-trees.o \
diff --git a/str-static.c b/str-static.c
new file mode 100644
index 0000000..a3f48f8
--- /dev/null
+++ b/str-static.c
@@ -0,0 +1,40 @@
+#include "str-static.h"
+
+void str_static_append(struct string_static *str, const char *cstr)
+{
+	unsigned int avail = str->size - str->len;
+	unsigned int len = strlen(cstr);
+
+	if (len >= avail) {
+		len = avail - 1;
+		str->overflowed = 1;
+	}
+	memcpy(str->buf + str->len, cstr, len);
+	str->len += len;
+	str->buf[str->len] = '\0';
+}
+
+void str_static_printfa(struct string_static *str, const char *fmt, ...)
+{
+	unsigned int avail = str->size - str->len;
+	va_list va;
+	int ret;
+
+	va_start(va, fmt);
+	ret = vsnprintf(str->buf + str->len, avail, fmt, va);
+	if (ret < (int)avail)
+		str->len += ret;
+	else {
+		str->len += avail - 1;
+		str->overflowed = 1;
+	}
+	va_end(va);
+}
+
+void str_static_truncate(struct string_static *str, unsigned int len)
+{
+	if (len >= str->size)
+		len = str->size - 1;
+	str->len = len;
+	str->buf[len] = '\0';
+}
diff --git a/str-static.h b/str-static.h
new file mode 100644
index 0000000..19cb28f
--- /dev/null
+++ b/str-static.h
@@ -0,0 +1,33 @@
+#ifndef STR_STATIC_H
+#define STR_STATIC_H
+
+#include "git-compat-util.h"
+
+struct string_static {
+	unsigned int size;
+	unsigned int len:31;
+	unsigned int overflowed:1;
+	char buf[];
+};
+
+#define STR_STATIC(name, size) \
+	union { \
+	  struct string_static string; \
+	  char string_buf[sizeof(struct string_static) + (size) + 1]; \
+	} name = { { (size)+1, 0, 0 } }
+
+extern void str_static_append(struct string_static *str, const char *cstr);
+extern void str_static_printfa(struct string_static *str, const char *fmt, ...)
+	__attribute__((format (printf, 2, 3)));
+extern void str_static_truncate(struct string_static *str, unsigned int len);
+
+#define sstr_append(str, cstr) str_static_append(&(str).string, cstr)
+#define sstr_printfa(str, fmt, ...) \
+	str_static_printfa(&(str).string, fmt, __VA_ARGS__)
+#define sstr_truncate(str, len) str_static_truncate(&(str).string, len)
+
+#define sstr_c(str) ((str).string.buf)
+#define sstr_len(str) ((str).string.len)
+#define sstr_overflowed(str) ((str).string.overflowed)
+
+#endif
diff --git a/str.c b/str.c
new file mode 100644
index 0000000..7530073
--- /dev/null
+++ b/str.c
@@ -0,0 +1,75 @@
+#include "str.h"
+#include "git-compat-util.h"
+
+extern struct string *str_alloc(unsigned int initial_size)
+{
+	struct string *str;
+
+	str = xmalloc(sizeof(*str));
+	str->len = 0;
+	str->size = initial_size + 1;
+	str->buf = xmalloc(str->size);
+	str->buf[0] = '\0';
+	return str;
+}
+
+void str_free(struct string **_str)
+{
+	struct string *str = *_str;
+
+	free(str->buf);
+	str->buf = NULL;
+	free(str);
+
+	*_str = NULL;
+}
+
+static void str_grow_if_needed(struct string *str, unsigned int len)
+{
+	unsigned int avail = str->size - str->len;
+
+	if (len >= avail) {
+		str->size = (str->len + len) * 2;
+		str->buf = xrealloc(str->buf, str->size);
+	}
+}
+
+void str_append(struct string *str, const char *cstr)
+{
+	unsigned int len = strlen(cstr);
+
+	str_grow_if_needed(str, len);
+	memcpy(str->buf + str->len, cstr, len);
+	str->len += len;
+	str->buf[str->len] = '\0';
+}
+
+void str_printfa(struct string *str, const char *fmt, ...)
+{
+	unsigned int avail = str->size - str->len;
+	va_list va, va2;
+	int ret;
+
+	va_start(va, fmt);
+	va_copy(va2, va);
+	ret = vsnprintf(str->buf + str->len, avail, fmt, va);
+	assert(ret >= 0);
+
+	if ((unsigned int)ret >= avail) {
+		str_grow_if_needed(str, ret);
+		avail = str->size - str->len;
+
+		ret = vsnprintf(str->buf + str->len, avail, fmt, va2);
+		assert(ret >= 0 && (unsigned int)ret < avail);
+	}
+	str->len += ret;
+	va_end(va);
+}
+
+void str_truncate(struct string *str, unsigned int len)
+{
+	if (len >= str->size)
+		len = str->size - 1;
+	str->len = len;
+	str->buf[len] = '\0';
+}
diff --git a/str.h b/str.h
new file mode 100644
index 0000000..329aad4
--- /dev/null
+++ b/str.h
@@ -0,0 +1,20 @@
+#ifndef STR_H
+#define STR_H
+
+struct string {
+	unsigned int len, size;
+	char *buf;
+};
+
+extern struct string *str_alloc(unsigned int initial_size);
+extern void str_free(struct string **str);
+
+extern void str_append(struct string *str, const char *cstr);
+extern void str_printfa(struct string *str, const char *fmt, ...)
+	__attribute__((format (printf, 2, 3)));
+extern void str_truncate(struct string *str, unsigned int len);
+
+#define str_c(str) ((str)->buf)
+#define str_len(str) ((str)->len)
+
+#endif