Fixed broken files/code and other errors

1 files changed, 129 insertions, 0 deletions

diff --git a/src/string_utils.c b/src/string_utils.c
new file mode 100644
index 0000000..65af0f2
--- /dev/null
+++ b/src/string_utils.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright (c) Yuxuan Shui <[email protected]>
+
+#include <string.h>
+
+#include <test.h>
+
+#include "compiler.h"
+#include "string_utils.h"
+#include "utils.h"
+
+#pragma GCC diagnostic push
+
+// gcc warns about legitimate strncpy in mstrjoin and mstrextend
+// strncpy(str, src1, len1) intentional truncates the null byte from src1.
+// strncpy(str+len1, src2, len2) uses bound depends on the source argument,
+// but str is allocated with len1+len2+1, so this strncpy can't overflow
+#pragma GCC diagnostic ignored "-Wpragmas"
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+#pragma GCC diagnostic ignored "-Wstringop-overflow"
+
+/**
+ * Allocate the space and join two strings.
+ */
+char *mstrjoin(const char *src1, const char *src2) {
+	auto len1 = strlen(src1);
+	auto len2 = strlen(src2);
+	auto len = len1 + len2 + 1;
+	auto str = ccalloc(len, char);
+
+	strncpy(str, src1, len1);
+	strncpy(str + len1, src2, len2);
+	str[len - 1] = '\0';
+
+	return str;
+}
+
+TEST_CASE(mstrjoin) {
+	char *str = mstrjoin("asdf", "qwer");
+	TEST_STREQUAL(str, "asdfqwer");
+	free(str);
+
+	str = mstrjoin("", "qwer");
+	TEST_STREQUAL(str, "qwer");
+	free(str);
+
+	str = mstrjoin("asdf", "");
+	TEST_STREQUAL(str, "asdf");
+	free(str);
+}
+
+/**
+ * Concatenate a string on heap with another string.
+ */
+void mstrextend(char **psrc1, const char *src2) {
+	if (!*psrc1) {
+		*psrc1 = strdup(src2);
+		return;
+	}
+
+	auto len1 = strlen(*psrc1);
+	auto len2 = strlen(src2);
+	auto len = len1 + len2 + 1;
+	*psrc1 = crealloc(*psrc1, len);
+
+	strncpy(*psrc1 + len1, src2, len2);
+	(*psrc1)[len - 1] = '\0';
+}
+
+TEST_CASE(mstrextend) {
+	char *str1 = NULL;
+	mstrextend(&str1, "asdf");
+	TEST_STREQUAL(str1, "asdf");
+
+	mstrextend(&str1, "asd");
+	TEST_STREQUAL(str1, "asdfasd");
+
+	mstrextend(&str1, "");
+	TEST_STREQUAL(str1, "asdfasd");
+	free(str1);
+}
+
+#pragma GCC diagnostic pop
+
+/// Parse a floating point number of form (+|-)?[0-9]*(\.[0-9]*)
+double strtod_simple(const char *src, const char **end) {
+	double neg = 1;
+	if (*src == '-') {
+		neg = -1;
+		src++;
+	} else if (*src == '+') {
+		src++;
+	}
+
+	double ret = 0;
+	while (*src >= '0' && *src <= '9') {
+		ret = ret * 10 + (*src - '0');
+		src++;
+	}
+
+	if (*src == '.') {
+		double frac = 0, mult = 0.1;
+		src++;
+		while (*src >= '0' && *src <= '9') {
+			frac += mult * (*src - '0');
+			mult *= 0.1;
+			src++;
+		}
+		ret += frac;
+	}
+
+	*end = src;
+	return ret * neg;
+}
+
+TEST_CASE(strtod_simple) {
+	const char *end;
+	double result = strtod_simple("1.0", &end);
+	TEST_EQUAL(result, 1);
+	TEST_EQUAL(*end, '\0');
+
+	result = strtod_simple("-1.0", &end);
+	TEST_EQUAL(result, -1);
+	TEST_EQUAL(*end, '\0');
+
+	result = strtod_simple("+.5", &end);
+	TEST_EQUAL(result, 0.5);
+	TEST_EQUAL(*end, '\0');
+}