Add stubs for many libc functions, and a few implemenations too

1 files changed, 80 insertions, 0 deletions

diff --git a/src/lib/libc/stdlib.c b/src/lib/libc/stdlib.c
new file mode 100644
index 0000000..d8598dd
--- /dev/null
+++ b/src/lib/libc/stdlib.c
@@ -0,0 +1,80 @@
+#include <stdlib.h>
+#include <ctype.h>
+
+#include <kogata/debug.h>
+
+int rand(void) {
+	return 0;		// TODO
+}
+
+void srand(unsigned int seed) {
+	//TODO
+}
+
+void abort() {
+	PANIC("Aborted.");
+}
+
+float strtof(const char *nptr, const char **endptr) {
+	return (float)strtod(nptr, endptr);
+}
+double strtod(const char *nptr, const char **endptr) {
+	// TODO: better (inf, nan, ...)
+
+	const char* p = nptr;
+	while (isspace(*p)) p++;
+
+	double val = 0;
+	double sign = 1;
+	if (*p == '-') sign = -1;
+	if (*p == '-' || *p == '+') p++;
+	while (isdigit(*p)) {
+		val = val*10. + (double)((int)*p - '0');
+		p++;
+	}
+	if (*p == '.') {
+		p++;
+		double fac = 0.1;
+		while (isdigit(*p)) {
+			val += fac * (double)((int)*p - '0');
+			fac /= 10.;
+			p++;
+		}
+	}
+	if (*p == 'e' || *p == 'E') {
+		p++;
+		int exp = 0;
+		int sexp = 1;
+		if (*p == '-') sexp = -1;
+		if (*p == '-' || *p =='+') p++;
+		while (isdigit(*p)) {
+			exp = exp * 10 + (*p - '0');
+			p++;
+		}
+		if (sexp == 1) {
+			for (int i = 0; i < exp; i++) val *= 10;
+		} else {
+			for (int i = 0; i < exp; i++) val /= 10;
+		}
+	}
+	if (endptr != NULL) *endptr = p-1;
+
+	return val * sign;
+}
+
+char *getenv(const char *name) {
+	// TODO
+	return 0;
+}
+
+int system(const char *command) {
+	// TODO
+	return -1;
+}
+
+int abs(int j) {
+	if (j < 0) return -j;
+	return j;
+}
+
+/* vim: set sts=0 ts=4 sw=4 tw=0 noet :*/