1 files changed, 109 insertions, 21 deletions
diff --git a/std/common.cup b/std/common.cup
index 004eaa9..24e24b7 100644
--- a/std/common.cup
+++ b/std/common.cup
@@ -1,26 +1,40 @@
-fn min(a: int, b: int): int {
-    return a < b ? a : b;
+const true = 1;
+const false = 0;
+
+///////////////////////////////////////////////////////////////////////////////
+// Syscalls
+
+fn write(fd: int, s: char*, n: int): int {
+    return syscall3(SYS_write, fd, s, n);
 }
 
-fn max(a: int, b: int): int {
-    return a > b ? a : b;
+fn exit(status: int): int {
+    return syscall1(SYS_exit, status);
 }
 
-fn sign(a: int): int {
-    return a > 0 ? 1 : a == 0 ? 0 : -1;
+fn read(fd: int, s: char*, n: int): int {
+    return syscall3(SYS_read, fd, s, n);
 }
 
-fn abs(a: int): int {
-    return a * sign(a);
+fn open(path: char*, flags: int, mode: int): int {
+    return syscall3(SYS_open, path, flags, mode);
 }
 
-fn factorial(n: int): int {
-    let res: int = 1;
-    for (;n > 0; n = n - 1)
-        res = res * n;
-    return res;
+fn openat(fd: int, path: char*, flags: int, mode: int): int {
+    return syscall4(SYS_openat, fd, path, flags, mode);
 }
 
+fn fork(): int {
+    return syscall0(SYS_fork);
+}
+
+fn wait(status: int*): int {
+    return syscall4(SYS_wait4, -1, status, 0, 0);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Strings
 
 fn strlen(s: char *): int {
     let count: int = 0;
@@ -62,6 +76,47 @@ fn streq(s1: char *, s2: char *): int {
     return *s1 == *s2;
 }
 
+fn strrev(s: char *) {
+    let len: int = strlen(s);
+    let i: int = 0;
+    let j: int = len - 1;
+    while (i < j) {
+        let tmp: char = s[i];
+        s[i] = s[j];
+        s[j] = tmp;
+        i = i + 1;
+        j = j - 1;
+    }
+}
+
+fn atoi_end(s: char *, end: char**): int {
+    let i: int = 0;
+    let sign: int = 1;
+    if (*s == '-') {
+        sign = -1;
+        s = s + 1;
+    }
+    while (*s >= '0' && *s <= '9') {
+        i = i * 10 + (*s - '0');
+        s = s + 1;
+    }
+    *end = s;
+    return i * sign;
+}
+
+fn atoi(s: char *): int {
+    let tmp: char*;
+    return atoi_end(s, &tmp);
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// I/O
+
+const stdin = 0;
+const stdout = 1;
+const stderr = 2;
+
 fn putc(c: char) {
     write(0, &c, 1);
 }
@@ -76,15 +131,48 @@ fn putsln(c: char *) {
     putc('\n');
 }
 
-fn strrev(s: char *) {
-    let len: int = strlen(s);
+fn putu(n: int) {
+    let buf: char[32];
     let i: int = 0;
-    let j: int = len - 1;
-    while (i < j) {
-        let tmp: char = s[i];
-        s[i] = s[j];
-        s[j] = tmp;
+    while (n > 0) {
+        buf[i] = (n % 10) + '0';
+        n = n / 10;
         i = i + 1;
-        j = j - 1;
     }
+    if (i == 0)
+        buf[i] = '0';
+    else
+        strrev(buf);
+    write(0, buf, i);
+}
+
+fn die(msg: char *) {
+    putsln(msg);
+    exit(1);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// Math
+
+fn min(a: int, b: int): int {
+    return a < b ? a : b;
+}
+
+fn max(a: int, b: int): int {
+    return a > b ? a : b;
+}
+
+fn sign(a: int): int {
+    return a > 0 ? 1 : a == 0 ? 0 : -1;
+}
+
+fn abs(a: int): int {
+    return a * sign(a);
+}
+
+fn factorial(n: int): int {
+    let res: int = 1;
+    for (;n > 0; n = n - 1)
+        res = res * n;
+    return res;
 }