Initial commit

1 files changed, 84 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 00000000..4ee5ef7a
--- /dev/null
+++ b/util.c
@@ -0,0 +1,84 @@
+#include <ctype.h>
+#include <gc.h>
+#include <gc/cord.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+
+public char *heap_strn(const char *str, size_t len)
+{
+    if (!str) return NULL;
+    if (len == 0) return "";
+    char *heaped = GC_MALLOC_ATOMIC(len + 1);
+    memcpy(heaped, str, len);
+    heaped[len] = '\0';
+    return heaped;
+}
+
+public char *heap_str(const char *str)
+{
+    if (!str) return NULL;
+    return heap_strn(str, strlen(str));
+}
+
+public char *heap_strf(const char *fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    char *tmp = NULL;
+    int len = vasprintf(&tmp, fmt, args);
+    if (len < 0) return NULL;
+    va_end(args);
+    char *ret = heap_strn(tmp, (size_t)len);
+    free(tmp);
+    return ret;
+}
+
+// Name mangling algorithm to produce valid identifiers:
+// Escape individual chars as "_x%02X" 
+// Things being escaped:
+// - Leading digit
+// - Non alphanumeric/non-underscore characters
+// - "_" when followed by "x" and two uppercase hex digits
+public char *mangle(const char *name)
+{
+    size_t len = 0;
+    for (const char *p = name; *p; p++) {
+        if ((!isalnum(*p) && *p != '_') // Non-identifier character
+            || (p == name && isdigit(*p)) // Leading digit
+            || (p[0] == '_' && p[1] == 'x' && strspn(p+2, "ABCDEF0123456789") >= 2)) { // Looks like hex escape
+            len += strlen("_x00"); // Hex escape
+        } else {
+            len += 1;
+        }
+    }
+    char *mangled = GC_MALLOC_ATOMIC(len + 1);
+    char *dest = mangled;
+    for (const char *src = name; *src; src++) {
+        if ((!isalnum(*src) && *src != '_') // Non-identifier character
+            || (src == name && isdigit(*src)) // Leading digit
+            || (src[0] == '_' && src[1] == 'x' && strspn(src+2, "ABCDEF0123456789") >= 2)) { // Looks like hex escape
+            dest += sprintf(dest, "_x%02X", *src); // Hex escape
+        } else {
+            *(dest++) = *src;
+        }
+    }
+    mangled[len] = '\0';
+    return mangled;
+}
+
+CORD CORD_asprintf(const char *fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    CORD c = NULL;
+    CORD_vsprintf(&c, fmt, args);
+    va_end(args);
+    return c;
+}
+
+
+// vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1,\:0