hw8: Initial commit

08_TestingCoverage/buf.c

@@ -0,0 +1,31 @@
+#include "buf.h"
+
+void *
+buf_grow1(void *v, size_t esize, ptrdiff_t n)
+{
+    struct buf *p;
+    size_t max = (size_t)-1 - sizeof(struct buf);
+    if (v) {
+        p = buf_ptr(v);
+        if (n > 0 && p->capacity + n > max / esize)
+            goto fail; /* overflow */
+        p = realloc(p, sizeof(struct buf) + esize * (p->capacity + n));
+        if (!p)
+            goto fail;
+        p->capacity += n;
+        if (p->size > p->capacity)
+            p->size = p->capacity;
+    } else {
+        if ((size_t)n > max / esize)
+            goto fail; /* overflow */
+        p = malloc(sizeof(struct buf) + esize * n);
+        if (!p)
+            goto fail;
+        p->capacity = n;
+        p->size = 0;
+    }
+    return p->buffer;
+fail:
+    BUF_ABORT;
+    return 0;
+}