harec

commit 3fa71772e8769a24939a8f7db9379776fece4098
parent 89f77d6f4fa5ad5af97ceee51491ae1448ae5e8c
Author: Eyal Sawady <ecs@d2evs.net>
Date:   Wed,  3 Feb 2021 18:40:39 -0500

Add rt::ensure

Diffstat:
M
rt/Makefile
 | 
1
+
A
rt/ensure.ha
 | 
15
+++++++++++++++

2 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/rt/Makefile b/rt/Makefile
@@ -1,6 +1,7 @@
 libhart_srcs+=\
 	rt/abort.ha \
 	rt/compile.ha \
+	rt/ensure.ha \
 	rt/malloc.ha \
 	rt/memcpy.ha \
 	rt/memset.ha \
diff --git a/rt/ensure.ha b/rt/ensure.ha
@@ -0,0 +1,15 @@
+export type slice = struct {
+	data: *void,
+	length: size,
+	capacity: size,
+};
+
+export fn ensure(s: *slice, membsz: size, length: size) void = {
+	// TODO: make sure length * membsz < SIZE_MAX
+	for (s.capacity < length) {
+		s.capacity *= 2z;
+	};
+	let data = realloc(s.data, s.capacity * membsz);
+	assert(data != null: nullable *void);
+	s.data = data;
+};