From 5fad442525c47c6f3e75d81b6368ec1fca5eccd1 Mon Sep 17 00:00:00 2001
From: Thomas Voss <mail@thomasvoss.com>
Date: Sun, 10 Mar 2024 18:39:41 +0100
Subject: Add the bufalloc_noterm() function

---
 include/alloc.h             |  3 ++-
 lib/alloc/bufalloc.c        | 23 +----------------------
 lib/alloc/bufalloc_noterm.c | 28 ++++++++++++++++++++++++++++
 3 files changed, 31 insertions(+), 23 deletions(-)
 create mode 100644 lib/alloc/bufalloc_noterm.c

diff --git a/include/alloc.h b/include/alloc.h
index 920a9a8..f96c28f 100644
--- a/include/alloc.h
+++ b/include/alloc.h
@@ -3,6 +3,7 @@
 
 #include <stddef.h>
 
-void *bufalloc(void *, size_t, size_t);
+[[gnu::returns_nonnull]] void *bufalloc(void *, size_t, size_t);
+void *bufalloc_noterm(void *, size_t, size_t);
 
 #endif /* !MLIB_ALLOC_H */
diff --git a/lib/alloc/bufalloc.c b/lib/alloc/bufalloc.c
index dcb0a93..c688ab1 100644
--- a/lib/alloc/bufalloc.c
+++ b/lib/alloc/bufalloc.c
@@ -1,31 +1,10 @@
-#include <errno.h>
-#if __has_include(<stdckdint.h>)
-#	include <stdckdint.h>
-#	ifdef __APPLE__
-#		warning "stdckdint.h now available on Mac; remove manual ckd_*() code"
-#	endif
-#elifdef __GNUC__
-#	define ckd_add(r, a, b) ((bool)__builtin_add_overflow(a, b, r))
-#	define ckd_mul(r, a, b) ((bool)__builtin_mul_overflow(a, b, r))
-#else
-#	define ckd_add(r, a, b) (*(r) = (a) + (b))
-#	define ckd_mul(r, a, b) (*(r) = (a) * (b))
-#	warning "ckd_*() not supported on the current platform"
-#endif
-#include <stdlib.h>
-
 #include "alloc.h"
 #include "errors.h"
 
 void *
 bufalloc(void *p, size_t n, size_t m)
 {
-	if (ckd_mul(&n, n, m)) {
-		errno = EOVERFLOW;
-		err(__func__);
-	}
-
-	if (!(p = realloc(p, n)))
+	if ((p = bufalloc_noterm(p, n, m)) == nullptr)
 		err(__func__);
 	return p;
 }
diff --git a/lib/alloc/bufalloc_noterm.c b/lib/alloc/bufalloc_noterm.c
new file mode 100644
index 0000000..8258521
--- /dev/null
+++ b/lib/alloc/bufalloc_noterm.c
@@ -0,0 +1,28 @@
+#include <errno.h>
+#if __has_include(<stdckdint.h>)
+#	include <stdckdint.h>
+#	ifdef __APPLE__
+#		warning "stdckdint.h now available on Mac; remove manual ckd_*() code"
+#	endif
+#elifdef __GNUC__
+#	define ckd_add(r, a, b) ((bool)__builtin_add_overflow(a, b, r))
+#	define ckd_mul(r, a, b) ((bool)__builtin_mul_overflow(a, b, r))
+#else
+#	define ckd_add(r, a, b) (*(r) = (a) + (b))
+#	define ckd_mul(r, a, b) (*(r) = (a) * (b))
+#	warning "ckd_*() not supported on the current platform"
+#endif
+#include <stdlib.h>
+
+#include "alloc.h"
+
+void *
+bufalloc_noterm(void *p, size_t n, size_t m)
+{
+	if (ckd_mul(&n, n, m)) {
+		errno = EOVERFLOW;
+		return nullptr;
+	}
+
+	return realloc(p, n);
+}
-- 
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