From fcedfddf00b3f994e4f4e40332ac7fc192c63244 Mon Sep 17 00:00:00 2001
From: polwex <polwex@sortug.com>
Date: Sun, 5 Oct 2025 21:56:51 +0700
Subject: claude is gud

---
 vere/ext/nasm/nasmlib/mmap.c | 139 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 vere/ext/nasm/nasmlib/mmap.c

(limited to 'vere/ext/nasm/nasmlib/mmap.c')

diff --git a/vere/ext/nasm/nasmlib/mmap.c b/vere/ext/nasm/nasmlib/mmap.c
new file mode 100644
index 0000000..5fc5646
--- /dev/null
+++ b/vere/ext/nasm/nasmlib/mmap.c
@@ -0,0 +1,139 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 1996-2017 The NASM Authors - All Rights Reserved
+ *   See the file AUTHORS included with the NASM distribution for
+ *   the specific copyright holders.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following
+ *   conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include "file.h"
+
+/* ----------------------------------------------------------------------- *
+ *   Unix-style memory mapping, using mmap().
+ * ----------------------------------------------------------------------- */
+#if defined(HAVE_FILENO) && defined(HAVE_MMAP)
+
+/*
+ * System page size
+ */
+
+/* File scope since not all compilers like static data in inline functions */
+static size_t nasm_pagemask;
+
+static size_t get_pagemask(void)
+{
+    size_t ps = 0;
+
+# if defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE)
+    ps = sysconf(_SC_PAGESIZE);
+# elif defined(HAVE_GETPAGESIZE)
+    ps = getpagesize();
+# elif defined(PAGE_SIZE)
+    ps = PAGE_SIZE;
+# endif
+
+    nasm_pagemask = ps = is_power2(ps) ? (ps - 1) : 0;
+    return ps;
+}
+
+static inline size_t pagemask(void)
+{
+    size_t pm = nasm_pagemask;
+
+    if (unlikely(!pm))
+        return get_pagemask();
+
+    return pm;
+}
+
+/*
+ * Try to map an input file into memory
+ */
+const void *nasm_map_file(FILE *fp, off_t start, off_t len)
+{
+    const char *p;
+    off_t  astart;              /* Aligned start */
+    size_t salign;              /* Amount of start adjustment */
+    size_t alen;                /* Aligned length */
+    const size_t page_mask = pagemask();
+
+    if (unlikely(!page_mask))
+        return NULL;            /* Page size undefined? */
+
+    if (unlikely(!len))
+        return NULL;            /* Mapping nothing... */
+
+    if (unlikely(len != (off_t)(size_t)len))
+        return NULL;            /* Address space insufficient */
+
+    astart = start & ~(off_t)page_mask;
+    salign = start - astart;
+    alen = (len + salign + page_mask) & ~page_mask;
+
+    p = mmap(NULL, alen, PROT_READ, MAP_SHARED, fileno(fp), astart);
+    return unlikely(p == MAP_FAILED) ? NULL : p + salign;
+}
+
+/*
+ * Unmap an input file
+ */
+void nasm_unmap_file(const void *p, size_t len)
+{
+    const size_t page_mask = pagemask();
+    uintptr_t astart;
+    size_t salign;
+    size_t alen;
+
+    if (unlikely(!page_mask))
+        return;
+
+    astart = (uintptr_t)p & ~(uintptr_t)page_mask;
+    salign = (uintptr_t)p - astart;
+    alen = (len + salign + page_mask) & ~page_mask;
+
+    munmap((void *)astart, alen);
+}
+
+/* ----------------------------------------------------------------------- *
+ *   No memory map support at all
+ *   XXX: Add a section with Windows support
+ * ----------------------------------------------------------------------- */
+#else
+
+const void *nasm_map_file(FILE *fp, off_t start, off_t len)
+{
+    (void)fp; (void)start; (void)len;
+    return NULL;
+}
+
+void nasm_unmap_file(const void *p, size_t len)
+{
+    (void)p; (void)len;
+}
+
+#endif
-- 
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