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authorpolwex <polwex@sortug.com>2025-10-05 21:56:51 +0700
committerpolwex <polwex@sortug.com>2025-10-05 21:56:51 +0700
commitfcedfddf00b3f994e4f4e40332ac7fc192c63244 (patch)
tree51d38e62c7bdfcc5f9a5e9435fe820c93cfc9a3d /vere/ext/nasm/nasmlib/mmap.c
claude is gud
Diffstat (limited to 'vere/ext/nasm/nasmlib/mmap.c')
-rw-r--r--vere/ext/nasm/nasmlib/mmap.c139
1 files changed, 139 insertions, 0 deletions
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