From e99ba2eb5565de921f4f589bf6991e0ac3cdf2a0 Mon Sep 17 00:00:00 2001
From: midipix <writeonce@midipix.org>
Date: Feb 12 2023 02:10:00 +0000
Subject: helper: added slbt_map_input(), slbt_unmap_input().


---

diff --git a/include/slibtool/slibtool.h b/include/slibtool/slibtool.h
index ee34b9a..ca32efe 100644
--- a/include/slibtool/slibtool.h
+++ b/include/slibtool/slibtool.h
@@ -125,6 +125,11 @@ enum slbt_warning_level {
 	SLBT_WARNING_LEVEL_NONE,
 };
 
+struct slbt_input {
+	void *		addr;
+	size_t		size;
+};
+
 struct slbt_source_version {
 	int		major;
 	int		minor;
@@ -268,6 +273,13 @@ struct slbt_driver_ctx {
 	void *				any;
 };
 
+/* raw input api */
+slbt_api int  slbt_map_input            (const struct slbt_driver_ctx *,
+                                         int, const char *, int,
+                                         struct slbt_input *);
+
+slbt_api int  slbt_unmap_input          (struct slbt_input *);
+
 /* driver api */
 slbt_api int  slbt_get_driver_ctx       (char ** argv, char ** envp, uint32_t flags,
                                          const struct slbt_fd_ctx *,
diff --git a/project/common.mk b/project/common.mk
index 4893b49..31d0ff4 100644
--- a/project/common.mk
+++ b/project/common.mk
@@ -4,6 +4,7 @@ API_SRCS = \
 	src/helper/slbt_archive_import.c \
 	src/helper/slbt_copy_file.c \
 	src/helper/slbt_dump_machine.c \
+	src/helper/slbt_map_input.c \
 	src/helper/slbt_realpath.c \
 	src/logic/slbt_exec_compile.c \
 	src/logic/slbt_exec_ctx.c \
diff --git a/src/helper/slbt_map_input.c b/src/helper/slbt_map_input.c
new file mode 100644
index 0000000..5cd7774
--- /dev/null
+++ b/src/helper/slbt_map_input.c
@@ -0,0 +1,67 @@
+/*******************************************************************/
+/*  slibtool: a skinny libtool implementation, written in C        */
+/*  Copyright (C) 2015--2023  SysDeer Technologies, LLC            */
+/*  Released under the Standard MIT License; see COPYING.SLIBTOOL. */
+/*******************************************************************/
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <slibtool/slibtool.h>
+#include "slibtool_driver_impl.h"
+#include "slibtool_errinfo_impl.h"
+
+int slbt_map_input(
+	const struct slbt_driver_ctx *	dctx,
+	int				fd,
+	const char *			path,
+	int				prot,
+	struct slbt_input *		map)
+{
+	int		ret;
+	struct stat	st;
+	bool		fnew;
+	int		fdcwd;
+
+	fdcwd = slbt_driver_fdcwd(dctx);
+
+	if ((fnew = (fd < 0)))
+		fd  = openat(fdcwd,path,O_RDONLY | O_CLOEXEC);
+
+	if (fd < 0)
+		return SLBT_SYSTEM_ERROR(dctx,path);
+
+	if ((ret = fstat(fd,&st) < 0) && fnew)
+		close(fd);
+
+	else if ((st.st_size == 0) && fnew)
+		close(fd);
+
+	if (ret < 0)
+		return SLBT_SYSTEM_ERROR(dctx,path);
+
+	if (st.st_size == 0) {
+		map->size = 0;
+		map->addr = 0;
+	} else {
+		map->size = st.st_size;
+		map->addr = mmap(0,map->size,prot,MAP_PRIVATE,fd,0);
+	}
+
+	if (fnew)
+		close(fd);
+
+	return (map->addr == MAP_FAILED)
+		? SLBT_SYSTEM_ERROR(dctx,path)
+		: 0;
+}
+
+int slbt_unmap_input(struct slbt_input * map)
+{
+	return map->size ? munmap(map->addr,map->size) : 0;
+}