1 @c -*- mode: texinfo -*-
2 @deftypefn Extension {simple_object_read *} simple_object_open_read (int @var{descriptor}, off_t @var{offset}, const char *{segment_name}, const char **@var{errmsg}, int *@var{err})
4 Opens an object file for reading. Creates and returns an
5 @code{simple_object_read} pointer which may be passed to other
6 functions to extract data from the object file.
8 @var{descriptor} holds a file descriptor which permits reading.
10 @var{offset} is the offset into the file; this will be @code{0} in the
11 normal case, but may be a different value when reading an object file
14 @var{segment_name} is only used with the Mach-O file format used on
15 Darwin aka Mac OS X. It is required on that platform, and means to
16 only look at sections within the segment with that name. The
17 parameter is ignored on other systems.
19 If an error occurs, this functions returns @code{NULL} and sets
20 @code{*@var{errmsg}} to an error string and sets @code{*@var{err}} to
21 an errno value or @code{0} if there is no relevant errno.
25 @deftypefn Extension {const char *} simple_object_find_sections (simple_object_read *@var{simple_object}, int (*@var{pfn}) (void *@var{data}, const char *@var{name}, off_t @var{offset}, off_t @var{length}), void *@var{data}, int *@var{err})
27 This function calls @var{pfn} for each section in @var{simple_object}.
28 It calls @var{pfn} with the section name, the offset within the file
29 of the section contents, and the length of the section contents. The
30 offset within the file is relative to the offset passed to
31 @code{simple_object_open_read}. The @var{data} argument to this
32 function is passed along to @var{pfn}.
34 If @var{pfn} returns @code{0}, the loop over the sections stops and
35 @code{simple_object_find_sections} returns. If @var{pfn} returns some
36 other value, the loop continues.
38 On success @code{simple_object_find_sections} returns. On error it
39 returns an error string, and sets @code{*@var{err}} to an errno value
40 or @code{0} if there is no relevant errno.
44 @deftypefn Extension {int} simple_object_find_section (simple_object_read *@var{simple_object} off_t *@var{offset}, off_t *@var{length}, const char **@var{errmsg}, int *@var{err})
46 Look for the section @var{name} in @var{simple_object}. This returns
47 information for the first section with that name.
49 If found, return 1 and set @code{*@var{offset}} to the offset in the
50 file of the section contents and set @code{*@var{length}} to the
51 length of the section contents. The value in @code{*@var{offset}}
52 will be relative to the offset passed to
53 @code{simple_object_open_read}.
55 If the section is not found, and no error occurs,
56 @code{simple_object_find_section} returns @code{0} and set
57 @code{*@var{errmsg}} to @code{NULL}.
59 If an error occurs, @code{simple_object_find_section} returns
60 @code{0}, sets @code{*@var{errmsg}} to an error message, and sets
61 @code{*@var{err}} to an errno value or @code{0} if there is no
66 @deftypefn Extension {void} simple_object_release_read (simple_object_read *@var{simple_object})
68 Release all resources associated with @var{simple_object}. This does
69 not close the file descriptor.
73 @deftypefn Extension {simple_object_attributes *} simple_object_fetch_attributes (simple_object_read *@var{simple_object}, const char **@var{errmsg}, int *@var{err})
75 Fetch the attributes of @var{simple_object}. The attributes are
76 internal information such as the format of the object file, or the
77 architecture it was compiled for. This information will persist until
78 @code{simple_object_attributes_release} is called, even if
79 @var{simple_object} itself is released.
81 On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
82 error message, and sets @code{*@var{err}} to an errno value or
83 @code{0} if there is no relevant errno.
87 @deftypefn Extension {const char *} simple_object_attributes_compare (simple_object_attributes *@var{attrs1}, simple_object_attributes *@var{attrs2}, int *@var{err})
89 Compare @var{attrs1} and @var{attrs2}. If they could be linked
90 together without error, return @code{NULL}. Otherwise, return an
91 error message and set @code{*@var{err}} to an errno value or @code{0}
92 if there is no relevant errno.
96 @deftypefn Extension {void} simple_object_release_attributes (simple_object_attributes *@var{attrs})
98 Release all resources associated with @var{attrs}.
102 @deftypefn Extension {simple_object_write *} simple_object_start_write (simple_object_attributes @var{attrs}, const char *@var{segment_name}, const char **@var{errmsg}, int *@var{err})
104 Start creating a new object file using the object file format
105 described in @var{attrs}. You must fetch attribute information from
106 an existing object file before you can create a new one. There is
107 currently no support for creating an object file de novo.
109 @var{segment_name} is only used with Mach-O as found on Darwin aka Mac
110 OS X. The parameter is required on that target. It means that all
111 sections are created within the named segment. It is ignored for
112 other object file formats.
114 On error @code{simple_object_start_write} returns @code{NULL}, sets
115 @code{*@var{ERRMSG}} to an error message, and sets @code{*@var{err}}
116 to an errno value or @code{0} if there is no relevant errno.
120 @deftypefn Extension {simple_object_write_section *} simple_object_write_create_section (simple_object_write *@var{simple_object}, const char *@var{name}, unsigned int @var{align}, const char **@var{errmsg}, int *@var{err})
122 Add a section to @var{simple_object}. @var{name} is the name of the
123 new section. @var{align} is the required alignment expressed as the
124 number of required low-order 0 bits (e.g., 2 for alignment to a 32-bit
127 The section is created as containing data, readable, not writable, not
128 executable, not loaded at runtime. The section is not written to the
129 file until @code{simple_object_write_to_file} is called.
131 On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
132 error message, and sets @code{*@var{err}} to an errno value or
133 @code{0} if there is no relevant errno.
137 @deftypefn Extension {const char *} simple_object_write_add_data (simple_object_write *@var{simple_object}, simple_object_write_section *@var{section}, const void *@var{buffer}, size_t @var{size}, int @var{copy}, int *@var{err})
139 Add data @var{buffer}/@var{size} to @var{section} in
140 @var{simple_object}. If @var{copy} is non-zero, the data will be
141 copied into memory if necessary. If @var{copy} is zero, @var{buffer}
142 must persist until @code{simple_object_write_to_file} is called. is
145 On success this returns @code{NULL}. On error this returns an error
146 message, and sets @code{*@var{err}} to an errno value or 0 if there is
151 @deftypefn Extension {const char *} simple_object_write_to_file (simple_object_write *@var{simple_object}, int @var{descriptor}, int *@var{err})
153 Write the complete object file to @var{descriptor}, an open file
154 descriptor. This writes out all the data accumulated by calls to
155 @code{simple_object_write_create_section} and
156 @var{simple_object_write_add_data}.
158 This returns @code{NULL} on success. On error this returns an error
159 message and sets @code{*@var{err}} to an errno value or @code{0} if
160 there is no relevant errno.
164 @deftypefn Extension {void} simple_object_release_write (simple_object_write *@var{simple_object})
166 Release all resources associated with @var{simple_object}.