1 @c -*- mode: texinfo -*- 2 @deftypefn Extension {simple_object_read *} simple_object_open_read @ 3 (int @var{descriptor}, off_t @var{offset}, const char *{segment_name}, @ 4 const char **@var{errmsg}, int *@var{err}) 5 6 Opens an object file for reading. Creates and returns an 7 @code{simple_object_read} pointer which may be passed to other 8 functions to extract data from the object file. 9 10 @var{descriptor} holds a file descriptor which permits reading. 11 12 @var{offset} is the offset into the file; this will be @code{0} in the 13 normal case, but may be a different value when reading an object file 14 in an archive file. 15 16 @var{segment_name} is only used with the Mach-O file format used on 17 Darwin aka Mac OS X. It is required on that platform, and means to 18 only look at sections within the segment with that name. The 19 parameter is ignored on other systems. 20 21 If an error occurs, this functions returns @code{NULL} and sets 22 @code{*@var{errmsg}} to an error string and sets @code{*@var{err}} to 23 an errno value or @code{0} if there is no relevant errno. 24 25 @end deftypefn 26 27 @deftypefn Extension {const char *} simple_object_find_sections @ 28 (simple_object_read *@var{simple_object}, int (*@var{pfn}) (void *@var{data}, @ 29 const char *@var{name}, off_t @var{offset}, off_t @var{length}), @ 30 void *@var{data}, int *@var{err}) 31 32 This function calls @var{pfn} for each section in @var{simple_object}. 33 It calls @var{pfn} with the section name, the offset within the file 34 of the section contents, and the length of the section contents. The 35 offset within the file is relative to the offset passed to 36 @code{simple_object_open_read}. The @var{data} argument to this 37 function is passed along to @var{pfn}. 38 39 If @var{pfn} returns @code{0}, the loop over the sections stops and 40 @code{simple_object_find_sections} returns. If @var{pfn} returns some 41 other value, the loop continues. 42 43 On success @code{simple_object_find_sections} returns. On error it 44 returns an error string, and sets @code{*@var{err}} to an errno value 45 or @code{0} if there is no relevant errno. 46 47 @end deftypefn 48 49 @deftypefn Extension {int} simple_object_find_section @ 50 (simple_object_read *@var{simple_object} off_t *@var{offset}, @ 51 off_t *@var{length}, const char **@var{errmsg}, int *@var{err}) 52 53 Look for the section @var{name} in @var{simple_object}. This returns 54 information for the first section with that name. 55 56 If found, return 1 and set @code{*@var{offset}} to the offset in the 57 file of the section contents and set @code{*@var{length}} to the 58 length of the section contents. The value in @code{*@var{offset}} 59 will be relative to the offset passed to 60 @code{simple_object_open_read}. 61 62 If the section is not found, and no error occurs, 63 @code{simple_object_find_section} returns @code{0} and set 64 @code{*@var{errmsg}} to @code{NULL}. 65 66 If an error occurs, @code{simple_object_find_section} returns 67 @code{0}, sets @code{*@var{errmsg}} to an error message, and sets 68 @code{*@var{err}} to an errno value or @code{0} if there is no 69 relevant errno. 70 71 @end deftypefn 72 73 @deftypefn Extension {void} simple_object_release_read @ 74 (simple_object_read *@var{simple_object}) 75 76 Release all resources associated with @var{simple_object}. This does 77 not close the file descriptor. 78 79 @end deftypefn 80 81 @deftypefn Extension {simple_object_attributes *} simple_object_fetch_attributes @ 82 (simple_object_read *@var{simple_object}, const char **@var{errmsg}, int *@var{err}) 83 84 Fetch the attributes of @var{simple_object}. The attributes are 85 internal information such as the format of the object file, or the 86 architecture it was compiled for. This information will persist until 87 @code{simple_object_attributes_release} is called, even if 88 @var{simple_object} itself is released. 89 90 On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an 91 error message, and sets @code{*@var{err}} to an errno value or 92 @code{0} if there is no relevant errno. 93 94 @end deftypefn 95 96 @deftypefn Extension {const char *} simple_object_attributes_compare @ 97 (simple_object_attributes *@var{attrs1}, simple_object_attributes *@var{attrs2}, @ 98 int *@var{err}) 99 100 Compare @var{attrs1} and @var{attrs2}. If they could be linked 101 together without error, return @code{NULL}. Otherwise, return an 102 error message and set @code{*@var{err}} to an errno value or @code{0} 103 if there is no relevant errno. 104 105 @end deftypefn 106 107 @deftypefn Extension {void} simple_object_release_attributes @ 108 (simple_object_attributes *@var{attrs}) 109 110 Release all resources associated with @var{attrs}. 111 112 @end deftypefn 113 114 @deftypefn Extension {simple_object_write *} simple_object_start_write @ 115 (simple_object_attributes @var{attrs}, const char *@var{segment_name}, @ 116 const char **@var{errmsg}, int *@var{err}) 117 118 Start creating a new object file using the object file format 119 described in @var{attrs}. You must fetch attribute information from 120 an existing object file before you can create a new one. There is 121 currently no support for creating an object file de novo. 122 123 @var{segment_name} is only used with Mach-O as found on Darwin aka Mac 124 OS X. The parameter is required on that target. It means that all 125 sections are created within the named segment. It is ignored for 126 other object file formats. 127 128 On error @code{simple_object_start_write} returns @code{NULL}, sets 129 @code{*@var{ERRMSG}} to an error message, and sets @code{*@var{err}} 130 to an errno value or @code{0} if there is no relevant errno. 131 132 @end deftypefn 133 134 @deftypefn Extension {simple_object_write_section *} simple_object_write_create_section @ 135 (simple_object_write *@var{simple_object}, const char *@var{name}, @ 136 unsigned int @var{align}, const char **@var{errmsg}, int *@var{err}) 137 138 Add a section to @var{simple_object}. @var{name} is the name of the 139 new section. @var{align} is the required alignment expressed as the 140 number of required low-order 0 bits (e.g., 2 for alignment to a 32-bit 141 boundary). 142 143 The section is created as containing data, readable, not writable, not 144 executable, not loaded at runtime. The section is not written to the 145 file until @code{simple_object_write_to_file} is called. 146 147 On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an 148 error message, and sets @code{*@var{err}} to an errno value or 149 @code{0} if there is no relevant errno. 150 151 @end deftypefn 152 153 @deftypefn Extension {const char *} simple_object_write_add_data @ 154 (simple_object_write *@var{simple_object}, @ 155 simple_object_write_section *@var{section}, const void *@var{buffer}, @ 156 size_t @var{size}, int @var{copy}, int *@var{err}) 157 158 Add data @var{buffer}/@var{size} to @var{section} in 159 @var{simple_object}. If @var{copy} is non-zero, the data will be 160 copied into memory if necessary. If @var{copy} is zero, @var{buffer} 161 must persist until @code{simple_object_write_to_file} is called. is 162 released. 163 164 On success this returns @code{NULL}. On error this returns an error 165 message, and sets @code{*@var{err}} to an errno value or 0 if there is 166 no relevant erro. 167 168 @end deftypefn 169 170 @deftypefn Extension {const char *} simple_object_write_to_file @ 171 (simple_object_write *@var{simple_object}, int @var{descriptor}, int *@var{err}) 172 173 Write the complete object file to @var{descriptor}, an open file 174 descriptor. This writes out all the data accumulated by calls to 175 @code{simple_object_write_create_section} and 176 @var{simple_object_write_add_data}. 177 178 This returns @code{NULL} on success. On error this returns an error 179 message and sets @code{*@var{err}} to an errno value or @code{0} if 180 there is no relevant errno. 181 182 @end deftypefn 183 184 @deftypefn Extension {void} simple_object_release_write @ 185 (simple_object_write *@var{simple_object}) 186 187 Release all resources associated with @var{simple_object}. 188 189 @end deftypefn 190
