5 llvm-ar - LLVM archiver
9 B<llvm-ar> [-X32_64] [-]{dmpqrtx}[Rabfouz] [relpos] [count] <archive-file> [files...]
14 The B<llvm-ar> command is similar to the common Unix utility, C<ar>. It
15 archives several files together into a single file. The intent for this is
16 to produce archive libraries by LLVM bytecode that can be linked into an
17 LLVM program. However, the archive can contain any kind of file. If requested,
18 B<llvm-ar> can generate a symbol table that makes linking faster because
19 only the symbol table needs to be consulted, not each individual file member
22 While the B<llvm-ar> command produces files that are similar to the format
23 used by older C<ar> implementations, it has several significant departures
24 in order to make the archive appropriate for LLVM. Consequently, archives
25 produced with B<llvm-ar> probably won't be readable or editable with any
26 C<ar> implementation unless the archive content is very simple.
28 Here's where B<llvm-ar> departs from previous C<ar> implementations:
34 Since B<llvm-ar> is intended to archive bytecode files, the symbol table
35 won't make much sense to anything but LLVM. Consequently, the symbol table's
36 format has been simplified. It consists simply of a sequence of pairs
37 of a file member index number as an LSB 4byte integer and a null-terminated
42 Some C<ar> implementations (SVR4) use a separate file member to record long
43 path names (> 15 characters). B<llvm-ar> takes the BSD 4.4 and Mac OS X
44 approach which is to simply store the full path name immediately preceding
45 the data for the file. The path name is null terminated and may contain the
50 B<llvm-ar> can compress the members of an archive to save space. The
51 compression used depends on what's available on the platform but favors
52 bzip2 and then zlib. Note that for very small files, bzip2 may increase
53 the file size but generally does about 10% better than zlib on LLVM
56 =item I<Directory Recursion>
58 Most C<ar> implementations do not recurse through directories but simply
59 ignore directories if they are presented to the program in the F<files>
60 option. B<llvm-ar>, however, can recurse through directory structures and
61 add all the files under a directory, if requested.
63 =item I<TOC Verbose Output>
65 When B<llvm-ar> prints out the verbose table of contents (C<tv> option), it
66 precedes the usual output with a character indicating the basic kind of
67 content in the file. A blank means the file is a regular file. A 'Z' means
68 the file is compressed. A 'B' means the file is an LLVM bytecode file. An
69 'S' means the file is the symbol table.
75 The options to B<llvm-ar> are compatible with other C<ar> implementations.
76 However, there are a few modifiers (F<zR>) that are not found in other
77 C<ar>s. The options to B<llvm-ar> specify a single basic operation to
78 perform on the archive, a variety of modifiers for that operation, the
79 name of the archive file, and an optional list of file names. These options
80 are used to determine how B<llvm-ar> should process the archive file.
82 The Operations and Modifiers are explained in the sections below. The minimal
83 set of options is at least one operator and the name of the archive. Typically
84 archive files end with a C<.a> suffix, but this is not required. Following
85 the F<achive-name> comes a list of F<files> that indicate the specific members
86 of the archive to operate on. If the F<files> option is not specified, it
87 generally means either "none" or "all" members, depending on the operation.
95 Delete files from the archive. No modifiers are applicable to this operation.
96 The F<files> options specify which members should be removed from the
97 archive. It is not an error if a specified file does not appear in the archive.
98 If no F<files> are specified, the archive is not modified.
102 Move files from one location in the archive to another. The F<a>, F<b>, and
103 F<i> modifiers apply to this operation. The F<files> will all be moved
104 to the location given by the modifiers. If no modifiers are used, the files
105 will be moved to the end of the archive. If no F<files> are specified, the
106 archive is not modified.
110 Print files to the standard output. No modifiers are applicable to this
111 operation. This operation simply prints the F<files> indicated to the
112 standard output. If no F<files> are specified, the entire archive is printed.
113 Printing bytecode files is ill-advised as they might confuse your terminal
114 settings. The F<p> operation never modifies the archive.
118 Quickly append files to the end of the archive. The F<R>, F<f>, and F<z>
119 modifiers apply to this operation. This operation quickly adds the
120 F<files> to the archive without checking for duplicates that shoud be
121 removed first. If no F<files> are specified, the archive is not modified.
122 Becasue of the way that B<llvm-ar> constructs the archive file, its dubious
123 whether the F<q> operation is any faster than the F<r> operation.
127 Replace or insert file members. The F<R>, F<a>, F<b>, F<f>, F<u>, and F<z>
128 modifiers apply to this operation. This operation will replace existing
129 F<files> or insert them at the end of the archive if they do not exist. If no
130 F<files> are specified, the archive is not modified.
134 Print the table of contents. Without any modifiers, this operation just prints
135 the names of the members to the standard output. With the F<v> modifier,
136 B<llvm-ar> also prints out the file type (B=bytecode, Z=compressed, S=symbol
137 table, blank=regular file), the permission mode, the owner and group, the
138 size, and the date. If any F<files> are specified, the listing is only for
139 those files. If no F<files> are specified, the table of contents for the
140 whole archive is printed.
144 Extract archive members back to files. The F<o> modifier applies to this
145 operation. This operation retrieves the indicated F<files> from the archive
146 and writes them back to the operating system's file system. If no
147 F<files> are specified, the entire archive is extract.
151 =head2 Modifiers (operation specific)
157 put F<files> after [relpos]
161 put F<files> before [relpos] (same as [i])
165 truncate inserted file names
169 put file(s) before [relpos] (same as [b])
173 use instance [count] of name
177 preserve original dates
181 use full path names when matching
185 recurse through directories when inserting
189 update only files newer than archive contents
193 compress/uncompress files before inserting/extracting
197 =head2 Modifiers (generic)
203 do not warn if the library had to be created
207 create an archive index (cf. ranlib)
211 do not build a symbol table
215 recursively process directories
225 If B<llvm-as> succeeds, it will exit with 0. A usage error, results
226 in an exit code of 1. A hard (file system typically) error results in an
227 exit code of 2. Miscellaneous or unknown errors result in an
236 Maintained by the LLVM Team (L<http://llvm.cs.uiuc.edu>).