docs/CommandGuide/llvm-extract.rst

llvm-extract - extract a function from an LLVM module
=====================================================


SYNOPSIS
--------


**llvm-extract** [*options*] **--func** *function-name* [*filename*]


DESCRIPTION
-----------


The **llvm-extract** command takes the name of a function and extracts it from
the specified LLVM bitcode file.  It is primarily used as a debugging tool to
reduce test cases from larger programs that are triggering a bug.

In addition to extracting the bitcode of the specified function,
**llvm-extract** will also remove unreachable global variables, prototypes, and
unused types.

The **llvm-extract** command reads its input from standard input if filename is
omitted or if filename is -.  The output is always written to standard output,
unless the **-o** option is specified (see below).


OPTIONS
-------



**-f**

 Enable binary output on terminals.  Normally, **llvm-extract** will refuse to
 write raw bitcode output if the output stream is a terminal. With this option,
 **llvm-extract** will write raw bitcode regardless of the output device.



**--func** *function-name*

 Extract the function named *function-name* from the LLVM bitcode. May be
 specified multiple times to extract multiple functions at once.



**--rfunc** *function-regular-expr*

 Extract the function(s) matching *function-regular-expr* from the LLVM bitcode.
 All functions matching the regular expression will be extracted.  May be
 specified multiple times.



**--glob** *global-name*

 Extract the global variable named *global-name* from the LLVM bitcode. May be
 specified multiple times to extract multiple global variables at once.



**--rglob** *glob-regular-expr*

 Extract the global variable(s) matching *global-regular-expr* from the LLVM
 bitcode. All global variables matching the regular expression will be extracted.
 May be specified multiple times.



**-help**

 Print a summary of command line options.



**-o** *filename*

 Specify the output filename.  If filename is "-" (the default), then
 **llvm-extract** sends its output to standard output.



**-S**

 Write output in LLVM intermediate language (instead of bitcode).




EXIT STATUS
-----------


If **llvm-extract** succeeds, it will exit with 0.  Otherwise, if an error
occurs, it will exit with a non-zero value.


SEE ALSO
--------


bugpoint|bugpoint