llvm-extract.1

LLVM-EXTRACT

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXIT STATUS
SEE ALSO
AUTHOR
COPYRIGHT

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NAME

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

−−alias alias−name

Extract the alias named function−name from the LLVM bitcode. May be specified multiple times to extract multiple alias at once.

−−ralias alias−regular−expr

Extract the alias matching alias−regular−expr from the LLVM bitcode. All alias matching the regular expression will be extracted. May be specified multiple times.

−−bb basic−block−specifier

Extract basic blocks(s) specified in basic−block−specifier. May be specified multiple times. Each <function:bb[;bb]> specifier pair will create a function. If multiple basic blocks are specified in one pair, the first block in the sequence should dominate the rest.

−−delete

Delete specified Globals from Module.

−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.

−−keep−const−init

Preserve the values of constant globals.

−−recursive

Recursively extract all called functions

−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(1)

AUTHOR

Maintained by the LLVM Team (https://llvm.org/).

COPYRIGHT

2003-2025, LLVM Project

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