{program}llvm-extract [options] --func function-name [filename]
The {program}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, {program}llvm-extract will also remove unreachable global variables, prototypes, and unused types.
The {program}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).
:::{option} --alias Extract the alias named function-name from the LLVM bitcode. May be specified multiple times to extract multiple alias at once. :::
:::{option} --ralias 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. :::
:::{option} --bb 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. :::
:::{option} --delete Delete specified Globals from Module. :::
:::{option} -f Enable binary output on terminals. Normally, {program}llvm-extract will refuse to write raw bitcode output if the output stream is a terminal. With this option, {program}llvm-extract will write raw bitcode regardless of the output device. :::
:::{option} --func Extract the function named function-name from the LLVM bitcode. May be specified multiple times to extract multiple functions at once. :::
:::{option} --rfunc 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. :::
:::{option} --glob Extract the global variable named global-name from the LLVM bitcode. May be specified multiple times to extract multiple global variables at once. :::
:::{option} --rglob 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. :::
:::{option} --keep-const-init Preserve the values of constant globals. :::
:::{option} --recursive Recursively extract all called functions :::
:::{option} -help Print a summary of command line options. :::
:::{option} -o Specify the output filename. If filename is “-” (the default), then {program}llvm-extract sends its output to standard output. :::
:::{option} -S Write output in LLVM intermediate language (instead of bitcode). :::
If {program}llvm-extract succeeds, it will exit with 0. Otherwise, if an error occurs, it will exit with a non-zero value.
{manpage}llvm-reduce(1)