llvm-extract - extract a function from an LLVM module
llvm-extract [options] –func
function-name [filename]
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).
–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).
If llvm-extract succeeds, it will exit with 0. Otherwise,
if an error occurs, it will exit with a non-zero value.
Maintained by the LLVM Team (https://llvm.org/).