go.elara.ws/pcre

pcre

This package provides a CGo-free port of the PCRE2 regular expression library. The lib directory contains source code automatically translated from PCRE2's C source. This package wraps that code and provides an interface as close as possible to Go's stdlib regexp package

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IMPORTANT NOTE!

Due to the use of PCRE2, this library contains extra features such as lookaheads/lookbehinds. The stdlib regex engine, RE2, left these features out for a reason. It's easy to create regular expressions with this library that have exponential runtime. This creates the possibility of a denial of service attack. Only use this library if the extra features are needed and the user providing the regex is trusted (such as if it's in a config file). Otherwise, use the standard library regexp package.

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Supported GOOS/GOARCH:

• linux/amd64
• linux/386
• linux/arm64
• linux/arm
• linux/riscv64
• darwin/amd64
• darwin/arm64

More OS support is planned.

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How to transpile pcre2

In order to transpile pcre2, a Go and C compiler (preferably GCC) will be needed.

• First, install ccgo

• Then, download the pcre source code. It can be found here: https://github.com/PCRE2Project/pcre2.

• Once downloaded, cd into the source directory

• Run ./configure. If cross-compiling, provide the path to the cross-compiler in the CC variable, and set --target to the target architecture.

• When it completes, there should be a Makefile in the directory.

• Run ccgo -compiledb pcre.json make. Do not add -j arguments to the make command.

• Run the following command (replace items in triangle brackets):

CC=/usr/bin/gcc ccgo -o pcre2_<os>_<arch>.go -pkgname lib -trace-translation-units -export-externs X -export-defines D -export-fields F -export-structs S -export-typedefs T pcre.json .libs/libpcre2-8.a

• If cross-compiling, set the CCGO_CC variable to to path of the cross-compiler, and the CCGO_AR variable to the path of the cross-compiler's ar binary. Also, set TARGET_GOARCH to the GOARCH you're targeting and TARGET_GOOS to the OS you're targeting.

• Once the command completes, two go files will be created. One will start with pcre2, the other with capi. Copy both of these to the lib directory in this repo.