josh build - C build scripts without an agenda

Many existing build systems have issues that impose problems onto the engineer that is just trying to get shit done. Usually there is a combination of:

• adopting a new programming language
• learning some insurmountable API, the documentation for which could fill entire libraries
• downloading the build system program to every machine that you must build from
• interacting with crazy people

josh build does not require the user to deal with any of the bullshit:

• build scripts are plain C code that get concatenated with a josh_build.h header
• the most useful bits of the API take seconds to understand
  • JB_RUN(mkdir -p build); executes mkdir -p build just as it would on a command line
  • build an executable in 3 lines of code JBExecutable josh = {"josh"}; josh.sources = (const char *[]){"src/main.c", NULL}; jb_build_exe(&josh);
• josh library produces a copy of josh_build.h to be #include'd so that you never need the josh driver again
• written by a person without an agenda

Build

Unix (mac, linux)

Run ./bootstrap.sh to build the josh driver. For fun, ./build/josh build will build the driver again but using the josh build system in build.josh.

Windows

Either from a Visual Studio Developer Command Prompt, or after running vcvarsall.bat or VsDevCmd.bat, run "bootstrap.bat" to build the josh driver.

Usage

Quick Start

Run josh init in an empty folder to create a template project. This creates a new build.josh and src/main.c. Run josh build to build the project template.

Running External Commands

JB_RUN(cmd, ...) (and jb_run_string(const char *cmd, const char *extra[])) will transform cmd tokens into a string, then parse the string into its individual arguments to then feed to jb_run(char *const argv[]). The va-list/extras may be used to provide additional arguments as C strings that can't be described at compile-time or requires a comma be used.

Example:

JB_RUN(echo Hello World!)
JB_RUN(echo, "Hello, World!");

Output:

Hello World!
Hello, World!

JB_RUN() and jb_run_string() additionally parse bash-style environment variable syntax and inject the environment variable value into the command:

JB_RUN(echo Hello $USER);

Output:

Hello josh

Cross-compiling

Set JBExecutable.toolchain to instruct josh build to cross-compile. Find a target toolchain via jb_find_toolchain().

JBToolchain *toolchain = jb_find_toolchain(JB_ENUM(ARM64), JB_ENUM(Linux), JB_ENUM(GNU));
if (toolchain != jb_native_toolchain()) {
    if(!toolchain) {
        printf("WARNING: no toolchain for arm64-linux-gnu; skipping build...\n");
    }
    else {
        // Cross build linux executable
        JBExecutable josh = {"josh_linux"};
        josh.sources = (const char *[]){"src/main.c", NULL};
        josh.build_folder = "build";

        josh.toolchain = toolchain;
        jb_build_exe(&josh);
    }
}
else {
    printf("Host is running arm64-linux-gnu; skipping cross-build...\n");
}

By default, josh build searches for /toolchains in the current working directory. Call jb_set_toolchain_directory() to use a custom path.

The toolchains folder is typically expected to contain:

/bin/<target>-gcc
/bin/<target>-g++
/bin/<target>-ld

/<target>/sys-root/ -- sysroot containing system headers, libc, libc++, and other packages

Building a Toolchain

josh toolchain <triple> can be used to build a basic Linux cross-compiler with Linux kernel headers, glibc, libstdc++, etc...

The script tools/toolchain_builder.josh may also be used:

josh build-file tools/toolchain_builder.josh arm64-linux-gnu

License

This program is beer-ware, see header in src/josh_build.h.