goodmake 0.1.0

A simpler build system

What’s GoodMake?

GoodMake is a simpler build system. It lets you use a scripting language of your choice to define recipes and dependencies, and then intelligently runs just the right recipes, in parallel, to build the result you want. You do not have to know ahead of time what the dependencies will be. This greatly simplifies writing build recipes – you just specify target patterns and don’t have to learn a special-purpose build system language.

GoodMake’s design borrows heavily from the grand-daddy of make systems, Gnu Make, and from the wonderful Redo system.

Compared to Gnu Make

GoodMake is designed to allow much more powerful descriptions of the dependencies between recipes, while being simple to read, write, and debug, resulting in more reliable build systems. GoodMake:

• Lets you use any scripting language for your recipes

• Doesn’t require you to learn a make file “language”

• Lets you write arbitrary code to determine dependencies

• Lets you organize your recipes into separate make files

• Uses file checksums to determine if dependencies have changed

• Does not require your make files to be in any particular place

Compared to Redo

GoodMake:

• Lets you use any scripting language for your recipes

• Lets you consolidate multiple recipes into a single file

• Lets you specify multiple target patterns that use the same recipe

• Does not require your make files to be in any particular place

Usage

A shell-script “make.sh” file could look like this:

#! /usr/local/bin/goodmake /bin/sh -se

#? !default
    $0 doclist
    for DOC in $(cat doclist); do
        echo tgt/$DOC
    done | xargs --delimiter '\n' $0

#? tgt/*
    SRC=src/$(basename $1)
    $0 $SRC
    sort $SRC > $1

#! doclist
    ls src > $1

To sort all the files, you’d simply type:

./make.sh

This will sort all the files in the directory src, and put the sorted results in tgt. The $0 variable is the make script ./make.sh, and the $1 variable is the target currently being built. The build works as follows:

1. The ./make.sh script with no arguments runs the recipe for default

2. The default recipe requires doclist, which lists the files in src into a file called doclist. If new files are added to src, the doclist will change, causing the default recipe to re-run.

3. Next, the default recipe requires corresponding tgt/filename dependencies for each src/filename from the doclist. If any of these src files have changed, the corresponding tgt/* pattern recipe will be run.

4. A tgt/filename requirement uses the tgt/* recipe to create by running sort on the corresponding src file.

If you want to create or update just one sorted file, you could type:

./make.sh tgt/filename

GoodMake script file syntax

The first line is the OS “shebang” that says this should be executed with GoodMake. The remainder of the line is an interpreter command that is passed to GoodMake. Here is a Python shebang:

#! /usr/local/bin/goodmake /usr/bin/python3 -

and a Bash shebang:

#! /usr/local/bin/goodmake /bin/sh -se

Subsequent blank and comment lines are ignored. “Stanzas” of code are introduced with a “sheque” comment that specifies (shell glob) targets that the stanza will apply to. For example a Python or Bash script might include the target line:

#? tgt/sorted.txt

And a node script might include the target line:

//? tgt/sorted.txt

A “shebang” anywhere other that the first line, is like a “sheque” but indicates the recipe should always be run, regardless of any dependencies:

#! tgt/sorted.txt

After a shebang, lines are interpreted. A recipe for a target is built out of all of the matching stanzas. In the recipe, the positional arguments are set:

0. The script path (depending on the interpreter)

1. The target

2. The script path (regardless of interpreter)

Here’s a full python “build.py” script file example:

#! /usr/local/bin/goodmake /usr/bin/python3 -

#? tgt/*
    import subprocess
    import sys

#? tgt/sorted.txt
    inputFile = 'src/input.txt'
    subprocess.run([sys.argv[2], inputFile])

    with open(inputFile) as input:
        lines = input.readlines()
        lines.sort()
        with open(sys.argv[1], 'w') as output:
            output.writelines(lines)

#! !sayhi
    print("Hello, World")

When recipes are run

When an recipe is run, it may update the target, it creates a checksum, and it logs a build. A recipe is run when one of its target patterns is requested, and:

• The recipe starts with shebang (#!), or

• There’s no successful build log, or

• The checksum has changed, or

• The recipe has changed, or

• if any known dependencies have changed

When targets are considered changed

A checksum is taken on dependency targets that are existing files. Targets that are missing, or are directories, or whose patterns started with “!”, don’t have checksums. A target is considered changed if:

• The target checksum exists and has changed, or

• There is no checksum, and the recipe has been re-run

It’s a “missing recipe” error if there’s no recipe and no checksum and the target doesn’t already exist.

Parallel Builds

If a script is called with multiple dependencies, then these dependencies are checked (and rebuilt if necessary) in parallel, in batches of up to 8 at a time.

What to clean

You may want to clean out all GoodMake files. After such a clean, no files will have build logs, so all encountered recipes will be run when updating. This is pretty safe.

find -name '*.gm' -delete

You may want to delete all the built files. When a recipe is run, it creates a build log file. You could delete all files that have an accompanying .gm file. This is less safe, if you have any recipes that don’t actually know how to create their targets.

Environment Variables

• LOG - Set logging level to ERROR, WARN (default), INFO, or DEBUG.

• GM__REMAKE - Set to TRUE to cause all targets to be re-made.

• GM__TIMEOUT - Number of seconds to wait for concurrency locks.

• GM__FILE - Internal variable for communicating between GoodMake processes.

• GM__STARTTIME - Internal variable for communicating between GoodMake processes.

• GM_THREADS - Set the maximum number of threads for parallel builds.

Examples

Specifying an external file dependency

#? my_target
    $0 external_file

The first successful build will create a build log for my_target with checksums for both external_file and my_target. If the external_file changes, then it will trigger a re-run of my_target recipe.

How to identify a missing dependency recipe

#? my_target
    $0 nosuchdep

Sometimes you may have an erroneous set of recipes that list a non-existent dependency with no recipe to build it. If nosuchdep does not exist, or is a directory, look in the logs for a message that says “missing recipe”.

Ensuring a recipe is always run

This is useful if some dependencies are not identifiable ahead of time. We still want to use a checksum to see if anything has changed.

#! my_target
    ls >$1

If the pattern line starts with shebang instead of sheque, the recipe is always run. my_target will only be considered changed if its checksum changes.

Combining multiple dependencies into a single target

#? !my_prereqs
    $0 dep1 dep2 dep3

Since !my_prereqs starts with a “!”, any checksum is ignored, and so my_prereqs will be considered changed every time the recipe is run, which will be every time the dependencies are changed.

Naming a simple script to run from the command line

#! doit
    ls -lht

This recipe will always run, because it starts with a shebang.

Refreshing after a certain amount of time

#! .every-day
    touch -d yesterday .yesterday
    [ $1 -nt .yesterday ] || date>$1

#! .each-boot
    touch -d $(uptime -s) .reboot
    [ $1 -nt .reboot ] || date>$1

#! .each-install
    # This should work on debian systems
    FILE=$(ls -1t /var/log/installer | tail -1)
    [ $1 -nt "$FILE" ] || date>$1

#! .each-upgrade
    [ $1 -nt /etc/lsb-release ] || date>$1

Looping over dependencies

#? !sort-all
    $0 doclist.txt

    for DOC in $(cat doclist.txt); do
        echo ${DOC}_sorted.txt
    done | xargs --delimiter '\n' $0

License

GoodMake is distributed under the terms of the GNU General Public License v3.0.