fobos — the FoBiS makefile

A fobos file is FoBiS.py's project configuration file. It replaces makefiles entirely, using a simple INI-like syntax.

Overview

When FoBiS.py runs, it automatically looks for a file named fobos in the current working directory. Options in the fobos file override the CLI defaults, and for cflags, lflags, and preproc they are combined with any additional values passed on the command line.

Design principle

Brevity is a design parameter. The fobos file uses the same option names as the CLI switches — there is nothing new to learn.

Basic structure

A minimal single-mode fobos file:

[default]
compiler  = gnu
cflags    = -c -O2
src       = ./src/
build_dir = ./build/
obj_dir   = ./obj/
mod_dir   = ./mod/
target    = src/main.f90
output    = myapp

A multi-mode fobos file:

[modes]
modes = debug release

[debug]
compiler  = gnu
cflags    = -c -O0 -g -Wall
build_dir = ./build/debug/

[release]
compiler  = gnu
cflags    = -c -O3
build_dir = ./build/release/

Loading a fobos file

Scenario	Command
Default name and location	Loaded automatically
Custom name or path	FoBiS.py build -f /path/to/my_fobos
Select a specific mode	FoBiS.py build -mode release
List available modes	FoBiS.py build -lmodes

Case sensitivity

By default fobos option names are case-sensitive. To make them case-insensitive:

FoBiS.py build -fci

Or in the fobos file itself, this is implicit for the option names (values remain as written).

Available options

All CLI options accepted by build and clean are available in a fobos mode section with identical names (using the long form without the leading --). A representative set:

Option	Description
compiler	Compiler identifier (gnu, intel, …)
fc	Compiler executable (for custom compiler)
cflags	Compilation flags
lflags	Linking flags
preproc	Preprocessor macro flags
src	Root source directory (space-separated list)
build_dir	Build output directory
obj_dir	Compiled objects directory
mod_dir	Module interface files directory
lib_dir	External library search directories
include	Include files search directories
target	Build target file
output	Output executable name
exclude	Files to exclude from the build
libs	External libraries (full paths)
vlibs	Volatile external libraries (full paths)
ext_libs	External libraries (by name, in linker path)
ext_vlibs	Volatile external libraries (by name)
dependon	Interdependent external fobos files
mklib	Build a library: static or shared
ar	Archiver executable for static libraries (default: ar)
arflags	Archiver flags (default: -rcs)
ranlib	Ranlib executable; set to empty string to skip (default: ranlib)
mpi	Enable MPI compiler variant
openmp	Enable OpenMP
coarray	Enable coarrays
coverage	Enable coverage instrumentation
jobs	Number of parallel compile jobs
colors	Coloured terminal output
quiet	Suppress verbose output
log	Write build log file
cflags_heritage	Track flag changes and force rebuild on change

Special sections

Beyond the mode sections, a fobos file can contain several top-level sections with fixed names:

Section	Purpose	Documentation
[modes]	Lists the available named mode sections	Many-mode fobos
[project]	Project metadata: name, version, authors, …	Project metadata
[dependencies]	GitHub-hosted build dependencies	Fetch Dependencies
[rule-NAME]	Custom shell-command rules	Rules

[dependencies] section

Declares GitHub-hosted dependencies. Each entry maps a short name to a repository spec:

[dependencies]
deps_dir = .fobis_deps          # optional: where to clone deps (same as --deps-dir)
penf     = https://github.com/szaghi/PENF :: tag=v1.5.0
stdlib   = https://github.com/fortran-lang/stdlib :: tag=v0.5.0 :: use=fobos :: mode=gnu

The use= field selects the integration mode:

• sources (default) — dependency sources are compiled inline with your project
• fobos — dependency is built as a separate library and linked

See Fetch Dependencies for the full syntax and workflow.

Comments

Lines beginning with # are ignored:

[default]
# This is a comment
compiler = gnu  # inline comments are also supported
cflags   = -c -O2

Further reading

• Single-mode fobos — the simplest configuration
• Many-mode fobos — multiple build configurations in one file
• Templates — share common settings across modes
• Variables — define reusable $variable values
• Rules — custom task automation (documentation, archives, …)
• Intrinsic rules — built-in automation rules
• Project metadata — [project] section: name, version, authors, and more
• Fetch Dependencies — [dependencies] section: GitHub-hosted build dependencies