Variables in Project.meta

bake allows you to use

user defined
predefined
environment

variables in your Project.meta file. Every environment and predefined variable can be overwritten by the user. If a variable is not found at all, it will be set to an empty string (see below how to change that default behaviour).

Using variables

Variables can be used using the following syntax:

$(ABC)

The variable ABC will be substituted by its value, therefore a real life usage would look something like this:

IncludeDir "$(ABC)"

User defined variables

There are two ways to create user defined variables.

The variable is defined with the –set command line option:

User@Host:~$ bake ... --set MyVar="Hello world!"

The variable is defined directly in the Project.meta file.

Set MyVar, value: "Hello world!"
Set MyVar, cmd: "ruby calcVar.rb"

In the latter one the variable is set to the output of the command.

Predefined bake environment variables

Variable	Description	Example
$(MainConfigName)	Evaluates to the main config name	Debug
$(MainProjectName)	Evaluates to the main project name	bootloader
$(ConfigName)	Evaluates to the config name	lib
$(ProjectName)	Evaluates to the project name	canDriver
$(ProjectDir)	Evaluates to the full path of the project directory	C:/Root/MyProject
$(MainProjectDir)	Evaluates to the full path of the root projec directory	C:/Root/Main
$(OutputDir)	Evaluates to the full path of the output directory of the current config	build/lib_bootloader_Debug
$(OutputDir,projName,confName)	Evaluates to the output dir of a specific config	build/lib_some_Debug
$(WorkingDir)	Directory from which bake is called	c:/Workspaces/Project
$(OriginalDir)	Directory of the containing meta file. Useful for relative paths from Adapt files.	c:/Root/admin/adapt/coverage
$(ArtifactName)	Evaluates to the artifact.	bootloader_1.0.elf
$(ArtifactNameBase)	Evaluates to the base artifact name (Without file exension)	bootloader_1.0
$(Time)	Evaluates to the current time	2012-12-24 20:00:00 +0200
$(Hostname)	Evaluates to the hostname	MY_COMPUTER
$(Uid)	CRC32 over relative path to MainProjectDir plus MainConfigName, e.g. “../libs/utils,Debug”	03FAB429
$(CPPPath)	Evaluates to the base path of the c++ compiler	/usr/bin
$(CPath)	Evaluates to the base path of the c compiler	/usr/bin
$(ASMPath)	Evaluates to the base path of the assembler	/usr/bin
$(ArchiverPath)	Evaluates to the base path of the archiver	/usr/bin
$(LinkerPath)	Evaluates to the base path of the linker	/usr/bin
$(ToolchainName)	Names of the used DefaultToolchain	GCC
$(/)	Evalutes to the directory path seperator of the current platform	Windows: \, Other: /
$(:)	Evaluates to the path variable seperator of the current platform	Windows: ;, Other: :
$(QacActive)	Evaluates to “yes” if QAC is running (via bakeqac), otherwise “no”.	yes, no

Environment variables

Usually used if system dependent stuff is needed like path to a specific tool etc.

Nested variables

It is also possible to nest variables.

Example:

$(ABC$(DEF)GH)

Complex variables

bake supports three complex variables:

$(OutputDir, <project name>, <config name>)
e.g.:
$(OutputDir, MyGreatLib, Debug)

This will evaluate to the output directory of a specific configuration.

$(ProjectDir, <project name>)

This will evaluate to the directory of a specific project.

$(FilterArguments, <filterName>)

If a filter is specified, the argument of the filter is returned.

Example:

cmd: “bake … –do run=–gtest_repeat=2”
Project.meta: $(FilterArguments, –gtest_repeat)
result: 2

Mandatory variables

If a variable is not found at all, it will be set to an empty string. This can be changed to an error with a “!” sign:

$(PATH_TO_ABC!)
$(OutputDir!, application, Debug)

For convenience, the “!” can be used on every parameter (which means exactly the same as using on the first parameter).

$(OutputDir, application!, Debug)
$(OutputDir, application, Debug!)

Notes and warnings

Equal variables in the main config:

Variable	Is equal to
$(MainConfigName)	$(ConfigName)
$(MainProjectName)	$(ProjectName)

Warning

Variables in Dependency definitions are not allowed!