Use of GNU Make; Build Details
teem

THIS IS UNFINISHED

Teem uses a system of GNU makefiles in order to build the software. The actions of "make" depends on where its invoked in the tree, what environment variables set, and of course, what targets are specified. This system has evolved over the years to match my pattern of development, which includes working simultaneously on different platforms which share a file system. This page aims to describe the functioning of GNU make with teem, starting with the useful and ending with the obscure. Referring to information about the directory structure may be useful.

Some terminology. Teem is made of a number of libraries, such as nrrd. One result of compiling a library is the creation of some files such as libnrrd.a and libnrrd.so. To distinguish between the nrrd "library" in general, and these lib files, I call the lib files "libs". Teem also comes with some simple command-line programs which demonstrate and use the libraries, I call these "bins". Many of the libraries have associated testing programs, compiled from sources in the test subdirectory of each library. These programs are called "tests".

Here is an overview of the different ways that you can invoke make, and how it will behave according to where you're starting it from.

The makefiles are:

• teem/src/GNUmakefile: The "top-level" makefile. This defines variables and functions that are used by all the other files.
• teem/src/make/errorCheck.mk: Does error checking on the values of environment variables.
• teem/src/make/<arch>.mk: For all the architectures supported (except Windows), there is an "architecture-specific" makefile which records the specifics of that platform. Which of these is used depends on the value of the environment variable TEEM_ARCH.
• teem/src/<library>/GNUmakefile: Each library has its own makefile, recording all library-specific information, such as names of the public and private headers, and all the object files required to make the lib.
• teem/src/bin/GNUmakefile: All the bins are made according to this makefile, different in structure to the library makefiles.
• teem/src/make/template.mk: This is included by all the library makefiles, but in a way which is effectively templated on the name of the library. It is actually the most important makefile, because it expresses all the intra- and inter- library dependencies.
• teem/src/make/externals.mk: This helps coordinate the optional linking in of external libraries that extend the functionality of teem, such as gzip compression for nrrd.
• teem/src/make/compare.sh: Not actually a makefile, but used by template.mk (via the newer.than function defined in teem/src/GNUmakefile) to compare file dates, in a way seperate from make's network of targets and prerequisites.