Build Environment Effort/Gbuild Bootstrapping

Build Environment Effort
Quick Navigation Customers Build Performance Elimination of Non-Pro Dependencies Module Problems Split Build Scalability HID List New Build System Requirements External Source Tarballs ToDo Build System Analysis Zen of gbuild Gbuild Bootstrapping Module Migration Module Migration Tips Build System Analysis:capstone2013 windows build Capstone 2013 Client Requirements Document Capstone 2013 Technology Review & Implementation Document
About this template

How gbuild starts up from a makefile

When gbuild is started with a "make" command the initial makefile in the module or repository root will:

• check if there is an basic environment set
• set the variable GBUILDDIR to the directory where the gbuild system is found
• include gbuild.mk from that directory (see details below)
• include/read:
  • all the declarations of targets relative to the current directory (module makefile)
  • all the declarations of targets in all repos
• build all target needed for the goal

What gbuild.mk does when it is included in the makefile

• It sets a few global variables: SHELL, true, false, NEWLINE, WHITESPACE, COMMA
• It includes $(GBUILDDIR)/Output.mk for the output helper functions (announce, error ...)
• It includes $(GBUILDDIR)/BuildDirs.mk to setup the variables WORKDIR, OUTDIR, REPODIR
• It set up some global variables: gb_PRODUCT, gb_DEBUGLEVEL, gb_ENABLE_PCH, gb_FULLDEPS
• It includes $(GBUILDDIR)/Helper.mk for the global registries and misc. helper functions
• It includes $(GBUILDDIR)/TargetLocations.mk for the functions that return the filesystem paths for targets
• It sets up the global registries
• It reads all the Repository.mk files in the repository root (from gb_REPOS). This:
  • sets up the name for the repository (for example: SRCDIR)
  • sets up the group a library or executable belongs to
• It then reads the platform specific part from $(GBUILDDIR)/platform. This:
  • sets up the layer a library/executable belongs to by the group of the library
  • sets up the filename of the libraries and executables by the group of the library (on windows, this is the lib-file)
  • sets up the dll filename of the library (windows only)
  • sets up the rpaths for the layers (solaris and linux only - and macosx in its own special way)
• It then reads the RepositoryFixes.mk files in the repository root (from gb_REPOS). This is to keep compatibility with some unwarranted creativity in naming libraries. For example the default filenames created for the platform can be overwritten here.
• It then collects all the libraries that are known from the registries. Linking is only allowed against known libraries.
• It then sets up the global defines for C/C++ compilation
• It then reads $(GBUILDDIR)/Deliver.mk for the copy to OUTDIR commands and the collecting of filenames for the deliver.log
• It then reads all the specific classes with the build rules for the targets: ComponentTarget, AllLangResTarget, LinkTarget, ....
• It then reads any file ending with .mk in $(GBUILDDIR)/extensions

library/executable groups, layers, filename and dll filename registries

• Each library and execuatble is in a group. Valid groups are listed in gb_Library_VALIDGROUPS and gb_Executable_VALIDGROUPS.
• The platform file has to set the layer, the filename and (on windows) the dll filename for a library or executable.
  • The layer is stored in a registry in the variables gb_Library_LAYER and gb_Executable_LAYER
  • The filename is stored in a registry in the variables gb_Library_FILENAMES and gb_Executable_FILENAMES
  • The dll filename is stored in a registry in the variables gb_Library_DLLFILENAMES

The registry is a whitespace separated list of key value pairs. The key and value are again separated by a colon. E.g.

gb_Library_FILENAMES := sw:libswlx.so cppu:libuno_cppu.so jvmfwk:libjvmfwk.so salhelper:libuno_salhelpergcc3.so ...

To get a value for key $(KEY) from a registry $(REGISTRY) the following form is used:

$(patsubst $(KEY):%,%,$(filter $(KEY):%,$(REGISTRY)))

Keys can contain everything but whitespace and colon and must be escaped with $(subst) otherwise. Values can contain everything but whitespace and must be escaped $(subst) otherwise. Example escaping functions:

• Key encode:

NULL :=
WHITESPACE := $(NULL) $(NULL)
$(subst $(WHITESPACE),\WS,$(subst :,\C,$(subst \,\BS,$(1))))

• Key decode:

NULL :=
WHITESPACE := $(NULL) $(NULL)
$(subst \BS,\,$(subst :,\C,$(subst \WS,$(WHITESPACE),$(1))))