Merge pull request #164 from atgeirr/remove-gnumakefile

Remove confusing GNUmakefile and document cmake building process.

CMakeLists.txt

@@ -273,9 +273,3 @@ configure_la (${project} ${${project}_TARGET} ${project}_LIBTOOL_ARCHIVE)
 ### clean in-source builds ###
 include (OpmDistClean)
 opm_dist_clean (${project})
-
-# smart wrapper that auto-parallelizes builds
-file (COPY
-	GNUmakefile
-	DESTINATION ${PROJECT_BINARY_DIR}
-	)

GNUmakefile

@@ -1,43 +0,0 @@
-# GNUmakefile is processed before Makefile, which is why we arrive here
-# first; when we call the other makefile, then we must specify its real
-# name with the -f parameter
-
-# figure out the number of processors from the system, add one and round
-# to nearest integer. this is the maximum number of processes we want running
-# at the same time (one for each core and one stuck on I/O)
-# if we are running this is a VM, then /proc won't be mounted and we revert
-# to single CPU processing
-CPUINFO:=/proc/cpuinfo
-NUM_CPUS:=$(shell test -r $(CPUINFO) && grep -P -c '^processor\t:' $(CPUINFO) || echo 0)
-PROCS:=$(shell echo "("$(NUM_CPUS)+1")"/1 | bc)
-
-# use these utilities if they are available
-IONICE:=$(shell test -x "$$(which ionice)" && echo ionice -c2 -n7)
-NICE:=$(shell test -x "$$(which nice)" && echo nice)
-
-# we do dependency management the right way; don't attempt to cache
-export CCACHE_DISABLE:=1
-
-# ignore that there may be files with these names, we are going to call
-# the other make regardless
-.PHONY: __everything $(MAKECMDGOALS)
-
-# outsource the processing to the real makefile, running in parallel and
-# in a nice environment so that it doesn't hog our workstation. if there
-# is nothing else happening on the box, then it will run just as fast
-# the leading plus makes us run this regardless of options, see
-# http://www.gnu.org/software/make/manual/make.html#Instead-of-Execution
-__everything:
-# only put on a parallel flag if there isn't already one; otherwise we
-# get the warning "-jN forced in submake: disabling jobserver mode".
-# this have to happen inside the rule, because -j option is removed from
-# MAKEFLAGS outside
-	+@$(IONICE) $(NICE) $(MAKE) --no-print-directory -f Makefile $(if $(findstring -j,$(MAKEFLAGS)),,-j $(PROCS)) $(MAKECMDGOALS)
-
-# automatically generate all the goals we are asked to make and delegate
-# processing of them to the real makefile through the dependency (since
-# everything depends on the same thing, then we only call the other make
-# once). the dummy command is just there to make sure that make doesn't
-# show the "Nothing to do for `foo'" message after processing
-$(MAKECMDGOALS): __everything
-	@true

README

@@ -115,16 +115,61 @@ If you want to contribute, fork OPM/opm-core on github.
 BUILDING
 --------
 
-There are two ways to build the opm-core library:
+There are two ways to build the opm-core library.
 
 1. As a stand-alone library.
- cd opm-core
- ./configure
- make
+In this setup we recommend creating an entirely separate directory
+outside the directory containing the source code and doing the build
+from that separate directory (termed "the build directory").  This
+configuration is sometimes referred to as an "out-of-source build".
 
-If you want to install the library:
+As an example, consider the following layout in which "opm-core" refers
+to the directory containing the package source code as downloaded from
+GitHub
+
+    workspace
+      |
+      +-- build
+      |
+      +-- opm-core
+      |     |
+      |     +-- ...
+      |     |
+      |     +-- opm
+      |     |
+      |     +-- ...
+
+We will configure a release-type (optimised) build using traditional
+Unix Makefiles within the "build" directory.  The following command
+configures the build
+
+    cd path/to/build
+    cmake ../opm-core -DCMAKE_BUILD_TYPE=Release
+
+Building the software then amounts to typing
+
+    make
+
+in the top-level "build" directory; i.e., the directory from which we
+invoked the "cmake" utility.  On a multi-core computer system you may
+want to build the software in parallel (make(1)'s "job-server" mode) in
+order to reduce the total amount of time needed to complete the build.
+To do so, replace the above "make" command with
+
+    make -j N
+
+or, possibly,
+
+    nice -20 make -j N
+
+in which "N" is an integer that should typically not exceed the number
+of cores in the system.
+
+Once the library has been built, it can be installed in a central,
+system-wide location (often in "/usr/local") through the command
+
+    sudo make install
 
- sudo make install
 
 2. As a dune module.
  - Put the opm-core directory in the same directory