First attempt at a Linux build (#193)

* First attempt at a Linux build

- Fix up places where C++ idioms were written assuming lenient behavior of Microsoft's compiler

- Add a few more alternatives for platform-specific behavior where Windows was the only platform accounted for.

- Add a basic Makefile that can at least invoke our build, even if it isn't going good dependency tracking, etc.

- Build `libslang.so` and `slangc` that depends on it, using a relative `RPATH` to make the binary portable (I hope)

- Add an initial `.travis.yml` to see if we can trigger their build process.

* Fixup: const bug in `List::Sort`

I'm not clear why this gets picked up by the gcc *and* clang that Travis uses, but not the (newer) gcc I'm using on Ubuntu here, but I'm hoping it is just some missing `const` qualifiers.

* Fixup: reorder specialization of "class info"

Clang complains about things being specialized after being instantiated (implicilty), and I hope it is just the fact that I generate the class info for the roots of the hierarchy after the other cases. We'll see.

* Fixup: add `platform.cpp` to unified/lumped build

* Fixup: Windows uses `FreeLibrary`

and not `UnloadLibrary`

* Fixup: fix Windows project file to include new source file

This obviously points to the fact that we are going to need to be generating these files sooner or later.

1 files changed, 116 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 000000000..138322165
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,116 @@
+# Makefile
+#
+# This file provides a simpliistic (perhaps *overly* simplistic) way to
+# build Slang from source on Linux, which could probably be adapted for
+# building on other Unix-y targets.
+#
+# This build is not intended to be used for active development right now,
+# so it doesn't actually try to compile the `.cpp` files separately,
+# or track fine-grained dependencies, so almost any source change will
+# trigger a full rebuild. Anybody who wants to do their active development
+# on a platform supported by this Makefile should feel free to contribute
+# improvements, with the caveat that we will not be adoptttting autoconf,
+# CMake, or any other build system that has a tendency to "infect" a codebbbase.
+#
+
+#
+# The Windows build (using Visual Studio) tries to output things to
+# directories that take the target platform (and build configuration) into
+# account. For now we will do something simplistic and request the target
+# "triple" from the compiler (which we assume is either gcc or clang) and
+# call that our target "platformm"
+#
+TARGET := $(shell $(CXX) -dumpmachine)
+
+#
+# TODO: We need a way to control the "configuration" (debug  vs. release)
+# but for now just geting *something* working will be a good start.
+#
+
+#
+# We will define  an ouput directory for our binaries, based on
+# the target platform chosen. If we ever have steps that need to
+# output intermediate files, we'd set up the directory here.
+#
+OUTPUTDIR := bin/$(TARGET)/
+INTERMEDIATEDIR := intermediate/$(TARGET)/
+
+#
+# Now we will start defining a bunch of variables for build
+# options and properties of the target. We are going to unconditionallyy
+# set these to what we need/want on our Linux target for now, but
+# we will eventually need to do a bit more work to detect the
+# platform.
+#
+SHARED_LIB_PREFIX := lib
+SHARED_LIB_SUFFIX := .so
+BIN_SUFFIX :=
+# Note: we set `visibility=hidden` to avoid exporting more symbols than
+# we really need.
+CFLAGS := -std=c++11 -fvisibility=hidden
+LDFLAGS := -L$(OUTPUTDIR)
+SHARED_LIB_LDFLAGS := -shared
+SHARED_LIB_CFLAGS := -fPIC
+
+# Make sure that shared library inherits build flags
+# from the default case.
+SHARED_LIB_LDFLAGS += $(LDFLAGS)
+SHARED_LIB_CFLAGS += $(CFLAGS)
+
+RELATIVE_RPATH_INCANTATION := "-Wl,-rpath,"'$$'"ORIGIN/"
+
+# TODO: Make sure I'm using these Makefile incantations  correctly.
+.SUFFIXES:
+.PHONY: all clean slang slangc test
+
+#
+# Here we define lists of files (source vs. header dependencies)
+# for each logical project we want to build.
+# This is the one place where we do any kiind of "dependency" work,
+# by making a project depend on the headers for sub-projects it usses.
+#
+CORE_SOURCES := source/core/*.cpp
+CORE_HEADERS := source/core/*.h
+
+SLANG_SOURCES := source/slang/*.cpp
+SLANG_HEADERS := slang.h source/slang/*.h
+SLANG_SOURCES += $(CORE_SOURCES)
+SLANG_HEADERS += $(CORE_HEADERS)
+
+SLANGC_SOURCES := source/slangc/*.cpp
+SLANGC_HEADERS := $(SLANG_HEADERS)
+
+#
+# Each project will have a variable that is an alias for
+# the binary it should produce.
+#
+SLANG := $(OUTPUTDIR)$(SHARED_LIB_PREFIX)slang$(SHARED_LIB_SUFFIX)
+SLANGC := $(OUTPUTDIR)slangc$(BIN_SUFFIX)
+
+# By default, when the user invokes `make`, we will build the
+# `slang` shared library, and the `slangc` front-end application.
+all: slang slangc
+
+mkdirs: $(OUTPUTDIR)
+
+# Project-specific targets depend on making theappropriate binary.
+slang: mkdirs $(SLANG)
+slangc: mkdirs $(SLANGC)
+
+
+$(SLANG): $(SLANG_SOURCES) $(SLANG_HEADERS)
+	$(CXX) $(SHARED_LIB_LDFLAGS) -o $@ -DSLANG_DYNAMIC_EXPORT $(SHARED_LIB_CFLAGS) $(SLANG_SOURCES)
+
+$(SLANGC): $(SLANGC_SOURCES) $(SLANGC_HEADERS) $(SLANG)
+	$(CXX) $(LDFLAGS) -o $@ $(CFLAGS) $(SLANGC_SOURCES) $(CORE_SOURCES) -ldl $(RELATIVE_RPATH_INCANTATION) -lslang
+
+
+
+$(OUTPUTDIR):
+	mkdir -p $(OUTPUTDIR)
+
+test:
+	# TODO need to actually run the test runner
+
+clean:
+	rm -rf $(OUTPUTDIR)