Since the old llvmc was removed, rename llvmc2 to llvmc.

llvm-svn: 60048

26 files changed, 1829 insertions, 0 deletions

diff --git a/llvm/tools/llvmc/CMakeLists.txt b/llvm/tools/llvmc/CMakeLists.txt
new file mode 100644
index 00000000000..f8204199041
--- /dev/null
+++ b/llvm/tools/llvmc/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_subdirectory(driver)
+
+# TODO: support plugins and user-configured builds.
+# See ./doc/LLVMC-Reference.rst "Customizing LLVMC: the compilation graph"
diff --git a/llvm/tools/llvmc/Makefile b/llvm/tools/llvmc/Makefile
new file mode 100644
index 00000000000..8eb35cbe9cc
--- /dev/null
+++ b/llvm/tools/llvmc/Makefile
@@ -0,0 +1,19 @@
+##===- tools/llvmc/Makefile --------------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open
+# Source License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+
+BUILTIN_PLUGINS = Base
+DRIVER_NAME = llvmc
+DIRS = plugins driver
+
+export BUILTIN_PLUGINS
+export DRIVER_NAME
+
+include $(LEVEL)/Makefile.common
diff --git a/llvm/tools/llvmc/doc/LLVMC-Reference.rst b/llvm/tools/llvmc/doc/LLVMC-Reference.rst
new file mode 100644
index 00000000000..77d9d2bd3a4
--- /dev/null
+++ b/llvm/tools/llvmc/doc/LLVMC-Reference.rst
@@ -0,0 +1,517 @@
+===================================
+Customizing LLVMC: Reference Manual
+===================================
+:Author: Mikhail Glushenkov <foldr@codedegers.com>
+
+LLVMC is a generic compiler driver, designed to be customizable and
+extensible. It plays the same role for LLVM as the ``gcc`` program
+does for GCC - LLVMC's job is essentially to transform a set of input
+files into a set of targets depending on configuration rules and user
+options. What makes LLVMC different is that these transformation rules
+are completely customizable - in fact, LLVMC knows nothing about the
+specifics of transformation (even the command-line options are mostly
+not hard-coded) and regards the transformation structure as an
+abstract graph. The structure of this graph is completely determined
+by plugins, which can be either statically or dynamically linked. This
+makes it possible to easily adapt LLVMC for other purposes - for
+example, as a build tool for game resources.
+
+Because LLVMC employs TableGen [1]_ as its configuration language, you
+need to be familiar with it to customize LLVMC.
+
+
+.. contents::
+
+
+Compiling with LLVMC
+====================
+
+LLVMC tries hard to be as compatible with ``gcc`` as possible,
+although there are some small differences. Most of the time, however,
+you shouldn't be able to notice them::
+
+     $ # This works as expected:
+     $ llvmc -O3 -Wall hello.cpp
+     $ ./a.out
+     hello
+
+One nice feature of LLVMC is that one doesn't have to distinguish
+between different compilers for different languages (think ``g++`` and
+``gcc``) - the right toolchain is chosen automatically based on input
+language names (which are, in turn, determined from file
+extensions). If you want to force files ending with ".c" to compile as
+C++, use the ``-x`` option, just like you would do it with ``gcc``::
+
+      $ # hello.c is really a C++ file
+      $ llvmc -x c++ hello.c
+      $ ./a.out
+      hello
+
+On the other hand, when using LLVMC as a linker to combine several C++
+object files you should provide the ``--linker`` option since it's
+impossible for LLVMC to choose the right linker in that case::
+
+    $ llvmc -c hello.cpp
+    $ llvmc hello.o
+    [A lot of link-time errors skipped]
+    $ llvmc --linker=c++ hello.o
+    $ ./a.out
+    hello
+
+
+Predefined options
+==================
+
+LLVMC has some built-in options that can't be overridden in the
+configuration files:
+
+* ``-o FILE`` - Output file name.
+
+* ``-x LANGUAGE`` - Specify the language of the following input files
+  until the next -x option.
+
+* ``-load PLUGIN_NAME`` - Load the specified plugin DLL. Example:
+  ``-load $LLVM_DIR/Release/lib/LLVMCSimple.so``.
+
+* ``-v`` - Enable verbose mode, i.e. print out all executed commands.
+
+* ``--view-graph`` - Show a graphical representation of the compilation
+  graph. Requires that you have ``dot`` and ``gv`` programs
+  installed. Hidden option, useful for debugging.
+
+* ``--write-graph`` - Write a ``compilation-graph.dot`` file in the
+  current directory with the compilation graph description in the
+  Graphviz format. Hidden option, useful for debugging.
+
+* ``--save-temps`` - Write temporary files to the current directory
+  and do not delete them on exit. Hidden option, useful for debugging.
+
+* ``--help``, ``--help-hidden``, ``--version`` - These options have
+  their standard meaning.
+
+
+Compiling LLVMC plugins
+=======================
+
+It's easiest to start working on your own LLVMC plugin by copying the
+skeleton project which lives under ``$LLVMC_DIR/plugins/Simple``::
+
+   $ cd $LLVMC_DIR/plugins
+   $ cp -r Simple MyPlugin
+   $ cd MyPlugin
+   $ ls
+   Makefile PluginMain.cpp Simple.td
+
+As you can see, our basic plugin consists of only two files (not
+counting the build script). ``Simple.td`` contains TableGen
+description of the compilation graph; its format is documented in the
+following sections. ``PluginMain.cpp`` is just a helper file used to
+compile the auto-generated C++ code produced from TableGen source. It
+can also contain hook definitions (see `below`__).
+
+__ hooks_
+
+The first thing that you should do is to change the ``LLVMC_PLUGIN``
+variable in the ``Makefile`` to avoid conflicts (since this variable
+is used to name the resulting library)::
+
+   LLVMC_PLUGIN=MyPlugin
+
+It is also a good idea to rename ``Simple.td`` to something less
+generic::
+
+   $ mv Simple.td MyPlugin.td
+
+Note that the plugin source directory must be placed under
+``$LLVMC_DIR/plugins`` to make use of the existing build
+infrastructure. To build a version of the LLVMC executable called
+``mydriver`` with your plugin compiled in, use the following command::
+
+   $ cd $LLVMC_DIR
+   $ make BUILTIN_PLUGINS=MyPlugin DRIVER_NAME=mydriver
+
+To build your plugin as a dynamic library, just ``cd`` to its source
+directory and run ``make``. The resulting file will be called
+``LLVMC$(LLVMC_PLUGIN).$(DLL_EXTENSION)`` (in our case,
+``LLVMCMyPlugin.so``). This library can be then loaded in with the
+``-load`` option. Example::
+
+    $ cd $LLVMC_DIR/plugins/Simple
+    $ make
+    $ llvmc -load $LLVM_DIR/Release/lib/LLVMCSimple.so
+
+Sometimes, you will want a 'bare-bones' version of LLVMC that has no
+built-in plugins. It can be compiled with the following command::
+
+    $ cd $LLVMC_DIR
+    $ make BUILTIN_PLUGINS=""
+
+How plugins are loaded
+======================
+
+It is possible for LLVMC plugins to depend on each other. For example,
+one can create edges between nodes defined in some other plugin. To
+make this work, however, that plugin should be loaded first. To
+achieve this, the concept of plugin priority was introduced. By
+default, every plugin has priority zero; to specify the priority
+explicitly, put the following line in your ``.td`` file::
+
+    def Priority : PluginPriority<$PRIORITY_VALUE>;
+    # Where PRIORITY_VALUE is some integer > 0
+
+Plugins are loaded in order of their (increasing) priority, starting
+with 0. Therefore, the plugin with the highest priority value will be
+loaded last.
+
+
+Customizing LLVMC: the compilation graph
+========================================
+
+Each TableGen configuration file should include the common
+definitions::
+
+   include "llvm/CompilerDriver/Common.td"
+   // And optionally:
+   // include "llvm/CompilerDriver/Tools.td"
+   // which contains some useful tool definitions.
+
+Internally, LLVMC stores information about possible source
+transformations in form of a graph. Nodes in this graph represent
+tools, and edges between two nodes represent a transformation path. A
+special "root" node is used to mark entry points for the
+transformations. LLVMC also assigns a weight to each edge (more on
+this later) to choose between several alternative edges.
+
+The definition of the compilation graph (see file
+``plugins/Base/Base.td`` for an example) is just a list of edges::
+
+    def CompilationGraph : CompilationGraph<[
+        Edge<"root", "llvm_gcc_c">,
+        Edge<"root", "llvm_gcc_assembler">,
+        ...
+
+        Edge<"llvm_gcc_c", "llc">,
+        Edge<"llvm_gcc_cpp", "llc">,
+        ...
+
+        OptionalEdge<"llvm_gcc_c", "opt", (case (switch_on "opt"),
+                                          (inc_weight))>,
+        OptionalEdge<"llvm_gcc_cpp", "opt", (case (switch_on "opt"),
+                                                  (inc_weight))>,
+        ...
+
+        OptionalEdge<"llvm_gcc_assembler", "llvm_gcc_cpp_linker",
+            (case (input_languages_contain "c++"), (inc_weight),
+                  (or (parameter_equals "linker", "g++"),
+                      (parameter_equals "linker", "c++")), (inc_weight))>,
+        ...
+
+        ]>;
+
+As you can see, the edges can be either default or optional, where
+optional edges are differentiated by an additional ``case`` expression
+used to calculate the weight of this edge. Notice also that we refer
+to tools via their names (as strings). This makes it possible to add
+edges to an existing compilation graph in plugins without having to
+know about all tool definitions used in the graph.
+
+The default edges are assigned a weight of 1, and optional edges get a
+weight of 0 + 2*N where N is the number of tests that evaluated to
+true in the ``case`` expression. It is also possible to provide an
+integer parameter to ``inc_weight`` and ``dec_weight`` - in this case,
+the weight is increased (or decreased) by the provided value instead
+of the default 2.
+
+When passing an input file through the graph, LLVMC picks the edge
+with the maximum weight. To avoid ambiguity, there should be only one
+default edge between two nodes (with the exception of the root node,
+which gets a special treatment - there you are allowed to specify one
+default edge *per language*).
+
+To get a visual representation of the compilation graph (useful for
+debugging), run ``llvmc --view-graph``. You will need ``dot`` and
+``gsview`` installed for this to work properly.
+
+
+Writing a tool description
+==========================
+
+As was said earlier, nodes in the compilation graph represent tools,
+which are described separately. A tool definition looks like this
+(taken from the ``include/llvm/CompilerDriver/Tools.td`` file)::
+
+  def llvm_gcc_cpp : Tool<[
+      (in_language "c++"),
+      (out_language "llvm-assembler"),
+      (output_suffix "bc"),
+      (cmd_line "llvm-g++ -c $INFILE -o $OUTFILE -emit-llvm"),
+      (sink)
+      ]>;
+
+This defines a new tool called ``llvm_gcc_cpp``, which is an alias for
+``llvm-g++``. As you can see, a tool definition is just a list of
+properties; most of them should be self-explanatory. The ``sink``
+property means that this tool should be passed all command-line
+options that lack explicit descriptions.
+
+The complete list of the currently implemented tool properties follows:
+
+* Possible tool properties:
+
+  - ``in_language`` - input language name. Can be either a string or a
+    list, in case the tool supports multiple input languages.
+
+  - ``out_language`` - output language name.
+
+  - ``output_suffix`` - output file suffix.
+
+  - ``cmd_line`` - the actual command used to run the tool. You can
+    use ``$INFILE`` and ``$OUTFILE`` variables, output redirection
+    with ``>``, hook invocations (``$CALL``), environment variables
+    (via ``$ENV``) and the ``case`` construct (more on this below).
+
+  - ``join`` - this tool is a "join node" in the graph, i.e. it gets a
+    list of input files and joins them together. Used for linkers.
+
+  - ``sink`` - all command-line options that are not handled by other
+    tools are passed to this tool.
+
+The next tool definition is slightly more complex::
+
+  def llvm_gcc_linker : Tool<[
+      (in_language "object-code"),
+      (out_language "executable"),
+      (output_suffix "out"),
+      (cmd_line "llvm-gcc $INFILE -o $OUTFILE"),
+      (join),
+      (prefix_list_option "L", (forward),
+                          (help "add a directory to link path")),
+      (prefix_list_option "l", (forward),
+                          (help "search a library when linking")),
+      (prefix_list_option "Wl", (unpack_values),
+                          (help "pass options to linker"))
+      ]>;
+
+This tool has a "join" property, which means that it behaves like a
+linker. This tool also defines several command-line options: ``-l``,
+``-L`` and ``-Wl`` which have their usual meaning. An option has two
+attributes: a name and a (possibly empty) list of properties. All
+currently implemented option types and properties are described below:
+
+* Possible option types:
+
+   - ``switch_option`` - a simple boolean switch, for example ``-time``.
+
+   - ``parameter_option`` - option that takes an argument, for example
+     ``-std=c99``;
+
+   - ``parameter_list_option`` - same as the above, but more than one
+     occurence of the option is allowed.
+
+   - ``prefix_option`` - same as the parameter_option, but the option name
+     and parameter value are not separated.
+
+   - ``prefix_list_option`` - same as the above, but more than one
+     occurence of the option is allowed; example: ``-lm -lpthread``.
+
+   - ``alias_option`` - a special option type for creating
+     aliases. Unlike other option types, aliases are not allowed to
+     have any properties besides the aliased option name. Usage
+     example: ``(alias_option "preprocess", "E")``
+
+
+* Possible option properties:
+
+   - ``append_cmd`` - append a string to the tool invocation command.
+
+   - ``forward`` - forward this option unchanged.
+
+   - ``forward_as`` - Change the name of this option, but forward the
+     argument unchanged. Example: ``(forward_as "--disable-optimize")``.
+
+   - ``output_suffix`` - modify the output suffix of this
+     tool. Example: ``(switch "E", (output_suffix "i")``.
+
+   - ``stop_compilation`` - stop compilation after this phase.
+
+   - ``unpack_values`` - used for for splitting and forwarding
+     comma-separated lists of options, e.g. ``-Wa,-foo=bar,-baz`` is
+     converted to ``-foo=bar -baz`` and appended to the tool invocation
+     command.
+
+   - ``help`` - help string associated with this option. Used for
+     ``--help`` output.
+
+   - ``required`` - this option is obligatory.
+
+
+Option list - specifying all options in a single place
+======================================================
+
+It can be handy to have all information about options gathered in a
+single place to provide an overview. This can be achieved by using a
+so-called ``OptionList``::
+
+    def Options : OptionList<[
+    (switch_option "E", (help "Help string")),
+    (alias_option "quiet", "q")
+    ...
+    ]>;
+
+``OptionList`` is also a good place to specify option aliases.
+
+Tool-specific option properties like ``append_cmd`` have (obviously)
+no meaning in the context of ``OptionList``, so the only properties
+allowed there are ``help`` and ``required``.
+
+Option lists are used at file scope. See the file
+``plugins/Clang/Clang.td`` for an example of ``OptionList`` usage.
+
+.. _hooks:
+
+Using hooks and environment variables in the ``cmd_line`` property
+==================================================================
+
+Normally, LLVMC executes programs from the system ``PATH``. Sometimes,
+this is not sufficient: for example, we may want to specify tool names
+in the configuration file. This can be achieved via the mechanism of
+hooks - to write your own hooks, just add their definitions to the
+``PluginMain.cpp`` or drop a ``.cpp`` file into the
+``$LLVMC_DIR/driver`` directory. Hooks should live in the ``hooks``
+namespace and have the signature ``std::string hooks::MyHookName
+(void)``. They can be used from the ``cmd_line`` tool property::
+
+    (cmd_line "$CALL(MyHook)/path/to/file -o $CALL(AnotherHook)")
+
+It is also possible to use environment variables in the same manner::
+
+   (cmd_line "$ENV(VAR1)/path/to/file -o $ENV(VAR2)")
+
+To change the command line string based on user-provided options use
+the ``case`` expression (documented below)::
+
+    (cmd_line
+      (case
+        (switch_on "E"),
+           "llvm-g++ -E -x c $INFILE -o $OUTFILE",
+        (default),
+           "llvm-g++ -c -x c $INFILE -o $OUTFILE -emit-llvm"))
+
+Conditional evaluation: the ``case`` expression
+===============================================
+
+The 'case' construct can be used to calculate weights of the optional
+edges and to choose between several alternative command line strings
+in the ``cmd_line`` tool property. It is designed after the
+similarly-named construct in functional languages and takes the form
+``(case (test_1), statement_1, (test_2), statement_2, ... (test_N),
+statement_N)``. The statements are evaluated only if the corresponding
+tests evaluate to true.
+
+Examples::
+
+    // Increases edge weight by 5 if "-A" is provided on the
+    // command-line, and by 5 more if "-B" is also provided.
+    (case
+        (switch_on "A"), (inc_weight 5),
+        (switch_on "B"), (inc_weight 5))
+
+    // Evaluates to "cmdline1" if option "-A" is provided on the
+    // command line, otherwise to "cmdline2"
+    (case
+        (switch_on "A"), "cmdline1",
+        (switch_on "B"), "cmdline2",
+        (default), "cmdline3")
+
+Note the slight difference in 'case' expression handling in contexts
+of edge weights and command line specification - in the second example
+the value of the ``"B"`` switch is never checked when switch ``"A"`` is
+enabled, and the whole expression always evaluates to ``"cmdline1"`` in
+that case.
+
+Case expressions can also be nested, i.e. the following is legal::
+
+    (case (switch_on "E"), (case (switch_on "o"), ..., (default), ...)
+          (default), ...)
+
+You should, however, try to avoid doing that because it hurts
+readability. It is usually better to split tool descriptions and/or
+use TableGen inheritance instead.
+
+* Possible tests are:
+
+  - ``switch_on`` - Returns true if a given command-line switch is
+    provided by the user. Example: ``(switch_on "opt")``. Note that
+    you have to define all possible command-line options separately in
+    the tool descriptions. See the next section for the discussion of
+    different kinds of command-line options.
+
+  - ``parameter_equals`` - Returns true if a command-line parameter equals
+    a given value. Example: ``(parameter_equals "W", "all")``.
+
+  - ``element_in_list`` - Returns true if a command-line parameter list
+    includes a given value. Example: ``(parameter_in_list "l", "pthread")``.
+
+  - ``input_languages_contain`` - Returns true if a given language
+    belongs to the current input language set. Example:
+    ``(input_languages_contain "c++")``.
+
+  - ``in_language`` - Evaluates to true if the language of the input
+    file equals to the argument. At the moment works only with
+    ``cmd_line`` property on non-join nodes. Example: ``(in_language
+    "c++")``.
+
+  - ``not_empty`` - Returns true if a given option (which should be
+    either a parameter or a parameter list) is set by the
+    user. Example: ``(not_empty "o")``.
+
+  - ``default`` - Always evaluates to true. Should always be the last
+    test in the ``case`` expression.
+
+  - ``and`` - A standard logical combinator that returns true iff all
+    of its arguments return true. Used like this: ``(and (test1),
+    (test2), ... (testN))``. Nesting of ``and`` and ``or`` is allowed,
+    but not encouraged.
+
+  - ``or`` - Another logical combinator that returns true only if any
+    one of its arguments returns true. Example: ``(or (test1),
+    (test2), ... (testN))``.
+
+
+Language map
+============
+
+One last thing that you will need to modify when adding support for a
+new language to LLVMC is the language map, which defines mappings from
+file extensions to language names. It is used to choose the proper
+toolchain(s) for a given input file set. Language map definition looks
+like this::
+
+    def LanguageMap : LanguageMap<
+        [LangToSuffixes<"c++", ["cc", "cp", "cxx", "cpp", "CPP", "c++", "C"]>,
+         LangToSuffixes<"c", ["c"]>,
+         ...
+        ]>;
+
+Debugging
+=========
+
+When writing LLVMC plugins, it can be useful to get a visual view of
+the resulting compilation graph. This can be achieved via the command
+line option ``--view-graph``. This command assumes that Graphviz [2]_ and
+Ghostview [3]_ are installed. There is also a ``--dump-graph`` option that
+creates a Graphviz source file(``compilation-graph.dot``) in the
+current directory.
+
+
+References
+==========
+
+.. [1] TableGen Fundamentals
+       http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html
+
+.. [2] Graphviz
+       http://www.graphviz.org/
+
+.. [3] Ghostview
+       http://pages.cs.wisc.edu/~ghost/
diff --git a/llvm/tools/llvmc/doc/LLVMC-Tutorial.rst b/llvm/tools/llvmc/doc/LLVMC-Tutorial.rst
new file mode 100644
index 00000000000..d41f90d6349
--- /dev/null
+++ b/llvm/tools/llvmc/doc/LLVMC-Tutorial.rst
@@ -0,0 +1,100 @@
+======================
+Tutorial - Using LLVMC
+======================
+:Author: Mikhail Glushenkov <foldr@codedegers.com>
+
+LLVMC is a generic compiler driver, which plays the same role for LLVM
+as the ``gcc`` program does for GCC - the difference being that LLVMC
+is designed to be more adaptable and easier to customize. Most of
+LLVMC functionality is implemented via plugins, which can be loaded
+dynamically or compiled in. This tutorial describes the basic usage
+and configuration of LLVMC.
+
+
+.. contents::
+
+
+Compiling with LLVMC
+====================
+
+In general, LLVMC tries to be command-line compatible with ``gcc`` as
+much as possible, so most of the familiar options work::
+
+     $ llvmc -O3 -Wall hello.cpp
+     $ ./a.out
+     hello
+
+This will invoke ``llvm-g++`` under the hood (you can see which
+commands are executed by using the ``-v`` option). For further help on
+command-line LLVMC usage, refer to the ``llvmc --help`` output.
+
+
+Using LLVMC to generate toolchain drivers
+=========================================
+
+LLVMC plugins are written mostly using TableGen [1]_, so you need to
+be familiar with it to get anything done.
+
+Start by compiling ``plugins/Simple/Simple.td``, which is a primitive
+wrapper for ``gcc``::
+
+    $ cd $LLVM_DIR/tools/llvmc
+    $ make DRIVER_NAME=mygcc BUILTIN_PLUGINS=Simple
+    $ cat > hello.c
+    [...]
+    $ mygcc hello.c
+    $ ./hello.out
+    Hello
+
+Here we link our plugin with the LLVMC core statically to form an
+executable file called ``mygcc``. It is also possible to build our
+plugin as a standalone dynamic library; this is described in the
+reference manual.
+
+Contents of the file ``Simple.td`` look like this::
+
+    // Include common definitions
+    include "llvm/CompilerDriver/Common.td"
+
+    // Tool descriptions
+    def gcc : Tool<
+    [(in_language "c"),
+     (out_language "executable"),
+     (output_suffix "out"),
+     (cmd_line "gcc $INFILE -o $OUTFILE"),
+     (sink)
+    ]>;
+
+    // Language map
+    def LanguageMap : LanguageMap<[LangToSuffixes<"c", ["c"]>]>;
+
+    // Compilation graph
+    def CompilationGraph : CompilationGraph<[Edge<"root", "gcc">]>;
+
+As you can see, this file consists of three parts: tool descriptions,
+language map, and the compilation graph definition.
+
+At the heart of LLVMC is the idea of a compilation graph: vertices in
+this graph are tools, and edges represent a transformation path
+between two tools (for example, assembly source produced by the
+compiler can be transformed into executable code by an assembler). The
+compilation graph is basically a list of edges; a special node named
+``root`` is used to mark graph entry points.
+
+Tool descriptions are represented as property lists: most properties
+in the example above should be self-explanatory; the ``sink`` property
+means that all options lacking an explicit description should be
+forwarded to this tool.
+
+The ``LanguageMap`` associates a language name with a list of suffixes
+and is used for deciding which toolchain corresponds to a given input
+file.
+
+To learn more about LLVMC customization, refer to the reference
+manual and plugin source code in the ``plugins`` directory.
+
+References
+==========
+
+.. [1] TableGen Fundamentals
+       http://llvm.cs.uiuc.edu/docs/TableGenFundamentals.html
diff --git a/llvm/tools/llvmc/doc/Makefile b/llvm/tools/llvmc/doc/Makefile
new file mode 100644
index 00000000000..864376f9d90
--- /dev/null
+++ b/llvm/tools/llvmc/doc/Makefile
@@ -0,0 +1,21 @@
+##===- tools/llvmc/doc/Makefile ----------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+RST2HTML=rst2html --stylesheet=llvm.css --link-stylesheet
+
+all : LLVMC-Reference.html LLVMC-Tutorial.html
+
+LLVMC-Tutorial.html : LLVMC-Tutorial.rst llvm.css
+	$(RST2HTML) $< $@
+
+LLVMC-Reference.html : LLVMC-Reference.rst llvm.css
+	$(RST2HTML) $< $@
+
+clean :
+	rm *.html
diff --git a/llvm/tools/llvmc/doc/img/lines.gif b/llvm/tools/llvmc/doc/img/lines.gif
new file mode 100644
index 00000000000..88f491edc30
--- /dev/null
+++ b/llvm/tools/llvmc/doc/img/lines.gif
diff --git a/llvm/tools/llvmc/doc/llvm.css b/llvm/tools/llvmc/doc/llvm.css
new file mode 100644
index 00000000000..1c7e5cc504d
--- /dev/null
+++ b/llvm/tools/llvmc/doc/llvm.css
@@ -0,0 +1,86 @@
+/*
+ * LLVM documentation style sheet
+ */
+
+/* Common styles */
+.body { color: black; background: white; margin: 0 0 0 0 }
+
+/* No borders on image links */
+a:link img, a:visited img {border-style: none}
+
+address img { float: right; width: 88px; height: 31px; }
+address     { clear: right; }
+
+TR, TD      { border: 2px solid gray; padding: 4pt 4pt 2pt 2pt; }
+TH          { border: 2px solid gray; font-weight: bold; font-size: 105%;
+              background: url("img/lines.gif");
+              font-family: "Georgia,Palatino,Times,Roman,SanSerif"; text-align:center;
+              vertical-align: middle; }
+TABLE       { text-align: center; border: 2px solid black;
+              border-collapse: collapse; margin-top: 1em; margin-left: 1em;
+              margin-right: 1em; margin-bottom: 1em; }
+/*
+ * Documentation
+ */
+/* Common for title and header */
+h1 {
+  color: black; background: url("img/lines.gif");
+  font-family: "Georgia,Palatino,Times,Roman,SanSerif"; font-weight: bold;
+  border-width: 1px;
+  border-style: solid none solid none;
+  text-align: center;
+  vertical-align: middle;
+  padding-left: 8pt;
+  padding-top: 1px;
+  padding-bottom: 2px
+}
+
+.doc_title      { text-align: left;   font-size: 25pt }
+.doc_section    { text-align: center; font-size: 22pt;
+                  margin: 20pt 0pt 5pt 0pt; }
+.doc_subsection { width: 75%;
+                  text-align: left;  font-size: 12pt; padding: 4pt 4pt 4pt 4pt;
+                  margin: 1.5em 0.5em 0.5em 0.5em }
+
+.doc_subsubsection { margin: 2.0em 0.5em 0.5em 0.5em;
+                     font-weight: bold; font-style: oblique;
+                     border-bottom: 1px solid #999999; font-size: 12pt;
+                     width: 75%; }
+.doc_author     { text-align: left; font-weight: bold; padding-left: 20pt }
+.doc_text       { text-align: left; padding-left: 20pt; padding-right: 10pt }
+
+.doc_footer     { text-align: left; padding: 0 0 0 0 }
+
+.doc_hilite     { color: blue; font-weight: bold; }
+
+.doc_table      { text-align: center; width: 90%;
+                  padding: 1px 1px 1px 1px; border: 1px; }
+
+.doc_table_nw   { text-align: center; border: 1px;
+                  padding: 1px 1px 1px 1px; }
+
+.doc_warning    { color: red; font-weight: bold }
+
+.literal-block  { border: solid 1px gray; background: #eeeeee;
+                  margin: 0 1em 0 1em;
+                  padding: 0 1em 0 1em;
+                  display:table;
+                }
+.doc_notes      { background: #fafafa; border: 1px solid #cecece; padding: 0.1em }
+
+TABLE.layout    { text-align: left; border: none; border-collapse: collapse;
+                  padding: 4px 4px 4px 4px; }
+TR.layout       { border: none; padding: 4pt 4pt 2pt 2pt; }
+TD.layout       { border: none; padding: 4pt 4pt 2pt 2pt;
+                  vertical-align: top;}
+TD.left         { border: none; padding: 4pt 4pt 2pt 2pt; text-align: left;
+                  vertical-align: top;}
+TD.right        { border: none; padding: 4pt 4pt 2pt 2pt; text-align: right;
+                  vertical-align: top;}
+TH.layout       { border: none; font-weight: bold; font-size: 105%;
+                  text-align:center; vertical-align: middle; }
+
+/* Left align table cell */
+.td_left        { border: 2px solid gray; text-align: left; }
+
+.toc-backref    { color: black; }
diff --git a/llvm/tools/llvmc/driver/Action.cpp b/llvm/tools/llvmc/driver/Action.cpp
new file mode 100644
index 00000000000..c0a1b849bcd
--- /dev/null
+++ b/llvm/tools/llvmc/driver/Action.cpp
@@ -0,0 +1,78 @@
+//===--- Action.cpp - The LLVM Compiler Driver ------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Action class - implementation and auxiliary functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CompilerDriver/Action.h"
+
+#include "llvm/Support/CommandLine.h"
+#include "llvm/System/Program.h"
+
+#include <iostream>
+#include <stdexcept>
+
+using namespace llvm;
+using namespace llvmc;
+
+extern cl::opt<bool> DryRun;
+extern cl::opt<bool> VerboseMode;
+
+namespace {
+  int ExecuteProgram(const std::string& name,
+                     const StrVector& args) {
+    sys::Path prog = sys::Program::FindProgramByName(name);
+
+    if (prog.isEmpty())
+      throw std::runtime_error("Can't find program '" + name + "'");
+    if (!prog.canExecute())
+      throw std::runtime_error("Program '" + name + "' is not executable.");
+
+    // Build the command line vector and the redirects array.
+    const sys::Path* redirects[3] = {0,0,0};
+    sys::Path stdout_redirect;
+
+    std::vector<const char*> argv;
+    argv.reserve((args.size()+2));
+    argv.push_back(name.c_str());
+
+    for (StrVector::const_iterator B = args.begin(), E = args.end();
+         B!=E; ++B) {
+      if (*B == ">") {
+        ++B;
+        stdout_redirect.set(*B);
+        redirects[1] = &stdout_redirect;
+      }
+      else {
+        argv.push_back((*B).c_str());
+      }
+    }
+    argv.push_back(0);  // null terminate list.
+
+    // Invoke the program.
+    return sys::Program::ExecuteAndWait(prog, &argv[0], 0, &redirects[0]);
+  }
+
+  void print_string (const std::string& str) {
+    std::cerr << str << ' ';
+  }
+}
+
+int llvmc::Action::Execute() const {
+  if (DryRun || VerboseMode) {
+    std::cerr << Command_ << " ";
+    std::for_each(Args_.begin(), Args_.end(), print_string);
+    std::cerr << '\n';
+  }
+  if (DryRun)
+    return 0;
+  else
+    return ExecuteProgram(Command_, Args_);
+}
diff --git a/llvm/tools/llvmc/driver/CMakeLists.txt b/llvm/tools/llvmc/driver/CMakeLists.txt
new file mode 100644
index 00000000000..7d4e967b73a
--- /dev/null
+++ b/llvm/tools/llvmc/driver/CMakeLists.txt
@@ -0,0 +1,9 @@
+set(LLVM_LINK_COMPONENTS support system)
+set(LLVM_REQUIRES_EH 1)
+
+add_llvm_tool(llvmc2
+  Action.cpp
+  CompilationGraph.cpp
+  llvmc.cpp
+  Plugin.cpp
+  )
diff --git a/llvm/tools/llvmc/driver/CompilationGraph.cpp b/llvm/tools/llvmc/driver/CompilationGraph.cpp
new file mode 100644
index 00000000000..81283babb48
--- /dev/null
+++ b/llvm/tools/llvmc/driver/CompilationGraph.cpp
@@ -0,0 +1,438 @@
+//===--- CompilationGraph.cpp - The LLVM Compiler Driver --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Compilation graph - implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Error.h"
+#include "llvm/CompilerDriver/CompilationGraph.h"
+
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/DOTGraphTraits.h"
+#include "llvm/Support/GraphWriter.h"
+
+#include <algorithm>
+#include <iterator>
+#include <limits>
+#include <queue>
+#include <stdexcept>
+
+using namespace llvm;
+using namespace llvmc;
+
+extern cl::list<std::string> InputFilenames;
+extern cl::opt<std::string> OutputFilename;
+extern cl::list<std::string> Languages;
+
+namespace llvmc {
+
+  const std::string& LanguageMap::GetLanguage(const sys::Path& File) const {
+    LanguageMap::const_iterator Lang = this->find(File.getSuffix());
+    if (Lang == this->end())
+      throw std::runtime_error("Unknown suffix: " + File.getSuffix());
+    return Lang->second;
+  }
+}
+
+namespace {
+
+  /// ChooseEdge - Return the edge with the maximum weight.
+  template <class C>
+  const Edge* ChooseEdge(const C& EdgesContainer,
+                         const InputLanguagesSet& InLangs,
+                         const std::string& NodeName = "root") {
+    const Edge* MaxEdge = 0;
+    unsigned MaxWeight = 0;
+    bool SingleMax = true;
+
+    for (typename C::const_iterator B = EdgesContainer.begin(),
+           E = EdgesContainer.end(); B != E; ++B) {
+      const Edge* e = B->getPtr();
+      unsigned EW = e->Weight(InLangs);
+      if (EW > MaxWeight) {
+        MaxEdge = e;
+        MaxWeight = EW;
+        SingleMax = true;
+      } else if (EW == MaxWeight) {
+        SingleMax = false;
+      }
+    }
+
+    if (!SingleMax)
+      throw std::runtime_error("Node " + NodeName +
+                               ": multiple maximal outward edges found!"
+                               " Most probably a specification error.");
+    if (!MaxEdge)
+      throw std::runtime_error("Node " + NodeName +
+                               ": no maximal outward edge found!"
+                               " Most probably a specification error.");
+    return MaxEdge;
+  }
+
+}
+
+CompilationGraph::CompilationGraph() {
+  NodesMap["root"] = Node(this);
+}
+
+Node& CompilationGraph::getNode(const std::string& ToolName) {
+  nodes_map_type::iterator I = NodesMap.find(ToolName);
+  if (I == NodesMap.end())
+    throw std::runtime_error("Node " + ToolName + " is not in the graph");
+  return I->second;
+}
+
+const Node& CompilationGraph::getNode(const std::string& ToolName) const {
+  nodes_map_type::const_iterator I = NodesMap.find(ToolName);
+  if (I == NodesMap.end())
+    throw std::runtime_error("Node " + ToolName + " is not in the graph!");
+  return I->second;
+}
+
+// Find the tools list corresponding to the given language name.
+const CompilationGraph::tools_vector_type&
+CompilationGraph::getToolsVector(const std::string& LangName) const
+{
+  tools_map_type::const_iterator I = ToolsMap.find(LangName);
+  if (I == ToolsMap.end())
+    throw std::runtime_error("No tool corresponding to the language "
+                             + LangName + " found");
+  return I->second;
+}
+
+void CompilationGraph::insertNode(Tool* V) {
+  if (NodesMap.count(V->Name()) == 0)
+    NodesMap[V->Name()] = Node(this, V);
+}
+
+void CompilationGraph::insertEdge(const std::string& A, Edge* Edg) {
+  Node& B = getNode(Edg->ToolName());
+  if (A == "root") {
+    const char** InLangs = B.ToolPtr->InputLanguages();
+    for (;*InLangs; ++InLangs)
+      ToolsMap[*InLangs].push_back(IntrusiveRefCntPtr<Edge>(Edg));
+    NodesMap["root"].AddEdge(Edg);
+  }
+  else {
+    Node& N = getNode(A);
+    N.AddEdge(Edg);
+  }
+  // Increase the inward edge counter.
+  B.IncrInEdges();
+}
+
+namespace {
+  sys::Path MakeTempFile(const sys::Path& TempDir, const std::string& BaseName,
+                         const std::string& Suffix) {
+    sys::Path Out;
+
+    // Make sure we don't end up with path names like '/file.o' if the
+    // TempDir is empty.
+    if (TempDir.empty()) {
+      Out.set(BaseName);
+    }
+    else {
+      Out = TempDir;
+      Out.appendComponent(BaseName);
+    }
+    Out.appendSuffix(Suffix);
+    // NOTE: makeUnique always *creates* a unique temporary file,
+    // which is good, since there will be no races. However, some
+    // tools do not like it when the output file already exists, so
+    // they have to be placated with -f or something like that.
+    Out.makeUnique(true, NULL);
+    return Out;
+  }
+}
+
+// Pass input file through the chain until we bump into a Join node or
+// a node that says that it is the last.
+void CompilationGraph::PassThroughGraph (const sys::Path& InFile,
+                                         const Node* StartNode,
+                                         const InputLanguagesSet& InLangs,
+                                         const sys::Path& TempDir,
+                                         const LanguageMap& LangMap) const {
+  bool Last = false;
+  sys::Path In = InFile;
+  const Node* CurNode = StartNode;
+
+  while(!Last) {
+    sys::Path Out;
+    Tool* CurTool = CurNode->ToolPtr.getPtr();
+
+    if (CurTool->IsJoin()) {
+      JoinTool& JT = dynamic_cast<JoinTool&>(*CurTool);
+      JT.AddToJoinList(In);
+      break;
+    }
+
+    // Since toolchains do not have to end with a Join node, we should
+    // check if this Node is the last.
+    if (!CurNode->HasChildren() || CurTool->IsLast()) {
+      if (!OutputFilename.empty()) {
+        Out.set(OutputFilename);
+      }
+      else {
+        Out.set(In.getBasename());
+        Out.appendSuffix(CurTool->OutputSuffix());
+      }
+      Last = true;
+    }
+    else {
+      Out = MakeTempFile(TempDir, In.getBasename(), CurTool->OutputSuffix());
+    }
+
+    if (int ret = CurTool->GenerateAction(In, Out, InLangs, LangMap).Execute())
+      throw error_code(ret);
+
+    if (Last)
+      return;
+
+    CurNode = &getNode(ChooseEdge(CurNode->OutEdges,
+                                  InLangs,
+                                  CurNode->Name())->ToolName());
+    In = Out; Out.clear();
+  }
+}
+
+// Find the head of the toolchain corresponding to the given file.
+// Also, insert an input language into InLangs.
+const Node* CompilationGraph::
+FindToolChain(const sys::Path& In, const std::string* ForceLanguage,
+              InputLanguagesSet& InLangs, const LanguageMap& LangMap) const {
+
+  // Determine the input language.
+  const std::string& InLanguage =
+    ForceLanguage ? *ForceLanguage : LangMap.GetLanguage(In);
+
+  // Add the current input language to the input language set.
+  InLangs.insert(InLanguage);
+
+  // Find the toolchain for the input language.
+  const tools_vector_type& TV = getToolsVector(InLanguage);
+  if (TV.empty())
+    throw std::runtime_error("No toolchain corresponding to language "
+                             + InLanguage + " found");
+  return &getNode(ChooseEdge(TV, InLangs)->ToolName());
+}
+
+// Helper function used by Build().
+// Traverses initial portions of the toolchains (up to the first Join node).
+// This function is also responsible for handling the -x option.
+void CompilationGraph::BuildInitial (InputLanguagesSet& InLangs,
+                                     const sys::Path& TempDir,
+                                     const LanguageMap& LangMap) {
+  // This is related to -x option handling.
+  cl::list<std::string>::const_iterator xIter = Languages.begin(),
+    xBegin = xIter, xEnd = Languages.end();
+  bool xEmpty = true;
+  const std::string* xLanguage = 0;
+  unsigned xPos = 0, xPosNext = 0, filePos = 0;
+
+  if (xIter != xEnd) {
+    xEmpty = false;
+    xPos = Languages.getPosition(xIter - xBegin);
+    cl::list<std::string>::const_iterator xNext = llvm::next(xIter);
+    xPosNext = (xNext == xEnd) ? std::numeric_limits<unsigned>::max()
+      : Languages.getPosition(xNext - xBegin);
+    xLanguage = (*xIter == "none") ? 0 : &(*xIter);
+  }
+
+  // For each input file:
+  for (cl::list<std::string>::const_iterator B = InputFilenames.begin(),
+         CB = B, E = InputFilenames.end(); B != E; ++B) {
+    sys::Path In = sys::Path(*B);
+
+    // Code for handling the -x option.
+    // Output: std::string* xLanguage (can be NULL).
+    if (!xEmpty) {
+      filePos = InputFilenames.getPosition(B - CB);
+
+      if (xPos < filePos) {
+        if (filePos < xPosNext) {
+          xLanguage = (*xIter == "none") ? 0 : &(*xIter);
+        }
+        else { // filePos >= xPosNext
+          // Skip xIters while filePos > xPosNext
+          while (filePos > xPosNext) {
+            ++xIter;
+            xPos = xPosNext;
+
+            cl::list<std::string>::const_iterator xNext = llvm::next(xIter);
+            if (xNext == xEnd)
+              xPosNext = std::numeric_limits<unsigned>::max();
+            else
+              xPosNext = Languages.getPosition(xNext - xBegin);
+            xLanguage = (*xIter == "none") ? 0 : &(*xIter);
+          }
+        }
+      }
+    }
+
+    // Find the toolchain corresponding to this file.
+    const Node* N = FindToolChain(In, xLanguage, InLangs, LangMap);
+    // Pass file through the chain starting at head.
+    PassThroughGraph(In, N, InLangs, TempDir, LangMap);
+  }
+}
+
+// Sort the nodes in topological order.
+void CompilationGraph::TopologicalSort(std::vector<const Node*>& Out) {
+  std::queue<const Node*> Q;
+  Q.push(&getNode("root"));
+
+  while (!Q.empty()) {
+    const Node* A = Q.front();
+    Q.pop();
+    Out.push_back(A);
+    for (Node::const_iterator EB = A->EdgesBegin(), EE = A->EdgesEnd();
+         EB != EE; ++EB) {
+      Node* B = &getNode((*EB)->ToolName());
+      B->DecrInEdges();
+      if (B->HasNoInEdges())
+        Q.push(B);
+    }
+  }
+}
+
+namespace {
+  bool NotJoinNode(const Node* N) {
+    return N->ToolPtr ? !N->ToolPtr->IsJoin() : true;
+  }
+}
+
+// Call TopologicalSort and filter the resulting list to include
+// only Join nodes.
+void CompilationGraph::
+TopologicalSortFilterJoinNodes(std::vector<const Node*>& Out) {
+  std::vector<const Node*> TopSorted;
+  TopologicalSort(TopSorted);
+  std::remove_copy_if(TopSorted.begin(), TopSorted.end(),
+                      std::back_inserter(Out), NotJoinNode);
+}
+
+int CompilationGraph::Build (const sys::Path& TempDir,
+                             const LanguageMap& LangMap) {
+
+  InputLanguagesSet InLangs;
+
+  // Traverse initial parts of the toolchains and fill in InLangs.
+  BuildInitial(InLangs, TempDir, LangMap);
+
+  std::vector<const Node*> JTV;
+  TopologicalSortFilterJoinNodes(JTV);
+
+  // For all join nodes in topological order:
+  for (std::vector<const Node*>::iterator B = JTV.begin(), E = JTV.end();
+       B != E; ++B) {
+
+    sys::Path Out;
+    const Node* CurNode = *B;
+    JoinTool* JT = &dynamic_cast<JoinTool&>(*CurNode->ToolPtr.getPtr());
+    bool IsLast = false;
+
+    // Are there any files in the join list?
+    if (JT->JoinListEmpty())
+      continue;
+
+    // Is this the last tool in the toolchain?
+    // NOTE: we can process several toolchains in parallel.
+    if (!CurNode->HasChildren() || JT->IsLast()) {
+      if (OutputFilename.empty()) {
+        Out.set("a");
+        Out.appendSuffix(JT->OutputSuffix());
+      }
+      else
+        Out.set(OutputFilename);
+      IsLast = true;
+    }
+    else {
+      Out = MakeTempFile(TempDir, "tmp", JT->OutputSuffix());
+    }
+
+    if (int ret = JT->GenerateAction(Out, InLangs, LangMap).Execute())
+      throw error_code(ret);
+
+    if (!IsLast) {
+      const Node* NextNode =
+        &getNode(ChooseEdge(CurNode->OutEdges, InLangs,
+                            CurNode->Name())->ToolName());
+      PassThroughGraph(Out, NextNode, InLangs, TempDir, LangMap);
+    }
+  }
+
+  return 0;
+}
+
+// Code related to graph visualization.
+
+namespace llvm {
+  template <>
+  struct DOTGraphTraits<llvmc::CompilationGraph*>
+    : public DefaultDOTGraphTraits
+  {
+
+    template<typename GraphType>
+    static std::string getNodeLabel(const Node* N, const GraphType&)
+    {
+      if (N->ToolPtr)
+        if (N->ToolPtr->IsJoin())
+          return N->Name() + "\n (join" +
+            (N->HasChildren() ? ")"
+             : std::string(": ") + N->ToolPtr->OutputLanguage() + ')');
+        else
+          return N->Name();
+      else
+        return "root";
+    }
+
+    template<typename EdgeIter>
+    static std::string getEdgeSourceLabel(const Node* N, EdgeIter I) {
+      if (N->ToolPtr) {
+        return N->ToolPtr->OutputLanguage();
+      }
+      else {
+        const char** InLangs = I->ToolPtr->InputLanguages();
+        std::string ret;
+
+        for (; *InLangs; ++InLangs) {
+          if (*(InLangs + 1)) {
+            ret += *InLangs;
+            ret +=  ", ";
+          }
+          else {
+            ret += *InLangs;
+          }
+        }
+
+        return ret;
+      }
+    }
+  };
+
+}
+
+void CompilationGraph::writeGraph() {
+  std::ofstream O("compilation-graph.dot");
+
+  if (O.good()) {
+    llvm::WriteGraph(this, "compilation-graph");
+    O.close();
+  }
+  else {
+    throw std::runtime_error("Error opening file 'compilation-graph.dot'"
+                             " for writing!");
+  }
+}
+
+void CompilationGraph::viewGraph() {
+  llvm::ViewGraph(this, "compilation-graph");
+}
diff --git a/llvm/tools/llvmc/driver/Error.h b/llvm/tools/llvmc/driver/Error.h
new file mode 100644
index 00000000000..c0aaff1a724
--- /dev/null
+++ b/llvm/tools/llvmc/driver/Error.h
@@ -0,0 +1,33 @@
+//===--- Error.h - The LLVM Compiler Driver ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Exception classes for LLVMC.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVMC2_ERROR_H
+#define LLVM_TOOLS_LLVMC2_ERROR_H
+
+#include <stdexcept>
+
+namespace llvmc {
+
+  class error_code: public std::runtime_error {
+    int Code_;
+  public:
+    error_code (int c)
+      : std::runtime_error("Tool returned error code"), Code_(c)
+    {}
+
+    int code() const { return Code_; }
+  };
+
+}
+
+#endif //LLVM_TOOLS_LLVMC2_ERROR_H
diff --git a/llvm/tools/llvmc/driver/Makefile b/llvm/tools/llvmc/driver/Makefile
new file mode 100644
index 00000000000..d3aa2cd52ad
--- /dev/null
+++ b/llvm/tools/llvmc/driver/Makefile
@@ -0,0 +1,19 @@
+##===- tools/llvmc/driver/Makefile -------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open
+# Source License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../../..
+TOOLNAME = $(DRIVER_NAME)
+LINK_COMPONENTS = support system
+REQUIRES_EH := 1
+
+ifneq ($(BUILTIN_PLUGINS),)
+USEDLIBS = $(patsubst %,LLVMC%,$(BUILTIN_PLUGINS))
+endif
+
+include $(LEVEL)/Makefile.common
diff --git a/llvm/tools/llvmc/driver/Plugin.cpp b/llvm/tools/llvmc/driver/Plugin.cpp
new file mode 100644
index 00000000000..75abbd041d3
--- /dev/null
+++ b/llvm/tools/llvmc/driver/Plugin.cpp
@@ -0,0 +1,73 @@
+//===--- Plugin.cpp - The LLVM Compiler Driver ------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Plugin support.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CompilerDriver/Plugin.h"
+
+#include <algorithm>
+#include <vector>
+
+namespace {
+
+  // Registry::Add<> does not do lifetime management (probably issues
+  // with static constructor/destructor ordering), so we have to
+  // implement it here.
+  //
+  // All this static registration/life-before-main model seems
+  // unnecessary convoluted to me.
+
+  static bool pluginListInitialized = false;
+  typedef std::vector<const llvmc::BasePlugin*> PluginList;
+  static PluginList Plugins;
+
+  struct ByPriority {
+    bool operator()(const llvmc::BasePlugin* lhs,
+                    const llvmc::BasePlugin* rhs) {
+      return lhs->Priority() < rhs->Priority();
+    }
+  };
+}
+
+namespace llvmc {
+
+  PluginLoader::PluginLoader() {
+    if (!pluginListInitialized) {
+      for (PluginRegistry::iterator B = PluginRegistry::begin(),
+             E = PluginRegistry::end(); B != E; ++B)
+        Plugins.push_back(B->instantiate());
+      std::sort(Plugins.begin(), Plugins.end(), ByPriority());
+    }
+    pluginListInitialized = true;
+  }
+
+  PluginLoader::~PluginLoader() {
+    if (pluginListInitialized) {
+      for (PluginList::iterator B = Plugins.begin(), E = Plugins.end();
+           B != E; ++B)
+        delete (*B);
+    }
+    pluginListInitialized = false;
+  }
+
+  void PluginLoader::PopulateLanguageMap(LanguageMap& langMap) {
+    for (PluginList::iterator B = Plugins.begin(), E = Plugins.end();
+         B != E; ++B)
+      (*B)->PopulateLanguageMap(langMap);
+  }
+
+  void PluginLoader::PopulateCompilationGraph(CompilationGraph& graph) {
+    for (PluginList::iterator B = Plugins.begin(), E = Plugins.end();
+         B != E; ++B)
+      (*B)->PopulateCompilationGraph(graph);
+  }
+
+}
diff --git a/llvm/tools/llvmc/driver/llvmc.cpp b/llvm/tools/llvmc/driver/llvmc.cpp
new file mode 100644
index 00000000000..f3a1e571926
--- /dev/null
+++ b/llvm/tools/llvmc/driver/llvmc.cpp
@@ -0,0 +1,119 @@
+//===--- llvmc.cpp - The LLVM Compiler Driver -------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open
+// Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This tool provides a single point of access to the LLVM
+//  compilation tools.  It has many options. To discover the options
+//  supported please refer to the tools' manual page or run the tool
+//  with the --help option.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Error.h"
+
+#include "llvm/CompilerDriver/CompilationGraph.h"
+#include "llvm/CompilerDriver/Plugin.h"
+
+#include "llvm/System/Path.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/PluginLoader.h"
+
+#include <iostream>
+#include <stdexcept>
+#include <string>
+
+namespace cl = llvm::cl;
+namespace sys = llvm::sys;
+using namespace llvmc;
+
+// Built-in command-line options.
+// External linkage here is intentional.
+
+cl::list<std::string> InputFilenames(cl::Positional, cl::desc("<input file>"),
+                                     cl::ZeroOrMore);
+cl::opt<std::string> OutputFilename("o", cl::desc("Output file name"),
+                                    cl::value_desc("file"));
+cl::list<std::string> Languages("x",
+          cl::desc("Specify the language of the following input files"),
+          cl::ZeroOrMore);
+cl::opt<bool> DryRun("dry-run",
+                     cl::desc("Only pretend to run commands"));
+cl::opt<bool> VerboseMode("v",
+                          cl::desc("Enable verbose mode"));
+cl::opt<bool> WriteGraph("write-graph",
+                         cl::desc("Write compilation-graph.dot file"),
+                         cl::Hidden);
+cl::opt<bool> ViewGraph("view-graph",
+                         cl::desc("Show compilation graph in GhostView"),
+                         cl::Hidden);
+cl::opt<bool> SaveTemps("save-temps",
+                         cl::desc("Keep temporary files"),
+                         cl::Hidden);
+
+namespace {
+  /// BuildTargets - A small wrapper for CompilationGraph::Build.
+  int BuildTargets(CompilationGraph& graph, const LanguageMap& langMap) {
+    int ret;
+    const sys::Path& tempDir = SaveTemps
+      ? sys::Path("")
+      : sys::Path(sys::Path::GetTemporaryDirectory());
+
+    try {
+      ret = graph.Build(tempDir, langMap);
+    }
+    catch(...) {
+      tempDir.eraseFromDisk(true);
+      throw;
+    }
+
+    if (!SaveTemps)
+      tempDir.eraseFromDisk(true);
+    return ret;
+  }
+}
+
+int main(int argc, char** argv) {
+  try {
+    LanguageMap langMap;
+    CompilationGraph graph;
+
+    cl::ParseCommandLineOptions
+      (argc, argv, "LLVM Compiler Driver (Work In Progress)", true);
+
+    PluginLoader Plugins;
+    Plugins.PopulateLanguageMap(langMap);
+    Plugins.PopulateCompilationGraph(graph);
+
+    if (WriteGraph) {
+      graph.writeGraph();
+      if (!ViewGraph)
+        return 0;
+    }
+
+    if (ViewGraph) {
+      graph.viewGraph();
+      return 0;
+    }
+
+    if (InputFilenames.empty()) {
+      throw std::runtime_error("no input files");
+    }
+
+    return BuildTargets(graph, langMap);
+  }
+  catch(llvmc::error_code& ec) {
+    return ec.code();
+  }
+  catch(const std::exception& ex) {
+    std::cerr << argv[0] << ": " << ex.what() << '\n';
+  }
+  catch(...) {
+    std::cerr << argv[0] << ": unknown error!\n";
+  }
+  return 1;
+}
diff --git a/llvm/tools/llvmc/plugins/Base/Base.td b/llvm/tools/llvmc/plugins/Base/Base.td
new file mode 100644
index 00000000000..85a37cb41a7
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Base/Base.td
@@ -0,0 +1,59 @@
+//===- Base.td - LLVMC2 toolchain descriptions -------------*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains compilation graph description used by llvmc2.
+//
+//===----------------------------------------------------------------------===//
+
+include "llvm/CompilerDriver/Common.td"
+include "llvm/CompilerDriver/Tools.td"
+
+// Toolchains
+
+def CompilationGraph : CompilationGraph<[
+    Edge<"root", "llvm_gcc_c">,
+    Edge<"root", "llvm_gcc_assembler">,
+    Edge<"root", "llvm_gcc_cpp">,
+    Edge<"root", "llvm_gcc_m">,
+    Edge<"root", "llvm_gcc_mxx">,
+    Edge<"root", "llvm_as">,
+
+    Edge<"llvm_gcc_c", "llc">,
+    Edge<"llvm_gcc_cpp", "llc">,
+    Edge<"llvm_gcc_m", "llc">,
+    Edge<"llvm_gcc_mxx", "llc">,
+    Edge<"llvm_as", "llc">,
+
+    OptionalEdge<"llvm_gcc_c", "opt", (case (switch_on "opt"), (inc_weight))>,
+    OptionalEdge<"llvm_gcc_cpp", "opt", (case (switch_on "opt"), (inc_weight))>,
+    OptionalEdge<"llvm_gcc_m", "opt", (case (switch_on "opt"), (inc_weight))>,
+    OptionalEdge<"llvm_gcc_mxx", "opt", (case (switch_on "opt"), (inc_weight))>,
+    OptionalEdge<"llvm_as", "opt", (case (switch_on "opt"), (inc_weight))>,
+    Edge<"opt", "llc">,
+
+    Edge<"llc", "llvm_gcc_assembler">,
+    Edge<"llvm_gcc_assembler", "llvm_gcc_linker">,
+    OptionalEdge<"llvm_gcc_assembler", "llvm_gcc_cpp_linker",
+                 (case
+                     (or (input_languages_contain "c++"),
+                         (input_languages_contain "objective-c++")),
+                     (inc_weight),
+                     (or (parameter_equals "linker", "g++"),
+                         (parameter_equals "linker", "c++")), (inc_weight))>,
+
+
+    Edge<"root", "llvm_gcc_linker">,
+    OptionalEdge<"root", "llvm_gcc_cpp_linker",
+                 (case
+                     (or (input_languages_contain "c++"),
+                         (input_languages_contain "objective-c++")),
+                     (inc_weight),
+                     (or (parameter_equals "linker", "g++"),
+                         (parameter_equals "linker", "c++")), (inc_weight))>
+    ]>;
diff --git a/llvm/tools/llvmc/plugins/Base/Makefile b/llvm/tools/llvmc/plugins/Base/Makefile
new file mode 100644
index 00000000000..5ca6048508a
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Base/Makefile
@@ -0,0 +1,13 @@
+##===- tools/llvmc/plugins/Base/Makefile -------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LLVMC_PLUGIN = Base
+BUILT_SOURCES = AutoGenerated.inc
+
+include ../Makefile
diff --git a/llvm/tools/llvmc/plugins/Base/PluginMain.cpp b/llvm/tools/llvmc/plugins/Base/PluginMain.cpp
new file mode 100644
index 00000000000..add8acb4a57
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Base/PluginMain.cpp
@@ -0,0 +1 @@
+#include "AutoGenerated.inc"
diff --git a/llvm/tools/llvmc/plugins/Clang/Clang.td b/llvm/tools/llvmc/plugins/Clang/Clang.td
new file mode 100644
index 00000000000..0f5d8cd9180
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Clang/Clang.td
@@ -0,0 +1,85 @@
+// A (first stab at a) replacement for the Clang's ccc script.
+// To compile, use this command:
+//    cd $LLVMC2_DIR
+//    make DRIVER_NAME=ccc2 BUILTIN_PLUGINS=Clang
+
+include "llvm/CompilerDriver/Common.td"
+
+
+def Options : OptionList<[
+(switch_option "E",
+    (help "Stop after the preprocessing stage, do not run the compiler"))
+]>;
+
+class clang_base<string language, dag cmdline> : Tool<
+[(in_language language),
+ (out_language "llvm-bitcode"),
+ (output_suffix "bc"),
+ (cmd_line cmdline),
+ (switch_option "E", (stop_compilation), (output_suffix "i")),
+ (sink)
+]>;
+
+def clang_c : clang_base<"c",
+(case
+(switch_on "E"),
+    (case
+    (not_empty "o"),
+        "clang -E -x c $INFILE -o $OUTFILE",
+    (default),
+        "clang -E -x c $INFILE"),
+(default),
+    "clang -emit-llvm-bc -x c $INFILE -o $OUTFILE")>;
+
+def clang_cpp : clang_base<"c++",
+(case
+(switch_on "E"),
+    (case
+    (not_empty "o"),
+        "clang -E -x c++ $INFILE -o $OUTFILE",
+    (default),
+        "clang -E -x c++ $INFILE"),
+(default),
+    "clang -emit-llvm-bc -x c++ $INFILE -o $OUTFILE")>;
+
+def clang_objective_c : clang_base<"objective-c",
+(case
+(switch_on "E"),
+    (case
+    (not_empty "o"),
+        "clang -E -x objective-c $INFILE -o $OUTFILE",
+    (default),
+        "clang -E -x objective-c $INFILE"),
+(default),
+    "clang -emit-llvm-bc -x objective-c $INFILE -o $OUTFILE")>;
+
+// Default linker
+def llvm_ld : Tool<
+[(in_language "llvm-bitcode"),
+ (out_language "executable"),
+ (output_suffix "out"),
+ (cmd_line "llvm-ld -native -disable-internalize $INFILE -o $OUTFILE"),
+ (prefix_list_option "L", (forward), (help "Specify a library search path")),
+ (join)
+]>;
+
+// Language map
+
+def LanguageMap : LanguageMap<
+    [LangToSuffixes<"c++", ["cc", "cp", "cxx", "cpp", "CPP", "c++", "C"]>,
+     LangToSuffixes<"c", ["c"]>,
+     LangToSuffixes<"objective-c", ["m"]>,
+     LangToSuffixes<"c-cpp-output", ["i"]>,
+     LangToSuffixes<"objective-c-cpp-output", ["mi"]>
+     ]>;
+
+// Compilation graph
+
+def CompilationGraph : CompilationGraph<[
+    Edge<"root", "clang_c">,
+    Edge<"root", "clang_cpp">,
+    Edge<"root", "clang_objective_c">,
+    Edge<"clang_c", "llvm_ld">,
+    Edge<"clang_cpp", "llvm_ld">,
+    Edge<"clang_objective_c", "llvm_ld">
+    ]>;
diff --git a/llvm/tools/llvmc/plugins/Clang/Makefile b/llvm/tools/llvmc/plugins/Clang/Makefile
new file mode 100644
index 00000000000..32060138c23
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Clang/Makefile
@@ -0,0 +1,13 @@
+##===- tools/llvmc/plugins/Clang/Makefile ------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LLVMC_PLUGIN = Clang
+BUILT_SOURCES = AutoGenerated.inc
+
+include ../Makefile
diff --git a/llvm/tools/llvmc/plugins/Clang/PluginMain.cpp b/llvm/tools/llvmc/plugins/Clang/PluginMain.cpp
new file mode 100644
index 00000000000..add8acb4a57
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Clang/PluginMain.cpp
@@ -0,0 +1 @@
+#include "AutoGenerated.inc"
diff --git a/llvm/tools/llvmc/plugins/Hello/Hello.cpp b/llvm/tools/llvmc/plugins/Hello/Hello.cpp
new file mode 100644
index 00000000000..2ecd2f1c5b9
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Hello/Hello.cpp
@@ -0,0 +1,30 @@
+//===- Hello.cpp - Example code from "Writing an LLVM Pass" ---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Test plugin for LLVMC.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CompilerDriver/CompilationGraph.h"
+#include "llvm/CompilerDriver/Plugin.h"
+
+#include <iostream>
+
+namespace {
+struct MyPlugin : public llvmc::BasePlugin {
+  void PopulateLanguageMap(llvmc::LanguageMap&) const
+  { std::cout << "Hello!\n"; }
+
+  void PopulateCompilationGraph(llvmc::CompilationGraph&) const
+  {}
+};
+
+static llvmc::RegisterPlugin<MyPlugin> RP("Hello", "Hello World plugin");
+
+}
diff --git a/llvm/tools/llvmc/plugins/Hello/Makefile b/llvm/tools/llvmc/plugins/Hello/Makefile
new file mode 100644
index 00000000000..181dd0c6050
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Hello/Makefile
@@ -0,0 +1,12 @@
+##===- tools/llvmc/plugins/Hello/Makefile ------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LLVMC_PLUGIN = Hello
+
+include ../Makefile
diff --git a/llvm/tools/llvmc/plugins/Makefile b/llvm/tools/llvmc/plugins/Makefile
new file mode 100644
index 00000000000..dab58e07581
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Makefile
@@ -0,0 +1,55 @@
+##===- tools/llvmc/plugins/Makefile.plugins ----------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open
+# Source License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+ifndef LLVMC_PLUGIN
+
+LEVEL = ../../..
+DIRS = $(BUILTIN_PLUGINS)
+
+# TOFIX: Should we also build DSO versions of plugins?
+export BUILTIN_LLVMC_PLUGIN=1
+
+include $(LEVEL)/Makefile.common
+
+else # LLVMC_PLUGIN
+
+LEVEL = ../../../..
+
+LIBRARYNAME := $(patsubst %,LLVMC%,$(LLVMC_PLUGIN))
+REQUIRES_EH = 1
+
+ifndef BUILTIN_LLVMC_PLUGIN
+LOADABLE_MODULE = 1
+endif
+
+ifneq ($(BUILT_SOURCES),)
+BUILD_AUTOGENERATED_INC=1
+endif
+
+include $(LEVEL)/Makefile.common
+
+# TOFIX: This probably should go into Makefile.rules
+
+ifdef BUILD_AUTOGENERATED_INC
+
+TOOLS_SOURCE := $(strip $(wildcard $(PROJ_SRC_DIR)/*.td))
+
+TD_COMMON :=$(strip $(wildcard \
+		$(LLVM_SRC_ROOT)/include/llvm/CompilerDriver/*.td))
+
+$(ObjDir)/AutoGenerated.inc.tmp: $(TOOLS_SOURCE) $(ObjDir)/.dir \
+				$(TBLGEN) $(TD_COMMON)
+	$(Echo) "Building LLVMC configuration library with tblgen"
+	$(Verb) $(TableGen) -gen-llvmc -o $(call SYSPATH, $@) $<
+
+AutoGenerated.inc : $(ObjDir)/AutoGenerated.inc.tmp
+	$(Verb) $(CMP) -s $@ $< || $(CP) $< $@
+endif # BUILD_AUTOGENERATED_INC
+
+endif # LLVMC_PLUGIN
diff --git a/llvm/tools/llvmc/plugins/Simple/Makefile b/llvm/tools/llvmc/plugins/Simple/Makefile
new file mode 100644
index 00000000000..1cd5af7a15e
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Simple/Makefile
@@ -0,0 +1,13 @@
+##===- tools/llvmc/plugins/Simple/Makefile -----------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LLVMC_PLUGIN = Simple
+BUILT_SOURCES = AutoGenerated.inc
+
+include ../Makefile
diff --git a/llvm/tools/llvmc/plugins/Simple/PluginMain.cpp b/llvm/tools/llvmc/plugins/Simple/PluginMain.cpp
new file mode 100644
index 00000000000..add8acb4a57
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Simple/PluginMain.cpp
@@ -0,0 +1 @@
+#include "AutoGenerated.inc"
diff --git a/llvm/tools/llvmc/plugins/Simple/Simple.td b/llvm/tools/llvmc/plugins/Simple/Simple.td
new file mode 100644
index 00000000000..b974cbc95eb
--- /dev/null
+++ b/llvm/tools/llvmc/plugins/Simple/Simple.td
@@ -0,0 +1,30 @@
+// A simple wrapper for gcc.
+// To compile, use this command:
+//
+//      $ cd $LLVMC2_DIR
+//      $ make DRIVER_NAME=mygcc BUILTIN_PLUGINS=Simple
+//
+// To build this plugin as a dynamic library:
+//
+//      $ cd $LLVMC2_DIR
+//      $ make BUILTIN_PLUGINS=""
+//      $ cd plugins/Simple
+//      $ make
+//
+// Run as:
+//
+//      $ llvmc2 -load $LLVM_DIR/Release/lib/LLVMCSimple.so
+
+include "llvm/CompilerDriver/Common.td"
+
+def gcc : Tool<
+[(in_language "c"),
+ (out_language "executable"),
+ (output_suffix "out"),
+ (cmd_line "gcc $INFILE -o $OUTFILE"),
+ (sink)
+]>;
+
+def LanguageMap : LanguageMap<[LangToSuffixes<"c", ["c"]>]>;
+
+def CompilationGraph : CompilationGraph<[Edge<"root", "gcc">]>;