[OCaml] Build stub OCaml libraries for all configured targets

This allows to only link in the needed targets, reducing binary
size and more importantly link time.

Note that this is an incomplete implementation: currently,
LLVM does not have the plumbing which would allow to conditionally
link in AsmPrinter, AsmParser and Disassembler for the targets
which support them. This should be improved in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194670 91177308-0d34-0410-b5e6-96231b3b80d8

bindings/ocaml/backends/META.llvm_backend.in

@@ -0,0 +1,8 @@
+name = "llvm_@TARGET@"
+version = "@PACKAGE_VERSION@"
+description = "@TARGET@ Backend for LLVM"
+requires = "llvm"
+archive(byte) = "llvm_@[email protected]"
+archive(native) = "llvm_@[email protected]"
+directory = "."
+linkopts = "-ccopt -lstdc++"

bindings/ocaml/backends/Makefile

@@ -0,0 +1,56 @@
+##===- bindings/ocaml/backends/Makefile --------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+#
+# This is the master makefile for backend-specific bindings. It works by
+# creating a stub makefile for each configured target, e.g. Makefile.ARM, and
+# invoking it to compile the corresponding library, e.g. Llvm_ARM.
+#
+# This scheme allows to keep changes to Makefile.ocaml minimal.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL := ../../..
+ExtraMakefiles = $(PROJ_OBJ_DIR)/Makefile.common
+
+include $(LEVEL)/Makefile.config
+include $(LEVEL)/Makefile.common
+
+all-local:: all-backends
+clean-local:: clean-backends
+install-local:: install-backends
+uninstall-local:: uninstall-backends
+
+stubs:
+	$(Verb) for i in $(TARGETS_TO_BUILD); do \
+		$(ECHO) "TARGET := $$i"           >  Makefile.$$i; \
+		$(ECHO) "include Makefile.common" >> Makefile.$$i; \
+	done
+
+all-backends: stubs
+	$(Verb) for i in $(TARGETS_TO_BUILD); do \
+		$(MAKE) -f Makefile.$$i all; \
+	done
+
+clean-backends: stubs
+	$(Verb) for i in $(TARGETS_TO_BUILD); do \
+		$(MAKE) -f Makefile.$$i clean; \
+		$(RM) -f Makefile.$$i; \
+	done
+
+install-backends: stubs
+	$(Verb) for i in $(TARGETS_TO_BUILD); do \
+		$(MAKE) -f Makefile.$$i install; \
+	done
+
+uninstall-backends: stubs
+	$(Verb) for i in $(TARGETS_TO_BUILD); do \
+		$(MAKE) -f Makefile.$$i uninstall; \
+	done
+
+.PHONY: all-backends clean-backends install-backends uninstall-backends

bindings/ocaml/backends/Makefile.common

@@ -0,0 +1,65 @@
+##===- bindings/ocaml/backends/Makefile.common -------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+#
+# This is the slave makefile for backend-specific bindings. This makefile should
+# be included after defining TARGET. It will then substitute @TARGET@ for
+# the value of TARGET in various *.in files and build an OCaml library in
+# a regular way.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL := ../../..
+LIBRARYNAME := llvm_$(TARGET)
+UsedComponents := $(TARGET)
+UsedOcamlInterfaces := llvm
+
+include $(LEVEL)/Makefile.config
+
+SOURCES       := $(TARGET)_ocaml.c
+OcamlHeaders1 := $(PROJ_SRC_DIR)/llvm_$(TARGET).mli
+OcamlSources1 := $(PROJ_SRC_DIR)/llvm_$(TARGET).ml
+
+include ../Makefile.ocaml
+
+$(ObjDir)/llvm_$(TARGET).ml: $(PROJ_SRC_DIR)/llvm_backend.ml.in $(ObjDir)/.dir
+	$(Verb) $(SED) -e 's/@TARGET@/$(TARGET)/' $< > $@
+
+$(ObjDir)/llvm_$(TARGET).mli: $(PROJ_SRC_DIR)/llvm_backend.mli.in $(ObjDir)/.dir
+	$(Verb) $(SED) -e 's/@TARGET@/$(TARGET)/' $< > $@
+
+$(ObjDir)/$(TARGET)_ocaml.o: $(PROJ_SRC_DIR)/backend_ocaml.c $(ObjDir)/.dir
+	$(Echo) "Compiling $*.c for $(BuildMode) build" $(PIC_FLAG)
+	$(Verb) $(Compile.C) -DTARGET=$(TARGET) $< -o $@
+
+
+##===- OCamlFind Package --------------------------------------------------===##
+
+all-local:: copy-meta
+install-local:: install-meta
+uninstall-local:: uninstall-meta
+
+DestMETA := $(PROJ_libocamldir)/META.llvm_$(TARGET)
+
+# Easy way of generating META in the objdir
+copy-meta: $(OcamlDir)/META.llvm_$(TARGET)
+
+$(OcamlDir)/META.llvm_$(TARGET): META.llvm_backend.in
+	$(Verb) $(SED) -e 's/@TARGET@/$(TARGET)/' \
+								 -e 's/@PACKAGE_VERSION@/$(LLVMVersion)/' $< > $@
+
+install-meta:: $(OcamlDir)/META.llvm_$(TARGET)
+	$(Echo) "Install $(BuildMode) $(DestMETA)"
+	$(Verb) $(MKDIR) $(PROJ_libocamldir)
+	$(Verb) $(DataInstall) $< "$(DestMETA)"
+
+uninstall-meta::
+	$(Echo) "Uninstalling $(DestMETA)"
+	-$(Verb) $(RM) -f "$(DestMETA)"
+
+.PHONY: copy-meta install-meta uninstall-meta

bindings/ocaml/backends/backend_ocaml.c

@@ -0,0 +1,37 @@
+/*===-- backend_ocaml.c - LLVM OCaml Glue -----------------------*- C++ -*-===*\
+|*                                                                            *|
+|*                     The LLVM Compiler Infrastructure                       *|
+|*                                                                            *|
+|* This file is distributed under the University of Illinois Open Source      *|
+|* License. See LICENSE.TXT for details.                                      *|
+|*                                                                            *|
+|*===----------------------------------------------------------------------===*|
+|*                                                                            *|
+|* This file glues LLVM's OCaml interface to its C interface. These functions *|
+|* are by and large transparent wrappers to the corresponding C functions.    *|
+|*                                                                            *|
+|* Note that these functions intentionally take liberties with the CAMLparamX *|
+|* macros, since most of the parameters are not GC heap objects.              *|
+|*                                                                            *|
+\*===----------------------------------------------------------------------===*/
+
+#include "llvm-c/Target.h"
+#include "caml/alloc.h"
+#include "caml/memory.h"
+
+#define INITIALIZER1(target) \
+  CAMLprim value llvm_initialize_ ## target(value Unit) {  \
+    LLVMInitialize ## target ## TargetInfo();              \
+    LLVMInitialize ## target ## Target();                  \
+    LLVMInitialize ## target ## TargetMC();                \
+    // TODO: Figure out how to call these only for targets \
+    // which support them.                                 \
+    // LLVMInitialize ## target ## AsmPrinter();           \
+    // LLVMInitialize ## target ## AsmParser();            \
+    // LLVMInitialize ## target ## Disassembler();         \
+    return Val_unit;                                       \
+  }
+
+#define INITIALIZER(target) INITIALIZER1(target)
+
+INITIALIZER(TARGET)

bindings/ocaml/backends/llvm_backend.ml.in

@@ -0,0 +1,10 @@
+(*===-- llvm_backend.ml.in - LLVM OCaml Interface -------------*- OCaml -*-===*
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ *===----------------------------------------------------------------------===*)
+
+external initialize : unit -> unit = "llvm_initialize_@TARGET@"

bindings/ocaml/backends/llvm_backend.mli.in

@@ -0,0 +1,19 @@
+(*===-- llvm_backend.mli.in - LLVM OCaml Interface ------------*- OCaml -*-===*
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ *===----------------------------------------------------------------------===*)
+
+(** @TARGET@ Initialization.
+
+    This interface provides an OCaml API for initialization of
+    the @TARGET@ LLVM target. By referencing this module, you will cause
+    OCaml to load or link in the LLVM libraries corresponding to the target.
+    By calling [initialize], you will register components of this target
+    in the target registry, which is necessary in order to emit assembly,
+    object files, and so on. *)
+
+external initialize : unit -> unit = "llvm_initialize_@TARGET@"