Adding llvm-shlib to CMake build system with a few new bells and whistles

Summary:
This patch adds a new CMake build setting LLVM_BUILD_LLVM_DYLIB, which defaults to OFF. When set to ON, this will generate a shared library containing most of LLVM. The contents of the shared library can be overriden by specifying LLVM_DYLIB_COMPONENTS. LLVM_DYLIB_COMPONENTS can be set to a semi-colon delimited list of any LLVM components that you llvm-config can resolve.

On Windows, unless you are using Cygwin, you must specify an explicit symbol export file using LLVM_EXPORTED_SYMBOL_FILE. On Cygwin and all unix-like platforms if you do not specify LLVM_EXPORTED_SYMBOL_FILE, an export file containing only the LLVM C API will be auto-generated from the list of LLVM components specified in LLVM_DYLIB_COMPONENTS.

Reviewers: rnk

Reviewed By: rnk

Subscribers: rnk, llvm-commits

Differential Revision: http://reviews.llvm.org/D5890

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220490 91177308-0d34-0410-b5e6-96231b3b80d8

CMakeLists.txt

@@ -302,6 +302,8 @@ option (LLVM_ENABLE_SPHINX "Use Sphinx to generate llvm documentation." OFF)
 option (LLVM_BUILD_EXTERNAL_COMPILER_RT
   "Build compiler-rt as an external project." OFF)
 
+option(LLVM_BUILD_LLVM_DYLIB "Build libllvm dynamic library" OFF)
+
 # All options referred to from HandleLLVMOptions have to be specified
 # BEFORE this include, otherwise options will not be correctly set on
 # first cmake run

tools/CMakeLists.txt

@@ -74,6 +74,12 @@ else()
   ignore_llvm_tool_subdirectory(gold)
 endif()
 
+if( LLVM_BUILD_LLVM_DYLIB )
+  add_llvm_tool_subdirectory(llvm-shlib)
+else()
+  ignore_llvm_tool_subdirectory(llvm-shlib)
+endif()
+
 add_llvm_external_project(clang)
 
 if( NOT LLVM_INCLUDE_TOOLS STREQUAL "bootstrap-only" )

tools/llvm-shlib/CMakeLists.txt

@@ -0,0 +1,95 @@
+# This tool creates a shared library from the LLVM libraries. Generating this
+# library is enabled by setting LLVM_BUILD_LLVM_DYLIB=yes on the CMake
+# commandline. By default the shared library only exports the LLVM C API.
+
+
+# You can configure which libraries from LLVM you want to include in the shared
+# library by setting LLVM_DYLIB_COMPONENTS to a semi-colon delimited list of
+# LLVM components. All compoenent names handled by llvm-config are valid.
+
+if(NOT DEFINED LLVM_DYLIB_COMPONENTS)
+  set(LLVM_LINK_COMPONENTS
+    ${LLVM_TARGETS_TO_BUILD}
+    Analysis
+    AsmPrinter
+    BitWriter
+    CodeGen
+    Core
+    ExecutionEngine
+    IPA
+    IPO
+    IRReader
+    InstCombine
+    Instrumentation
+    Interpreter
+    Linker
+    MC
+    MCJIT
+    ObjCARCOpts
+    Object
+    ScalarOpts
+    SelectionDAG
+    Support
+    Target
+    TransformUtils
+    Vectorize
+    native
+    )
+else()
+  set(LLVM_LINK_COMPONENTS ${LLVM_DYLIB_COMPONENTS})
+endif()
+
+add_definitions( -DLLVM_VERSION_INFO=\"${PACKAGE_VERSION}\" )
+
+set(SOURCES
+  libllvm.cpp
+  )
+
+if(NOT DEFINED LLVM_EXPORTED_SYMBOL_FILE)
+
+  if( WIN32 AND NOT CYGWIN )
+    message(FATAL_ERROR "Auto-generation not implemented for Win32 without GNU utils. Please specify LLVM_EXPORTED_SYMBOL_FILE.")
+  endif()
+
+  # To get the export list for a single llvm library:
+  # nm ${LIB_PATH} | awk "/T _LLVM/ { print $3 }" | sort -u | sed -e "s/^_//g" > ${LIB_PATH}.exports
+
+  set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_BINARY_DIR}/libllvm.exports)
+
+  llvm_map_components_to_libnames(LIB_NAMES ${LLVM_LINK_COMPONENTS})
+
+  foreach (lib ${LIB_NAMES})
+    
+    set(LIB_DIR ${CMAKE_BINARY_DIR}/${CMAKE_CFG_INTDIR}/lib)
+    set(LIB_NAME ${LIB_DIR}/${CMAKE_STATIC_LIBRARY_PREFIX}${lib})
+    set(LIB_PATH ${LIB_NAME}${CMAKE_STATIC_LIBRARY_SUFFIX})
+    set(LIB_EXPORTS_PATH ${LIB_NAME}.exports)
+
+    list(APPEND LLVM_DYLIB_REQUIRED_EXPORTS ${LIB_EXPORTS_PATH})
+
+    add_custom_command(OUTPUT ${LIB_EXPORTS_PATH}
+      COMMAND nm ${LIB_PATH} | awk "/T _LLVM/ || /T LLVM/ { print $3 }" | sort -u | sed -e "s/^_//g" > ${LIB_EXPORTS_PATH}
+      WORKING_DIRECTORY ${LIB_DIR}
+      DEPENDS ${lib}
+      COMMENT "Generating Export list for ${lib}..."
+      VERBATIM )
+  endforeach ()
+
+  add_custom_command(OUTPUT ${LLVM_EXPORTED_SYMBOL_FILE}
+    COMMAND cat ${LLVM_DYLIB_REQUIRED_EXPORTS} > ${LLVM_EXPORTED_SYMBOL_FILE}
+    WORKING_DIRECTORY ${LIB_DIR}
+    DEPENDS ${LLVM_DYLIB_REQUIRED_EXPORTS}
+    COMMENT "Generating combined export list...")
+
+endif()
+
+add_llvm_library(LLVM SHARED ${SOURCES})
+
+add_dependencies(LLVM ${LLVM_EXPORTED_SYMBOL_FILE})
+
+if (APPLE)
+  set_property(TARGET LLVM APPEND_STRING PROPERTY
+              LINK_FLAGS
+              " -compatibility_version ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR} -current_version ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}")
+endif()
+

tools/llvm-shlib/libllvm.cpp

@@ -0,0 +1,13 @@
+//===-libllvm.cpp - LLVM Shared Library -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is empty and serves only the purpose of making CMake happy because
+// you can't define a target with no sources.
+//
+//===----------------------------------------------------------------------===//