For PR780:

1. Change the usage of LOADABLE_MODULE so that it implies all the things
   necessary to make a loadable module. This reduces the user's burdern to
   get a loadable module correctly built.
2. Document the usage of LOADABLE_MODULE in the MakefileGuide
3. Adjust the makefile for lib/Transforms/Hello to use the new specification
   for building loadable modules
4. Adjust the sample project to not attempt to build a shared library for
   its little library. This was just wasteful and not instructive at all.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29551 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/Makefile.rules b/Makefile.rules
index 3fe8090c9bdad67172e28dd5635591182ba8f919..c9795ec6969d8bb8e20670bf21e3d72c2fe43437 100644 (file)
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -323,12 +323,17 @@ LLVMGXXWITHPATH  := PATH="$(LLVMToolDir):$(PATH)" $(LLVMGXX)
 
 # Adjust LD.Flags and Libtool.Flags depending on the kind of library that is
 # to be built. Note that if LOADABLE_MODULE is specified then the resulting
-# shared library can be opened with dlopen
+# shared library can be opened with dlopen. Also, LOADABLE_MODULE implies 
+# several other things so we force them to be defined/on.
+ifdef LOADABLE_MODULE
+  SHARED_LIBRARY := 1
+  DONT_BUILD_RELINKED := 1
+  LINK_LIBS_IN_SHARED := 1
+  LD.Flags += -module
+endif
+
 ifdef SHARED_LIBRARY
   LD.Flags += -rpath $(LibDir)
-  ifdef LOADABLE_MODULE
-    LD.Flags += -module
-  endif
 else
   LibTool.Flags += --tag=disable-shared
 endif
@@ -425,10 +430,12 @@ LTCompile.CXX = $(LIBTOOL) $(LibTool.Flags) --mode=compile $(Compile.CXX)
 BCCompile.CXX = $(LLVMGXXWITHPATH) $(CPP.Flags) $(CompileCommonOpts) \
                 $(CXX.Flags)
 Preprocess.CXX= $(CXX) $(CPP.Flags) $(CompileCommonOpts) $(CXX.Flags) -E
-Link          = $(LIBTOOL) $(LibTool.Flags) --mode=link $(CXX) $(CPP.Flags) \
-               $(CXX.Flags) $(CompileCommonOpts) $(LD.Flags) $(Strip)
-Relink        = $(LIBTOOL) $(LibTool.Flags) --mode=link $(CXX) $(CPP.Flags) \
-                $(CXX.Flags) $(CompileCommonOpts) $(Relink.Flags)
+Link          = $(CXX) $(CPP.Flags) $(CXX.Flags) $(CompileCommonOpts) \
+               $(LD.Flags) $(Strip)
+LTLink        = $(LIBTOOL) $(LibTool.Flags) --mode=link $(Link)
+Relink        = $(CXX) $(CPP.Flags) $(CXX.Flags) $(CompileCommonOpts) \
+               $(Relink.Flags)
+LTRelink      = $(LIBTOOL) $(LibTool.Flags) --mode=link $(Relink)
 LTInstall     = $(LIBTOOL) $(LibTool.Flags) --mode=install $(INSTALL) \
                $(Install.Flags)
 ProgInstall   = $(INSTALL) $(Install.StripFlag) -m 0755 
@@ -772,15 +779,21 @@ ifdef SHARED_LIBRARY
 all-local:: $(LibName.LA)
 
 ifdef LINK_LIBS_IN_SHARED
+ifdef LOADABLE_MODULE
+SharedLibKindMessage := "Lodable Module"
+else
+SharedLibKindMessage := "Shared Library"
+endif
 $(LibName.LA): $(ObjectsLO) $(LibDir)/.dir
-       $(Echo) Linking $(BuildMode) Shared Library $(LIBRARYNAME)$(SHLIBEXT)
-       $(Verb) $(Link) -o $@ $(ObjectsLO) \
-         $(ProjLibsOptions) $(LLVMLibsOptions)
+       $(Echo) Linking $(BuildMode) $(SharedLibKindMessage) \
+         $(LIBRARYNAME)$(SHLIBEXT)
+       $(Verb) $(LTLink) -o $@ $(ObjectsLO) $(ProjLibsOptions) \
+         $(LLVMLibsOptions)
        $(Verb) $(LTInstall) $@ $(LibDir)
 else
 $(LibName.LA): $(ObjectsLO) $(LibDir)/.dir
        $(Echo) Linking $(BuildMode) Shared Library $(LIBRARYNAME)$(SHLIBEXT)
-       $(Verb) $(Link) -o $@ $(ObjectsLO)
+       $(Verb) $(LTLink) -o $@ $(ObjectsLO)
        $(Verb) $(LTInstall) $@ $(LibDir)
 endif
 
@@ -884,7 +897,7 @@ all-local:: $(LibName.O)
 
 $(LibName.O): $(ObjectsO) $(LibDir)/.dir
        $(Echo) Linking $(BuildMode) Object Library $(notdir $@)
-       $(Verb) $(Relink) -o $@ $(ObjectsO)
+       $(Verb) $(LTRelink) -o $@ $(ObjectsO)
 
 clean-local::
 ifneq ($(strip $(LibName.O)),)
@@ -983,7 +996,7 @@ endif
 
 $(ToolBuildPath): $(ObjectsO) $(ProjLibsPaths) $(LLVMLibsPaths)
        $(Echo) Linking $(BuildMode) executable $(TOOLNAME) $(StripWarnMsg)
-       $(Verb) $(Link) -o $@ $(TOOLLINKOPTS) $(ObjectsO) $(ProjLibsOptions) \
+       $(Verb) $(LTLink) -o $@ $(TOOLLINKOPTS) $(ObjectsO) $(ProjLibsOptions) \
        $(LLVMLibsOptions) $(ExtraLibs) $(TOOLLINKOPTSB) $(LIBS)
        $(Echo) ======= Finished Linking $(BuildMode) Executable $(TOOLNAME) \
           $(StripWarnMsg) 

diff --git a/docs/MakefileGuide.html b/docs/MakefileGuide.html
index ca19f5f23d3f1c256d94f9589ab0e85f77e51a67..a1aa934fb826c112dc5df438cf8439434445d990 100644 (file)
--- a/docs/MakefileGuide.html
+++ b/docs/MakefileGuide.html
@@ -30,7 +30,8 @@
     <ol>
       <li><a href="#libraries">Libraries</a>
         <ol>
-         <li><a href="#Modules">Bytecode Modules</a></li>
+         <li><a href="#BCModules">Bytecode Modules</a></li>
+         <li><a href="#LoadableModules">Loadable Modules</a></li>
        </ol>
       </li>
       <li><a href="#tools">Tools</a>
@@ -259,7 +260,7 @@
 </div>
 
 <!-- ======================================================================= -->
-<div class="doc_subsubsection"><a name="Modules">Bytecode Modules</a></div>
+<div class="doc_subsubsection"><a name="BCModules">Bytecode Modules</a></div>
 <div class="doc_text">
   <p>In some situations, it is desireable to build a single bytecode module from
   a variety of sources, instead of an archive, shared library, or bytecode 
@@ -279,6 +280,40 @@
   </p>
 </div>
 
+<!-- ======================================================================= -->
+<div class="doc_subsubsection">
+  <a name="LodableModules">Loadable Modules</a>
+</div>
+<div class="doc_text">
+  <p>In some situations, you need to create a loadable module. Loadable modules
+  can be loaded into programs like <tt>opt</tt> or <tt>llc</tt> to specify
+  additional passes to run or targets to support.  Loadable modules are also
+  useful for debugging a pass or providing a pass with another package if that
+  pass can't be included in LLVM.</p>
+  <p>LLVM provides complete support for building such a module. All you need to
+  do is use the LOADABLE_MODULE variable in your Makefile. For example, to 
+  build a loadable module named <tt>MyMod</tt> that uses the LLVM libraries
+  <tt>LLVMSupport.a</tt> and <tt>LLVMSystem.a</tt>, you would specify:</p>
+  <pre><tt>
+     LIBRARYNAME := MyMod
+     LOADABLE_MODULE := 1
+     USEDLIBS := LLVMSupport.a LLVMSystem.a
+  </tt></pre>
+  <p>Use of the <tt>LOADABLE_MODULE</tt> facility implies several things:</p>
+  <ol>
+    <li>There will be no "lib" prefix on the module. This differentiates it from
+    a standard shared library of the same name.</li>
+    <li>The <a href="#SHARED_LIBRARY">SHARED_LIBRARY</a> variable is turned 
+    on.</li>
+    <li>The <a href="#LINK_LIBS_IN_SHARED">LINK_LIBS_IN_SHARED</a> variable
+    is turned on.</li>
+    <li>The <a href="#DONT_BUILD_RELINKED">DONT_BUILD_RELINKED</a> variable
+    is turned on.</li>
+  </ol>
+  <p>A loadable module is loaded by LLVM via the facilities of libtool's libltdl
+  library which is part of <tt>lib/System</tt> implementation.</p>
+</div>
+
 <!-- ======================================================================= -->
 <div class="doc_subsection"><a name="tools">Tools</a></div>
 <div class="doc_text">

diff --git a/lib/Transforms/Hello/Makefile b/lib/Transforms/Hello/Makefile
index ccd9caff16a6f961ca7080cac35a7224828ed6af..606fcfedf530dfa799a544626213c7831c9cfe1b 100644 (file)
--- a/lib/Transforms/Hello/Makefile
+++ b/lib/Transforms/Hello/Makefile
@@ -9,8 +9,8 @@
 
 LEVEL = ../../..
 LIBRARYNAME = LLVMHello
-SHARED_LIBRARY = 1
 LOADABLE_MODULE = 1
+USEDLIBS = LLVMSupport.a LLVMSystem.a
 
 include $(LEVEL)/Makefile.common
 

diff --git a/projects/sample/lib/sample/Makefile b/projects/sample/lib/sample/Makefile
index 6b1ea05361b641d6f7f8adca180801626b59ccce..c85ae1a711cf9997d322cb3834ce8834041d380e 100644 (file)
--- a/projects/sample/lib/sample/Makefile
+++ b/projects/sample/lib/sample/Makefile
@@ -9,10 +9,8 @@ LEVEL=../..
 # Give the name of a library.  This will build a dynamic version.
 #
 LIBRARYNAME=sample
-SHARED_LIBRARY=1
-LOADABLE_MODULE=1
-#DONT_BUILD_RELINKED=1
-#ARCHIVE_LIBRARY=1
+DONT_BUILD_RELINKED=1
+BUILD_ARCHIVE=1
 
 #
 # Include Makefile.common so we know what to do.

diff --git a/projects/sample/tools/sample/Makefile b/projects/sample/tools/sample/Makefile
index 1127f7557557ff0d70b255d841ca3055e7a19b36..39da928329ecc102c0cd2f9662167263425a267c 100644 (file)
--- a/projects/sample/tools/sample/Makefile
+++ b/projects/sample/tools/sample/Makefile
@@ -14,7 +14,7 @@ TOOLNAME=sample
 # List libraries that we'll need
 # We use LIBS because sample is a dynamic library.
 #
-USEDLIBS = sample
+USEDLIBS = sample.a
 
 #
 # Include Makefile.common so we know what to do.