From e2c3a49c8029ebd9ef530101cc24c66562e3dff5 Mon Sep 17 00:00:00 2001 From: mike-m Date: Fri, 7 May 2010 00:28:04 +0000 Subject: Revert r103213. It broke several sections of live website. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103219 91177308-0d34-0410-b5e6-96231b3b80d8 --- docs/UsingLibraries.html | 439 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 439 insertions(+) create mode 100644 docs/UsingLibraries.html (limited to 'docs/UsingLibraries.html') diff --git a/docs/UsingLibraries.html b/docs/UsingLibraries.html new file mode 100644 index 0000000..b1a3b4d --- /dev/null +++ b/docs/UsingLibraries.html @@ -0,0 +1,439 @@ + + + + Using The LLVM Libraries + + + +
Using The LLVM Libraries
+
    +
  1. Abstract
    2. +
  2. Introduction
    3. +
  3. Library Descriptions
    4. +
  4. Library Dependencies
    5. +
  5. Linkage Rules Of Thumb +
      +
    1. Always link LLVMCore, LLVMSupport, LLVMSystem +
    2. Never link both archive and re-linked +
    +
    6. +
+ +
+

Written by Reid Spencer

+
+ +

Warning: This document is out of date, please see llvm-config for more information.

+ + +
Abstract
+
+

Amongst other things, LLVM is a toolkit for building compilers, linkers, + runtime executives, virtual machines, and other program execution related + tools. In addition to the LLVM tool set, the functionality of LLVM is + available through a set of libraries. To use LLVM as a toolkit for + constructing tools, a developer needs to understand what is contained in the + various libraries, what they depend on, and how to use them. Fortunately, + there is a tool, llvm-config to aid with this. This document + describes the contents of the libraries and how to use llvm-config + to generate command line options. +

+
+ + +
Introduction
+
+

If you're writing a compiler, virtual machine, or any other utility based + on LLVM, you'll need to figure out which of the many libraries files you will + need to link with to be successful. An understanding of the contents of these + libraries will be useful in coming up with an optimal specification for the + libraries to link with. The purpose of this document is to reduce some of + the trial and error that the author experienced in using LLVM.

+

LLVM produces two types of libraries: archives (ending in .a) and + objects (ending in .o). However, both are libraries. Libraries ending + in .o are known as re-linked libraries because they contain all the + compilation units of the library linked together as a single .o file. + Furthermore, several of the libraries have both forms of library. The + re-linked libraries are used whenever you want to include all symbols from the + library. The archive libraries are used whenever you want to only resolve + outstanding symbols at that point in the link without including everything in + the library.

+

If you're using the LLVM Makefile system to link your tools,you will use + the LLVMLIBS make variable. + (see the Makefile Guide for + details). This variable specifies which LLVM libraries to link into your tool + and the order in which they will be linked. You specify re-linked libraries by + naming the library without a suffix. You specify archive libraries by naming + the library with a .a suffix but without the lib prefix. The + order in which the libraries appear in the LLVMLIBS variable + definition is the order in which they will be linked. Getting this order + correct for your tool can sometimes be challenging. +

+ +
Library Descriptions
+
+

The table below categorizes each library + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
LibraryFormsDescription
Core Libraries
LLVMArchive.aLLVM archive reading and writing
LLVMAsmParser.aLLVM assembly parsing
LLVMBCReader.aLLVM bitcode reading
LLVMBCWriter.aLLVM bitcode writing
LLVMCore.aLLVM core intermediate representation
LLVMDebugger.aSource level debugging support
LLVMLinker.aBitcode and archive linking interface
LLVMSupport.aGeneral support utilities
LLVMSystem.aOperating system abstraction layer
LLVMbzip2.aBZip2 compression library
Analysis Libraries
LLVMAnalysis.aVarious analysis passes.
LLVMDataStructure.oData structure analysis passes.
LLVMipa.aInter-procedural analysis passes.
Transformation Libraries
LLVMInstrumentation.aInstrumentation passes.
LLVMipo.aAll inter-procedural optimization passes.
LLVMScalarOpts.aAll scalar optimization passes.
LLVMTransformUtils.aTransformation utilities used by many passes.
Code Generation Libraries
LLVMCodeGen.oNative code generation infrastructure
LLVMSelectionDAG.oAggressive instruction selector for directed acyclic graphs
Target Libraries
LLVMAlpha.oCode generation for Alpha architecture
LLVMARM.oCode generation for ARM architecture
LLVMCBackend.o'C' language code generator.
LLVMPowerPC.oCode generation for PowerPC architecture
LLVMSparc.oCode generation for Sparc architecture
LLVMTarget.aGeneric code generation utilities.
LLVMX86.oCode generation for Intel x86 architecture
Runtime Libraries
LLVMInterpreter.oBitcode Interpreter
LLVMJIT.oBitcode JIT Compiler
LLVMExecutionEngine.oVirtual machine engine
+

+ + +
Using llvm-config
+
+

The llvm-config tool is a perl script that produces on its output + various kinds of information. For example, the source or object directories + used to build LLVM can be accessed by passing options to llvm-config. + For complete details on this tool, please see the + manual page.

+

To understand the relationships between libraries, the llvm-config + can be very useful. If all you know is that you want certain libraries to + be available, you can generate the complete set of libraries to link with + using one of four options, as below:

+
    +
  1. --ldflags. This generates the command line options necessary to + be passed to the ld tool in order to link with LLVM. Most notably, + the -L option is provided to specify a library search directory + that contains the LLVM libraries.
    2. +
  2. --libs. This generates command line options suitable for + use with a gcc-style linker. That is, libraries are given with a -l option + and object files are given with a full path.
    3. +
  3. --libnames. This generates a list of just the library file + names. If you know the directory in which these files reside (see --ldflags) + then you can find the libraries there.
    4. +
  4. --libfiles. This generates the full path names of the + LLVM library files.
    5. +
+

If you wish to delve further into how llvm-config generates the + correct order (based on library dependencies), please see the tool named + GenLibDeps.pl in the utils source directory of LLVM.

+ + + + + + + +

Dependency Relationships Of Libraries

+

This graph shows the dependency of archive libraries on other archive + libraries or objects. Where a library has both archive and object forms, only + the archive form is shown.

+ Library Dependencies +

Dependency Relationships Of Object Files

+

This graph shows the dependency of object files on archive libraries or + other objects. Where a library has both object and archive forms, only the + dependency to the archive form is shown.

+ Object File Dependencies +

The following list shows the dependency relationships between libraries in + textual form. The information is the same as shown on the graphs but arranged + alphabetically.

+
+
libLLVMAnalysis.a
    +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
libLLVMArchive.a
    +
  • libLLVMBCReader.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMAsmParser.a
    +
  • libLLVMCore.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMBCReader.a
    +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMBCWriter.a
    +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMCodeGen.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMScalarOpts.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMTransformUtils.a
    • +
+
libLLVMCore.a
    +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMDebugger.a
    +
  • libLLVMBCReader.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMInstrumentation.a
    +
  • libLLVMCore.a
    • +
  • libLLVMScalarOpts.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMTransformUtils.a
    • +
+
libLLVMLinker.a
    +
  • libLLVMArchive.a
    • +
  • libLLVMBCReader.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMScalarOpts.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMTransformUtils.a
    • +
+
libLLVMSelectionDAG.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMTransformUtils.a
    • +
+
libLLVMSupport.a
    +
  • libLLVMSystem.a
    • +
  • libLLVMbzip2.a
    • +
+
libLLVMSystem.a
    +
+
libLLVMTarget.a
    +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMTransformUtils.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMipa.a
    • +
+
libLLVMbzip2.a
    +
+
libLLVMipa.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
+
libLLVMipo.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMTransformUtils.a
    • +
  • libLLVMipa.a
    • +
+
libLLVMlto.a
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMBCReader.a
    • +
  • libLLVMBCWriter.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMLinker.a
    • +
  • libLLVMScalarOpts.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMipa.a
    • +
  • libLLVMipo.a
    • +
+
LLVMARM.o
    +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSelectionDAG.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMAlpha.o
    +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSelectionDAG.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMCBackend.o
    +
  • libLLVMAnalysis.a
    • +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMScalarOpts.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
  • libLLVMTransformUtils.a
    • +
  • libLLVMipa.a
    • +
+
LLVMExecutionEngine.o
    +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMInterpreter.o
    +
  • LLVMExecutionEngine.o
    • +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMJIT.o
    +
  • LLVMExecutionEngine.o
    • +
  • libLLVMCore.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMPowerPC.o
    +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSelectionDAG.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMSparc.o
    +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSelectionDAG.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
LLVMX86.o
    +
  • libLLVMCodeGen.a
    • +
  • libLLVMCore.a
    • +
  • libLLVMSelectionDAG.a
    • +
  • libLLVMSupport.a
    • +
  • libLLVMSystem.a
    • +
  • libLLVMTarget.a
    • +
+
+
+ + +
Linkage Rules Of Thumb
+
+

This section contains various "rules of thumb" about what files you + should link into your programs.

+
+ +
Always Link LLVMCore, LLVMSupport, + and LLVMSystem
+
+

No matter what you do with LLVM, the last three entries in the value of + your LLVMLIBS make variable should always be: + LLVMCore LLVMSupport.a LLVMSystem.a. There are no LLVM + programs that don't depend on these three.

+
+ +
Never link both archive and + re-linked library
+
+

There is never any point to linking both the re-linked (.o) and + the archive (.a) versions of a library. Since the re-linked version + includes the entire library, the archive version will not resolve any symbols. + You could even end up with link error if you place the archive version before + the re-linked version on the linker's command line.

+
+ +
+
+
+ Valid CSS + Valid HTML 4.01 + Reid Spencer +
+The LLVM Compiler Infrastructure +
Last modified: $Date$
+ + + -- cgit v1.1