This document describes the contents of the many objects files and libraries -that are produced by compiling LLVM. To make use of LLVM this information is -needed in order to understand what files should be linked into your program. +
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. This document + describes the contents of the libraries and how and when to use them.
If you're writing a compiler, virtual machine, or any other utility for - LLVM, you'll need to figure out which of the many .a (archive) and .o - (object) files you will need to link with to be successful. An - understanding of the contents of these files and their inter-relationships - will be useful in coming up with an optimal specification for the objects - and libraries to link with. -
-The purpose of this document is to hopefully reduce some of the trial and - error that the author experienced in using LLVM. -
+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 + files and their inter-relationships 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, many 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.
+When linking 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.
The table below provides a summary of the basic contents of each file.
-| Summary Of LLVM Library And Object Files - | -||
Library |
- Description |
-|
| libipo.a | -- An archive of all interprocedural optimizations. - | -|
| libscalaropts.a | -- An archive of all scalar optimizations. - | -|
| libtransforms.a | -Uncategorized transformations. | -|
| libtarget.a | -An archive containing generic code generator support. | -|
| libanalysis.a | -An archive containing intraprocedural analyses. | -|
| libdatastructure.a | -An archive containing Data Structure Analysis. | -|
| libinstrument.a | -Intraprocedural instrumentation and utilities. | -|
| libsparcv9regalloc.a | -SparcV9 graph-coloring register allocator. | -|
| libipa.a | -An archive containing interprocedural analyses | -|
| libtransformutils.a | -Utility functions for transformations. | -|
| libsupport.a | -General support utilities | -|
Object File |
- Description |
-|
| support.o | -General support utilities | -|
| asmparser.o | -Assembler Parser | -|
| bcreader.o | -Bytecode Reader | -|
| bcwriter.o | -Bytecode Writer | -|
| sched.o | -SparcV9 instruction scheduler | -|
| selectiondag.o | -Aggressive instruction selector for Directed Acyclic Graphs | -|
| transformutils.o | -Utilities for code transformations | -|
| ipa.o | -Interprocedural Analyses | -|
| sparcv9select.o | -SparcV9 instruction selector | -|
| cwriter.o | -"C" Code Writer | -|
| profpaths.o | -Path profiling instrumentation | -|
| sparcv9regalloc.o | -SparcV9 graph-coloring register allocator | -|
| instrument.o | -Intraprocedural instrumentation and utilities. | -|
| datastructure.o | -Data Structure Analysis | -|
| codegen.o | -Native code generation | -|
| sparcv9livevar.o | -SparcV9 Live Variable Analysis | -|
| vmcore.o | -Virtual Machine Core | -|
| lli-interpreter.o | -Interpreter for LLVM ByteCode | -|
| lli-jit.o | -- Just-In-Time Compiler For LLVM ByteCode - | -|
| executionengine.o | -Engine for LLI | -|
| debugger.o | -Source Level Debugging Support | -|
| analysis.o | -General framework for Analysis | -|
| sparcv9.o | -SparcV9 backend | -|
| target.o | -Generic backend support | -|
| transforms.o | -Uncategorized transformations. | -|
| x86.o | -Intel x86 backend | -|
| powerpc.o | -PowerPC backend | -|
| scalaropts.o | -Optimizations For Scalars | -|
| ipo.o | -Interprocedural Optimizations | -|
| trace.o | -Support For Tracing/Debugging? | -|
| profile_rt.o | -Runtime Library For Profiler | -|
| sample.o | -Sample Program ? | -|
| stkr_compiler.o | -Stacker Language Compiler Library | -|
| stkr_runtime.o | -Stacker Language Runtime Library | -|
| Library | Forms | Description |
|---|---|---|
| Core Libraries | ||
| LLVMAsmParser | .o | LLVM Assembly Parsing |
| LLVMBCReader | .o | LLVM Bytecode Reading |
| LLVMBCWriter | .o | LLVM Bytecode Writing |
| LLVMDebugger | .o | Source Level Debugging Support |
| LLVMSupport | .a .o | General support utilities |
| LLVMSystem | .a .o | Operating system abstraction |
| LLVMCore | .o | LLVM Core IR |
| Analysis Libraries | ||
| LLVMAnalysis | .a .o | Various analysis passes. |
| LLVMDataStructure | .a .o | Data structure analysis passes. |
| LLVMipa | .a .o | Inter-procedural analysis passes. |
| Transformation Libraries | +||
| LLVMInstrumentation | .a .o | Instrumentation passes. |
| LLVMipo | .a .o | All inter-procedural optimization passes. |
| LLVMScalarOpts | .a .o | All scalar optimization passes. |
| LLVMTransforms | .a .o | Uncategorized transformation passes. |
| LLVMTransformUtils | .a .o | Transformation utilities. |
| LLVMProfilePaths | .o | Profile paths for instrumentation. |
| Code Generation Libraries | ||
| LLVMCodeGen | .o | Native code generation infrastructure |
| Target Libraries | ||
| LLVMCBackend | .o | 'C' language code generator. |
| LLVMPowerPC | .o | PowerPC code generation backend |
| LLVMSelectionDAG | .o | Aggressive instruction selector for Directed Acyclic Graphs. |
| LLVMSkeleton | .a .o | Skeleton for a code generation backend. |
| LLVMSparcV9 | .o | Code generation for SparcV9. |
| LLVMSparcV9RegAlloc | .a .o | Graph-coloring register allocator for SparcV9. |
| LLVMSparcV9InstrSched | .o | Instruction scheduling for SparcV9. |
| LLVMSparcV9LiveVar | .o | Live variable analysis SparcV9. |
| LLVMSparcV9ModuloSched | .o | Modulo scheduling for SparcV9. |
| LLVMTarget | .a .o | Generic code generation utilities. |
| LLVMX86 | .o | Intel x86 code generation backend |
| Runtime Libraries | ||
| LLVMInterpreter | .o | Bytecode Interpreter |
| LLVMJIT | .o | Bytecode JIT Compiler |
| LLVMExecutionEngine | .o | Virtual machine engine |
| LLVMexecve | .o | execve(2) replacement for llee |
No matter what you do with LLVM, you'll always need to link with vmcore.o - and support.a.
+No matter what you do with LLVM, the last three entries in your linke line + should always be: LLVMCore LLVMSupport.a LLVMSystem.a.
Need more rules of thumb here.
+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 is you place the archive version before + the re-linked version on the linker's command line.