The Visual Studio port has some limitations. It is suitable for - use if you are writing your own compiler front end or otherwise have a - need to dynamically generate machine code. The JIT and interpreter are - functional, but it is currently not possible to generate assembly code which - is then assembled into an executable. You can output object files - in COFF format, though. You can also indirectly create executables - by using the C backend.
+Welcome to LLVM on Windows! This document only covers native Windows, not + mingw or cygwin. In order to get started, you first need to know some basic + information.
-llvm-gcc is based on GCC, which cannot be bootstrapped - using VC++. There are llvm-gcc binaries based on MinGW - available on the - LLVM download - page. Eventually, Clang - will be able to produce executables on Windows.
+There are many different projects that compose LLVM. The first is the LLVM + suite. This contains all of the tools, libraries, and header files needed to + use the low level virtual machine. It contains an assembler, disassembler, + bitcode analyzer and bitcode optimizer. It also contains a test suite that can + be used to test the LLVM tools.
-bugpoint does build, but does not work. The other tools - 'should' work, but have not been fully tested.
+Another useful project on Windows is + clang. Clang is a C family + ([Objective]C/C++) compiler. Clang fully works on Windows, but does not + currently understand all of the Microsoft extensions to C and C++. Because of + this, clang cannot parse the C++ standard library included with Visual Studio, + nor parts of the Windows Platform SDK. However, most standard C programs do + compile. Clang can be used to emit bitcode, directly emit object files or + even linked executables using Visual Studio's link.exe
+ +The LLVM test suite cannot be run on the Visual Studio port at this + time.
+ +Most of the tools build and work. bugpoint does build, but does + not work.
Additional information about the LLVM directory structure and tool chain can be found on the main Getting Started @@ -85,7 +92,7 @@
Any system that can adequately run Visual Studio .NET 2005 SP1 is fine. +
Any system that can adequately run Visual Studio .NET 2005 SP1 is fine. The LLVM source tree and object files, libraries and executables will consume approximately 3GB.
@@ -97,16 +104,17 @@You will need Visual Studio .NET 2005 SP1 or higher. The VS2005 SP1 beta and the normal VS2005 still have bugs that are not completely - compatible. VS2003 would work except (at last check) it has a bug with - friend classes that you can work-around with some minor code rewriting - (and please submit a patch if you do). Earlier versions of Visual Studio - do not support the C++ standard well enough and will not work.
- + compatible. Earlier versions of Visual Studio do not support the C++ standard + well enough and will not work. +You will also need the CMake build system since it generates the project files you will use to build with.
-- Do not install the LLVM directory tree into a path containing spaces (e.g. +
If you would like to run the LLVM tests you will need + Python. Versions 2.4-2.7 are known to + work.
+ +Do not install the LLVM directory tree into a path containing spaces (e.g. C:\Documents and Settings\...) as the configure step will fail.
+% llvm-lit test ++
Note that quite a few of these test will fail.
++% llvm-lit test/path/to/test ++
-% llvm-gcc -c hello.c -emit-llvm -o hello.bc +% clang -c hello.c -emit-llvm -o hello.bc
Note: you will need the llvm-gcc binaries from the - LLVM - download page
+ +Alternatively you can directly output an executable with clang with: +
+ ++% clang hello.c -o hello.exe ++
The -o hello.exe is required because clang currently outputs + a.out when neither -o nor -c are given.
Run the program using the just-in-time compiler:
- +% lli hello.bc
Note: this will only work for trivial C programs. Non-trivial programs - (and any C++ program) will have dependencies on the GCC runtime that - won't be satisfied by the Microsoft runtime libraries.
Use the llvm-dis utility to take a look at the LLVM assembly code:
@@ -251,40 +280,27 @@ int main() {Compile the program to C using the LLC code generator:
+Compile the program to object code using the LLC code generator:
-% llc -march=c hello.bc +% llc -filetype=obj hello.bc- -
Note: you need to add the C backend to the LLVM build, - which amounts to setting the CMake - variable LLVM_TARGETS_TO_BUILD to "X86;CBackend" when - you generate the VS solution files. See - the LLVM CMake guide for more - information about how to configure the LLVM - build.
-Compile to binary using Microsoft C:
+Link to binary using Microsoft link:
-% cl hello.cbe.c +% link hello.obj -defaultlib:libcmt
Note: this will only work for trivial C programs. Non-trivial programs - (and any C++ program) will have dependencies on the GCC runtime that won't - be satisfied by the Microsoft runtime libraries.
Execute the native code program:
-% hello.cbe.exe +% hello.exe