From 222e2a7620e6520ffaf4fc4e69d79c18da31542e Mon Sep 17 00:00:00 2001 From: "Zancanaro; Carlo" Date: Mon, 24 Sep 2012 09:58:17 +1000 Subject: Add the clang library to the repo (with some of my changes, too). --- clang/www/get_started.html | 306 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 306 insertions(+) create mode 100644 clang/www/get_started.html (limited to 'clang/www/get_started.html') diff --git a/clang/www/get_started.html b/clang/www/get_started.html new file mode 100644 index 0000000..d819532 --- /dev/null +++ b/clang/www/get_started.html @@ -0,0 +1,306 @@ + + + + + Clang - Getting Started + + + + + + + +
+ +

Getting Started: Building and Running Clang

+ +

This page gives you the shortest path to checking out Clang and demos a few +options. This should get you up and running with the minimum of muss and fuss. +If you like what you see, please consider getting +involved with the Clang community. If you run into problems, please file +bugs in LLVM Bugzilla.

+ +

Release Clang Versions

+ +

Clang has been released as part of regular LLVM releases since LLVM 2.6. You +can download the release versions +from http://llvm.org/releases/.

+ +

Building Clang and Working with the Code

+ +

On Unix-like Systems

+ +

If you would like to check out and build Clang, the current procedure is as +follows:

+ +
    +
  1. Get the required tools. + + +
  2. Checkout LLVM: +
      +
    • Change directory to where you want the llvm directory placed.
      • +
    • svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
      • +
    +
    3. +
  3. Checkout Clang: +
      +
    • cd llvm/tools +
    • svn co http://llvm.org/svn/llvm-project/cfe/trunk clang
      • +
    +
    4. +
  4. Checkout Compiler-RT: +
      +
    • cd ../.. (back to where you started)
      • +
    • cd llvm/projects +
    • svn co http://llvm.org/svn/llvm-project/compiler-rt/trunk + compiler-rt
      • +
    +
    5. +
  5. Build LLVM and Clang: +
      +
    • cd ../.. (back to where you started)
      • +
    • mkdir build (for building without polluting the source dir) +
      • +
    • cd build
      • +
    • ../llvm/configure
      • +
    • make
      • +
    • This builds both LLVM and Clang for debug mode.
      • +
    • Note: For subsequent Clang development, you can just do make at the + clang directory level.
      • +
    • It is also possible to use CMake instead of the makefiles. With CMake + it is also possible to generate project files for several IDEs: Eclipse + CDT4, CodeBlocks, Qt-Creator (use the CodeBlocks generator), KDevelop3.
      • +
    +
    6. + +
  6. If you intend to work on Clang C++ support, you may need to tell it how + to find your C++ standard library headers. If Clang cannot find your + system libstdc++ headers, please follow these instructions: +
      +
    • 'gcc -v -x c++ /dev/null -fsyntax-only' to get the + path.
      • +
    • Look for the comment "FIXME: temporary hack: + hard-coded paths" in clang/lib/Frontend/InitHeaderSearch.cpp and + change the lines below to include that path.
      • +
    +
    7. +
  7. Try it out (assuming you add llvm/Debug+Asserts/bin to your path): +
      +
    • clang --help
      • +
    • clang file.c -fsyntax-only (check for correctness)
      • +
    • clang file.c -S -emit-llvm -o - (print out unoptimized llvm code)
      • +
    • clang file.c -S -emit-llvm -o - -O3
      • +
    • clang file.c -S -O3 -o - (output native machine code)
      • +
    +
    8. +
+ +

Note that the C front-end uses LLVM, but does not depend on llvm-gcc. If you +encounter problems with building Clang, make sure you have the latest SVN +version of LLVM. LLVM contains support libraries for Clang that will be updated +as well as development on Clang progresses.

+ +

Simultaneously Building Clang and LLVM:

+ +

Once you have checked out Clang into the llvm source tree it will build along +with the rest of llvm. To build all of LLVM and Clang together all at +once simply run make from the root LLVM directory.

+ +

Note: Observe that Clang is technically part of a separate +Subversion repository. As mentioned above, the latest Clang sources are tied to +the latest sources in the LLVM tree. You can update your toplevel LLVM project +and all (possibly unrelated) projects inside it with make +update. This will run svn update on all subdirectories related +to subversion.

+ +

Using Visual Studio

+ +

The following details setting up for and building Clang on Windows using +Visual Studio:

+ +
    +
  1. Get the required tools: + +
    2. + +
  2. Checkout LLVM: +
      +
    • svn co http://llvm.org/svn/llvm-project/llvm/trunk llvm
      • +
    +
    3. +
  3. Checkout Clang: +
      +
    • cd llvm\tools +
    • svn co http://llvm.org/svn/llvm-project/cfe/trunk clang
      • +
    +
    4. +
  4. Run cmake to generate the Visual Studio solution and project files: +
      +
    • cd ..\.. (back to where you started)
      • +
    • mkdir build (for building without polluting the source dir)
      • +
    • cd build
      • +
    • If you are using Visual Studio 2008: cmake -G "Visual Studio 9 2008" ..\llvm
      • +
    • Or if you are using Visual Studio 2010: cmake -G "Visual Studio 10" ..\llvm
      • +
    • By default, cmake will target LLVM to X86. If you want all targets + (needed if you want to run the LLVM tests), add the -DLLVM_TARGETS_TO_BUILD=all option to the + cmake command line. Or specify a target from the LLVM_TARGETS_TO_BUILD + definition in CMakeLists.txt.
      • +
    • See the LLVM CMake guide for + more information on other configuration options for cmake.
      • +
    • The above, if successful, will have created an LLVM.sln file in the + build directory. +
    +
    5. +
  5. Build Clang: +
      +
    • Open LLVM.sln in Visual Studio.
      • +
    • Build the "clang" project for just the compiler driver and front end, or + the "ALL_BUILD" project to build everything, including tools.
      • +
    +
    6. +
  6. Try it out (assuming you added llvm/debug/bin to your path). (See the + running examples from above.)
    7. +
  7. See + Hacking on clang - Testing using Visual Studio on Windows for information + on running regression tests on Windows.
    8. +
+ +

Note that once you have checked out both llvm and clang, to synchronize +to the latest code base, use the svn update command in both the +llvm and llvm\tools\clang directories, as they are separate repositories.

+ +

Clang Compiler Driver (Drop-in Substitute for GCC)

+ +

The clang tool is the compiler driver and front-end, which is +designed to be a drop-in replacement for the gcc command. Here are +some examples of how to use the high-level driver: +

+ +
+$ cat t.c
+#include <stdio.h>
+int main(int argc, char **argv) { printf("hello world\n"); }
+$ clang t.c
+$ ./a.out
+hello world
+
+ +

The 'clang' driver is designed to work as closely to GCC as possible to + maximize portability. The only major difference between the two is that + Clang defaults to gnu99 mode while GCC defaults to gnu89 mode. If you see + weird link-time errors relating to inline functions, try passing -std=gnu89 + to clang.

+ +

Examples of using Clang

+ + + +
+$ cat ~/t.c
+typedef float V __attribute__((vector_size(16)));
+V foo(V a, V b) { return a+b*a; }
+
+ + +

Preprocessing:

+ +
+$ clang ~/t.c -E
+# 1 "/Users/sabre/t.c" 1
+
+typedef float V __attribute__((vector_size(16)));
+
+V foo(V a, V b) { return a+b*a; }
+
+ + +

Type checking:

+ +
+$ clang -fsyntax-only ~/t.c
+
+ + +

GCC options:

+ +
+$ clang -fsyntax-only ~/t.c -pedantic
+/Users/sabre/t.c:2:17: warning: extension used
+typedef float V __attribute__((vector_size(16)));
+                ^
+1 diagnostic generated.
+
+ + +

Pretty printing from the AST:

+ +

Note, the -cc1 argument indicates the the compiler front-end, and +not the driver, should be run. The compiler front-end has several additional +Clang specific features which are not exposed through the GCC compatible driver +interface.

+ +
+$ clang -cc1 ~/t.c -ast-print
+typedef float V __attribute__(( vector_size(16) ));
+V foo(V a, V b) {
+   return a + b * a;
+}
+
+ + +

Code generation with LLVM:

+ +
+$ clang ~/t.c -S -emit-llvm -o -
+define <4 x float> @foo(<4 x float> %a, <4 x float> %b) {
+entry:
+         %mul = mul <4 x float> %b, %a
+         %add = add <4 x float> %mul, %a
+         ret <4 x float> %add
+}
+$ clang -fomit-frame-pointer -O3 -S -o - t.c # On x86_64
+...
+_foo:
+Leh_func_begin1:
+	mulps	%xmm0, %xmm1
+	addps	%xmm1, %xmm0
+	ret
+Leh_func_end1:
+
+ +
+ + -- cgit v1.2.3