<li><a href="#build">Build Problems</a>
<ol>
<li>When I run configure, it finds the wrong C compiler.</li>
- <li>I compile the code, and I get some error about <tt>/localhome</tt>.</li>
<li>The <tt>configure</tt> script finds the right C compiler, but it uses the
LLVM linker from a previous build. What do I do?</li>
<li>When creating a dynamic library, I get a strange GLIBC error.</li>
- <li>I've updated my source tree from CVS, and now my build is trying to use a
- file/directory that doesn't exist.</li>
+ <li>I've updated my source tree from Subversion, and now my build is trying
+ to use a file/directory that doesn't exist.</li>
<li>I've modified a Makefile in my source tree, but my build tree keeps using
the old version. What do I do?</li>
<li>I've upgraded to a new version of LLVM, and I get strange build
<li>Compiling LLVM with GCC 3.3.2 fails, what should I do?</li>
<li>When I use the test suite, all of the C Backend tests fail. What is
wrong?</li>
- <li>After CVS update, rebuilding gives the error "No rule to make
- target".</li>
+ <li>After Subversion update, rebuilding gives the error "No rule to make
+ target".</li>
+ <li><a href="#llvmc">The <tt>llvmc</tt> program gives me errors/doesn't
+ work.</li></a>
</ol></li>
<li><a href="#felangs">Source Languages</a>
<li><a href="#langs">What source languages are supported?</a></li>
<li><a href="#langhlsupp">What support is there for higher level source
language constructs for building a compiler?</a></li>
+ <li><a href="GetElementPtr.html">I don't understand the GetElementPtr
+ instruction. Help!</a></li>
</ol>
<li><a href="#cfe">Using the GCC Front End</a>
</div>
-<div class="question">
-<p>I compile the code, and I get some error about <tt>/localhome</tt>.</p>
-</div>
-
-<div class="answer">
-
-<p>There are several possible causes for this. The first is that you didn't set
-a pathname properly when using <tt>configure</tt>, and it defaulted to a
-pathname that we use on our research machines.</p>
-
-<p>Another possibility is that we hardcoded a path in our Makefiles. If you see
-this, please email the LLVM bug mailing list with the name of the offending
-Makefile and a description of what is wrong with it.</p>
-
-</div>
-
<div class="question">
<p>The <tt>configure</tt> script finds the right C compiler, but it uses the
LLVM linker from a previous build. What do I do?</p>
</div>
<div class="question">
-<p>I've updated my source tree from CVS, and now my build is trying to use a
-file/directory that doesn't exist.</p>
+ <p>I've updated my source tree from Subversion, and now my build is trying to
+ use a file/directory that doesn't exist.</p>
</div>
<div class="answer">
<p>For example, if you built LLVM with the command:</p>
-<p><tt>gmake ENABLE_PROFILING=1</tt>
+<div class="doc_code">
+<pre>
+% gmake ENABLE_PROFILING=1
+</pre>
+</div>
<p>...then you must run the tests with the following commands:</p>
-<p><tt>cd llvm/test<br>gmake ENABLE_PROFILING=1</tt></p>
+<div class="doc_code">
+<pre>
+% cd llvm/test
+% gmake ENABLE_PROFILING=1
+</pre>
+</div>
</div>
</div>
<div class="question">
-<p>After CVS update, rebuilding gives the error "No rule to make target".</p>
+ <p>After Subversion update, rebuilding gives the error
+ "No rule to make target".</p>
</div>
<div class="answer">
<p>If the error is of the form:</p>
<div class="doc_code">
-<tt>
+<pre>
gmake[2]: *** No rule to make target `/path/to/somefile', needed by
`/path/to/another/file.d'.<br>
Stop.
-</tt>
+</pre>
</div>
-<p>This may occur anytime files are moved within the CVS repository or removed
-entirely. In this case, the best solution is to erase all <tt>.d</tt> files,
-which list dependencies for source files, and rebuild:</p>
+<p>This may occur anytime files are moved within the Subversion repository or
+removed entirely. In this case, the best solution is to erase all
+<tt>.d</tt> files, which list dependencies for source files, and rebuild:</p>
<div class="doc_code">
<pre>
rebuilding.</p>
</div>
+<div class="question">
+ <a name="llvmc"<p>The <tt>llvmc</tt> program gives me errors/doesn't
+ work.</p></a>
+</div>
+
+<div class="answer">
+ <p><tt>llvmc</tt> is experimental and isn't really supported. We suggest
+ using <tt>llvm-gcc</tt> instead.</p>
+</div>
+
<!-- *********************************************************************** -->
<div class="doc_section"><a name="felangs">Source Languages</a></div>
available through a special version of GCC that LLVM calls the
<a href="#cfe">C Front End</a></p>
<p>There is an incomplete version of a Java front end available in the
- <tt>llvm-java</tt> CVS repository. There is no documentation on this yet so
+ <tt>java</tt> module. There is no documentation on this yet so
you'll need to download the code, compile it, and try it.</p>
- <p>In the <tt>examples/BFtoLLVM</tt> directory is a translator for the
- BrainF*** language (2002 Language Specification).</p>
- <p>In the <tt>projects/Stacker</tt> directory is a compiler and runtime
+ <p>In the <tt>stacker</tt> module is a compiler and runtime
library for the Stacker language, a "toy" language loosely based on Forth.</p>
<p>The PyPy developers are working on integrating LLVM into the PyPy backend
so that PyPy language can translate to LLVM.</p>
<a href="CompilerDriver.html">compiler driver</a> which simplifies the task
of running optimizations, linking, and executable generation.</p>
</div>
+
+<div class="question"><a name="langhlsupp">
+ <p>I don't understand the GetElementPtr
+ instruction. Help!</a></p>
+</div>
+<div class="answer">
+ <p>See <a href="GetElementPtr.html">The Often Misunderstood GEP
+ Instruction</a>.</li>
+</div>
+
<!-- *********************************************************************** -->
<div class="doc_section">
<a name="cfe">Using the GCC Front End</a>
<p>
To work around this, perform the following steps:
</p>
-
<ol>
- <li>
- Make sure the CC and CXX environment variables contains the full path to the
- LLVM GCC front end.
- </li>
+ <li>Make sure the CC and CXX environment variables contains the full path to
+ the LLVM GCC front end.</li>
- <li>
- Make sure that the regular C compiler is first in your PATH.
- </li>
+ <li>Make sure that the regular C compiler is first in your PATH. </li>
- <li>
- Add the string "-Wl,-native" to your CFLAGS environment variable.
- </li>
+ <li>Add the string "-Wl,-native" to your CFLAGS environment variable.</li>
</ol>
<p>
-This will allow the gccld linker to create a native code executable instead of
-a shell script that runs the JIT. Creating native code requires standard
-linkage, which in turn will allow the configure script to find out if code is
-not linking on your system because the feature isn't available on your system.
-</p>
+This will allow the <tt>llvm-ld</tt> linker to create a native code executable
+instead of shell script that runs the JIT. Creating native code requires
+standard linkage, which in turn will allow the configure script to find out if
+code is not linking on your system because the feature isn't available on your
+system.</p>
</div>
<div class="question">
<p>
The only way this can happen is if you haven't installed the runtime library. To
correct this, do:</p>
+
+<div class="doc_code">
<pre>
- % cd llvm/runtime
- % make clean ; make install-bytecode
+% cd llvm/runtime
+% make clean ; make install-bytecode
</pre>
</div>
+</div>
<div class="question">
<p>
<ol>
<li><p>Compile your program as normal with llvm-g++:</p></li>
-<div class="doc_code">$ llvm-g++ x.cpp -o program</div>
+<div class="doc_code">
+<pre>
+% llvm-g++ x.cpp -o program
+</pre>
+</div>
<p>or:</p>
<div class="doc_code">
- llvm-g++ a.cpp -c
- llvm-g++ b.cpp -c
- llvm-g++ a.o b.o -o program
+<pre>
+% llvm-g++ a.cpp -c
+% llvm-g++ b.cpp -c
+% llvm-g++ a.o b.o -o program
+</pre>
</div>
<p>With llvm-gcc3, this will generate program and program.bc. The .bc file is
<li><p>Convert the LLVM code to C code, using the LLC tool with the C
backend:</p></li>
-<div class="doc_code">$ llc -march=c program.bc -o program.c</div>
+<div class="doc_code">
+<pre>
+% llc -march=c program.bc -o program.c
+</pre>
+</div>
<li><p>Finally, compile the c file:</p></li>
-<div class="doc_code">$ cc x.c</div>
+<div class="doc_code">
+<pre>
+% cc x.c
+</pre>
+</div>
</ol>
use setjmp/longjmp to implement exception support that is correct but
relatively slow.
</p>
+
+<p>Also note: this specific sequence of commands won't work if you use a
+function defined in the C++ runtime library (or any other C++ library). To
+access an external C++ library, you must manually
+compile libstdc++ to LLVM bitcode, statically link it into your program, then
+use the commands above to convert the whole result into C code. Alternatively,
+you can compile the libraries and your application into two different chunks
+of C code and link them.</p>
+
</div>
variable before you use it. For example, the C function:</p>
<div class="doc_code">
- <tt>int X() { int i; return i; }</tt>
+<pre>
+int X() { int i; return i; }
+</pre>
</div>
-<p>Is compiled to "<tt>ret int undef</tt>" because "i" never has a value
-specified for it.
-</p>
+<p>Is compiled to "<tt>ret i32 undef</tt>" because "<tt>i</tt>" never has
+a value specified for it.</p>
</div>
<!-- *********************************************************************** -->
projects / oota-llvm.git / blobdiff