<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><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>
<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>or:</p>
<div class="doc_code">
- llvm-g++ a.cpp -c
- llvm-g++ b.cpp -c
+ llvm-g++ a.cpp -c<br>
+ llvm-g++ b.cpp -c<br>
llvm-g++ a.o b.o -o program
</div>
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 bytecode, 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>