updates.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44761 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/www/comparison.html b/www/comparison.html
index df79d6e..7e6c1df 100644
--- a/www/comparison.html
+++ b/www/comparison.html
@@ -41,23 +41,25 @@
the variants we are interested in. clang's support for C++ in
particular is nowhere near what GCC supports.</li>
<li>GCC is popular and widely adopted.</li>
+ <li>GCC does not require a C++ compiler to build it.</li>
</ul>
<p>Pros of clang vs GCC:</p>
<ul>
- <li>GCC has a very old codebase which presents a steep learning curve to new
- developers. The Clang ASTs and design are intended to be easily
- understandable to anyone who is familiar with the languages involved
- and have a basic understanding of how a compiler works.</li>
- <li>GCC is built as a monolithic static compiler, which makes it extremely
- difficult to use as an API and integrate into other tools (e.g. an IDE).
- Its historic design and <a
+ <li>The Clang ASTs and design are intended to be easily understandable to
+ anyone who is familiar with the languages involved and who have a basic
+ understanding of how a compiler works. GCC has a very old codebase
+ which presents a steep learning curve to new developers.</li>
+ <li>Clang is designed as an API from its inception, allowing it to be reused
+ by source analysis tools, refactoring, IDEs (etc) as well as for code
+ generation. GCC is built as a monolithic static compiler, which makes
+ it extremely difficult to use as an API and integrate into other tools.
+ Further, its historic design and <a
href="http://gcc.gnu.org/ml/gcc/2007-11/msg00460.html">current</a>
<a href="http://gcc.gnu.org/ml/gcc/2004-12/msg00888.html">policy</a>
- makes it difficult to decouple the front-end from
- the rest of the compiler. Clang is designed as an API from its
- inception.</li>
+ makes it difficult to decouple the front-end from the rest of the
+ compiler. </li>
<li>Various GCC design decisions make it very difficult to reuse: its build
system is difficult to modify, you can't link multiple targets into one
binary, you can't link multiple front-ends into one binary, it uses a
@@ -70,18 +72,26 @@
<li>GCC simplifies code as it parses it. As one simple example, if you
write "x-x" in your source code, the GCC AST will contain "0", with no
mention of x. This is extremely bad for a refactoring tool that wants
- to rename 'x' for example.</li>
+ to rename 'x'.</li>
<li>GCC does not have a way to serialize the AST of a file out to disk and
read it back into another program. Its PCH mechanism is architecturally
- only able to read the dump back into the exact same binary.</li>
- <li>GCC is <a href="features.html#performance">very slow and uses a large
- amount of memory</a>.</li>
- <li>The diagnostics produced by GCC are acceptable, but are often confusing
- and it does not support <a
- href="features.html#expressivediags">expressive diagnostics</a>.</li>
+ only able to read the dump back into the exact same executable as the
+ one that produced it.</li>
+ <li>Clang is <a href="features.html#performance">much faster and uses far
+ less memory</a> than GCC.</li>
+ <li>Clang aims to provide extremely clear and concise diagnostics (error and
+ warning messages), and includes support for <a
+ href="features.html#expressivediags">expressive diagnostics</a>. GCC's
+ warnings are acceptable, but are often confusing and it does not support
+ expressive diagnostics. Clang also preserves typedefs in diagnostics
+ consistently.</li>
<li>GCC is licensed under the GPL license. clang uses a BSD license, which
allows it to be used by projects that do not themselves want to be
GPL.</li>
+ <li>Clang inherits a number of features from its use of LLVM as a backend,
+ including support for a bytecode representation for intermediate code,
+ pluggable optimizers, link-time optimization support, Just-In-Time
+ compilation, etc.</li>
</ul>
<!--=====================================================================-->
@@ -143,7 +153,8 @@
<ul>
<li>PCC dates from the 1970's and has been dormant for most of that time.
The clang + llvm community are very active.</li>
- <li>PCC doesn't support Objective-C and doesn't aim to support C++.</li>
+ <li>PCC doesn't support C99, Objective-C, and doesn't aim to support
+ C++.</li>
<li>PCC's code generation is very limited compared to LLVM, it produces very
inefficient code and does not support many important targets.</li>
<li>PCC's does not have an integrated preprocessor, so it is extremely