hanchenye-llvm-project/clang
Chandler Carruth 8b4140d712 Move the emission of strict enum range metadata behind a flag (the same
flag as GCC uses: -fstrict-enums). There is a *lot* of code making
unwarranted assumptions about the underlying type of enums, and it
doesn't seem entirely reasonable to eagerly break all of it.

Much more importantly, the current state of affairs is *very* good at
optimizing based upon this information, which causes failures that are
very distant from the actual enum. Before we push for enabling this by
default, I think we need to implement -fcatch-undefined-behavior support
for instrumenting and trapping whenever we store or load a value outside
of the range. That way we can track down the misbehaving code very
quickly.

I discussed this with Rafael, and currently the only important cases he
is aware of are the bool range-based optimizations which are staying
hard enabled. We've not seen any issue with those either, and they are
much more important for performance.

llvm-svn: 153550
2012-03-27 23:58:37 +00:00
..
INPUTS Extend all-std-headers.cpp to include C++11 headers when building in C++11 mode. 2012-02-14 23:06:14 +00:00
bindings/python [clang.py] Implement Cursor.objc_type_encoding 2012-03-10 22:23:27 +00:00
docs Update the ARC specification for several changes made in the 2012-03-27 07:42:12 +00:00
examples clang-interpreter/Makefile: [PR12313] Update USEDLIBS to add clangEdit. 2012-03-21 06:25:42 +00:00
include Move the emission of strict enum range metadata behind a flag (the same 2012-03-27 23:58:37 +00:00
lib Move the emission of strict enum range metadata behind a flag (the same 2012-03-27 23:58:37 +00:00
runtime build/compiler-rt: Stop forcing off -integrated-as for compiler-rt builds. 2012-03-05 20:19:03 +00:00
test Move the emission of strict enum range metadata behind a flag (the same 2012-03-27 23:58:37 +00:00
tools Introduce a new libclang API to determine the parent context of a code 2012-03-27 23:34:16 +00:00
unittests [preprocessor] Handle correctly inclusion directives that have macro expansions, e.g 2012-03-27 18:47:48 +00:00
utils Remove the vestiges of the C backend. 2012-03-23 05:51:52 +00:00
www Forward-declared enumerations are now complete, except for an interaction 2012-03-26 20:31:41 +00:00
.gitignore Revert "Test commit" 2011-10-24 10:03:25 +00:00
CMakeLists.txt CMake: install libclang.dll to $CMAKE_INSTALL_PREFIX/bin. 2012-02-25 16:46:50 +00:00
INSTALL.txt
LICENSE.TXT Happy new year 2012! 2012-01-01 08:16:56 +00:00
Makefile Add the Clang tblgen backends to Clang, and flip the switch to cause 2011-10-06 13:03:08 +00:00
ModuleInfo.txt
NOTES.txt
README.txt commit access verified, revert change 2012-03-06 22:55:51 +00:00

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:              http://clang.llvm.org/
Building and using Clang:          http://clang.llvm.org/get_started.html
Clang Static Analyzer:             http://clang-analyzer.llvm.org/
Information on the LLVM project:   http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.cs.uiuc.edu/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/