llvm-project/clang
Rafael Espindola 0d4fb98504 [patch][pr19848] Produce explicit comdats in clang.
The llvm IR until recently had no support for comdats. This was a problem when
targeting C++ on ELF/COFF as just using weak linkage would cause quite a bit of
dead bits to remain on the executable (unless -ffunction-sections,
-fdata-sections and --gc-sections were used).

To fix the problem, llvm's codegen will just assume that any weak or linkonce
that is not in an explicit comdat should be output in one with the same name as
the global.

This unfortunately breaks cases like pr19848 where a weak symbol is not
xpected to be part of any comdat.

Now that we have explicit comdats in the IR, we can finally get both cases
right.

This first patch just makes clang give explicit comdats to GlobalValues where
t is allowed to.

A followup patch to llvm will then stop implicitly producing comdats.

llvm-svn: 225705
2015-01-12 22:13:53 +00:00
..
INPUTS
bindings [libclang] Add function to retrieve storage class in libclang. 2014-10-15 17:05:31 +00:00
cmake/modules Make it easier to build against a pre-built Clang package with CMake 2014-11-05 23:14:59 +00:00
docs Fix markup from r224894. 2014-12-28 02:12:59 +00:00
examples Driver: Update clang-interpreter example for r218938 2014-10-03 01:08:27 +00:00
include [PowerPC]To provide better compatibility with gcc I added the __bool keyword to the Alitivec support in clang. __bool is functionally identical to using bool when declaring vector types. For example: 2015-01-12 19:35:51 +00:00
lib [patch][pr19848] Produce explicit comdats in clang. 2015-01-12 22:13:53 +00:00
runtime [CMake] Add check-asan-dynamic command to external compiler-rt setup. 2014-12-18 21:40:39 +00:00
test [patch][pr19848] Produce explicit comdats in clang. 2015-01-12 22:13:53 +00:00
tools Add the shifted cursor position to XML output, so it can be used by editor integrations. 2015-01-09 10:03:47 +00:00
unittests Fix assertion in BreakableBlockComment (http://llvm.org/PR21916). 2015-01-12 13:11:12 +00:00
utils Attributes accepting an EnumArgument are allowed to pass a string literal, or an identifier. VariadicEnumArguments now behave consistently instead of only accepting a string literal. 2014-12-19 16:42:04 +00:00
www [analyzer] Updated progress for memory.ZeroAlloc 2014-12-24 01:04:38 +00:00
.arcconfig
.clang-format
.clang-tidy Enable display of compiler diagnostics in clang-tidy. 2014-10-29 17:28:51 +00:00
.gitignore
CMakeLists.txt clang/CMakeLists.txt: Introduce LLVM_SHLIB_OUTPUT_INTDIR also here, or plugins tests might fail. 2015-01-05 14:06:14 +00:00
CODE_OWNERS.TXT Relinquish ownership of MS-style inline assembly. 2014-10-13 16:45:21 +00:00
INSTALL.txt
LICENSE.TXT
Makefile
ModuleInfo.txt
NOTES.txt Remove trailing spaces 2014-07-13 17:11:45 +00:00
README.txt Remove whitespace from test commit. 2014-07-16 19:10:36 +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/