llvm-project/clang
David Blaikie 3945d1bd99 Reapply "DebugInfo: Generalize debug info location handling"
Originally committed in r224385 and reverted in r224441 due to concerns
this change might've introduced a crash. Turns out this change fixes the
crash introduced by one of my earlier more specific location handling
changes (those specific fixes are reverted by this patch, in favor of
the more general solution).

Original commit message:

This is a more scalable (fixed in mostly one place, rather than many
places that will need constant improvement/maintenance) solution to
several commits I've made recently to increase source fidelity for
subexpressions.

This resetting had to be done at the DebugLoc level (not the
SourceLocation level) to preserve scoping information (if the resetting
was done with CGDebugInfo::EmitLocation, it would've caused the tail end
of an expression's codegen to end up in a potentially different scope
than the start, even though it was at the same source location). The
drawback to this is that it might leave CGDebugInfo out of sync. Ideally
CGDebugInfo shouldn't have a duplicate sense of the current
SourceLocation, but for now it seems it does... - I don't think I'm
going to tackle removing that just now.

I expect this'll probably cause some more buildbot fallout & I'll
investigate that as it comes up.

Also these sort of improvements might be starting to show a weakness/bug
in LLVM's line table handling: we don't correctly emit is_stmt for
statements, we just put it on every line table entry. This means one
statement split over multiple lines appears as multiple 'statements' and
two statements on one line (without column info) are treated as one
statement.

I don't think we have any IR representation of statements that would
help us distinguish these cases and identify the beginning of each
statement - so that might be something we need to add (possibly to the
lexical scope chain - a scope for each statement). This does cause some
problems for GDB and possibly other DWARF consumers.

llvm-svn: 224941
2014-12-29 18:18:45 +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 [multilib] Teach Clang's code about multilib by threading 2014-12-29 12:09:08 +00:00
lib Reapply "DebugInfo: Generalize debug info location handling" 2014-12-29 18:18:45 +00:00
runtime [CMake] Add check-asan-dynamic command to external compiler-rt setup. 2014-12-18 21:40:39 +00:00
test Reapply "DebugInfo: Generalize debug info location handling" 2014-12-29 18:18:45 +00:00
tools clang-format: Make clang-format-diff.py format java files. 2014-12-08 19:39:03 +00:00
unittests clang-format: Fix incorrect detection of ObjC "in" keyword. 2014-12-18 12:11:01 +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 [multilib] Teach Clang's code about multilib by threading 2014-12-29 12:09:08 +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/