Sema: Do not merge new decls with invalid, old decls

Sema::MergeFunctionDecl attempts merging two decls even if the old decl
is invalid.  This can lead to interesting circumstances where we
successfully merge the decls but the result makes no sense.

Take the following for example:

template <typename T>
int main(void);

int main(void);

Sema will not consider these to be overloads of the same name because
main can't be overloaded, which means that this must be a redeclaration.

In this case the templated decl is compatible with the non-templated
decl allowing the Sema::CheckFunctionDeclaration machinery to move on
and do bizarre things like setting the previous decl of a non-templated
decl to a templated decl!

The way I see it, we should just bail from MergeFunctionDecl if the old
decl is invalid.

This fixes PR16531.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185779 91177308-0d34-0410-b5e6-96231b3b80d8
Use SmallVectorImpl::reverse_iterator instead of SmallVector to avoid specifying the vector size.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185784 91177308-0d34-0410-b5e6-96231b3b80d8
Function argument formatting fixes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185785 91177308-0d34-0410-b5e6-96231b3b80d8
Function argument formatting fixes. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185786 91177308-0d34-0410-b5e6-96231b3b80d8
Remove 'else' after 'return'

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185787 91177308-0d34-0410-b5e6-96231b3b80d8
Introduce a typedef for the type of NewlyDeducedPacks to avoid repeating the small size of the inner SmallVector.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185789 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify code. No functional change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185792 91177308-0d34-0410-b5e6-96231b3b80d8
AST/SourceLocationTest.cpp: Appease MS hosts to suppress CXXUnresolvedConstructExpr.SourceRange, for now.

FIXME: It could pass if MS-compatible mode were disabled with Args.push_back("-fno-delayed-template-parsing").

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185795 91177308-0d34-0410-b5e6-96231b3b80d8
clang/test/CodeGen/2008-01-25-ByValReadNone.c: Add explicit -triple x86_64-unknown-unknown.

It would emit @llvm.memcpy with "-triple x86_64-(mingw32|win32)" and had been failing since Nick's r185735.

  ; Function Attrs: nounwind
  declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #1

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185796 91177308-0d34-0410-b5e6-96231b3b80d8
clang/test/Misc/permissions.cpp: Suppress this on MSYS with the feature 'shell-preserves-root'.

FIXME: Could we introduce another feature for it?

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185797 91177308-0d34-0410-b5e6-96231b3b80d8
Documentation cleanup for include/clang/AST/ExprCXX.h.

This is mostly Doxygen formatting, but also updates some C++0x references
to C++11 and clarifies some wording.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185798 91177308-0d34-0410-b5e6-96231b3b80d8
clang/test/Index/comment-custom-block-command.cpp: This has not been failing since r175892 on valgrind.
That said, it fails with --vg-leak. Mark it as XFAIL: vg_leak instead.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185809 91177308-0d34-0410-b5e6-96231b3b80d8
clang/include/clang/AST/ExprCXX.h:260:5: Fix a warning -- unknown command tag name 'cc'; did you mean 'c'? [-Wdocumentation]

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185810 91177308-0d34-0410-b5e6-96231b3b80d8
Fix for corner cases in code handling leading "* " decorations in block comments

Summary:
Fixes problems that lead to incorrect formatting of these and similar snippets:
/*
 **
 */

/*
 **/

/*
 * */

/*
 *test
 */

Clang-format used to think that all the cases above use "* " decoration, and
failed to calculate insertion position properly. It also used to remove leading 
"* " in the last line.

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1113

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185818 91177308-0d34-0410-b5e6-96231b3b80d8
Fix use of invalidated iterator bug in AST match finder.

Pulled out the cache clearing in the case of descendant matching, too,
for consistency, also it is not technically needed there.

FIXME: Make cache size configurable and add unit test.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185820 91177308-0d34-0410-b5e6-96231b3b80d8
Prefer similar line breaks.

This adds a penalty for clang-format for each break that occurs in
a set of parentheses (including fake parenthesis that determine
the range of certain operator precendences) that have not yet been
broken. Thereby, clang-format prefers similar line breaks.

This fixes llvm.org/PR15506.

Before:
const int kTrackingOptions =
    NSTrackingMouseMoved | NSTrackingMouseEnteredAndExited |
    NSTrackingActiveAlways;

After:
const int kTrackingOptions = NSTrackingMouseMoved |
                             NSTrackingMouseEnteredAndExited |
                             NSTrackingActiveAlways;

Also removed ParenState::ForFakeParenthesis which has become unused.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185822 91177308-0d34-0410-b5e6-96231b3b80d8
Reformat clang-format's source files after r185822 and others.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185823 91177308-0d34-0410-b5e6-96231b3b80d8
Fixed testcase failing under MS by adding "-fno-delayed-template-parsing",
as suggested by Takumi. To this end, added a MatchVerifier::match()
overload accepting a vector of invocation arguments.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185827 91177308-0d34-0410-b5e6-96231b3b80d8
Fix incorrect incorrect cast identification in clang-format.

This fixes llvm.org/PR16534.

Before:
aaaaa& operator+(const aaaaa&)LLVM_DELETED_FUNCTION;
After:
aaaaa& operator+(const aaaaa&) LLVM_DELETED_FUNCTION;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185828 91177308-0d34-0410-b5e6-96231b3b80d8