that is in an anonymous namespace, give that function or variable
internal linkage.

This change models an oddity of the C++ standard, where names declared
in an anonymous namespace have external linkage but, because anonymous
namespace are really "uniquely-named" namespaces, the names cannot be
referenced from other translation units. That means that they have
external linkage for semantic analysis, but the only sensible
implementation for code generation is to give them internal
linkage. We now model this notion via the UniqueExternalLinkage
linkage type. There are several changes here:

  - Extended NamedDecl::getLinkage() to produce UniqueExternalLinkage
    when the declaration is in an anonymous namespace.
  - Added Type::getLinkage() to determine the linkage of a type, which
    is defined as the minimum linkage of the types (when we're dealing
    with a compound type that is not a struct/class/union).
  - Extended NamedDecl::getLinkage() to consider the linkage of the
    template arguments and template parameters of function template
    specializations and class template specializations.
  - Taught code generation to rely on NamedDecl::getLinkage() when
    determining the linkage of variables and functions, also
    considering the linkage of the types of those variables and
    functions (C++ only). Map UniqueExternalLinkage to internal
    linkage, taking out the explicit checks for
    isInAnonymousNamespace().

This fixes much of PR5792, which, as discovered by Anders Carlsson, is
actually the reason behind the pass-manager assertion that causes the
majority of clang-on-clang regression test failures. With this fix,
Clang-built-Clang+LLVM passes 88% of its regression tests (up from
67%). The specific numbers are:

LLVM:
  Expected Passes    : 4006
  Expected Failures  : 32
  Unsupported Tests  : 40
  Unexpected Failures: 736

Clang:
  Expected Passes    : 1903
  Expected Failures  : 14
  Unexpected Failures: 75

Overall:
  Expected Passes    : 5909
  Expected Failures  : 46
  Unsupported Tests  : 40
  Unexpected Failures: 811

Still to do:
  - Improve testing
  - Check whether we should allow the presence of types with
  InternalLinkage (in addition to UniqueExternalLinkage) given
  variables/functions internal linkage in C++, as mentioned in
  PR5792. 
  - Determine how expensive the getLinkage() calls are in practice;
  consider caching the result in NamedDecl.
  - Assess the feasibility of Chris's idea in comment #1 of PR5792.

llvm-svn: 95216

llvm-svn: 95201

realize that CXXConstructExpr is always implicit, so we should just
return its argument (if there is only one) rather than directly
invoking the constructor.

llvm-svn: 95192

- Don't use GlobalAliases with non-0 GEPs (GNU runtime) - this was unsupported and LLVM will be generating errors if you do it soon.  This also simplifies the code generated by the GNU runtime a bit.  

- Make GetSelector() return a constant (GNU runtime), not a load of a store of a constant.

- Recognise @selector() expressions as valid static initialisers (as GCC does).

- Add methods to GCObjCRuntime to emit selectors as constants (needed for using @selector() expressions as constants.  These need implementing for the Mac runtimes - I couldn't figure out how to do this, they seem to require a load.

- Store an ObjCMethodDecl in an ObjCSelectorExpr so that we can get at the type information for the selector.  This is needed for generating typed selectors from @selector() expressions (as GCC does).  Ideally, this information should be stored in the Selector, but that would be an invasive change.  We should eventually add checks for common uses of @selector() expressions.  Possibly adding an attribute that can be applied to method args providing the types of a selector so, for example, you'd do something like this:

- (id)performSelector: __attribute__((selector_types(id, SEL, id)))(SEL)
           withObject: (id)object;

Then, any @selector() expressions passed to the method will be check to ensure that it conforms to this signature.  We do this at run time on the GNU runtime already, but it would be nice to do it at compile time on all runtimes.

- Made @selector() expressions emit type info if available and the runtime supports it.

Someone more familiar with the Mac runtime needs to implement the GetConstantSelector() function in CGObjCMac.  This currently just assert()s.

llvm-svn: 95189

appropriately.  Call out a few missing cases in the expression mangler.

llvm-svn: 95176

WHAT!?!

It turns out that Type::isPromotableIntegerType() was not considering
enumeration types to be promotable, so we would never do the
promotion despite having properly computed the promotion type when the
enum was defined. Various operations on values of enum type just
"worked" because we could still compute the integer rank of an enum
type; the oddity, however, is that operations such as "add an enum and
an unsigned" would often have an enum result type (!). The bug
actually showed up as a spurious -Wformat diagnostic
(<rdar://problem/7595366>), but in theory it could cause miscompiles.

In this commit:
  - Enum types with a promotion type of "int" or "unsigned int" are
  promotable.
  - Tweaked the computation of promotable types for enums
  - For all of the ABIs, treat enum types the same way as their
  underlying types (*not* their promotion types) for argument passing
  and return values
  - Extend the ABI tester with support for enumeration types

llvm-svn: 95117

Set the correct vtable pointers _before_ generating code for any member initializers. Fixes about ~2000 clang/LLVM tests in the clang-on-clang build.

llvm-svn: 95116

unused variable warning.

llvm-svn: 95085

Eliminates a lot of spurious global initializers, fixing PR6205.

llvm-svn: 95077

llvm-svn: 95076

llvm-svn: 95066

llvm-svn: 95063

llvm-svn: 95030

llvm-svn: 95029

llvm-svn: 95023

llvm-svn: 95016

llvm-svn: 95010

llvm-svn: 95009

llvm-svn: 95008

llvm-svn: 95005

by setting the section of the generated global.  This is an
optimization done by the code generator, and the code being
removed didn't handle the case when the string contained an
embedded nul (which the code generator does correctly 
handle).  This is rdar://7589850

llvm-svn: 95003

In C++, an initializer on a variable doesn't necessarily mean it's the definition. With that in mind, rename getDefinition to getAnyInitializer (to distinguish it from getInit) and reimplement it in terms of isThisDeclarationADefinition. Update all code to use this new function.

llvm-svn: 94999

llvm-svn: 94991

not quite sure what we want to do about the AST representation; comments
welcome.

llvm-svn: 94967

llvm-svn: 94965

llvm-svn: 94964

(necessarily simultaneous) changes:

  - CXXBaseOrMemberInitializer now contains only a single initializer
    rather than a set of initialiation arguments + a constructor. The
    single initializer covers all aspects of initialization, including
    constructor calls as necessary but also cleanup of temporaries
    created by the initializer (which we never handled
    before!).

  - Rework + simplify code generation for CXXBaseOrMemberInitializers,
    since we can now just emit the initializer as an initializer.

  - Switched base and member initialization over to the new
    initialization code (InitializationSequence), so that it

  - Improved diagnostics for the new initialization code when
    initializing bases and members, to match the diagnostics produced
    by the previous (special-purpose) code.

  - Simplify the representation of type-checked constructor initializers in
    templates; instead of keeping the fully-type-checked AST, which is
    rather hard to undo at template instantiation time, throw away the
    type-checked AST and store the raw expressions in the AST. This
    simplifies instantiation, but loses a little but of information in
    the AST.

  - When type-checking implicit base or member initializers within a
    dependent context, don't add the generated initializers into the
    AST, because they'll look like they were explicit.

  - Record in CXXConstructExpr when the constructor call is to
  initialize a base class, so that CodeGen does not have to infer it
  from context. This ensures that we call the right kind of
  constructor.

There are also a few "opportunity" fixes here that were needed to not
regress, for example:

  - Diagnose default-initialization of a const-qualified class that
    does not have a user-declared default constructor. We had this
    diagnostic specifically for bases and members, but missed it for
    variables. That's fixed now.

  - When defining the implicit constructors, destructor, and
    copy-assignment operator, set the CurContext to that constructor
    when we're defining the body.

llvm-svn: 94952

When performing a derived-to-base cast that we know will not change the offset, we don't need to null check the input pointer. Fixes PR5965.

llvm-svn: 94942

When doing a base-to-derived cast we don't need to null check the derived value if the class offset is 0.

llvm-svn: 94939

llvm-svn: 94938

llvm-svn: 94920

llvm-svn: 94917

llvm-svn: 94849

llvm-svn: 94817

llvm-svn: 94811

llvm-svn: 94800

Add a new EmitLValueForFieldInitialization that will be used for initializing fields (and reference type fields in particular).

llvm-svn: 94799

Simplify EmitLValueForField - we can get whether the field is part of a union or not from the FieldDecl (through its DeclContext).

llvm-svn: 94798

the ABI spec, this turns out to simplify the code. We still have some annoying
code which mismatches the spec with regard to empty structures.

llvm-svn: 94796

llvm-svn: 94791