Static locals requiring initialization are not thread safe on Windows.
Unfortunately, it's possible to create static locals that are actually
externally visible with inline functions and templates. As a result, we
have to implement an initialization guard scheme that is compatible with
TUs built by MSVC, which makes thread safety prohibitively difficult.
MSVC's scheme is that every function that requires a guard gets an i32
bitfield. Each static local is assigned a bit that indicates if it has
been initialized, up to 32 bits, at which point a new bitfield is
created. MSVC rejects inline functions with more than 32 static locals,
and the externally visible mangling (?_B) only allows for one guard
variable per function.
On Eli's recommendation, I used MangleNumberingContext to track which
bit each static corresponds to.
Implements PR16888.
Reviewers: rjmccall, eli.friedman
Differential Revision: http://llvm-reviews.chandlerc.com/D1416
llvm-svn: 190427
Summary:
Handles all inheritance models for both data and function member
pointers.
Also implements isZeroInitializable() and refactors some of the null
member pointer code.
MSVC supports converting member pointers through virtual bases, which
clang does not (yet?) support. Implementing that extension is covered
by http://llvm.org/15713
Reviewers: rjmccall
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D613
llvm-svn: 179305
Summary:
This makes it possible to share code between lib/AST/MicrosoftCXXABI.cpp
and lib/CodeGen/MicrosoftCXXABI.cpp. No functionality change.
Also adds comments about the layout of the member pointer structs as I
currently understand them.
Reviewers: rjmccall
CC: timurrrr, cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D590
llvm-svn: 178548
Summary:
This also relaxes the requirement on Windows that the member pointer
class type be a complete type (http://llvm.org/PR12070). We still ask
for a complete type to instantiate any templates (MSVC does this), but
if that fails we continue as normal, relying on any inheritance
attributes on the declaration.
Reviewers: rjmccall
CC: triton, timurrrr, cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D568
llvm-svn: 178283
builtin types (When requested). This is another step toward making
ASTUnit build the ASTContext as needed when loading an AST file,
rather than doing so after the fact. No actual functionality change (yet).
llvm-svn: 138985