Commit Graph

618 Commits

Author SHA1 Message Date
Chris Lattner efa77170b5 convert some more stuff over to use new cursor APIs.
llvm-svn: 172932
2013-01-20 00:00:22 +00:00
Chris Lattner e7b154bcf8 switch a bunch of ASTReader to use the new BitstreamCursor::advance* methods,
which hide a bunch of private details of the cursor from clients and simplify
their code.  More to come.

llvm-svn: 172922
2013-01-19 21:39:22 +00:00
Argyrios Kyrtzidis 719736c581 [PCH/Modules] Revert r172843, it caused a module to fail building.
llvm-svn: 172884
2013-01-19 03:14:56 +00:00
Matt Beaumont-Gay 21c6c959ec Remove unused variable
llvm-svn: 172862
2013-01-18 22:34:17 +00:00
Argyrios Kyrtzidis 8bee90d5f3 [PCH/Modules] Re-apply r172620 and r172629, now with 100% less infinite loops!
Makes sure that a deserialized macro is only added to the preprocessor macro definitions only once.
Unfortunately I couldn't get a reduced test case.

rdar://13016031

llvm-svn: 172843
2013-01-18 20:59:01 +00:00
Will Dietz f54319c891 [ubsan] Add support for -fsanitize-blacklist
llvm-svn: 172808
2013-01-18 11:30:38 +00:00
Douglas Gregor 6a7cb9f8bc Revert Clang r172620 and r172629, which caused a hang when building
complicated modules (<rdar://problem/13038265>). Unfortunately, this
un-fixes <rdar://problem/13016031>.

llvm-svn: 172783
2013-01-18 04:34:14 +00:00
Argyrios Kyrtzidis 8078a5a449 [PCH/Modules] The iterator may become invalidated because a new macro can be added
while deserializing a macro, make sure to copy/move what we need from it.

Fixes clang-x86_64-debian-fast bot.

llvm-svn: 172629
2013-01-16 17:42:07 +00:00
Argyrios Kyrtzidis f40f67af43 [PCH/Modules] Change how macro [re]definitions are de/serialized.
Previously we would serialize the macro redefinitions as a list, part of
the identifier, and try to chain them together across modules individually
without having the info that they were already chained at definition time.

Change this by serializing the macro redefinition chain and then try
to synthesize the chain parts across modules. This allows us to correctly
pinpoint when 2 different definitions are ambiguous because they came from
unrelated modules.

Fixes bogus "ambiguous expansion of macro" warning when a macro in a PCH
is redefined without undef'ing it first.

rdar://13016031

llvm-svn: 172620
2013-01-16 16:19:38 +00:00
Douglas Gregor 6ddfca91e0 Implement parsing, AST, (de-)serialization, and placeholder global
metadata for linking against the libraries/frameworks for imported
modules.

The module map language is extended with a new "link" directive that
specifies what library or framework to link against when a module is
imported, e.g.,

  link "clangAST"

or

  link framework "MyFramework"

Importing the corresponding module (or any of its submodules) will
eventually link against the named library/framework.

For now, I've added some placeholder global metadata that encodes the
imported libraries/frameworks, so that we can test that this
information gets through to the IR. The format of the data is still
under discussion.

llvm-svn: 172437
2013-01-14 17:21:00 +00:00
Dmitri Gribenko f857950d39 Remove useless 'llvm::' qualifier from names like StringRef and others that are
brought into 'clang' namespace by clang/Basic/LLVM.h

llvm-svn: 172323
2013-01-12 19:30:44 +00:00
Douglas Gregor c147b0bc31 Provide Decl::getOwningModule(), which determines the (sub)module in
which a particular declaration resides. Use this information to
customize the "definition of 'blah' must be imported from another
module" diagnostic with the module the user actually has to
import. Additionally, recover by importing that module, so we don't
complain about other names in that module.

Still TODO: coming up with decent Fix-Its for these cases, and expand
this recovery approach for other name lookup failures.

llvm-svn: 172290
2013-01-12 01:29:50 +00:00
Argyrios Kyrtzidis c57e503c48 [PCH] Make the const_cast explicit to silence a compiler warning.
Patch by David Greene.

llvm-svn: 172262
2013-01-11 22:29:49 +00:00
Richard Smith 78165b53bf Truth in advertising: LocallyScopedExternalDecls actually only contains
external declarations with C language linkage.

llvm-svn: 172150
2013-01-10 23:43:47 +00:00
Argyrios Kyrtzidis 7572be2e44 [PCH] (De)serialize the end location of MacroInfo.
llvm-svn: 171772
2013-01-07 19:16:23 +00:00
Argyrios Kyrtzidis 2810e9dee0 [PCH/Modules] In ASTReader::completeVisibleDeclsMap, make sure to visit all
modules when getting the decls for a namespace or translation unit.

Otherwise the code-completion results will not be complete.

rdar://12889089

llvm-svn: 170596
2012-12-19 22:21:18 +00:00
Guy Benyei d8a08ea98d Re-commit r170428 changes with Linux style file endings.
Add OpenCL images as clang builtin types.

llvm-svn: 170432
2012-12-18 14:38:23 +00:00
Guy Benyei 11169dded0 Revert changes from r170428, as I accidentally changed the line endings of these files to Windows style.
llvm-svn: 170431
2012-12-18 14:30:41 +00:00
Guy Benyei b13abb952a Add OpenCL images as clang builtin types.
llvm-svn: 170428
2012-12-18 12:30:03 +00:00
Argyrios Kyrtzidis 3960540e30 [PCH] Make the new PCH format (control block) backwards compatible and
don't crash when loading a PCH with the older format.

The introduction of the control block broke compatibility with PCHs from
older versions. This patch allows loading (and rejecting) PCHs from an older
version and allows newer PCHs to be rejected from older clang versions as well.

rdar://12821386

llvm-svn: 170150
2012-12-13 21:38:23 +00:00
Argyrios Kyrtzidis 53c3877f94 [PCH] Remove redundant stat call when validating the input files.
This became redundant after we removed the stat cache.

llvm-svn: 169830
2012-12-11 07:48:14 +00:00
Chandler Carruth 3a02247dc9 Sort all of Clang's files under 'lib', and fix up the broken headers
uncovered.

This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.

I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.

llvm-svn: 169237
2012-12-04 09:13:33 +00:00
Argyrios Kyrtzidis f3d587ea7c Refactor recording the preprocessor conditional directive regions out of
PreprocessingRecord and into its own class, PPConditionalDirectiveRecord.

Decoupling allows a client to use the functionality of PPConditionalDirectiveRecord
without needing a PreprocessingRecord.

llvm-svn: 169229
2012-12-04 07:27:05 +00:00
Douglas Gregor 22103e3416 When we're emitting a diagnostic with a source location in an imported
module, provide a module import stack similar to what we would get for
an include stack, e.g.,

In module 'DependsOnModule' imported from build-fail-notes.m:4:
In module 'Module' imported from DependsOnModule.framework/Headers/DependsOnModule.h:1:
Inputs/Module.framework/Headers/Module.h:15:12: note: previous definition is here
@interface Module

<rdar://problem/12696425>

llvm-svn: 169042
2012-11-30 21:58:49 +00:00
Douglas Gregor 6fb03aeae1 Actually keep track of the source locations at which particular module
files are loaded.

llvm-svn: 169027
2012-11-30 19:28:05 +00:00
Argyrios Kyrtzidis 0f05fb9cba Introduce ASTUnresolvedSet, an UnresolvedSet-like class, whose contents are
allocated using the allocator associated with an ASTContext.

Use this inside CXXRecordDecl::DefinitionData instead of an UnresolvedSet to
avoid a potential memory leak.

rdar://12761275

llvm-svn: 168771
2012-11-28 03:56:16 +00:00
Argyrios Kyrtzidis 5259524b2f [modules] Use a memory buffer directly as input for the module includes,
instead of messing with virtual files.

llvm-svn: 168062
2012-11-15 18:57:27 +00:00
Argyrios Kyrtzidis 2ec2936778 [modules] Setup the import location of a module file and use it
as the include location of the main file of an imported module.

llvm-svn: 168061
2012-11-15 18:57:22 +00:00
Eli Friedman 14d3c79b45 Suppress elided variadic macro argument extension diagnostic for macros using
the related comma pasting extension.

In certain cases, we used to get two diagnostics for what is essentially one
extension.  This change suppresses the first diagnostic in certain cases
where we know we're going to print the second diagnostic.  The
diagnostic is redundant, and it can't be suppressed in the definition
of the macro because it points at the use of the macro, so we want to
avoid printing it if possible.

The implementation works by detecting constructs which look like comma
pasting at the time of the definition of the macro; this information
is then used when the macro is used.  (We can't actually detect
whether we're using the comma pasting extension until the macro is
actually used, but we can detecting constructs which will be comma
pasting if the varargs argument is elided.)

<rdar://problem/12292192>

llvm-svn: 167907
2012-11-14 02:18:46 +00:00
Argyrios Kyrtzidis 6566e23e13 Add a FileCharacteristic parameter to SourceManager::createFileIDForMemBuffer
for completeness and use it in CompilerInstance::InitializeSourceManager if
the input is a memory buffer.

llvm-svn: 167628
2012-11-09 19:40:45 +00:00
Douglas Gregor 188dbef26d When loading a module fails because it is out of date, rebuild that
module in place. <rdar://problem/10138913>

llvm-svn: 167539
2012-11-07 17:46:15 +00:00
Douglas Gregor 5290182856 Tease out the routine that reads the control block of an AST file from
the validation of an AST file against a specific set of options.

llvm-svn: 167504
2012-11-06 23:40:54 +00:00
Argyrios Kyrtzidis 2969e124a6 [PCH] Take into account the 'include' source location of a SM_SLOC_BUFFER_ENTRY.
llvm-svn: 167426
2012-11-06 00:35:04 +00:00
Argyrios Kyrtzidis 19c1706ecc [libclang] Correct how the index inside the local preprocessed entities array
is getting converted to a global PreprocessedEntityID.

llvm-svn: 167280
2012-11-02 02:31:22 +00:00
Argyrios Kyrtzidis d7c16b2543 [PCH] Remove the stat cache from the PCH file.
The stat cache became essentially useless ever since we started
validating all file entries in the PCH.
But the motivating reason for removing it now is that it also affected
correctness in this situation:

-You have a header without include guards (using "#pragma once" or #import)
-When creating the PCH:
  -The same header is referenced in an #include with different filename cases.
  -In the PCH, of course, we record only one file entry for the header file
  -But we cache in the PCH file the stat info for both filename cases

-Then the source files are updated and the header file is updated in a way that
 its size and modification time are the same but its inode changes

-When using the PCH:
  -We validate the headers, we check that header file and we create a file entry with its current inode
  -There's another #include with a filename with different case than the previously created file entry
  -In order to get its stat info we go through the cached stat info of the PCH and we receive the old inode
  -because of the different inodes, we think they are different files so we go ahead and include its contents.

Removing the stat cache will potentially break clients that are attempting to use the stat cache
as a way of avoiding having the actual input files available. If that use case is important, patches are welcome
to bring it back in a way that will actually work correctly (i.e., emit a PCH that is self-contained, coping with
literal strings, line/column computations, etc.).

This fixes rdar://5502805

llvm-svn: 167172
2012-10-31 20:59:50 +00:00
Rafael Espindola fd5e756ad0 getOriginalSourceFileName and getOriginalSourceFile can return a StringRef.
MaybeAddSystemRootToFilename doesn't need to return anything, it modifies
its argument.

llvm-svn: 166988
2012-10-30 00:38:13 +00:00
Argyrios Kyrtzidis efaa54a5a8 [PCH] The diagnostic state points can refer to previously created
diagnostic states; make sure the ASTReader sets the diagnostic state
properly instead of always recreating it.

Fixes rdar://12581618 & http://llvm.org/PR14181

llvm-svn: 166987
2012-10-30 00:27:21 +00:00
Douglas Gregor 164df7debd Remove the old predefines-buffer diffing code completely. It's been
replaced by the more efficient, cleaner preprocessor-option version
that occurs earlier in PCH validation.

llvm-svn: 166654
2012-10-25 00:30:23 +00:00
Douglas Gregor 471c1174c2 Fix computation of predefines buffer from the preprocessor-option
checking, and disable the old predefines-buffer-diff'ing code path.

llvm-svn: 166653
2012-10-25 00:25:27 +00:00
Douglas Gregor 55358ede64 The the preprocessor option validator to compute suggested
predefines. We're not quite ready to cut over to these suggested
predefines yet, however.

llvm-svn: 166648
2012-10-25 00:07:54 +00:00
Douglas Gregor b636875196 Teach the PCH validator to check the preprocessor options, especially
the macros that are #define'd or #undef'd on the command line. This
checking happens much earlier than the current macro-definition
checking and is far cleaner, because it does a direct comparison
rather than a diff of the predefines buffers. Moreover, it allows us
to use the result of this check to skip over PCH files within a
directory that have non-matching -D's or -U's on the command
line. Finally, it improves the diagnostics a bit for mismatches,
fixing <rdar://problem/8612222>.

The old predefines-buffer diff'ing will go away in a subsequent commit.

llvm-svn: 166641
2012-10-24 23:41:50 +00:00
Douglas Gregor b6af6c23cd (De-)serialize the preprocessor options, including macros defined,
-include'd files, etc. 

llvm-svn: 166614
2012-10-24 20:05:57 +00:00
Douglas Gregor 2d30236d16 (De-)serialize header search options.
llvm-svn: 166586
2012-10-24 16:50:34 +00:00
Douglas Gregor c6317dbf5e (De-)serialize the file system options.
llvm-svn: 166577
2012-10-24 15:49:58 +00:00
Douglas Gregor 8263ffb268 Serialize DiagnosticOptions to the AST file.
llvm-svn: 166572
2012-10-24 15:17:15 +00:00
Douglas Gregor fc9e7a2969 If the precompiled header named by "-include" is actually a directory,
check each of the files within that directory to determine if any of
them is an AST file that matches the language and target options. If
so, the first matching AST file is loaded. This fixes a longstanding
discrepency with GCC's precompiled header implementation.

llvm-svn: 166469
2012-10-23 06:18:24 +00:00
Douglas Gregor 4b29c16eec Allow clients of the AST reader to specify what kinds of AST load
failures they know how to tolerate, e.g., out-of-date input files or
configuration/version mismatches. Suppress the corresponding
diagnostics if the client can handle it.

No clients actually use this functionality, yet.

llvm-svn: 166449
2012-10-22 23:51:00 +00:00
Douglas Gregor 4750b77ea1 Collapse ASTReader::ReadSLocEntryRecord() into its only caller,
ReadSLocEntry(). No functionality change.

llvm-svn: 166447
2012-10-22 22:53:10 +00:00
Douglas Gregor c9ad5fb604 Distinguish the various kinds of AST file loading failures:
file corruption, compiler version mismatch, target/language
configuration mismatch, out-of-date AST file. No functionality change
yet.

llvm-svn: 166446
2012-10-22 22:50:17 +00:00
NAKAMURA Takumi 395a574ea2 ASTReader.cpp: Fix a warning. [-Wunused-variable]
llvm-svn: 166442
2012-10-22 21:50:39 +00:00
Douglas Gregor 3120d2c389 Eliminate the redundancy between source-file information in the source
manager block and input-file information in the control block. The
source manager entries now point back into the control block. Input
files are now lazily deserialized (if validation is disabled). Reduces
Cocoa's PCH by the ~70k I added when I introduced the redundancy in
r166251.

llvm-svn: 166429
2012-10-22 18:42:04 +00:00
Douglas Gregor 72be390e13 Move the set of files to be validated in an AST file into the control
block, so the input files are validated early on, before we've
committed to loading the AST file. This (accidentally) fixed a but
wherein the main file used to generate the AST file would *not* be
validated by the existing validation logic.

At the moment, this leads to some duplication of filenames between the
source manager block and input-file blocks, as well as validation
logic. This will be handled via an upcoming patch.

llvm-svn: 166251
2012-10-19 00:38:02 +00:00
Douglas Gregor 451dffaf64 Move OriginalDir from ASTReader to ModuleFile.
llvm-svn: 166233
2012-10-18 21:47:16 +00:00
Douglas Gregor 6bdae4b7c1 Move the "RelocatablePCH" bit from the ASTReader to the module file.
llvm-svn: 166229
2012-10-18 21:31:35 +00:00
Douglas Gregor e68c2cb502 Move information about the "original file" from the ASTReader into the
module files.

llvm-svn: 166228
2012-10-18 21:18:25 +00:00
Axel Naumann dd433f0b2f From Vassil Vassilev: enable Sema to deal with multiple ExternalSemaSources.
llvm-svn: 166208
2012-10-18 19:05:02 +00:00
Douglas Gregor fad10d8568 Collapse the original file name and original file ID records into a
single record. 

llvm-svn: 166206
2012-10-18 18:36:53 +00:00
Douglas Gregor 0aa21c98a6 Collapse the "version control revision/tag" AST file record into the
metadata record, which already had other version information. Clean up
the block info block along the way.

llvm-svn: 166204
2012-10-18 18:27:37 +00:00
Douglas Gregor 4d3611ca82 Split the target options out into their own record within the AST
file's control block.

llvm-svn: 166195
2012-10-18 17:58:09 +00:00
Douglas Gregor 112b907dbb Start factoring the on-disk records for an AST file into a control
block, which stores information about how the AST file to generated,
from the AST block, which stores the actual serialized AST. The
information in the control block should be enough to determine whether
the AST file is up-to-date and compatible with the current translation
unit, and reading it should not cause any side effects that aren't
easy to undo. That way, we can back out from an attempt to read an
incompatible or out-of-date AST file.

Note that there is still more factoring to do. In particular,
information about the source files used to generate the AST file
(along with their time stamps, sizes, etc.) still resides in the
source manager block. 

llvm-svn: 166166
2012-10-18 05:31:06 +00:00
Douglas Gregor cb177f15e7 Serialize TargetOptions into an AST file, and make sure that we keep
target options around so they can be accessed at any point (rather
than keeping them transient).

llvm-svn: 166072
2012-10-16 23:40:58 +00:00
Douglas Gregor 5952766628 Introduce the notion of excluded headers into the module map
description. Previously, one could emulate this behavior by placing
the header in an always-unavailable submodule, but Argyrios guilted me
into expressing this idea properly.

llvm-svn: 165921
2012-10-15 06:28:11 +00:00
Douglas Gregor cfa46a82b8 Track which particular submodule #undef's a macro, so that the actual
#undef only occurs if that submodule is imported.

llvm-svn: 165773
2012-10-12 00:16:50 +00:00
Douglas Gregor 5968b1b71f Diagnose the expansion of ambiguous macro definitions. This can happen
only with modules, when two disjoint modules #define the same
identifier to different token sequences.

llvm-svn: 165746
2012-10-11 21:07:39 +00:00
Douglas Gregor e740089d29 Introduce a simple "hint" scheme to eliminate the quadratic behavior
associated with deserializing macro history for an identifier.

llvm-svn: 165729
2012-10-11 17:41:54 +00:00
Douglas Gregor d2acff9c3e Make the deserialization of PendingMacroIDs deterministic.
llvm-svn: 165727
2012-10-11 17:31:34 +00:00
Douglas Gregor 2f8925e257 Remove the ASTDeserializationListener's MacroVisible() callback, which
is no longer necessary, as well as the little bit of infrastructure in
the AST writer that used it.

llvm-svn: 165684
2012-10-11 00:51:27 +00:00
Douglas Gregor 0634737452 Remove an unused bit from the serialized IdentifierInfo
llvm-svn: 165683
2012-10-11 00:48:48 +00:00
Douglas Gregor 5a4649b034 Deserialize macro history when we deserialize an identifier that has
macro history.

When deserializing macro history, we arrange history such that the
macros that have definitions (that haven't been #undef'd) and are
visible come at the beginning of the list, which is what the
preprocessor and other clients of Preprocessor::getMacroInfo()
expect. If additional macro definitions become visible later, they'll
be moved toward the front of the list. Note that it's possible to have
ambiguities, but we don't diagnose them yet.

There is a partially-implemented design decision here that, if a
particular identifier has been defined or #undef'd within the
translation unit, that definition (or #undef) hides any macro
definitions that come from imported modules. There's still a little
work to do to ensure that the right #undef'ing happens.

Additionally, we'll need to scope the update records for #undefs, so
they only kick in when the submodule containing that update record
becomes visible.

llvm-svn: 165682
2012-10-11 00:46:49 +00:00
Argyrios Kyrtzidis e445c7236e When indexing a module file, for the ppIncludedFile callback give
an invalid location if the location points to the synthetic buffer
for the module input.

llvm-svn: 165592
2012-10-10 02:12:47 +00:00
Argyrios Kyrtzidis 130190ffff [modules] Consistently construct a buffer as input to build the module.
This means the main file for modules will always be a virtual one.

llvm-svn: 165591
2012-10-10 02:12:39 +00:00
Douglas Gregor cb28f9d7ad Rework the (de-)serialization of macros, as stored in
MacroInfo*. Instead of simply dumping an offset into the current file,
give each macro definition a proper ID with all of the standard
modules-remapping facilities. Additionally, when a macro is modified
in a subsequent AST file (e.g., #undef'ing a macro loaded from another
module or from a precompiled header), provide a macro update record
rather than rewriting the entire macro definition. This gives us
greater consistency with the way we handle declarations, and ties
together macro definitions much more cleanly.

Note that we're still not actually deserializing macro history (we
never were), but it's far easy to do properly now.

llvm-svn: 165560
2012-10-09 23:05:51 +00:00
Douglas Gregor 7c0990ba35 Make the order of visitation of the pending bodies in the AST reader
deterministic.

llvm-svn: 165515
2012-10-09 17:50:23 +00:00
Douglas Gregor a6017bbd52 When we load a function or method body from an AST file, we check
whether that function/method already has a body (loaded from some
other AST file), as introduced in r165137. Delay this check until
after the redeclaration chains have been wired up.

While I'm here, make the loading of method bodies lazy.

llvm-svn: 165513
2012-10-09 17:21:28 +00:00
Douglas Gregor 8cb174654f If a macro has been #undef'd in a precompiled header, we still need to
write out the macro history for that macro. Similarly, we need to cope
with reading a macro definition that has been #undef'd.

Take advantage of this new ability so that global code-completion
results can refer to #undef'd macros, rather than losing them
entirely. For multiply defined/#undef'd macros, we will still get the
wrong result, but it's better than getting no result.

llvm-svn: 165502
2012-10-09 16:01:50 +00:00
Argyrios Kyrtzidis c597c8c48b [Modules] Introduce Module::TopHeaders which is a set of top-level headers
that are associated with a (sub)module.

llvm-svn: 165279
2012-10-05 00:22:33 +00:00
Abramo Bagnara aeeb989cc4 Fixed FunctionTypeLoc source range.
llvm-svn: 165259
2012-10-04 21:42:10 +00:00
Douglas Gregor 559458c830 Revert most of the functionality in r165001. Instead, make sure that
the ASTReader doesn't attach a body to a function that is already
defined elsewhere.

llvm-svn: 165137
2012-10-03 18:34:48 +00:00
Argyrios Kyrtzidis aedf7144d1 Set the file entry for a Module* that was created during deserialization
of a module file.

llvm-svn: 165086
2012-10-03 01:58:42 +00:00
Argyrios Kyrtzidis 10e7846abf [libclang] When indexing an AST file, only deserialize the file level
declarations of the current primary module.

llvm-svn: 165046
2012-10-02 21:09:13 +00:00
Argyrios Kyrtzidis d4fcf58070 [libclang] When indexing an AST file, only deserialize the preprocessing record
entities of the current primary module.

llvm-svn: 165023
2012-10-02 16:10:51 +00:00
Argyrios Kyrtzidis f590e094ad Add info in the preprocessing record whether an inclusion directive
resulted in an automatic module import.

llvm-svn: 165022
2012-10-02 16:10:46 +00:00
Axel Naumann d9a25b3c17 Only those InterestingDecls that got added to the AST should be passed to the ASTConsumer.
llvm-svn: 165001
2012-10-02 12:18:46 +00:00
Axel Naumann 63469422c4 Merge pending instantiations instead of overwriting existing ones.
Check whether a pending instantiation needs to be instantiated (or whether an instantiation already exists).
Verify the size of the PendingInstantiations record (was only checking size of existing PendingInstantiations).

Migrate Obj-C++ part of redecl-merge into separate test, now that this is growing.
templates.mm: test that CodeGen has seen exactly one definition of template instantiations.
redecl-merge.m: use "@" specifier for expected-diagnostics.

llvm-svn: 164993
2012-10-02 09:09:43 +00:00
Axel Naumann a8243e9aa2 The Redeclarable part of named decls is read before their name.
Lookup can nevertheless find them due to the serialized lookup table.
For instance when reading a template decl's templatedDecl, it will search for existing decls that it could be a redeclaration of, and find the half-read template decl.
Thus there is no point in asserting the names of decls.

llvm-svn: 164932
2012-10-01 09:51:27 +00:00
Eli Friedman b826a00857 Fix the AST representation for non-type template arguments to encode
enough information so we can mangle them correctly in cases involving
dependent parameter types. (This specifically impacts cases involving
null pointers and cases involving parameters of reference type.)
Fix the mangler to use this information instead of trying to scavenge
it out of the parameter declaration.

<rdar://problem/12296776>.

llvm-svn: 164656
2012-09-26 02:36:12 +00:00
Alexander Kornienko 1d26c02722 Macro history (de-)serialization. Deserialization currently reads only the latest macro definition. Needs more work.
Summary: Passes all tests (+ the new one with code completion), but needs a thorough review in part related to modules.

Reviewers: doug.gregor

Reviewed By: alexfh

CC: cfe-commits, rsmith

Differential Revision: http://llvm-reviews.chandlerc.com/D41

llvm-svn: 164610
2012-09-25 17:18:14 +00:00
Douglas Gregor e769d862ee Make sure that we don't end up making an #undef'd macro visible after
the fact. Test cases will come when we're actually (de-)serializing
macro history.

llvm-svn: 164549
2012-09-24 19:56:18 +00:00
Argyrios Kyrtzidis 6fa1682368 [PCH] After deserializing a DeclContext, if it has external lexical decls but not
external visible decls, call DeclContext::setMustBuildLookupTable so that the
"lazy decls" bit of the LookupPtr is set.

Previously, in non-C++, if there were no new declarations causing the "lazy decls" bit
to be set, then DeclContext::lookups_begin() would fail to return the decls from the PCH.

Fixes rdar://12316296.

llvm-svn: 164351
2012-09-21 01:30:00 +00:00
Eli Friedman 34866c7719 Change the representation of builtin functions in the AST
(__builtin_* etc.) so that it isn't possible to take their address.
Specifically, introduce a new type to represent a reference to a builtin
function, and a new cast kind to convert it to a function pointer in the
operand of a call.  Fixes PR13195.

llvm-svn: 162962
2012-08-31 00:14:07 +00:00
Benjamin Kramer fc6eb7d383 Reduce duplicated hash map lookups.
llvm-svn: 162361
2012-08-22 15:37:55 +00:00
Richard Smith 1226c60593 Remove trailing return flag from FunctionTypeLoc, since we now carry that
information on FunctionProtoType. (This also fixes one of *many* misalignment
problems in the TypeLoc hierarchy...)

llvm-svn: 161901
2012-08-14 22:51:13 +00:00
Richard Smith d3b5c90865 Final piece of core issue 1330: delay computing the exception specification of
a defaulted special member function until the exception specification is needed
(using the same criteria used for the delayed instantiation of exception
specifications for function temploids).

EST_Delayed is now EST_Unevaluated (using 1330's terminology), and, like
EST_Uninstantiated, carries a pointer to the FunctionDecl which will be used to
resolve the exception specification.

This is enabled for all C++ modes: it's a little faster in the case where the
exception specification isn't used, allows our C++11-in-C++98 extensions to
work, and is still correct for C++98, since in that mode the computation of the
exception specification can't fail.

The diagnostics here aren't great (in particular, we should include implicit
evaluation of exception specifications for defaulted special members in the
template instantiation backtraces), but they're not much worse than before.

Our approach to the problem of cycles between in-class initializers and the
exception specification for a defaulted default constructor is modified a
little by this change -- we now reject any odr-use of a defaulted default
constructor if that constructor uses an in-class initializer and the use is in
an in-class initialzer which is declared lexically earlier. This is a closer
approximation to the current draft solution in core issue 1351, but isn't an
exact match (but the current draft wording isn't reasonable, so that's to be
expected).

llvm-svn: 160847
2012-07-27 04:22:15 +00:00
Argyrios Kyrtzidis 6d7833f1b6 Introduce a flag in SourceManager to treat non-system source files
as "volatile", meaning there's a high enough chance that they may
change while we are trying to use them.

This flag is only enabled by libclang.
Currently "volatile" source files will be stat'ed immediately
before opening them, because the file size stat info
may not be accurate since when we got it (e.g. from the PCH).
This avoids crashes when trying to reference mmap'ed memory
from a file whose size is not what we expect.

Note that there's still a window for a racing issue to occur
but the window for it should be way smaller than before.
We can consider later on to avoid mmap completely on such files.

rdar://11612916

llvm-svn: 160074
2012-07-11 20:59:04 +00:00
Dmitri Gribenko 7dd29d4d3d Don't store pointers into a std::vector (RawCommentList::Comments). Although
currently we take address of std::vector's contents only after we finished
adding all comments (so no reallocation can happen), this will change in
future.

llvm-svn: 159845
2012-07-06 18:19:34 +00:00
Argyrios Kyrtzidis 442dd80715 [PCH] Make sure that all newly introduced visible decls in a DeclContext
coming from an AST file are registered for serialization.

A static data member instantiation of in a chained PCH could be missed
when serializing decls; the result was that when emitting the visible decls
map of its DeclContext, we would use a DeclID that was not actually emitted,
leading to crashes or hangs.

Fix this by making sure such decls are always registered for serialization.
Also introduce extra sanity checks to make sure we don't register new
declarations or types after we have serialized the types/decls block.

rdar://11728990

llvm-svn: 159550
2012-07-02 19:19:01 +00:00
Meador Inge cfb6090912 PR13189: va_list broken with precompiled headers
For some targets a structure named __va_list_tag is built to help define
the __builtin_va_list type.  However, __va_list_tag was not being treated as a
predefined type thus causing problems when serializing the AST.  This commit
fixes that oversight by adding the necessary support to treat __va_list_tag
as a predefined type.

llvm-svn: 159508
2012-07-01 15:57:25 +00:00
Chandler Carruth 029ea4ad29 Fix a warning on a fully covered switch with a default:
../tools/clang/lib/Serialization/ASTReader.cpp:6316:9: warning: default label in switch which covers all enumeration values [-Wcovered-switch-default]

Also fix the indentation here to match the coding conventions.

llvm-svn: 158794
2012-06-20 06:47:54 +00:00
John McCall 5fb5df9c83 Restructure how the driver communicates information about the
target Objective-C runtime down to the frontend:  break this
down into a single target runtime kind and version, and compute
all the relevant information from that.  This makes it
relatively painless to add support for new runtimes to the
compiler.  Make the new -cc1 flag, -fobjc-runtime=blah-x.y.z,
available at the driver level as a better and more general
alternative to -fgnu-runtime and -fnext-runtime.  This new
concept of an Objective-C runtime also encompasses what we
were previously separating out as the "Objective-C ABI", so
fragile vs. non-fragile runtimes are now really modelled as
different kinds of runtime, paving the way for better overall
differentiation.

As a sort of special case, continue to accept the -cc1 flag
-fobjc-runtime-has-weak, as a sop to PLCompatibilityWeak.

I won't go so far as to say "no functionality change", even
ignoring the new driver flag, but subtle changes in driver
semantics are almost certainly not intended.

llvm-svn: 158793
2012-06-20 06:18:46 +00:00
Kaelyn Uhrain 272d718808 Add the PCH file name to the message about not being able to read the PCH.
Also add a couple of unit tests to check the invalid-PCH error messages
to satisfy PR4568 and for the assertion (introduced in r149918 and fixed
in r158769) that would cause clang to crash when given an empty PCH.

llvm-svn: 158772
2012-06-20 00:36:03 +00:00
Dmitri Gribenko aab8383a2b Structured comment parsing, first step.
* Retain comments in the AST
* Serialize/deserialize comments
* Find comments attached to a certain Decl
* Expose raw comment text and SourceRange via libclang

llvm-svn: 158771
2012-06-20 00:34:58 +00:00
Meador Inge 5d3fb22bac Explicitly build __builtin_va_list.
The target specific __builtin_va_list types are now explicitly built instead
of injecting strings into the preprocessor input.

llvm-svn: 158592
2012-06-16 03:34:49 +00:00
Douglas Gregor 02c2dbf45e Switch LineTableInfo to use FileID instead of int for file references,
from Tom Honermann!

llvm-svn: 158211
2012-06-08 16:40:28 +00:00
Benjamin Kramer 6003ad5848 Plug a long standing memory leak in TemplateArgument.
The integral APSInt value is now stored in a decomposed form and the backing
store for large values is allocated via the ASTContext. This way its not
leaked as TemplateArguments are never destructed when they are allocated in
the ASTContext. Since the integral data is immutable it is now shared between
instances, making copying TemplateArguments a trivial operation.

Currently getting the integral data out of a TemplateArgument requires creating
a new APSInt object. This is cheap when the value is small but can be expensive
if it's not. If this turns out to be an issue a more efficient accessor could
be added.

llvm-svn: 158150
2012-06-07 15:09:51 +00:00
David Blaikie 40ed29730b Revert Decl's iterators back to pointer value_type rather than reference value_type
In addition, I've made the pointer and reference typedef 'void' rather than T*
just so they can't get misused. I would've omitted them entirely but
std::distance likes them to be there even if it doesn't use them.

This rolls back r155808 and r155869.

Review by Doug Gregor incorporating feedback from Chandler Carruth.

llvm-svn: 158104
2012-06-06 20:45:41 +00:00
Benjamin Kramer d1d76b2da7 Remove unused private member variables found by clang's new -Wunused-private-field.
llvm-svn: 158086
2012-06-06 17:32:50 +00:00
Argyrios Kyrtzidis 0f7d7ab968 [PCH] Really, pinky swear, fix for PR12689
rdar://11353109

llvm-svn: 156145
2012-05-04 01:49:36 +00:00
Argyrios Kyrtzidis 6eec06d0d4 [PCH] When validating that the files coming from PCH did not change, also
validate that we didn't override the contents of any of such files.

If this is detected, emit a diagnostic error and recover gracefully
by using the contents of the original file that the PCH was built from.

Part of rdar://11305263

llvm-svn: 156107
2012-05-03 21:50:39 +00:00
David Blaikie 2d7c57ec1d Remove the ref/value inconsistency in filter_decl_iterator.
filter_decl_iterator had a weird mismatch where both op* and op-> returned T*
making it difficult to generalize this filtering behavior into a reusable
library of any kind.

This change errs on the side of value, making op-> return T* and op* return
T&.

(reviewed by Richard Smith)

llvm-svn: 155808
2012-04-30 02:36:29 +00:00
Argyrios Kyrtzidis 0334d3300d [PCH] In ASTReader::completeVisibleDeclsMap, after we loaded all visible decls, mark
the declaration context as not having external visible storage any more.

This should improve performance as we won't needlessly reload the visible decls multiple times
and seems to fix the i386 crash in rdar://11327522.

llvm-svn: 155649
2012-04-26 18:34:14 +00:00
Richard Smith 8b987a9976 Fix serialization of uninstantiated exception specifications. Patch by Li Kan,
test by me.

llvm-svn: 155289
2012-04-21 17:47:47 +00:00
Nick Lewycky 2bd0ab2b11 Implement the all_lookups_iterator for PCH as a follow-up to r153970. This
includes a patch from Matthias Kleine with a regression testcase!

Adds a new iterator 'data_iterator' to OnDiskHashTable which doesn't try to
reconstruct the external_key from the internal_key, which is useful for traits
that don't store enough information to do that mapping in their key. Also
deletes the 'item_iterator' from OnDiskHashTable as dead code.

llvm-svn: 154784
2012-04-16 02:51:46 +00:00
Benjamin Kramer 89f0b2d8a2 Use forward declarations for ASTDeclContextNameLookupTable and add a missing delete.
It would be nice to use OwningPtr here, but DeclContextInfo is stored in a DenseMap.

llvm-svn: 154763
2012-04-15 12:36:49 +00:00
Ted Kremenek e69340c42c Remove dead assignment to local variable.
llvm-svn: 153985
2012-04-04 00:55:21 +00:00
Douglas Gregor 6a37784a35 Eliminate obvious use-after-free. Fixes PR12433 / <rdar://problem/11168333>.
llvm-svn: 153982
2012-04-04 00:34:49 +00:00
Argyrios Kyrtzidis bf6c3395db [PCH] When we are replacing a decl in a chained PCH that is also a DeclContext,
make sure to fully load its external lexical and visible declarations before
re-writing it.

rdar://10914192

llvm-svn: 153254
2012-03-22 16:08:04 +00:00
David Blaikie bbafb8a745 Unify naming of LangOptions variable/get function across the Clang stack (Lex to AST).
The member variable is always "LangOpts" and the member function is always "getLangOpts".

Reviewed by Chris Lattner

llvm-svn: 152536
2012-03-11 07:00:24 +00:00
Argyrios Kyrtzidis 8dbcfc39cd [libclang] Fix a crash when serializing a preprocessing record that contains
an #include entry that did not resolve to header file.

Part of rdar://11007039

llvm-svn: 152275
2012-03-08 01:08:28 +00:00
Argyrios Kyrtzidis 4a280ff48f [PCH] Mark a PCH file with a flag to indicate if the serialized AST had
compiler errors or not.

-Control whether ASTReader should reject such a PCH by a boolean flag at ASTReader's creation time.
By default, such a PCH file will be rejected with an error when trying to load it.

[libclang] Allow clang_saveTranslationUnit to create a PCH file even if compiler errors
occurred.
-Have libclang API calls accept a PCH that had compiler errors.

The general idea is that we want libclang to stay functional even if a PCH had a compiler error.
rdar://10976363.

llvm-svn: 152192
2012-03-07 01:51:17 +00:00
Argyrios Kyrtzidis 647dcd80f0 [preprocessor] Enhance PreprocessingRecord to keep track of locations of conditional directives.
Introduce PreprocessingRecord::rangeIntersectsConditionalDirective() which returns
true if a given range intersects with a conditional directive block.

llvm-svn: 152018
2012-03-05 05:48:17 +00:00
Argyrios Kyrtzidis 981a961d03 Move llvm/ADT/SaveAndRestore.h -> llvm/Support/SaveAndRestore.h.
Needs llvm update.

llvm-svn: 151829
2012-03-01 19:45:56 +00:00
Argyrios Kyrtzidis bb5abc7b49 Move "clang/Analysis/Support/SaveAndRestore.h" to "llvm/ADT/SaveAndRestore.h"
to make it more widely available.

Depends on llvm commit r151564

llvm-svn: 151566
2012-02-27 21:09:45 +00:00
Argyrios Kyrtzidis 335c5a42e9 Don't record nested macro expansions in the preprocessing record,
it can only bring pain when dealing with preprocessor abuse (see: boost).

rdar://10898986

llvm-svn: 151427
2012-02-25 02:41:16 +00:00
Argyrios Kyrtzidis 969fdfddd2 [PCH] Recover gracefully if the ASTReader detects that a file is different
from the one stored in the PCH/AST, while trying to load a SLocEntry.

We verify that all files of the PCH did not change before loading it but this is not enough because:

- The AST may have been 1) kept around, 2) to do queries on it.
- We may have 1) verified the PCH and 2) started parsing.

Between 1) and 2) files may change and we are going to have crashes because the rest of clang
cannot deal with the ASTReader failing to read a SLocEntry.

Handle this by recovering gracefully in such a case, by initializing the SLocEntry
with the info from the PCH/AST as well as reporting failure by the ASTReader.

rdar://10888929

llvm-svn: 151004
2012-02-20 23:58:07 +00:00
Douglas Gregor 81495f341d Within the body of a lambda expression, decltype((x)) for an
id-expression 'x' will compute the type based on the assumption that
'x' will be captured, even if it isn't captured, per C++11
[expr.prim.lambda]p18. There are two related refactors that go into
implementing this:

  1) Split out the check that determines whether we should capture a
  particular variable reference, along with the computation of the
  type of the field, from the actual act of capturing the
  variable. 
  2) Always compute the result of decltype() within Sema, rather than
  AST, because the decltype() computation is now context-sensitive.

llvm-svn: 150347
2012-02-12 18:42:33 +00:00
Richard Smith 5e580292ac Track whether a function type has a trailing return type as type sugar. Use this
to pretty-print such function types better, and to fix a case where we were not
instantiating templates in lexical order. In passing, move the Variadic bit from
Type's bitfields to FunctionProtoType to get the Type bitfields down to 32 bits.
Also ensure that we always substitute the return type of a function when
substituting explicitly-specified arguments, since that can cause us to bail
out with a SFINAE error before we hit a hard error in parameter substitution.

llvm-svn: 150241
2012-02-10 09:58:53 +00:00
Argyrios Kyrtzidis 5605de7c8b Fix ASTReader::FinishedDeserializing().
We were passing a decl to the consumer after all pending deserializations were finished
but this was not enough; due to processing by the consumer we may end up into yet another
deserialization process but the way FinishedDeserializing() was setup we would not ensure
that everything was fully deserialized before returning to the consumer.

Separate ASTReader::FinishedDeserializing() into two semantic actions.
The first is ensuring that a deserialization process ends up will fully deserialized decls/types even
if the process is started by the consumer.
The second is pushing "interesting" decls to the consumer; we make sure that we don't re-enter this
section recursively be checking a variable.

llvm-svn: 150160
2012-02-09 07:31:52 +00:00
Abramo Bagnara e0a70b2656 Added source location for the template keyword in DependentTemplateSpecializationTypeLoc nodes (DTSTLoc).
The new info is propagated to TSTLoc on template instantiation, getting rid of 3 FIXMEs in TreeTransform.h and another one Parser.cpp.

Simplified code in TypeSpecLocFiller visitor methods for DTSTLoc and DependentNameTypeLoc by removing what now seems to be dead code (adding corresponding assertions). 

llvm-svn: 149923
2012-02-06 22:45:07 +00:00
Abramo Bagnara 9033e2b358 Removed redundant location info from ElaboratedTypeLoc / DependentNameLoc / DependentTSTLoc. Uniformed names referencing elaborated keyword. No intended functionality changes.
llvm-svn: 149889
2012-02-06 19:09:27 +00:00
Abramo Bagnara 48c05be124 Added location for template keyword in TemplateSpecializationTypeLoc. In the process removed some naming ambiguities.
llvm-svn: 149870
2012-02-06 14:41:24 +00:00
Dylan Noblesmith 2c1dd2716a Basic: import SmallString<> into clang namespace
(I was going to fix the TODO about DenseMap too, but
that would break self-host right now. See PR11922.)

llvm-svn: 149799
2012-02-05 02:13:05 +00:00
Dylan Noblesmith e27789991d Basic: import OwningPtr<> into clang namespace
llvm-svn: 149798
2012-02-05 02:12:40 +00:00
Douglas Gregor 8992928274 Thread a TargetInfo through to the module map; we'll need it for
target-specific module requirements.

llvm-svn: 149224
2012-01-30 06:01:29 +00:00
Douglas Gregor a686e1b05d Introduce module attributes into the module map grammar, along with a
single attribute ("system") that allows us to mark a module as being a
"system" module. Each of the headers that makes up a system module is
considered to be a system header, so that we (for example) suppress
warnings there.

If a module is being inferred for a framework, and that framework
directory is within a system frameworks directory, infer it as a
system framework.

llvm-svn: 149143
2012-01-27 19:52:33 +00:00
Douglas Gregor 404cddec1b Reimplement (de-)serialization of Objective-C categories to eliminate
the direct serialization of the linked-list structure. Instead, use a
scheme similar to how we handle redeclarations, with redeclaration
lists on the side. This addresses several issues:
  - In cases involving mixing and matching of many categories across
  many modules, the linked-list structure would not be consistent
  across different modules, and categories would get lost.
  - If a module is loaded after the class definition and its other
  categories have already been loaded, we wouldn't see any categories
  in the newly-loaded module.

llvm-svn: 149112
2012-01-27 01:47:08 +00:00
Douglas Gregor d1f01d79e5 Introduce a generation number for selector lookups in the global
method pool, so that we don't perform the same lookups into the same
PCH/module file repeatedly.

llvm-svn: 148895
2012-01-25 01:14:32 +00:00
Douglas Gregor e171601ff6 Rework the external Sema source's ReadMethodPool() so that it doesn't
return pre-built lists. Instead, it feeds the methods it deserializes
to Sema so that Sema can unique them, which keeps the chains shorter.

llvm-svn: 148889
2012-01-25 00:49:42 +00:00
Douglas Gregor 247afcc6a9 Only mark an IdentifierInfo as having changed since deserialization
when it actually has changed (and not, e.g., when we've simply attached a
deserialized macro definition). Good for ~1.5% reduction in module
file size, mostly in the identifier table.

llvm-svn: 148808
2012-01-24 15:24:38 +00:00
Douglas Gregor 4fc9f3e819 Optimize unqualified/global name lookup in modules by introducing a
generational scheme for identifiers that avoids searching the hash
tables of a given module more than once for a given
identifier. Previously, loading any new module invalidated all of the
previous lookup results for all identifiers, causing us to perform the
lookups repeatedly.

llvm-svn: 148412
2012-01-18 20:56:22 +00:00
Douglas Gregor f3bccd77fc Rework the way in which we (de-)serialize the declarations
corresponding to TagType and ObjCInterfaceType. Previously, we would
serialize the definition (if available) or the canonical declaration
(if no definition was available). However, this can end up forcing the
deserialization of the definition even through we might not want to
yet. 

Instead, always serialize the canonical declaration reference in the
TagType/ObjCInterfaceType entry, and as part of loading a pending
definition, update the "decl" pointer within the type node to point at
the definition. This is more robust in hard-to-isolate cases
where the *Type gets built and filled in before we see the definition.

llvm-svn: 148323
2012-01-17 19:21:53 +00:00
Douglas Gregor d53ae83516 Delay the creation of the built-in Objective-C class 'Protocol' by
moving it from a "special type" to a predefined declaration, as we do
for id, Class, and SEL.

llvm-svn: 148313
2012-01-17 18:09:05 +00:00
David Blaikie 8a40f700e6 Remove unreachable code in Clang. (replace with llvm_unreachable where appropriate or when GCC requires it)
llvm-svn: 148292
2012-01-17 06:56:22 +00:00
Douglas Gregor 358cd44170 Completely re-implement (de-)serialization of redeclaration
chains, again. The prior implementation was very linked-list oriented, and
the list-splicing logic was both fairly convoluted (when loading from
multiple modules) and failed to preserve a reasonable ordering for the
redeclaration chains.

This new implementation uses a simpler strategy, where we store the
ordered redeclaration chains in an array-like structure (indexed based
on the first declaration), and use that ordering to add individual
deserialized declarations to the end of the existing chain. That way,
the chain mimics the ordering from its modules, and a bug somewhere is
far less likely to result in a broken linked list.

llvm-svn: 148222
2012-01-15 16:58:34 +00:00
Douglas Gregor 68444de354 Reimplement RedeclarableTemplateDecl in terms of
Redeclarable<RedeclarableTemplateDecl>, eliminating a bunch of
redeclaration-chain logic both in RedeclarableTemplateDecl and
especially in its (de-)serialization.

As part of this, eliminate the RedeclarableTemplate<> class template,
which was an abstraction that didn't actually save anything.

llvm-svn: 148181
2012-01-14 15:13:49 +00:00
Douglas Gregor cfe7dc6b2f Implement redeclaration merging for namespaces defined in distinct
modules. Teach name lookup into namespaces to search in each of the
merged DeclContexts as well as the (now-primary) DeclContext. This
supports the common case where two different modules put something
into the same namespace.

llvm-svn: 147778
2012-01-09 17:30:44 +00:00
Douglas Gregor 768e5b1e9a Introduce a "Hidden" bit into Decl, to track whether that declaration
is hidden from name lookup. The previous hack of tweaking the
ModulePrivate bit when loading a declaration from a hidden submodule
was brittle.

Note that we now have 34 bits in Decl. I'll fix that next.

llvm-svn: 147658
2012-01-06 16:22:39 +00:00
Douglas Gregor de95ead949 Teach DeclContext deserialization to pay attention to endianness, from
David Fang and Takumi Nakamura. Fixes many PCH failures on PowerPC.

llvm-svn: 147657
2012-01-06 16:09:53 +00:00
Argyrios Kyrtzidis 9afd449e8f When loading an AST file, set SourceManager::MainFileID to the main file of the AST file,
as suggested by Tom Honermann.

llvm-svn: 147612
2012-01-05 21:36:25 +00:00
Douglas Gregor eb90e83085 Store the submodules of a module in source order, as they are stored
in the module map. This provides a bit more predictability for the
user, as well as eliminating the need to sort the submodules when
serializing them.

llvm-svn: 147564
2012-01-04 23:32:19 +00:00
Douglas Gregor a715bfff98 Introduce the core infrastructure needed to model redeclaration chains
for Objective-C protocols, including:
  - Using the first declaration as the canonical declaration
  - Using the definition as the primary DeclContext
  - Making sure that all declarations have a pointer to the definition
  data, and that we know which declaration is the definition
  - Serialization support for redeclaration chains and for adding
  definitions to already-serialized declarations.

However, note that we're not taking advantage of much of this code
yet, because we're still re-using ObjCProtocolDecls.

llvm-svn: 147410
2012-01-01 19:51:50 +00:00