hitting a submodule that was never actually created, e.g., because
that header wasn't parsed. In such cases, complain (because the
module's umbrella headers don't cover everything) and fall back to
including the header.
Later, we'll add a warning at module-build time to catch all such
cases. However, this fallback is important to eliminate assertions in
the ASTWriter when this happens.
llvm-svn: 146933
with a definition pointer (e.g., C++ and Objective-C classes), zip
through the redeclaration chain to make sure that all of the
declarations point to the definition data.
As part of this, realized again why the first redeclaration of an
entity in a file is important, and brought back that idea.
llvm-svn: 146886
redeclaration templates (RedeclarableTemplateDecl), similarly to the
way (de-)serialization is implemented for Redeclarable<T>. In the
process, found a simpler formulation for handling redeclaration
chains and implemented that in both places.
The new test establishes that we're building the redeclaration chains
properly. However, the FIXME indicates where we're tickling a
different bug that has to do with us not setting the DefinitionData
pointer properly in redeclarations that we detected after the
definition itself was deserialized. The (separable) fix for that bug
is forthcoming.
llvm-svn: 146883
imported modules that don't introduce any new entities of a particular
kind. Allow these entries to be replaced with entries for another
loaded module.
In the included test case, selectors exhibit this behavior.
llvm-svn: 146870
which there are no redeclarations. This reduced by size of the PCH
file for Cocoa.h by ~650k: ~536k of that was in the new
LOCAL_REDECLARATIONS table, which went from a ridiculous 540k down to
an acceptable 3.5k, while the rest was due to the more compact
abbreviated representation of redeclarable declaration kinds (which no
longer need to store the 'first' declaration ID).
llvm-svn: 146869
variable is initialized by a non-constant expression, and pass in the variable
being declared so that earlier-initialized fields' values can be used.
Rearrange VarDecl init evaluation to make this possible, and in so doing fix a
long-standing issue in our C++ constant expression handling, where we would
mishandle cases like:
extern const int a;
const int n = a;
const int a = 5;
int arr[n];
Here, n is not initialized by a constant expression, so can't be used in an ICE,
even though the initialization expression would be an ICE if it appeared later
in the TU. This requires computing whether the initializer is an ICE eagerly,
and saving that information in PCH files.
llvm-svn: 146856
chains. The previous implementation relied heavily on the declaration
chain being stored as a (circular) linked list on disk, as it is in
memory. However, when deserializing from multiple modules, the
different chains could get mixed up, leading to broken declaration chains.
The new solution keeps track of the first and last declarations in the
chain for each module file. When we load a declaration, we search all
of the module files for redeclarations of that declaration, then
splice together all of the lists into a coherent whole (along with any
redeclarations that were actually parsed).
As a drive-by fix, (de-)serialize the redeclaration chains of
TypedefNameDecls, which had somehow gotten missed previously. Add a
test of this serialization.
This new scheme creates a redeclaration table that is fairly large in
the PCH file (on the order of 400k for Cocoa.h's 12MB PCH file). The
table is mmap'd in and searched via a binary search, but it's still
quite large. A future tweak will eliminate entries for declarations
that have no redeclarations anywhere, and should
drastically reduce the size of this table.
llvm-svn: 146841
including deserializing their bodies, so that any other declarations that
get referenced in the body will be fully deserialized by the time we pass them to the consumer.
Could not reduce to a test case unfortunately. rdar://10587158.
llvm-svn: 146817
applies to an actual definition. Plus, clarify the purpose of this
field and give the accessor a different name, since getLocEnd() is
supposed to be the same as getSourceRange().getEnd().
llvm-svn: 146694
declarations and definitions) as ObjCInterfaceDecls within the same
redeclaration chain. This new representation matches what we do for
C/C++ variables/functions/classes/templates/etc., and makes it
possible to answer the query "where are all of the declarations of
this class?"
llvm-svn: 146679
redeclaration chain for Objective-C classes, 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 the definition knows that it is the definition.
- Serialization support for when a definition gets added to a
declaration that comes from an AST file.
However, note that we're not taking advantage of much of this code
yet, because we're still re-using ObjCInterfaceDecls.
llvm-svn: 146667
separately-allocated DefinitionData structure, which we manage the
same way as CXXRecordDecl::DefinitionData. This prepares the way for
making ObjCInterfaceDecls redeclarable, to more accurately model
forward declarations of Objective-C classes and eliminate the mutation
of ObjCInterfaceDecl that causes us serious trouble in the AST reader.
Note that ObjCInterfaceDecl's accessors are fairly robust against
being applied to forward declarations, because Clang (and Sema in
particular) doesn't perform RequireCompleteType/hasDefinition() checks
everywhere it has to. Each of these overly-robust cases is marked with
a FIXME, which we can tackle over time.
llvm-svn: 146644
belonged in the Serialization library, it's setting up a compilation,
not just deserializing.
This should fix PR11512, making Serialization actually be layered below
Frontend, a long standing layering violation in Clang.
llvm-svn: 146233
different from what the comments indicated. Also drop a no longer used
include that also violates the layering between Serialization and
Frontend.
llvm-svn: 146230
part of HeaderSearch. This function just normalizes filenames for use
inside of a synthetic include directive, but it is used in both the
Frontend and Serialization libraries so it needs a common home.
llvm-svn: 146227
diagnostics. Conflating them was highly confusing and makes it harder to
establish a firm layering separation between these two libraries.
llvm-svn: 146207
umbrella headers in the sense that all of the headers within that
directory (and eventually its subdirectories) are considered to be
part of the module with that umbrella directory. However, unlike
umbrella headers, which are expected to include all of the headers
within their subdirectories, Clang will automatically include all of
the headers it finds in the named subdirectory.
The intent here is to allow a module map to trivially turn a
subdirectory into a module, where the module's structure can mimic the
directory structure.
llvm-svn: 146165
header to also support umbrella directories. The umbrella directory
for an umbrella header is the directory in which the umbrella header
resides.
No functionality change yet, but it's coming.
llvm-svn: 146158
to re-export anything that it imports. This opt-in feature makes a
module behave more like a header, because it can be used to re-export
the transitive closure of a (sub)module's dependencies.
llvm-svn: 145811
when deserialized, fixing random crashes in libclang.
Also simplifies how OpaqueValueExprs are [de]serialized.
The reader/writer automatically retains pointer equality of sub-statements (when a
statement node is referenced in multiple nodes), so no need to manually handle it.
llvm-svn: 145752
"main" files that import modules. When loading any of these kinds of
AST files, we make the modules that were imported visible into the
translation unit that loaded the PCH file or preamble.
llvm-svn: 145737
precompiled header. Previously, we were trying to gather predefines
buffers from all kinds of AST files (which doesn't make sense) and
were performing some validation when AST files were loaded as main
files.
With these tweaks, using PCH files that import modules no longer fails
immediately (due to mismatched predefines buffers). However, module
visibility is lost, so this feature does not yet work.
llvm-svn: 145709
only the macro definitions from visible (sub)modules will actually be
visible. This provides the same behavior for macros that r145640
provided for declarations.
llvm-svn: 145683
(sub)module, all of the names may be hidden, just the macro names may
be exposed (for example, after the preprocessor has seen the import of
the module but the parser has not), or all of the names may be
exposed. Importing a module makes its names, and the names in any of
its non-explicit submodules, visible to name lookup (transitively).
This commit only introduces the notion of name visible and marks
modules and submodules as visible when they are imported. The actual
name-hiding logic in the AST reader will follow (along with test cases).
llvm-svn: 145586
a standard global/local scheme, so that submodule definitions will
eventually be able to refer to submodules in other top-level
modules. We'll need this functionality soonish.
llvm-svn: 145549
library, since modules cut across all of the libraries. Rename
serialization::Module to serialization::ModuleFile to side-step the
annoying naming conflict. Prune a bunch of ModuleMap.h includes that
are no longer needed (most files only needed the Module type).
llvm-svn: 145538
we may end up having added more pending stuff to do, so go in a loop until everything
is cleared out.
This fixes the error in rdar://10278815 which has a certain David Lynch-esque quality..
error: unknown type name 'BOOL'; did you mean 'BOOL'?
llvm-svn: 145536
submodules. This information will eventually be used for name hiding
when dealing with submodules. For now, we only use it to ensure that
the module "key" returned when loading a module will always be a
module (rather than occasionally being a FileEntry).
llvm-svn: 145497
inside an objc container that "contains" other file-level declarations.
When getting the array of file-level declarations that overlap with a file region,
we failed to report that the region overlaps with an objc container, if
the container had other file-level declarations declared lexically inside it.
Fix this by marking such declarations as "isTopLevelDeclInObjCContainer" in the AST
and handling them appropriately.
llvm-svn: 145109
file in the source manager. This allows us to properly create and use
modules described by module map files without umbrella headers (or
with incompletely umbrella headers). More generally, we can actually
build a PCH file that makes use of file -> buffer remappings, which
could be useful in libclang in the future.
llvm-svn: 144830
it is going to be rewritten (and the chain will be serialized again), otherwise we may form a cycle in its
categories list when deserializing.
Also introduce ASTMutationListener::CompletedObjCForwardRef to notify that a forward reference
was completed; using Decl's isChangedSinceDeserialization/setChangedSinceDeserialization
is bug inducing and kinda gross, we should phase it out.
Fixes infinite loop in rdar://10418538.
llvm-svn: 144465
In certain cases ASTReader would call the normal DiagnosticsEngine API to initialize
the state of diagnostic pragmas but DiagnosticsEngine would try to compare source locations
leading to crash because the main FileID was not yet initialized.
Yet another case of the ASTReader trying to use the normal APIs and inadvertently breaking
invariants. Fix this by having the ASTReader set up the internal state directly.
llvm-svn: 144153
property references to use a new PseudoObjectExpr
expression which pairs a syntactic form of the expression
with a set of semantic expressions implementing it.
This should significantly reduce the complexity required
elsewhere in the compiler to deal with these kinds of
expressions (e.g. IR generation's special l-value kind,
the static analyzer's Message abstraction), at the lower
cost of specifically dealing with the odd AST structure
of these expressions. It should also greatly simplify
efforts to implement similar language features in the
future, most notably Managed C++'s properties and indexed
properties.
Most of the effort here is in dealing with the various
clients of the AST. I've gone ahead and simplified the
ObjC rewriter's use of properties; other clients, like
IR-gen and the static analyzer, have all the old
complexity *and* all the new complexity, at least
temporarily. Many thanks to Ted for writing and advising
on the necessary changes to the static analyzer.
I've xfailed a small diagnostics regression in the static
analyzer at Ted's request.
llvm-svn: 143867
that it retains source location information for the type. Aside from
general goodness (being able to walk the types described in that
information), we now have a proper representation for dependent
delegating constructors. Fixes PR10457 (for real).
llvm-svn: 143410
Introduce a FILE_SORTED_DECLS [de]serialization record that contains
a file sorted array of file-level DeclIDs in a PCH/Module.
The rationale is to allow "targeted" deserialization of decls inside
a range of a source file.
Cocoa PCH increased by 0.8%
Difference of creation time for Cocoa PCH is below the noise level.
llvm-svn: 143238
of decl bit offsets.
This allows us to easily get at the location of a decl without deserializing it.
It increases size of Cocoa PCH by only 0.2%.
llvm-svn: 143123
AST file more lazy, so that we don't eagerly load that information for
all known identifiers each time a new AST file is loaded. The eager
reloading made some sense in the context of precompiled headers, since
very few identifiers were defined before PCH load time. With modules,
however, a huge amount of code can get parsed before we see an
@import, so laziness becomes important here.
The approach taken to make this information lazy is fairly simple:
when we load a new AST file, we mark all of the existing identifiers
as being out-of-date. Whenever we want to access information that may
come from an AST (e.g., whether the identifier has a macro definition,
or what top-level declarations have that name), we check the
out-of-date bit and, if it's set, ask the AST reader to update the
IdentifierInfo from the AST files. The update is a merge, and we now
take care to merge declarations before/after imports with declarations
from multiple imports.
The results of this optimization are fairly dramatic. On a small
application that brings in 14 non-trivial modules, this takes modules
from being > 3x slower than a "perfect" PCH file down to 30% slower
for a full rebuild. A partial rebuild (where the PCH file or modules
can be re-used) is down to 7% slower. Making the PCH file just a
little imperfect (e.g., adding two smallish modules used by a bunch of
.m files that aren't in the PCH file) tips the scales in favor of the
modules approach, with 24% faster partial rebuilds.
This is just a first step; the lazy scheme could possibly be improved
by adding versioning, so we don't search into modules we already
searched. Moreover, we'll need similar lazy schemes for all of the
other lookup data structures, such as DeclContexts.
llvm-svn: 143100
essence, the redeclaration chain for a class could end up in an
inconsistent state while deserializing multiple declarations in that
chain, where the circular linked list was not, in fact,
circular. Since only two redeclarations of the same entity will get
loaded when we're in this state, restore circularity when both have
been loaded. Fixes <rdar://problem/10324940> / PR11195.
llvm-svn: 143037
expressions: expressions which refer to a logical rather
than a physical l-value, where the logical object is
actually accessed via custom getter/setter code.
A subsequent patch will generalize the AST for these
so that arbitrary "implementing" sub-expressions can
be provided.
Right now the only client is ObjC properties, but
this should be generalizable to similar language
features, e.g. Managed C++'s __property methods.
llvm-svn: 142914
statements. As noted in the documentation for the AST node, the
semantics of __if_exists/__if_not_exists are somewhat different from
the way Visual C++ implements them, because our parsed-template
representation can't accommodate VC++ semantics without serious
contortions. Hopefully this implementation is "good enough".
llvm-svn: 142901
preprocessed entities that are #included in the range that we are interested.
This is useful when we are interested in preprocessed entities of a specific file, e.g
when we are annotating tokens. There is also an optimization where we cache the last
result of PreprocessingRecord::getPreprocessedEntitiesInRange and we re-use it if
there is a call with the same range as before.
rdar://10313365
llvm-svn: 142887
in such a case just write out a reference of a previously serialized Stmt, instead
of serializing it all over again.
This saves memory + space + [de]serializing time, and avoids blowing up memory
with pathological cases. rdar://10293911
llvm-svn: 142696
-Add the location of the class name to all objc container decls, not just ObjCInterfaceDecl.
-Make objc decls consistent with the rest of the NamedDecls and have getLocation() point to the
class name, not the location of '@'.
llvm-svn: 141061
Instead of always storing all source locations for the selector identifiers
we check whether all the identifiers are in a "standard" position; "standard" position is
-Immediately before the arguments: -(id)first:(int)x second:(int)y;
-With a space between the arguments: -(id)first: (int)x second: (int)y;
-For nullary selectors, immediately before ';': -(void)release;
In such cases we infer the locations instead of storing them.
llvm-svn: 140989
Instead of always storing all source locations for the selector identifiers
we check whether all the identifiers are in a "standard" position; "standard" position is
-Immediately before the arguments: [foo first:1 second:2]
-With a space between the arguments: [foo first: 1 second: 2]
-For nullary selectors, immediately before ']': [foo release]
In such cases we infer the locations instead of storing them.
llvm-svn: 140987
PreprocessingRecord's getPreprocessedEntitiesInRange.
Also remove all the stuff that were added in ASTUnit that are unnecessary now
that we do a binary search for preprocessed entities and deserialize only
what is necessary.
llvm-svn: 140063
check whether the requested location points inside the precompiled preamble,
in which case the returned source location will be a "loaded" one.
llvm-svn: 140060
which will do a binary search and return a pair of iterators
for preprocessed entities in the given source range.
Source ranges of preprocessed entities are stored twice currently in
the PCH/Module file but this will be fixed in a subsequent commit.
llvm-svn: 140058
don't call ReadSLocEntryRecord() directly because the entry may have
already been loaded in which case calling ReadSLocEntryRecord()
directly would trigger an assertion in SourceManager.
llvm-svn: 140052
arbitrary amount of code. This forces us to stage the AST writer more
strictly, ensuring that we don't assign a declaration ID to a
declaration until after we're certain that no more modules will get
loaded.
llvm-svn: 139974
-Use an array of offsets for all preprocessed entities
-Get rid of the separate array of offsets for just macro definitions;
for references to macro definitions use an index inside the preprocessed
entities array.
-Deserialize each preprocessed entity lazily, at first request; not in bulk.
Paves the way for binary searching of preprocessed entities that will offer
efficiency and will simplify things on the libclang side a lot.
llvm-svn: 139809
to the consumer without being fully deserialized).
The regression was on compiling boost.python and it was too difficult to get a reduced
test case unfortunately.
Also modify the logic of how objc methods are getting passed to the consumer;
codegen depended on receiving objc methods before the implementation decl.
Since the interesting objc methods are ones with a body and such methods only
exist inside an ObjCImplDecl, deserialize and pass to consumer all the methods
of ObCImplDecl when we see one.
Fixes http://llvm.org/PR10922 & rdar://10117105.
llvm-svn: 139644
language options. Use that .def file to declare the LangOptions class
and initialize all of its members, eliminating a source of annoying
initialization bugs.
AST serialization changes are next up.
llvm-svn: 139605
modifying directly for the preamble.
This avoids an awful, hard to find, bug where "PreprocessorOpts.DisablePCHValidation = true"
would be persistent for subsequent reparses of the translation unit which would result
in defines, present in command-line but not in the PCH, being ignored.
Fixes rdar://9615399.
llvm-svn: 139512
than having CodeGen check whether a declaration comes from an AST file
(which it shouldn't know or care about), make sure that the AST writer and
reader pass along "interesting" declarations that CodeGen needs to
know about.
llvm-svn: 139441
declaration was deserialized from an AST file. Use this instead of
Decl::getPCHLevel() wherever possible. This is a simple step toward
killing off Decl::getPCHLevel().
llvm-svn: 139427
ASTContext reference. Remove all of the extra checking and logic that
was used to cope with a NULL ASTContext. No effective functionality
change.
llvm-svn: 139413
identifier, also make them visible in the translation unit," which
isn't needed now that John's eliminated the AST dependency in blocks
CodeGen.
llvm-svn: 139408
'id' that can be used (only!) via a contextual keyword as the result
type of an Objective-C message send. 'instancetype' then gives the
method a related result type, which we have already been inferring for
a variety of methods (new, alloc, init, self, retain). Addresses
<rdar://problem/9267640>.
llvm-svn: 139275
Preprocessor, eliminating the constructor that was used by ASTUnit
(which didn't provide an ASTContext or Prepreprocessor). Ensuring that
both objects are non-NULL will simplify module loading (but none of
that is done yet).
llvm-svn: 138986
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
include guards don't show up as macro definitions in every translation
unit that imports a module. Macro definitions can, however, be
exported with the intentionally-ugly #__export_macro__
directive. Implement this feature by not even bothering to serialize
non-exported macros to a module, because clients of that module need
not (should not) know that these macros even exist.
llvm-svn: 138943
The initial incentive was to fix a crash when PCH chaining categories
to an interface, but the fix was done in the "modules way" that I hear
is popular with the kids these days.
Each module stores the local chain of categories and we combine them
when the interface is loaded. We also warn if non-dependent modules
introduce duplicate named categories.
llvm-svn: 138926
sure that all of the CXXConversionDecls go into the same
bucket. Otherwise, name lookup might not find them all. Fixes
<rdar://problem/10041960>.
llvm-svn: 138824
Empty lookups can occur in the DeclContext map when we are chaining PCHs, where
the empty lookup indicates that we already looked in ExternalASTSource.
llvm-svn: 138816
, such as list of forward @class decls, in a DeclGroup
node. Deal with its consequence throught clang. This
is in preparation for more Sema work ahead. // rdar://8843851.
Feel free to reverse if it breaks something important
and I am unavailable.
llvm-svn: 138709
from the given source. -emit-module behaves similarly to -emit-pch,
except that Sema is somewhat more strict about the contents of
-emit-module. In the future, there are likely to be more interesting
differences.
llvm-svn: 138595
to "when loading a particular module" validation, since it was only
validating local information anyway. This shouldn't change anything.
llvm-svn: 138583
redeclarations of a particular entity would occur in source
order. Friend declarations that occur within class templates (or
member classes thereof) do not follow this, nor would modules. Big
thanks to Erik Verbruggen for reducing this problem from the Very
Large Qt preamble testcase he found.
llvm-svn: 138557
given selector, rather than walking the chain backwards. Teach its
visitor how to merge multiple result sets into a single result set,
combining the results of selector lookup in several different modules
into a single result set.
llvm-svn: 138556
table when serializing an AST file. This was a holdover from the days
before chained PCH, and is a complete waste of time and storage
now. It's a good thing it's useless, because I have no idea how I
would have implemented MaterializeVisibleDecls efficiently in the
presence of modules.
llvm-svn: 138496
which supports both pre-order and post-order traversal via a visitor
mechanism. Use this depth-first search with a post-order traversal to
give predictable ordering semantics when walking all of the lexical
declarations in the translation unit.
Eventually, module imports will occur in the source code rather than
at the beginning, and we'll have to revisit this walk.
llvm-svn: 138490
module DAG-based lookup scheme. This required some reshuffling, so
that each module stores its own mapping from DeclContexts to their
lexical and visible sets for those DeclContexts (rather than one big
"chain").
Overall, this allows simple qualified name lookup into the translation
unit to gather results from multiple modules, with the lookup results
in module B shadowing the lookup results in module A when B imports A.
Walking all of the lexical declarations in a module DAG is still a
mess; we'll end up walking the loaded module list backwards, which
works fine for chained PCH but doesn't make sense in a DAG. I'll
tackle this issue as a separate commit.
llvm-svn: 138463
Currently getMacroArgExpandedLocation is very inefficient and for the case
of a location pointing at the main file it will end up checking almost all of
the SLocEntries. Make it faster:
-Use a map of macro argument chunks to their expanded source location. The map
is for a single source file, it's stored in the file's ContentCache and lazily
computed, like the source lines cache.
-In SLocEntry's FileInfo add an 'unsigned NumCreatedFIDs' field that keeps track
of the number of FileIDs (files and macros) that were created during preprocessing
of that particular file SLocEntry. This is useful when computing the macro argument
map in skipping included files while scanning for macro arg FileIDs that lexed from
a specific source file. Due to padding, the new field does not increase the size
of SLocEntry.
llvm-svn: 138225
different modules) more robust. It already handled (simple) merges of
the set of declarations attached to that identifier, so add a test
case that shows us getting two different declarations for the same
identifier (one struct, one function) from different modules, and are
able to use both of them.
llvm-svn: 138189
modules (those that no other module depends on) and performs a search
over all of the modules, visiting a new module only when all of the
modules that depend on it have already been visited. The visitor can
abort the search for all modules that a module depends on, which
allows us to minimize the number of lookups necessary when performing
a search.
Switch identifier lookup from a linear walk over the set of modules to
this module visitation operation. The behavior is the same for simple
PCH and chained PCH, but provides the proper search order for
modules. Verified with printf debugging, since we don't have enough in
place to actually test this.
llvm-svn: 138187
has already been loaded before allocating a new Module structure. If
the module has already been loaded (uniquing based on file name), then
just return the existing module rather than trying to load it again.
This allows us to load a DAG of modules. Introduce a simple test case
that forms a diamond-shaped module graph, and illustrates that a
source file importing the bottom of the diamond can see declarations
in all four of the modules that make up the diamond.
Note that this version moves the file-opening logic into the module
manager, rather than splitting it between the module manager and the
AST reader. More importantly, it properly handles the
weird-but-possibly-useful case of loading an AST file from "-".
llvm-svn: 138030
Teach ModuleManager::addModule() to check whether a particular module
has already been loaded before allocating a new Module structure. If
the module has already been loaded (uniquing based on file name), then
just return the existing module rather than trying to load it again.
This allows us to load a DAG of modules. Introduce a simple test case
that forms a diamond-shaped module graph, and illustrates that a
source file importing the bottom of the diamond can see declarations
in all four of the modules that make up the diamond.
llvm-svn: 137971
has already been loaded before allocating a new Module structure. If
the module has already been loaded (uniquing based on file name), then
just return the existing module rather than trying to load it again.
This allows us to load a DAG of modules. Introduce a simple test case
that forms a diamond-shaped module graph, and illustrates that a
source file importing the bottom of the diamond can see declarations
in all four of the modules that make up the diamond.
llvm-svn: 137925
-import-module) vs. loaded because some other module depends on
them. As part of doing this, pass down the module that caused a module
to be loaded directly, rather than assuming that we're loading a
chain. Finally, write out all of the directly-loaded modules when
serializing an AST file (using the new IMPORTS record), so that an AST
file can depend on more than one other AST file, all of which will be
loaded when that AST file is loaded. This allows us to form and load a
tree of modules, but we can't yet load a DAG of modules.
llvm-svn: 137923
all AST files have a normal METADATA record that has the same form
regardless of whether we refer to a chained PCH or any other kind of
AST file.
Introduce the IMPORTS record, which describes all of the AST files
that are imported by this AST file, and how (as a module, a PCH file,
etc.). Currently, we emit at most one entry to this record, to support
chained PCH.
llvm-svn: 137869
Example:
template <class T>
class A {
public:
template <class U> void f(U p) { }
template <> void f(int p) { } // <== class scope specialization
};
This extension is necessary to parse MSVC standard C++ headers, MFC and ATL code.
BTW, with this feature in, clang can parse (-fsyntax-only) all the MSVC 2010 standard header files without any error.
llvm-svn: 137573