The global module index was querying the file manager for each of the
module files it knows about at load time, to prune out any out-of-date
information. The file manager would then cache the results of the
stat() falls used to find that module file.
Later, the same translation unit could end up trying to import one of the
module files that had previously been ignored by the module cache, but
after some other Clang instance rebuilt the module file to bring it
up-to-date. The stale stat() results in the file manager would
trigger a second rebuild of the already-up-to-date module, causing
failures down the line.
The global module index now lazily resolves its module file references
to actual AST reader module files only after the module file has been
loaded, eliminating the stat-caching race. Moreover, the AST reader
can communicate to its caller that a module file is missing (rather
than simply being out-of-date), allowing us to simplify the
module-loading logic and allowing the compiler to recover if a
dependent module file ends up getting deleted.
llvm-svn: 177367
When we're building a precompiled header or module against an SDK on
Darwin, there will be a file SDKSettings.plist in the sysroot. Since
stat()'ing every system header on which a module or PCH file depends
is performance suicide, we instead stat() just SDKSettings.plist. This
hack works well on Darwin; it's unclear how we want to handle this on
other platforms. If there is a canonical file, we should use it; if
not, we either have to take the performance hit of stat()'ing system
headers repeatedly or roll the dice by not checking anything.
llvm-svn: 177194
In a module-enabled Cocoa PCH file, we spend a lot of time stat'ing the headers
in order to associate the FileEntries with their modules and support implicit
module import.
Use a more lazy scheme by enhancing HeaderInfoTable to store extra info about
the module that a header belongs to, and associate it with its module only when
there is a request for loading the header info for a particular file.
Part of rdar://13391765
llvm-svn: 176976
This allows resolving top-header filenames of modules to FileEntries when
we need them, not eagerly.
Note that that this breaks ABI for libclang functions
clang_Module_getTopLevelHeader / clang_Module_getNumTopLevelHeaders
but this is fine because they are experimental and not widely used yet.
llvm-svn: 176975
Stat'ing all the headers from the PCH to make sure they are up-to-date takes significant time.
In a particular source file (whose PCH file included Cocoa.h) from total -fsyntax-only time
12% was just stat calls. Change pre-validation to only check non-system headers.
There are some notable disadvantages:
-If a system header, that is not include-guarded, changes after the PCH was created, we will not
find it in the header info table and we will #import it, effectively #importing it twice, thus
we will emit some error due to a multiple definition and after that the "header was modified" error will likely
be emitted, for example something like:
NSDictionary.h:12:1: error: duplicate interface definition for class 'NSDictionary'
@interface NSDictionary : NSObject <NSCopying, NSMutableCopying, NSSecureCoding, NSFastEnumeration>
^
NSDictionary.h:12:12: note: previous definition is here
@interface NSDictionary : NSObject <NSCopying, NSMutableCopying, NSSecureCoding, NSFastEnumeration>
^
fatal error: file 'NSDictionary.h' has been modified since the precompiled header was built
Though we get the "header was modified" error, this is a bit confusing.
-Theoretically it is possible that such a system header will cause no errors but it will just cause an
unfortunate semantic change, though I find this rather unlikely.
The advantages:
-Reduces compilation time when using a huge PCH like the Cocoa ones
-System headers change very infrequent and when they do, users/build systems should be able to know that
re-building from scratch is needed.
Addresses rdar://13056262
llvm-svn: 176567
Previously the hash would be the filename portion of the path, which could be
different for a filename with different case or a symbolic link with a different
name completely.
This did not actually create any issue so far because by validating all headers
in the PCH we created uniqued FileEntries based on inodes, so an #include of
a symbolic link (refering to a file from the PCH) would end up with a FileEntry
with filename same as the one recorded in the PCH.
llvm-svn: 176566
Add an ability to specify custom documentation block comment commands via a new
class CommentOptions. The intention is that this class will hold future
customizations for comment parsing, including defining documentation comments
with specific numbers of parameters, etc.
CommentOptions instance is a member of LangOptions.
CommentOptions is controlled by a new command-line parameter
-fcomment-block-commands=Foo,Bar,Baz.
llvm-svn: 175892
for the data specific to a macro definition (e.g. what the tokens are), and
MacroDirective class which encapsulates the changes to the "macro namespace"
(e.g. the location where the macro name became active, the location where it was undefined, etc.)
(A MacroDirective always points to a MacroInfo object.)
Usually a macro definition (MacroInfo) is where a macro name becomes active (MacroDirective) but
splitting the concepts allows us to better model the effect of modules to the macro namespace
(also as a bonus it allows better modeling of push_macro/pop_macro #pragmas).
Modules can have their own macro history, separate from the local (current translation unit)
macro history; MacroDirectives will be used to model the macro history (changes to macro namespace).
For example, if "@import A;" imports macro FOO, there will be a new local MacroDirective created
to indicate that "FOO" became active at the import location. Module "A" itself will contain another
MacroDirective in its macro history (at the point of the definition of FOO) and both MacroDirectives
will point to the same MacroInfo object.
Introducing the separation of macro concepts is the first part towards better modeling of module macros.
llvm-svn: 175585
This commit introduces a set of related changes to ensure that the
declaration that shows up in the identifier chain after deserializing
declarations with a given identifier is, in fact, the most recent
declaration. The primary change involves waiting until after we
deserialize and wire up redeclaration chains before updating the
identifier chains. There is a minor optimization in here to avoid
recursively deserializing names as part of looking to see whether
top-level declarations for a given name exist.
A related change that became suddenly more urgent is to property
record a merged declaration when an entity first declared in the
current translation unit is later deserialized from a module (that had
not been loaded at the time of the original declaration). Since we key
off the canonical declaration (which is parsed, not from an AST file)
for emitted redeclarations, we simply record this as a merged
declaration during AST writing and let the readers merge them.
Re-fixes <rdar://problem/13189985>, presumably for good this time.
llvm-svn: 175447
- The only group where it makes sense for the "ExternC" bit is System, so this
simplifies having to have the extra isCXXAware (or ImplicitExternC, depending
on what code you talk to) bit caried around.
llvm-svn: 173859
DeclContext. When the DeclContext is of a kind that can only be
defined once and never updated, we limit the search to the module file
that conatins the lookup table. Provides a 15% speedup in one
modules-heavy source file.
llvm-svn: 173050
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
consider (sub)module visibility.
The bulk of this change replaces myriad hand-rolled loops over the
linked list of Objective-C categories/extensions attached to an
interface declaration with loops using one of the four new category
iterator kinds:
visible_categories_iterator: Iterates over all visible categories
and extensions, hiding any that have their "hidden" bit set. This is
by far the most commonly used iterator.
known_categories_iterator: Iterates over all categories and
extensions, ignoring the "hidden" bit. This tends to be used for
redeclaration-like traversals.
visible_extensions_iterator: Iterates over all visible extensions,
hiding any that have their "hidden" bit set.
known_extensions_iterator: Iterates over all extensions, whether
they are visible to normal name lookup or not.
The effect of this change is that any uses of the visible_ iterators
will respect module-import visibility. See the new tests for examples.
Note that the old accessors for categories and extensions are gone;
there are *Raw() forms for some of them, for those (few) areas of the
compiler that have to manipulate the linked list of categories
directly. This is generally discouraged.
Part two of <rdar://problem/10634711>.
llvm-svn: 172665
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
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
rehashed, invaliding the iterator walking through the identifier
table. Separate out the identification of out-of-date identifiers from
updating them.
llvm-svn: 171756
This does limit these typedefs to being sequences, but no current usage
requires them to be contiguous (we could expand this to a more general
iterator pair range concept at some point).
Also, it'd be nice if SmallVector were constructible directly from an ArrayRef
but this is a bit tricky since ArrayRef depends on SmallVectorBaseImpl for the
inverse conversion. (& generalizing over all range-like things, while nice,
would require some nontrivial SFINAE I haven't thought about yet)
llvm-svn: 170482
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
the cases where we can't determine whether special members would be trivial
while building the class, we eagerly declare those special members. The impact
of this is bounded, since it does not trigger implicit declarations of special
members in classes which merely *use* those classes.
In order to determine whether we need to apply this rule, we also need to
eagerly declare move operations and destructors in cases where they might be
deleted. If a move operation were supposed to be deleted, it would instead
be suppressed, and we could need overload resolution to determine if we fall
back to a trivial copy operation. If a destructor were implicitly deleted,
it would cause the move constructor of any derived classes to be suppressed.
As discussed on cxx-abi-dev, C++11's selected constructor rules are also
retroactively applied as a defect resolution in C++03 mode, in order to
identify that class B has a non-trivial copy constructor (since it calls
A's constructor template, not A's copy constructor):
struct A { template<typename T> A(T &); };
struct B { mutable A a; };
llvm-svn: 169673
properly, rather than faking it up by pretending that a reference member makes
the default constructor non-trivial. That leads to rejects-valids when putting
such types inside unions.
llvm-svn: 169662
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
constructor/assignment operator with a const-qualified parameter type. The
prior method for determining this incorrectly used overload resolution.
llvm-svn: 168775
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
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
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
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
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
