that if two modules A and B both contain a declaration of a tag such
as
struct X;
and those two modules are unrelated, the two declarations of X will be
merged into a single redeclaration chain.
llvm-svn: 147488
modules. This leaves us without an explicit syntax for importing
modules in C/C++, because such a syntax needs to be discussed
first. In Objective-C/Objective-C++, the @import syntax is used to
import modules.
Note that, under -fmodules, C/C++ programs can import modules via the
#include mechanism when a module map is in place for that header. This
allows us to work with modules in C/C++ without committing to a syntax.
llvm-svn: 147467
features needed for a particular module to be available. This allows
mixed-language modules, where certain headers only work under some
language variants (e.g., in C++, std.tuple might only be available in
C++11 mode).
llvm-svn: 147387
found within that umbrella directory that were not actually included
by the umbrella header. They should either be referenced in the module
map or included by the umbrella header.
llvm-svn: 147207
set of (previously-canonical) declaration IDs to the module file, so
that future AST reader instances that load the module know which
declarations are merged. This is important in the fairly tricky case
where a declaration of an entity, e.g.,
@class X;
occurs before the import of a module that also declares that
entity. We merge the declarations, and record the fact that the
declaration of X loaded from the module was merged into the (now
canonical) declaration of X that we parsed.
llvm-svn: 147181
declaration of that same class that either came from some other module
or occurred in the translation unit loading the module. In this case,
we need to merge the two redeclaration chains immediately so that all
such declarations have the same canonical declaration in the resulting
AST (even though they don't in the module files we've imported).
Focusing on Objective-C classes until I'm happy with the design, then
I'll both (1) extend this notion to other kinds of declarations, and
(2) optimize away this extra checking when we're not dealing with
modules. For now, doing this checking for PCH files/preambles gives us
better testing coverage.
llvm-svn: 147123
visibility restrictions. This ensures that all declarations of the
same entity end up in the same redeclaration chain, even if some of
those declarations aren't visible. While this may seem unfortunate to
some---why can't two C modules have different functions named
'f'?---it's an acknowedgment that a module does not introduce a new
"namespace" of names.
As part of this, stop merging the 'module-private' bit from previous
declarations to later declarations, because we want each declaration
in a module to stand on its own because this can effect, for example,
submodule visibility.
Note that this notion of names that are invisible to normal name
lookup but are available for redeclaration lookups is how we should
implement friend declarations and extern declarations within local
function scopes. I'm not tackling that problem now.
llvm-svn: 146980
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
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
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
all of the headers below that particular directory. Use umbrella
directories as a clean way to deal with (1) directories/frameworks
that don't have an umbrella header, but don't want to enumerate all of
their headers, and (2) PrivateHeaders, which we never want to
enumerate and want to keep separate from the main umbrella header.
This also eliminates a little more of the "magic" for private headers,
and frameworks in general.
llvm-svn: 146235
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
a modifier for a header declarartion, e.g.,
umbrella header "headername"
Collapse the umbrella-handling code in the parser into the
header-handling code, so we don't duplicate the header-search logic.
llvm-svn: 146159
when we load a module map (module.map) from a directory, also load a
private module map (module_private.map) for that directory, if
present. That private module map can inject a new submodule that
captures private headers.
llvm-svn: 146012
frameworks). A submodule can now be labeled as a "framework", and
header search will look into the appropriate Headers/PrivateHeaders
subdirectories for named headers.
llvm-svn: 145941
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
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
within module maps, which will (eventually) be used to re-export a
module from another module. There are still some pieces missing,
however.
llvm-svn: 145665
check whether the named submodules themselves are actually
valid, and drill down to the named submodule (although we don't do
anything with it yet). Perform typo correction on the submodule names
when possible.
llvm-svn: 145477
the umbrella header's directory and its subdirectories are part of the
module (that's why it's an umbrella). Make sure that these headers are
considered to be part of the module for lookup purposes.
llvm-svn: 144859
into a submodule. Submodules aren't actually supported anywhere else,
but we do parse them, so this verifies that we're at least seeing
through them properly.
llvm-svn: 144436
the module is described in one of the module maps in a search path or
in a subdirectory off the search path that has the same name as the
module we're looking for.
llvm-svn: 144433
map, so long as they have an umbrella header. This makes it possible
to introduce a module map + umbrella header for a given set of
headers, to turn it into a module.
There are two major deficiencies here: first, we don't go hunting for
module map files when we just see a module import (so we won't know
about the modules described therein). Second, we don't yet have a way
to build modules that don't have umbrella headers, or have incomplete
umbrella headers.
llvm-svn: 144424
Module map files provide a way to map between headers and modules, so
that we can layer a module system on top of existing headers without
changing those headers at all.
This commit introduces the module map file parser and the module map
that it generates, and wires up the module map file parser so that
we'll automatically find module map files as part of header
search. Note that we don't yet use the information stored in the
module map.
llvm-svn: 144402
as part of the hash rather than ignoring them. This means we'll end up
building more module variants (overall), but it allows configuration
macros such as NDEBUG to work so long as they're specified via command
line. More to come in this space.
llvm-svn: 142187
the AST reader), merge that header file information with whatever
header file information we already have. Otherwise, we might forget
something we already knew (e.g., that the header was #import'd already).
llvm-svn: 139979
but there is a corresponding umbrella header in a framework, build the
module on-the-fly so it can be immediately loaded at the import
statement. This is very much proof-of-concept code, with details to be
fleshed out over time.
llvm-svn: 139558
existing practice with Python extension modules. Not that Python
extension modules should be using a double-underscored identifier
anyway, but...
llvm-svn: 138870
loads the named module. The syntax itself is intentionally hideous and
will be replaced at some later point with something more
palatable. For now, we're focusing on the semantics:
- Module imports are handled first by the preprocessor (to get macro
definitions) and then the same tokens are also handled by the parser
(to get declarations). If both happen (as in normal compilation),
the second one is redundant, because we currently have no way to
hide macros or declarations when loading a module. Chris gets credit
for this mad-but-workable scheme.
- The Preprocessor now holds on to a reference to a module loader,
which is responsible for loading named modules. CompilerInstance is
the only important module loader: it now knows how to create and
wire up an AST reader on demand to actually perform the module load.
- We search for modules in the include path, using the module name
with the suffix ".pcm" (precompiled module) for the file name. This
is a temporary hack; we hope to improve the situation in the
future.
llvm-svn: 138679
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
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
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
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
Douglas Gregor