r246546, with a workaround for an MSVC 2013 miscompile and an MSVC 2015
rejects-valid.
Original commit message:
[modules] Rework serialized DeclContext lookup table management. Instead of
walking the loaded ModuleFiles looking for lookup tables for the context, store
them all in one place, and merge them together if we find we have too many
(currently, more than 4). If we do merge, include the merged form in our
serialized lookup table, so that downstream readers never need to look at our
imports' tables.
This gives a huge performance improvement to builds with very large numbers of
modules (in some cases, more than a 2x speedup was observed).
llvm-svn: 246582
predictable diagnostic experience. The hash-of-DeclID order we were using
before gave different results on Win32 due to a different predefined
declaration of __builtin_va_list.
llvm-svn: 246521
walking the loaded ModuleFiles looking for lookup tables for the context, store
them all in one place, and merge them together if we find we have too many
(currently, more than 4). If we do merge, include the merged form in our
serialized lookup table, so that downstream readers never need to look at our
imports' tables.
This gives a huge performance improvement to builds with very large numbers of
modules (in some cases, more than a 2x speedup was observed).
llvm-svn: 246497
all modules and reduce the number of declarations we load when loading a
redeclaration chain.
The new approach is:
* when loading the first declaration of an entity within a module file, we
first load all declarations of the entity that were imported into that
module file, and then load all the other declarations of that entity from
that module file and build a suitable decl chain from them
* when loading any other declaration of an entity, we first load the first
declaration from the same module file
As before, we complete redecl chains through name lookup where necessary.
To make this work, I also had to change the way that template specializations
are stored -- it no longer suffices to track only canonical specializations; we
now emit all "first local" declarations when emitting a list of specializations
for a template.
On one testcase with several thousand imported module files, this reduces the
total runtime by 72%.
llvm-svn: 245779
We used to have a flag to enable module maps, and two more flags to enable
implicit module maps. This is all redundant; we don't need any flag for
enabling module maps in the abstract, and we don't usually have -fno- flags for
-cc1. We now have just a single flag, -fimplicit-module-maps, that enables
implicitly searching the file system for module map files and loading them.
The driver interface is unchanged for now. We should probably rename
-fmodule-maps to -fimplicit-module-maps at some point.
llvm-svn: 239789
if the merged definition is visible, and perform lookups into all merged copies
of the definition (not just for special members) so that we can complete the
redecl chains for members of the class.
llvm-svn: 233420
for a DeclContext, and fix propagation of exception specifications along
redeclaration chains.
This reverts r232905, r232907, and r232907, which reverted r232793, r232853,
and r232853.
One additional change is present here to resolve issues with LLDB: distinguish
between whether lexical decls missing from the lookup table are local or are
provided by the external AST source, and still look in the external source if
that's where they came from.
llvm-svn: 232928
When we need to build the lookup table for a DeclContext, we used to pull in
all lexical declarations for the context; instead, just build a lookup table
for the local lexical declarations. We previously didn't guarantee that the
imported declarations would be in the returned map, but in some cases we'd
happen to put them all in there regardless. Now we're even lazier about this.
This unnecessary work was papering over some other bugs:
- LookupVisibleDecls would use the DC for name lookups in the TU in C, and
this was not guaranteed to find all imported names (generally, the DC for
the TU in C is not a reliable place to perform lookups). We now use an
identifier-based lookup mechanism for this.
- We didn't actually load in the list of eagerly-deserialized declarations
when importing a module (so external definitions in a module wouldn't be
emitted by users of those modules unless they happened to be deserialized
by the user of the module).
llvm-svn: 232793
entity, put the originally-canonical decl IDs in the right places in the redecl
chain rather than reordering them all to the start. If we don't ensure that the
redecl chain order is consistent with the topological module order, we can fail
to make a declaration visible if later declarations are in more IDNSs than
earlier ones (for instance, because the earlier decls are invisible friends).
llvm-svn: 228978
of that entity, ensure that the redeclaration chain is reordered properly on
reload. Otherwise, the result of name lookup for that entity may point to an
entity that is too old; if that's an injected friend name or the like, that
can result in the name not being found at all.
llvm-svn: 228371
declaration in the instantiation if the previous declaration came from another
definition of the class template that got merged into the pattern definition.
llvm-svn: 219552
pattern of an alias template declaration. Use this to merge alias templates
properly when they're members of class template specializations.
llvm-svn: 216437
declared, rather than putting them into the template parameter scope. We
previously had *no record* in the scope for class template declarations, once
those declarations completed and their template parameter scopes were popped.
This in turn caused us to be unable to merge class template declarations that
were declared in the global scope (where we use scope lookup rather than
DeclContext lookup for merging), when loading a module.
llvm-svn: 216311
definitions (because some other declaration declares a special member that
isn't present in the canonical definition), we need to search *all* of them; we
can't just stop when we find the requested name in any of the definitions,
because that can fail to find things (and in particular, it can fail to find
the member of the canonical declaration and return a bogus ODR failure).
llvm-svn: 215612
redefinitions of that namespace have already been loaded. When writing out the
names in a namespace, if we see a name that is locally declared and had
imported declarations merged on top of it, export the local declaration as the
lookup result, because it will be the most recent declaration of that entity in
the redeclaration chain of an importer of the module.
llvm-svn: 215518
anyway. If -ast-dump *is* also provided, then dump the AST declarations as well
as the lookup results. This is invaluable for cross-correlating the lookup
information with the declarations actually found.
llvm-svn: 215393
into their container; we won't find them there. These things are already being
merged when they're added to their primary template's folding set, so this
merging is redundant (and causes us to reject-valid because we think we've
found an odr violation).
llvm-svn: 212788
gets explicitly specialized, don't reuse the previous class template
specialization declaration as a new declaration. The benefit here is fairly
marginal, it harms source fidelity, and this is horrible to model if the
specialization was imported from another module (without this change, it
asserts or worse).
llvm-svn: 209552
instantiated in another module, and the instantiation uses a partial
specialization, include the partial specialization and its template arguments
in the update record. We'll need them if someone imports the second module and
tries to instantiate a member of the template.
llvm-svn: 209472
whether the definition of the template is visible rather than checking whether
the instantiated definition happens to be in an imported module.
llvm-svn: 208150
together. This is extremely hairy, because in general we need to have loaded
both the template and the pattern before we can determine whether either should
be merged, so we temporarily violate the rule that all merging happens before
reading a decl ends, but *only* in the case where a template's pattern is being
loaded while loading the template itself.
In order to accomodate this for class templates, delay loading the injected
class name type for the pattern of the template until after we've loaded the
template itself, if we happen to load the template first.
llvm-svn: 207063
While investigating some debug info issues, Eric and I came across a
particular template case where the location of a decl was quite
different from the range of the same decl. It might've been rather
helpful if the dumper had actually showed us this.
llvm-svn: 205396
an out-of-date external decls list). This happens if we declare some names,
force the lookup table for the decl context to be built, import a module that
adds more decls for the name, then write out our module without looking up the
name.
llvm-svn: 204694
it is an implicit instantiation of a class template specialization), pick the
first-loaded definition to be the canonical definition, and merge all other
definitions into it.
This is still rather incomplete -- we need to extend every form of declaration
that can appear within a CXXRecordDecl to be redeclarable if it came from an
AST file (this includes fields, enumerators, ...).
llvm-svn: 190315
name lookup from lazily deserializing the other declarations with the same
name, by tracking a bit to indicate whether a name in a DeclContext might have
additional external results. This also allows lazier reconciling of the lookup
table if a module import adds decls to a pre-existing DC.
However, this exposes a pre-existing bug, which causes a regression in
test/Modules/decldef.mm: if we have a reference to a declaration, and a
later-imported module adds a redeclaration, nothing causes us to load that
redeclaration when we use or emit the reference (which can manifest as a
reference to an undefined inline function, a use of an incomplete type, and so
on). decldef.mm has been extended with an additional testcase which fails with
or without this change.
llvm-svn: 190293
in one module but is only declared as a friend in another module, keep it
visible in the result of the merge.
This is incomplete on two axes:
1) Our handling of local extern declarations is basically broken (we put them
in the wrong decl context, and don't find them in redeclaration lookup, unless
they've previously been declared), and this results in them making friends
visible after a merge.
2) Eventually we'll need to mark that this has happened, and more carefully
check whether a declaration should be visible if it was only visible in some
of the modules in which it was declared. Fortunately it's rare for the
identifier namespace of a declaration to change along its redeclaration chain.
llvm-svn: 187639
sufficient to only consider names visible at the point of instantiation,
because that may not include names that were visible when the template was
defined. More generally, if the instantiation backtrace goes through a module
M, then every declaration visible within M should be available to the
instantiation. Any of those declarations might be part of the interface that M
intended to export to a template that it instantiates.
The fix here has two parts:
1) If we find a non-visible declaration during name lookup during template
instantiation, check whether the declaration was visible from the defining
module of all entities on the active template instantiation stack. The defining
module is not the owning module in all cases: we look at the module in which a
template was defined, not the module in which it was first instantiated.
2) Perform pending instantiations at the end of a module, not at the end of the
translation unit. This is general goodness, since it significantly cuts down
the amount of redundant work that is performed in every TU importing a module,
and also implicitly adds the module containing the point of instantiation to
the set of modules checked for declarations in a lookup within a template
instantiation.
There's a known issue here with template instantiations performed while
building a module, if additional imports are added later on. I'll fix that
in a subsequent commit.
llvm-svn: 187167
numbers as we deserialize class template partial specializations. We can't
assume that the old sequence numbers will work.
The sequence numbers are still deterministic, but are now a lot less
predictable for class template partial specializations in modules/PCH.
llvm-svn: 184811
constructing a lookup table.
Previously, buildLookup would add lookup table entries for each item lexically
within the DC, and adding the first entry with a given name would trigger the
external source to add all its entries with that name. Then buildLookup would
carry on and re-add those entries all over again.
Instead, follow a simple rule: a declaration from an external source is only
ever made visible by the external source. One exception to this: since we don't
usually build a lookup table for the TU in C, and we never serialize one, we
don't expect the external source to provide lookups in the TU in C, so we build
those ones ourselves.
llvm-svn: 184696
Richard Smith