Original commit message:
[clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
This reverts commit 6775fc6ffa.
It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."
This reverts commit 03a3f86071.
We see some failures on the lldb infrastructure, these changes might play a role
in it. Let's revert it now and see if the bots will become green.
Ref: https://reviews.llvm.org/D104918
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
Pass on the filesystem error string `FileManager::getFileRef` in
`clang-import-test`'s `ParseSource` function. Also include "error:" and
a newline in the output. As a side effect, migrate to the `FileEntryRef`
overload of `SourceManager::createFileID`.
No real functionality change here, just slightly better output on error.
Differential Revision: https://reviews.llvm.org/D92971
Update clang-tools-extra, clang/tools, clang/unittests to migrate from
`SourceManager::getBuffer`, which returns an always dereferenceable
`MemoryBuffer*`, to `getBufferOrNone` or `getBufferOrFake`, both of
which return a `MemoryBufferRef`, depending on whether the call site was
checking for validity of the buffer. No functionality change intended.
Differential Revision: https://reviews.llvm.org/D89416
Most clients of SourceManager.h need to do things like turning source
locations into file & line number pairs, but this doesn't require
bringing in FileManager.h and LLVM's FS headers.
The main code change here is to sink SM::createFileID into the cpp file.
I reason that this is not performance critical because it doesn't happen
on the diagnostic path, it happens along the paths of macro expansion
(could be hot) and new includes (less hot).
Saves some includes:
309 - /usr/local/google/home/rnk/llvm-project/clang/include/clang/Basic/FileManager.h
272 - /usr/local/google/home/rnk/llvm-project/clang/include/clang/Basic/FileSystemOptions.h
271 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/VirtualFileSystem.h
267 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/FileSystem.h
266 - /usr/local/google/home/rnk/llvm-project/llvm/include/llvm/Support/Chrono.h
Differential Revision: https://reviews.llvm.org/D75406
Fix a bug in IRGen where it wasn't destructing compound literals in C
that are ObjC pointer arrays or non-trivial structs. Also diagnose jumps
that enter or exit the lifetime of the compound literals.
rdar://problem/51867864
Differential Revision: https://reviews.llvm.org/D64464
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
Update the callers of FileManager::getFile and FileManager::getDirectory to handle the new llvm::ErrorOr-returning methods.
Signed-off-by: Harlan Haskins <harlan@apple.com>
llvm-svn: 367616
This adds the -ast-dump=json cc1 flag (in addition to -ast-dump=default, which is the default if no dump format is specified), as well as some initial AST dumping functionality and tests.
llvm-svn: 360622
Requires making the llvm::MemoryBuffer* stored by SourceManager const,
which in turn requires making the accessors for that return const
llvm::MemoryBuffer*s and updating all call sites.
The original motivation for this was to use it and fix the TODO in
CodeGenAction.cpp's ConvertBackendLocation() by using the UnownedTag
version of createFileID, and since llvm::SourceMgr* hands out a const
llvm::MemoryBuffer* this is required. I'm not sure if fixing the TODO
this way actually works, but this seems like a good change on its own
anyways.
No intended behavior change.
Differential Revision: https://reviews.llvm.org/D60247
llvm-svn: 357724
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
We haven't supported compiling ObjC1 for a long time (and never will again), so
there isn't any reason to keep these separate. This patch replaces
LangOpts::ObjC1 and LangOpts::ObjC2 with LangOpts::ObjC.
Differential revision: https://reviews.llvm.org/D53547
llvm-svn: 345637
Summary: Also enable exceptions in clang-import-test so that we can parse the test files.
Reviewers: a.sidorin, a_sidorin
Reviewed By: a_sidorin
Subscribers: a_sidorin, martong, cfe-commits
Differential Revision: https://reviews.llvm.org/D50978
llvm-svn: 340220
Summary:
The ASTImporter does currently not handle const_casts. This patch adds the
missing const_cast importer code and the test case that discovered this.
Reviewers: a.sidorin, a_sidorin
Reviewed By: a_sidorin
Subscribers: a_sidorin, martong, cfe-commits
Differential Revision: https://reviews.llvm.org/D50932
llvm-svn: 340182
Summary:
`ASTPrinter` allows setting the ouput to any O-Stream, but that printer creates source-code-like syntax (and is also marked with a `FIXME`). The nice, colourful, mostly human-readable `ASTDumper` only works on the standard output, which is not feasible in case a user wants to see the AST of a file through a code navigation/comprehension tool.
This small addition of an overload solves generating a nice colourful AST block for the users of a tool I'm working on, [[ http://github.com/Ericsson/CodeCompass | CodeCompass ]], as opposed to having to duplicate the behaviour of definitions that only exist in the anonymous namespace of implementation TUs related to this module.
Reviewers: alexfh, klimek, rsmith
Reviewed By: alexfh
Subscribers: rnkovacs, dkrupp, gsd, xazax.hun, cfe-commits, #clang
Tags: #clang
Patch by Whisperity!
Differential Revision: https://reviews.llvm.org/D45096
llvm-svn: 329391
clang-3.8 complains that constructor for '...' must explicitly
initialize the const object. Newer clangs and gcc seem to be fine with
this, but explicitly initializing the variable does not hurt.
llvm-svn: 327383
ExternalASTMerger has hitherto relied on being able to look up
any Decl through its named DeclContext chain. This works for
many cases, but causes problems for function-local structs,
which cannot be looked up in their containing FunctionDecl. An
example case is
void f() {
{ struct S { int a; }; }
{ struct S { bool b; }; }
}
It is not possible to lookup either of the two Ses individually
(or even to provide enough information to disambiguate) after
parsing is over; and there is typically no need to, since they
are invisible to the outside world.
However, ExternalASTMerger needs to be able to complete either
S on demand. This led to an XFAIL on test/Import/local-struct,
which this patch removes. The way the patch works is:
It defines a new data structure, ExternalASTMerger::OriginMap,
which clients are expected to maintain (default-constructing
if the origin does not have an ExternalASTMerger servicing it)
As DeclContexts are imported, if they cannot be looked up by
name they are placed in the OriginMap. This allows
ExternalASTMerger to complete them later if necessary.
As DeclContexts are imported from an origin that already has
its own OriginMap, the origins are forwarded – but only for
those DeclContexts that are actually used. This keeps the
amount of stored data minimal.
The patch also applies several improvements from review:
- Thoroughly documents the interface to ExternalASTMerger;
- Adds optional logging to help track what's going on; and
- Cleans up a bunch of braces and dangling elses.
Differential Revision: https://reviews.llvm.org/D38208
llvm-svn: 314336
viewing of the final IR. This is useful for confirming that
structure layout was correct.
I've added two tests:
- A test that checks that structs in top-level code are completed
correctly during struct layout (they are)
- A test that checks that structs defined in function bodies are
cpmpleted correctly during struct layout (currently they are not,
so this is XFAIL).
The second test fails because LookupSameContext()
(ExternalASTMerger.cpp) can't find the struct. This is an issue I
intend to resolve separately.
Differential Revision: https://reviews.llvm.org/D36429
llvm-svn: 310318
This patch adds functionality and a test for importing Objective-C classes
and their methods.
It also adds a flag to clang-import-test to set the language used for
parsing. This takes the same argument format as the -x option to the
driver.
Differential Revision: https://reviews.llvm.org/D35274
llvm-svn: 309014
I didn't commit clang-import-test.cpp in r307600, but it had some
changes that were part of https://reviews.llvm.org/D35220
Corrected that now.
llvm-svn: 307602
Summary:
The ASTImporter should import CXX method overrides from the source context
when it imports a method decl.
Reviewers: spyffe, rsmith, doug.gregor
Reviewed By: spyffe
Differential Revision: https://reviews.llvm.org/D34371
llvm-svn: 305850
ASTImporter has some bugs when it's importing types
that themselves come from an ExternalASTSource. This
is exposed particularly in the behavior when
comparing complete TagDecls with forward
declarations. This patch does several things:
- Adds a test case making sure that conflicting
forward-declarations are resolved correctly;
- Extends the clang-import-test harness to test
two-level importing, so that we make sure we
complete types when necessary; and
- Fixes a few bugs I found this way. Failure to
complete types was one; however, I also discovered
that complete RecordDecls aren't properly added to
the redecls chain for existing forward
declarations.
llvm-svn: 302975
clang-import-test has until now been only able to report top-level Decls.
This is clearly insufficient; we should be able to look inside structs
and namespaces also. This patch adds new test cases for a variety of
lookups inside existing ASTContexts, and adds the functionality necessar
to make most of these testcases work. (One testcase is known to fail
because of ASTImporter limitations when importing templates; I'll look
into that separately.)
This patch also separates the core functionality out into
ExternalASTMerger, an interface that allows clients like LLDB to make
use of it. clang-import-test now only has the machinery necessary to
set up the tests.
Differential revision: https://reviews.llvm.org/D30435
llvm-svn: 299976
Aleksey Shlypanikov pointed out my mistake in migrating an explicit
unique_ptr to auto - I was expecting the function returned a unique_ptr,
but instead it returned a raw pointer - introducing a leak.
Thanks Aleksey!
This reapplies r291184, reverted in r291249.
llvm-svn: 291270
Recommitted after formal approval.
LLVM's JIT is now the foundation of dynamic-compilation features for many languages. Clang also has low-level support for dynamic compilation (ASTImporter and ExternalASTSource, notably). How the compiler is set up for dynamic parsing is generally left up to individual clients, for example LLDB's C/C++/Objective-C expression parser and the ROOT project.
Although this arrangement offers external clients the flexibility to implement dynamic features as they see fit, the lack of an in-tree client means that subtle bugs can be introduced that cause regressions in the external clients but aren't caught by tests (or users) until much later. LLDB for example regularly encounters complicated ODR violation scenarios where it is not immediately clear who is at fault.
Other external clients (notably, Cling) rely on similar functionality, and another goal is to break this functionality up into composable parts so that any client can be built easily on top of Clang without requiring extensive additional code.
I propose that the parts required to build a simple expression parser be added to Clang. Initially, I aim to have the following features:
A piece that looks up external declarations from a variety of sources (e.g., from previous dynamic compilations, from modules, or from DWARF) and uses clear conflict resolution rules to reconcile differences, with easily understood errors. This functionality will be supported by in-tree tests.
A piece that works hand in hand with the LLVM JIT to resolve the locations of external declarations so that e.g. variables can be redeclared and (for high-performance applications like DTrace) external variables can be accessed directly from the registers where they reside.
This commit adds a tester that parses a sequence of source files and then uses them as source data for an expression. External references are resolved using an ExternalASTSource that responds to name queries using an ASTImporter. This is the setup that LLDB uses, and the motivating reason for MinimalImport in ASTImporter. When complete, this tester will implement the first of the above goals.
Differential Revision: https://reviews.llvm.org/D27180
llvm-svn: 290367
LLVM's JIT is now the foundation of dynamic-compilation features for many languages. Clang also has low-level support for dynamic compilation (ASTImporter and ExternalASTSource, notably). How the compiler is set up for dynamic parsing is generally left up to individual clients, for example LLDB's C/C++/Objective-C expression parser and the ROOT project.
Although this arrangement offers external clients the flexibility to implement dynamic features as they see fit, the lack of an in-tree client means that subtle bugs can be introduced that cause regressions in the external clients but aren't caught by tests (or users) until much later. LLDB for example regularly encounters complicated ODR violation scenarios where it is not immediately clear who is at fault.
Other external clients (notably, Cling) rely on similar functionality, and another goal is to break this functionality up into composable parts so that any client can be built easily on top of Clang without requiring extensive additional code.
I propose that the parts required to build a simple expression parser be added to Clang. Initially, I aim to have the following features:
- A piece that looks up external declarations from a variety of sources (e.g., from previous dynamic compilations, from modules, or from DWARF) and uses clear conflict resolution rules to reconcile differences, with easily understood errors. This functionality will be supported by in-tree tests.
- A piece that works hand in hand with the LLVM JIT to resolve the locations of external declarations so that e.g. variables can be redeclared and (for high-performance applications like DTrace) external variables can be accessed directly from the registers where they reside.
This commit adds a tester that parses a sequence of source files and then uses them as source data for an expression. External references are resolved using an ExternalASTSource that responds to name queries using an ASTImporter. This is the setup that LLDB uses, and the motivating reason for MinimalImport in ASTImporter. When complete, this tester will implement the first of the above goals.
Differential Revision: https://reviews.llvm.org/D27180
llvm-svn: 290004
Vassil Vassilev