57 Commits

Author SHA1 Message Date
Fred Fu
5ab25a42ba Reland "[clang-repl] support code completion at a REPL."
Original commit message:
"
This patch enabled code completion for ClangREPL. The feature was built upon
three existing Clang components: a list completer for LineEditor, a
CompletionConsumer from SemaCodeCompletion, and the ASTUnit::codeComplete method.
The first component serves as the main entry point of handling interactive inputs.

Because a completion point for a compiler instance has to be unchanged once it
is set, an incremental compiler instance is created for each code
completion. Such a compiler instance carries over AST context source from the
main interpreter compiler in order to obtain declarations or bindings from
previous input in the same REPL session.

The most important API codeComplete in Interpreter/CodeCompletion is a thin
wrapper that calls with ASTUnit::codeComplete with necessary arguments, such as
a code completion point and a ReplCompletionConsumer, which communicates
completion results from SemaCodeCompletion back to the list completer for the
REPL.

In addition, PCC_TopLevelOrExpression and CCC_TopLevelOrExpression` top levels
were added so that SemaCodeCompletion can treat top level statements like
expression statements at the REPL. For example,

clang-repl> int foo = 42;
clang-repl> f<tab>

From a parser's persective, the cursor is at a top level. If we used code
completion without any changes, PCC_Namespace would be supplied to
Sema::CodeCompleteOrdinaryName, and thus the completion results would not
include foo.

Currently, the way we use PCC_TopLevelOrExpression and
CCC_TopLevelOrExpression is no different from the way we use PCC_Statement
and CCC_Statement respectively.

Differential revision: https://reviews.llvm.org/D154382
"

The new patch also fixes clangd and several memory issues that the bots reported.
2023-08-28 19:59:56 +00:00
Vassil Vassilev
f94a937cb3 Revert "[clang-repl] support code completion at a REPL."
This reverts commit eb0e6c3134ef6deafe0a4958e9e1a1214b3c2f14 due to failures in
clangd such as https://lab.llvm.org/buildbot/#/builders/57/builds/29377
2023-08-23 14:46:15 +00:00
Fred Fu
eb0e6c3134 [clang-repl] support code completion at a REPL.
This patch enabled code completion for ClangREPL. The feature was built upon
three existing Clang components: a list completer for LineEditor, a
CompletionConsumer from SemaCodeCompletion, and the ASTUnit::codeComplete method.
The first component serves as the main entry point of handling interactive inputs.

Because a completion point for a compiler instance has to be unchanged once it
is set, an incremental compiler instance is created for each code
completion. Such a compiler instance carries over AST context source from the
main interpreter compiler in order to obtain declarations or bindings from
previous input in the same REPL session.

The most important API codeComplete in Interpreter/CodeCompletion is a thin
wrapper that calls with ASTUnit::codeComplete with necessary arguments, such as
a code completion point and a ReplCompletionConsumer, which communicates
completion results from SemaCodeCompletion back to the list completer for the
REPL.

In addition, PCC_TopLevelOrExpression and CCC_TopLevelOrExpression` top levels
were added so that SemaCodeCompletion can treat top level statements like
expression statements at the REPL. For example,

clang-repl> int foo = 42;
clang-repl> f<tab>

From a parser's persective, the cursor is at a top level. If we used code
completion without any changes, PCC_Namespace would be supplied to
Sema::CodeCompleteOrdinaryName, and thus the completion results would not
include foo.

Currently, the way we use PCC_TopLevelOrExpression and
CCC_TopLevelOrExpression is no different from the way we use PCC_Statement
and CCC_Statement respectively.

Differential revision: https://reviews.llvm.org/D154382
2023-08-23 14:00:59 +00:00
Manna, Soumi
5bb0692465 [NFC][CLANG] Fix nullptr dereference issue in SetValueDataBasedOnQualType()
This patch uses castAs instead of getAs which will assert if the type doesn't match in SetValueDataBasedOnQualType(clang::Value &, unsigned long long).

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D151770
2023-05-31 10:18:13 -07:00
Anubhab Ghosh
ddeab07ca6 [clang-repl][CUDA] Re-land: Initial interactive CUDA support for clang-repl
CUDA support can be enabled in clang-repl with --cuda flag.
Device code linking is not yet supported. inline must be used with all
__device__ functions.

Differential Revision: https://reviews.llvm.org/D146389
2023-05-27 13:54:42 +05:30
Jun Zhang
5111286f06
Reland "Reland [clang-repl] Introduce Value to capture expression results"
This reverts commit 094ab4781262b6cb49d57b0ecdf84b047c879295.

Reland with changing `ParseAndExecute` to `Parse` in
`Interpreter::create`. This avoid creating JIT instance everytime even
if we don't really need them.

This should fixes failures like https://lab.llvm.org/buildbot/#/builders/38/builds/11955

The original reverted patch also causes GN bot fails on M1. (https://lab.llvm.org/buildbot/#/builders/38/builds/11955)
However, we can't reproduce it so let's reland it and see what happens.
See discussions here: https://reviews.llvm.org/rGd71a4e02277a64a9dece591cdf2b34f15c3b19a0
2023-05-23 19:32:31 +08:00
Anubhab Ghosh
0929f5b903 Revert "[clang-repl][CUDA] Initial interactive CUDA support for clang-repl"
This reverts commit 80e7eed6a610ab3c7289e6f9b7ec006bc7d7ae31.
2023-05-20 14:40:04 +05:30
Anubhab Ghosh
80e7eed6a6 [clang-repl][CUDA] Initial interactive CUDA support for clang-repl
CUDA support can be enabled in clang-repl with --cuda flag.
Device code linking is not yet supported. inline must be used with all
__device__ functions.

Differential Revision: https://reviews.llvm.org/D146389
2023-05-20 14:00:48 +05:30
Jun Zhang
094ab47812
Revert "Reland [clang-repl] Introduce Value to capture expression results"
This reverts commit d71a4e02277a64a9dece591cdf2b34f15c3b19a0.
See http://45.33.8.238/macm1/61024/step_7.txt
2023-05-19 20:56:21 +08:00
Simon Pilgrim
c10138a54f Fix MSVC "not all control paths return a value" warning. NFC. 2023-05-19 10:40:14 +01:00
Jun Zhang
d71a4e0227
Reland [clang-repl] Introduce Value to capture expression results
This reverts commit 7158fd381a0bc0222195d6a07ebb42ea57957bda.
* Fixes endianness issue on big endian machines like PowerPC-bl
* Disable tests on platforms that having trouble to support JIT

Signed-off-by: Jun Zhang <jun@junz.org>
2023-05-19 13:40:44 +08:00
Jun Zhang
7158fd381a
Revert "[clang-repl] Introduce Value to capture expression results"
This reverts commit a423b7f1d7ca8b263af85944f57a69aa08fc942c.
See https://lab.llvm.org/buildbot/#/changes/95083
2023-05-16 21:21:52 +08:00
Jun Zhang
a423b7f1d7
[clang-repl] Introduce Value to capture expression results
This is the second part of the below RFC:
https://discourse.llvm.org/t/rfc-handle-execution-results-in-clang-repl/68493

This patch implements a Value class that can be used to carry expression
results in clang-repl. In other words, when we see a top expression
without semi, it will be captured and stored to a Value object. You can
explicitly specify where you want to store the object, like:

```
Value V;
llvm::cantFail(Interp->ParseAndExecute("int x = 42;"));
llvm::cantFail(Interp->ParseAndExecute("x", &V));
```

`V` now stores some useful infomation about `x`, you can get its real
value (42), it's `clang::QualType` or anything interesting.

However, if you don't specify the optional argument, it will be captured
to a local variable, and automatically called `Value::dump`, which is
not implemented yet in this patch.

Signed-off-by: Jun Zhang <jun@junz.org>
2023-05-16 20:10:49 +08:00
Jun Zhang
fe1f34453d
[clang-repl] JITTargetAddress --> ExecutorAddr, NFC
Most of Orc and JITLink are movinng away from JITTargetAddress and
use ExecutorAddr instead.

Signed-off-by: Jun Zhang <jun@junz.org>

Differential Revision: https://reviews.llvm.org/D148434
2023-04-16 09:46:44 +08:00
Anubhab Ghosh
766d048d81 [clang-repl] Use std::move when converting Error to Expected 2023-03-29 08:18:36 +05:30
Anubhab Ghosh
d978730d8e [clang-repl] Add a command to load dynamic libraries
This commit adds the %lib <file> command to load a dynamic library to be
used by the currently running interpreted code.
For example `%lib libSDL2.so`.

Differential Revision: https://reviews.llvm.org/D141824
2023-03-29 08:04:50 +05:30
Archibald Elliott
d768bf994f [NFC][TargetParser] Replace uses of llvm/Support/Host.h
The forwarding header is left in place because of its use in
`polly/lib/External/isl/interface/extract_interface.cc`, but I have
added a GCC warning about the fact it is deprecated, because it is used
in `isl` from where it is included by Polly.
2023-02-10 09:59:46 +00:00
serge-sans-paille
a3c248db87
Move from llvm::makeArrayRef to ArrayRef deduction guides - clang/ part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141139
2023-01-09 12:15:24 +01:00
Vassil Vassilev
dc4889357a [clang-repl] Support statements on global scope in incremental mode.
This patch teaches clang to parse statements on the global scope to allow:
```
./bin/clang-repl
clang-repl> int i = 12;
clang-repl> ++i;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> printf("%d\n", i);
13
clang-repl> %quit
```

Generally, disambiguating between statements and declarations is a non-trivial
task for a C++ parser. The challenge is to allow both standard C++ to be
translated as if this patch does not exist and in the cases where the user typed
a statement to be executed as if it were in a function body.

Clang's Parser does pretty well in disambiguating between declarations and
expressions. We have added DisambiguatingWithExpression flag which allows us to
preserve the existing and optimized behavior where needed and implement the
extra rules for disambiguating. Only few cases require additional attention:
  * Constructors/destructors -- Parser::isConstructorDeclarator was used in to
    disambiguate between ctor-looking declarations and statements on the global
    scope(eg. `Ns::f()`).
  * The template keyword -- the template keyword can appear in both declarations
    and statements. This patch considers the template keyword to be a declaration
    starter which breaks a few cases in incremental mode which will be tackled
    later.
  * The inline (and similar) keyword -- looking at the first token in many cases
    allows us to classify what is a declaration.
  * Other language keywords and specifiers -- ObjC/ObjC++/OpenCL/OpenMP rely on
    pragmas or special tokens which will be handled in subsequent patches.

The patch conceptually models a "top-level" statement into a TopLevelStmtDecl.
The TopLevelStmtDecl is lowered into a void function with no arguments.
We attach this function to the global initializer list to execute the statement
blocks in the correct order.

Differential revision: https://reviews.llvm.org/D127284
2022-12-03 07:18:07 +00:00
Sunho Kim
c619d4f840 [clang-repl] Support destructors of global objects.
Supports destructors of global objects by properly calling jitdylib deinitialize which calls the global dtors of ir modules.

This supersedes https://reviews.llvm.org/D127945. There was an issue when calling deinitialize on windows but it got fixed by https://reviews.llvm.org/D128037.

Reviewed By: v.g.vassilev

Differential Revision: https://reviews.llvm.org/D128589
2022-07-29 02:38:40 +09:00
Jonas Hahnfeld
f22795de68 [Interpreter] Pass target features to JIT
This is required to support RISC-V where the '+d' target feature
indicates the presence of the D instruction set extension, which
changes to the Hard-float 'd' ABI.

Differential Revision: https://reviews.llvm.org/D128853
2022-06-30 21:25:14 +02:00
Sunho Kim
45b6c38145 Revert "[clang-repl] Support destructors of global objects."
This reverts commit 9de8b05bfe0de2915d2443d06159396c5f9d389f.
2022-06-26 22:10:28 +09:00
Jun Zhang
dea5a9cc92
[clang-repl] Implement code undo.
In interactive C++ it is convenient to roll back to a previous state of the
compiler. For example:
clang-repl> int x = 42;
clang-repl> %undo
clang-repl> float x = 24 // not an error

To support this, the patch extends the functionality used to recover from
errors and adds functionality to recover the low-level execution infrastructure.

The current implementation is based on watermarks. It exploits the fact that
at each incremental input the underlying compiler infrastructure is in a valid
state. We can only go N incremental inputs back to a previous valid state. We do
not need and do not do any further dependency tracking.

This patch was co-developed with V. Vassilev, relies on the past work of Purva
Chaudhari in clang-repl and is inspired by the past work on the same feature
in the Cling interpreter.

Co-authored-by: Purva-Chaudhari <purva.chaudhari02@gmail.com>
Co-authored-by: Vassil Vassilev <v.g.vassilev@gmail.com>
Signed-off-by: Jun Zhang <jun@junz.org>
2022-06-26 18:32:18 +08:00
Sunho Kim
9de8b05bfe [clang-repl] Support destructors of global objects.
Supports destructors of global objects by properly calling jitdylib deinitialize which calls the global dtors of ir modules.

This supersedes https://reviews.llvm.org/D127945. There was an issue when calling deinitialize on windows but it got fixed by https://reviews.llvm.org/D128037.

Reviewed By: v.g.vassilev

Differential Revision: https://reviews.llvm.org/D128589
2022-06-26 19:02:19 +09:00
Sunho Kim
7bc00ce5cd [clang-repl] Remove memory leak of ASTContext/TargetMachine.
Removes memory leak of ASTContext and TargetMachine. When DisableFree is turned on, it intentionally leaks these instances as they can be trivially deallocated. This patch turns this off and delete Parser instance early so that they will not reference dangling pargma headers.

Asan shouldn't detect these as leaks normally, since burypointer is called for them. But, every invocation of incremental parser createa an additional leak of TargetMachine. If there are many invocations within a single test case, we easily reach number of leaks exceeding kGraveYardMaxSize (which is 12) and leaks start to get reported by asan buildbots.

Reviewed By: v.g.vassilev

Differential Revision: https://reviews.llvm.org/D127991
2022-06-18 06:36:25 +09:00
Vassil Vassilev
788e0f7f3e [clang-repl] Add an accessor to our underlying execution engine
This patch will allow better incremental adoption of these changes in downstream
cling and other users which want to experiment by customizing the execution
engine.
2022-03-11 09:24:47 +00:00
Vassil Vassilev
4fb0805c65 [clang-repl] Allow Interpreter::getSymbolAddress to take a mangled name. 2021-11-10 12:52:05 +00:00
Vassil Vassilev
c24a58081b Reinstate "[clang-repl] Re-implement clang-interpreter as a test case."
Original commit message: "
  Original commit message: "
    Original commit message: "
       Original commit message:"
         The current infrastructure in lib/Interpreter has a tool, clang-repl, very
         similar to clang-interpreter which also allows incremental compilation.

         This patch moves clang-interpreter as a test case and drops it as conditionally
         built example as we already have clang-repl in place.
       "

       This patch also ignores ppc due to missing weak symbol for __gxx_personality_v0
       which may be a feature request for the jit infrastructure. Also, adds a missing
       build system dependency to the orc jit.
    "

    Additionally, this patch defines a custom exception type and thus avoids the
    requirement to include header <exception>, making it easier to deploy across
    systems without standard location of the c++ headers.
  "

  This patch also works around PR49692 and finds a way to use llvm::consumeError
  in rtti mode.
"

This patch also checks if stl is built with rtti.

Differential revision: https://reviews.llvm.org/D107049
2021-10-26 19:29:56 +00:00
Arthur Eubanks
19b07ec000 Reland [clang] Pass -clear-ast-before-backend in Clang::ConstructJob()
This clears the memory used for the Clang AST before we run LLVM passes.

https://llvm-compile-time-tracker.com/compare.php?from=d0a5f61c4f6fccec87fd5207e3fcd9502dd59854&to=b7437fee79e04464dd968e1a29185495f3590481&stat=max-rss
shows significant memory savings with no slowdown (in fact -O0 slightly speeds up).

For more background, see
https://lists.llvm.org/pipermail/cfe-dev/2021-September/068930.html.

Turn this off for the interpreter since it does codegen multiple times.

Relanding with fix for -print-stats: D111973

Relanding with fix for plugins: D112190

If you'd like to use this even with plugins, consider using the features
introduced in D112096.

This can be turned off with -Xclang -no-clear-ast-before-backend.

Differential Revision: https://reviews.llvm.org/D111270
2021-10-21 09:25:53 -07:00
Zequan Wu
57553ce432 Revert "Reland [clang] Pass -clear-ast-before-backend in Clang::ConstructJob()"
This reverts commit 1fb24fe85a19ae71b00875ff6c96ef1831dcf7e3.

This causes clang crash on chromium. See repro at https://bugs.chromium.org/p/chromium/issues/detail?id=1261551#c1.
2021-10-19 12:39:34 -07:00
Arthur Eubanks
1fb24fe85a Reland [clang] Pass -clear-ast-before-backend in Clang::ConstructJob()
This clears the memory used for the Clang AST before we run LLVM passes.

https://llvm-compile-time-tracker.com/compare.php?from=d0a5f61c4f6fccec87fd5207e3fcd9502dd59854&to=b7437fee79e04464dd968e1a29185495f3590481&stat=max-rss
shows significant memory savings with no slowdown (in fact -O0 slightly speeds up).

For more background, see
https://lists.llvm.org/pipermail/cfe-dev/2021-September/068930.html.

Turn this off for the interpreter since it does codegen multiple times.

Relanding with fix for -print-stats: D111973

Differential Revision: https://reviews.llvm.org/D111270
2021-10-18 09:08:16 -07:00
Arthur Eubanks
49562d3dfe Revert "[clang] Pass -clear-ast-before-backend in Clang::ConstructJob()"
This reverts commit 47eb99aa44ab1d20327d67a49d6c47163de76387.

This causes crashes with -print-stats: PR52193.
2021-10-16 12:05:41 -07:00
Arthur Eubanks
47eb99aa44 [clang] Pass -clear-ast-before-backend in Clang::ConstructJob()
This clears the memory used for the Clang AST before we run LLVM passes.

https://llvm-compile-time-tracker.com/compare.php?from=d0a5f61c4f6fccec87fd5207e3fcd9502dd59854&to=b7437fee79e04464dd968e1a29185495f3590481&stat=max-rss
shows significant memory savings with no slowdown (in fact -O0 slightly speeds up).

For more background, see
https://lists.llvm.org/pipermail/cfe-dev/2021-September/068930.html.

Turn this off for the interpreter since it does codegen multiple times.

Differential Revision: https://reviews.llvm.org/D111270
2021-10-15 10:13:17 -07:00
Arthur Eubanks
675ed4c82d [NFC][Interpreter] Remove unused CompilerInvocation 2021-10-14 15:17:49 -07:00
Leonard Chan
04aff39504 Revert "Reland "[clang-repl] Re-implement clang-interpreter as a test case.""
This reverts commit 1dba6b37bdc70210f75a480eff3715ebe1f1d8be.

Reverting because the ClangReplInterpreterExceptionTests test fails on
our builders with this patch.
2021-10-08 17:43:23 -07:00
Vassil Vassilev
1dba6b37bd Reland "[clang-repl] Re-implement clang-interpreter as a test case."
Original commit message: "
    Original commit message: "
        Original commit message:"
          The current infrastructure in lib/Interpreter has a tool, clang-repl, very
          similar to clang-interpreter which also allows incremental compilation.

          This patch moves clang-interpreter as a test case and drops it as conditionally
          built example as we already have clang-repl in place.

          Differential revision: https://reviews.llvm.org/D107049
        "

        This patch also ignores ppc due to missing weak symbol for __gxx_personality_v0
        which may be a feature request for the jit infrastructure. Also, adds a missing
        build system dependency to the orc jit.
    "

    Additionally, this patch defines a custom exception type and thus avoids the
    requirement to include header <exception>, making it easier to deploy across
    systems without standard location of the c++ headers.
  "

  This patch also works around PR49692 and finds a way to use llvm::consumeError
  in rtti mode.

Differential revision: https://reviews.llvm.org/D107049
2021-10-08 06:04:39 +00:00
Luke Drummond
6283d468e2 Workaround build error for mingw-g++
mingw-g++ does not correctly support the full `std::errc` namespace as
worded in the standard[1]. As such, we cannot reliably use all names
therein. This patch changes the use of
`std::errc::state_not_recoverable`, to use portable error codes from the
`llvm::errc` equivalent.

[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71444

Reviewed by v.g.vassilev
Differential Revision: https://reviews.llvm.org/D111315
2021-10-07 18:34:16 +01:00
Vassil Vassilev
8859640461 Revert "Reland "[clang-repl] Re-implement clang-interpreter as a test case.""
This reverts commit 6fe2beba7d2a41964af658c8c59dd172683ef739 which fails on
clang-hexagon-elf
2021-09-03 13:18:09 +00:00
Vassil Vassilev
6fe2beba7d Reland "[clang-repl] Re-implement clang-interpreter as a test case."
Original commit message: "
    Original commit message:"
      The current infrastructure in lib/Interpreter has a tool, clang-repl, very
      similar to clang-interpreter which also allows incremental compilation.

      This patch moves clang-interpreter as a test case and drops it as conditionally
      built example as we already have clang-repl in place.

      Differential revision: https://reviews.llvm.org/D107049
    "

    This patch also ignores ppc due to missing weak symbol for __gxx_personality_v0
    which may be a feature request for the jit infrastructure. Also, adds a missing
    build system dependency to the orc jit.
"

Additionally, this patch defines a custom exception type and thus avoids the
requirement to include header <exception>, making it easier to deploy across
systems without standard location of the c++ headers.

Differential revision: https://reviews.llvm.org/D107049
2021-09-03 12:02:58 +00:00
Jan Svoboda
555a817d1d [clang] NFC: Extract DiagnosticOptions parsing
The way we parse `DiagnosticOptions` is a bit involved.

`DiagnosticOptions` are parsed as part of the cc1-parsing function `CompilerInvocation::CreateFromArgs` which takes `DiagnosticsEngine` as an argument to be able to report errors in command-line arguments. But to create `DiagnosticsEngine`, `DiagnosticOptions` are needed. This is solved by exposing the `ParseDiagnosticArgs` to clients and making its `DiagnosticsEngine` argument optional, essentially breaking the dependency cycle.

The `ParseDiagnosticArgs` function takes `llvm::opt::ArgList &`, which each client needs to create from the command-line (typically represented as `std::vector<const char *>`). Creating this data structure in this context is somewhat particular. This code pattern is copy-pasted in some places across the upstream code base and also in downstream repos. To make things a bit more uniform, this patch extracts the code into a new reusable function: `CreateAndPopulateDiagOpts`.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D108918
2021-09-02 14:37:14 +02:00
Nico Weber
9b6c8132d3 Revert "Reland "[clang-repl] Re-implement clang-interpreter as a test case.""
This reverts commit f0514a4d26100239088f08d618f2ba100f59958e.
Test fails on macOS: https://reviews.llvm.org/D107049#2976603
2021-09-01 08:35:33 -04:00
Vassil Vassilev
f0514a4d26 Reland "[clang-repl] Re-implement clang-interpreter as a test case."
Original commit message:"
  The current infrastructure in lib/Interpreter has a tool, clang-repl, very
  similar to clang-interpreter which also allows incremental compilation.

  This patch moves clang-interpreter as a test case and drops it as conditionally
  built example as we already have clang-repl in place.

  Differential revision: https://reviews.llvm.org/D107049
"

This patch also ignores ppc due to missing weak symbol for __gxx_personality_v0
which may be a feature request for the jit infrastructure. Also, adds a missing
build system dependency to the orc jit.
2021-09-01 10:21:38 +00:00
Vassil Vassilev
04bbd189a9 Revert "[clang-repl] Re-implement clang-interpreter as a test case."
This reverts commit 319ce98011742141dad8dd95a2f9de9c0449be5c because it fails
on various platforms.
2021-09-01 06:49:52 +00:00
Vassil Vassilev
319ce98011 [clang-repl] Re-implement clang-interpreter as a test case.
The current infrastructure in lib/Interpreter has a tool, clang-repl, very
similar to clang-interpreter which also allows incremental compilation.

This patch moves clang-interpreter as a test case and drops it as conditionally
built example as we already have clang-repl in place.

Differential revision: https://reviews.llvm.org/D107049
2021-09-01 05:23:21 +00:00
Vassil Vassilev
11b47c103a Reland "[clang-repl] Implement partial translation units and error recovery."
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
2021-07-12 15:21:22 +00:00
Vassil Vassilev
5922f234c8 Revert "[clang-repl] Implement partial translation units and error recovery."
This reverts commit 6775fc6ffa3ca1c36b20c25fa4e7f48f81213cf2.

It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."

This reverts commit 03a3f86071c10a1f6cbbf7375aa6fe9d94168972.

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
2021-07-11 14:40:10 +00:00
Vassil Vassilev
6775fc6ffa [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
2021-07-11 10:23:41 +00:00
Melanie Blower
aaba37187f [clang][PATCH][nfc] Refactor TargetInfo::adjust to pass DiagnosticsEngine to allow diagnostics on target-unsupported options
Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D104729
2021-06-29 13:26:23 -04:00
Melanie Blower
1d85d0879a Revert "[clang][PATCH][nfc] Refactor TargetInfo::adjust to pass DiagnosticsEngine to allow diagnostics on target-unsupported options"
This reverts commit 2dbe1c675fe94eeb7973dcc25b049d25f4ca4fa0.
More buildbot failures
2021-06-28 15:47:21 -04:00
Melanie Blower
2dbe1c675f [clang][PATCH][nfc] Refactor TargetInfo::adjust to pass DiagnosticsEngine to allow diagnostics on target-unsupported options
Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D104729
2021-06-28 15:09:53 -04:00