28 Commits

Author SHA1 Message Date
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
247fa04116
[clang] Add a new annotation token: annot_repl_input_end
This patch is the first part of the below RFC:
https://discourse.llvm.org/t/rfc-handle-execution-results-in-clang-repl/68493

It adds an annotation token which will replace the original EOF token
when we are in the incremental C++ mode. In addition, when we're
parsing an ExprStmt and there's a missing semicolon after the
expression, we set a marker in the annotation token and continue
parsing.

Eventually, we propogate this info in ParseTopLevelStmtDecl and are able
to mark this Decl as something we want to do value printing. Below is a
example:

clang-repl> int x = 42;
clang-repl> x
// `x` is a TopLevelStmtDecl and without a semicolon, we should set
// it's IsSemiMissing bit so we can do something interesting in
// ASTConsumer::HandleTopLevelDecl.

The idea about annotation toke is proposed by Richard Smith, thanks!

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

Differential Revision: https://reviews.llvm.org/D148997
2023-05-16 20:10:43 +08:00
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
Fangrui Song
3f18f7c007 [clang] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D131346
2022-08-08 09:12:46 -07:00
Purva-Chaudhari
168d4e2945 Handles failing driver tests of clang
Added support for incremental mode 8 and 28 ie. `frontend::EmitBC:` and `frontend::PrintPreprocessedInput:`
Added supporting clang tests to test in clang-repl mode

Reviewed By: v.g.vassilev

Differential Revision: https://reviews.llvm.org/D125946
2022-08-02 12:29:26 +05:30
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
Tapasweni Pathak
946c45a4ed Implement soft reset of the diagnostics engine.
This patch implements soft reset and adds tests for soft reset success of the
diagnostics engine. This allows us to recover from errors in clang-repl without
resetting the pragma handlers' state.

Differential revision: https://reviews.llvm.org/D126183
2022-06-24 14:46:54 +00:00
Vassil Vassilev
ac6c5c5e8f Reland "[clang-repl] Recover the lookup tables of the primary context."
The asan issue was fixed in llvm/llvm-project@7bc00ce5cd

This reverts commit 575e297fcb289f0a9b0ac4b01d1d0fa051f5cc29.

Differential revision: https://reviews.llvm.org/D123674
2022-06-24 08:35:41 +00:00
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
575e297fcb Revert "[clang-repl] Recover the lookup tables of the primary context."
This reverts commit 5ff27fe1ff03d5aeaf8567c97618170f0cef8f58.

This patch caused failures in asan: https://lab.llvm.org/buildbot/#/builders/5/builds/24221
2022-05-31 06:25:37 +00:00
Purva-Chaudhari
5ff27fe1ff [clang-repl] Recover the lookup tables of the primary context.
Before this patch, there was re-declaration error if error was encountered in
the same line. The recovery support acted only if this type of error was
encountered in the first line of the program and not in subsequent lines.

For example:

```
clang-repl> int i=9;
clang-repl> int j=9; err;
input_line_3:1:5: error: redefinition of 'j'
int j = 9;
```

Differential revision: https://reviews.llvm.org/D123674
2022-05-29 04:59:40 +00:00
Iain Sandoe
ab28488efe [C++20][Modules][1/8] Track valid import state.
In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag).  If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.

We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules).  Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).

Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:

import module A;

int some_decl();

import module B;

where being in a module purview is insufficient to identify them.

Differential Revision: https://reviews.llvm.org/D118893
2022-02-21 09:09:37 +00:00
Iain Sandoe
673879249d Revert "[C++20][Modules][1/8] Track valid import state."
This reverts commit 8a3f9a584ad43369cf6a034dc875ebfca76d9033.

need to investigate build failures that do not show on CI or local
testing.
2022-02-20 10:22:07 +00:00
Iain Sandoe
8a3f9a584a [C++20][Modules][1/8] Track valid import state.
In C++20 modules imports must be together and at the start of the module.
Rather than growing more ad-hoc flags to test state, this keeps track of the
phase of of a valid module TU (first decl, global module frag, module,
private module frag).  If the phasing is broken (with some diagnostic) the
pattern does not conform to a valid C++20 module, and we set the state
accordingly.

We can thus issue diagnostics when imports appear in the wrong places and
decouple the C++20 modules state from other module variants (modules-ts and
clang modules).  Additionally, we attempt to diagnose wrong imports before
trying to find the module where possible (the latter will generally emit an
unhelpful diagnostic about the module not being available).

Although this generally simplifies the handling of C++20 module import
diagnostics, the motivation was that, in particular, it allows detecting
invalid imports like:

import module A;

int some_decl();

import module B;

where being in a module purview is insufficient to identify them.

Differential Revision: https://reviews.llvm.org/D118893
2022-02-20 10:13:57 +00:00
Kazu Hirata
298367ee6e [clang] Use nullptr instead of 0 or NULL (NFC)
Identified with modernize-use-nullptr.
2021-12-29 08:34:20 -08:00
Vassil Vassilev
4fb0805c65 [clang-repl] Allow Interpreter::getSymbolAddress to take a mangled name. 2021-11-10 12:52:05 +00:00
Vassil Vassilev
f4f9ad0f5d Reland "[clang-repl] Allow loading of plugins in clang-repl."
Differential revision: https://reviews.llvm.org/D110484
2021-10-05 13:04:01 +00:00
Vassil Vassilev
3e9d04f7e4 Revert "[clang-repl] Allow loading of plugins in clang-repl."
This reverts commit 81fb640f83b6a5d099f9124739ab3049be79ea56 due to bot failures:
https://lab.llvm.org/buildbot#builders/57/builds/10807
2021-10-05 06:10:38 +00:00
Vassil Vassilev
81fb640f83 [clang-repl] Allow loading of plugins in clang-repl.
Differential revision: https://reviews.llvm.org/D110484
2021-10-05 05:20:30 +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
Vassil Vassilev
8dd5ef01ef [clang-repl] Better match the underlying architecture.
In cases where -fno-integrated-as is specified we should overwrite the
EmitAssembly action as well.

We also should rely on the target triple from the process at least until we
implement out-of-process execution.

This patch should improve clang-repl on AIX.

Discussion available at: https://reviews.llvm.org/D96033

Differential revision: https://reviews.llvm.org/D102688
2021-05-18 19:14:33 +00:00
Vassil Vassilev
92f9852fc9 [clang-repl] Recommit "Land initial infrastructure for incremental parsing"
Original commit message:

  In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
  mentioned our plans to make some of the incremental compilation facilities
  available in llvm mainline.

  This patch proposes a minimal version of a repl, clang-repl, which enables
  interpreter-like interaction for C++. For instance:

  ./bin/clang-repl
  clang-repl> int i = 42;
  clang-repl> extern "C" int printf(const char*,...);
  clang-repl> auto r1 = printf("i=%d\n", i);
  i=42
  clang-repl> quit

  The patch allows very limited functionality, for example, it crashes on invalid
  C++. The design of the proposed patch follows closely the design of cling. The
  idea is to gather feedback and gradually evolve both clang-repl and cling to
  what the community agrees upon.

  The IncrementalParser class is responsible for driving the clang parser and
  codegen and allows the compiler infrastructure to process more than one input.
  Every input adds to the “ever-growing” translation unit. That model is enabled
  by an IncrementalAction which prevents teardown when HandleTranslationUnit.

  The IncrementalExecutor class hides some of the underlying implementation
  details of the concrete JIT infrastructure. It exposes the minimal set of
  functionality required by our incremental compiler/interpreter.

  The Transaction class keeps track of the AST and the LLVM IR for each
  incremental input. That tracking information will be later used to implement
  error recovery.

  The Interpreter class orchestrates the IncrementalParser and the
  IncrementalExecutor to model interpreter-like behavior. It provides the public
  API which can be used (in future) when using the interpreter library.

  Differential revision: https://reviews.llvm.org/D96033
2021-05-13 06:30:29 +00:00
Vassil Vassilev
f6907152db Revert "[clang-repl] Land initial infrastructure for incremental parsing"
This reverts commit 44a4000181e1a25027e87f2ae4e71cb876a7a275.

We are seeing build failures due to missing dependency to libSupport and
CMake Error at tools/clang/tools/clang-repl/cmake_install.cmake
file INSTALL cannot find
2021-05-13 04:44:19 +00:00
Vassil Vassilev
44a4000181 [clang-repl] Land initial infrastructure for incremental parsing
In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
mentioned our plans to make some of the incremental compilation facilities
available in llvm mainline.

This patch proposes a minimal version of a repl, clang-repl, which enables
interpreter-like interaction for C++. For instance:

./bin/clang-repl
clang-repl> int i = 42;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=42
clang-repl> quit

The patch allows very limited functionality, for example, it crashes on invalid
C++. The design of the proposed patch follows closely the design of cling. The
idea is to gather feedback and gradually evolve both clang-repl and cling to
what the community agrees upon.

The IncrementalParser class is responsible for driving the clang parser and
codegen and allows the compiler infrastructure to process more than one input.
Every input adds to the “ever-growing” translation unit. That model is enabled
by an IncrementalAction which prevents teardown when HandleTranslationUnit.

The IncrementalExecutor class hides some of the underlying implementation
details of the concrete JIT infrastructure. It exposes the minimal set of
functionality required by our incremental compiler/interpreter.

The Transaction class keeps track of the AST and the LLVM IR for each
incremental input. That tracking information will be later used to implement
error recovery.

The Interpreter class orchestrates the IncrementalParser and the
IncrementalExecutor to model interpreter-like behavior. It provides the public
API which can be used (in future) when using the interpreter library.

Differential revision: https://reviews.llvm.org/D96033
2021-05-13 04:23:24 +00:00