61 Commits

Author SHA1 Message Date
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
Archibald Elliott
f09cf34d00 [Support] Move TargetParsers to new component
This is a fairly large changeset, but it can be broken into a few
pieces:
- `llvm/Support/*TargetParser*` are all moved from the LLVM Support
  component into a new LLVM Component called "TargetParser". This
  potentially enables using tablegen to maintain this information, as
  is shown in https://reviews.llvm.org/D137517. This cannot currently
  be done, as llvm-tblgen relies on LLVM's Support component.
- This also moves two files from Support which use and depend on
  information in the TargetParser:
  - `llvm/Support/Host.{h,cpp}` which contains functions for inspecting
    the current Host machine for info about it, primarily to support
    getting the host triple, but also for `-mcpu=native` support in e.g.
    Clang. This is fairly tightly intertwined with the information in
    `X86TargetParser.h`, so keeping them in the same component makes
    sense.
  - `llvm/ADT/Triple.h` and `llvm/Support/Triple.cpp`, which contains
    the target triple parser and representation. This is very intertwined
    with the Arm target parser, because the arm architecture version
    appears in canonical triples on arm platforms.
- I moved the relevant unittests to their own directory.

And so, we end up with a single component that has all the information
about the following, which to me seems like a unified component:
- Triples that LLVM Knows about
- Architecture names and CPUs that LLVM knows about
- CPU detection logic for LLVM

Given this, I have also moved `RISCVISAInfo.h` into this component, as
it seems to me to be part of that same set of functionality.

If you get link errors in your components after this patch, you likely
need to add TargetParser into LLVM_LINK_COMPONENTS in CMake.

Differential Revision: https://reviews.llvm.org/D137838
2022-12-20 11:05:50 +00:00
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
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
Kazu Hirata
3650615fb2 [clang] Remove unused forward declarations (NFC) 2022-07-24 20:51:06 -07:00
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
Vassil Vassilev
b5eaf500f2 [clang] Add missing Interpreter -> ClangDriverOptions dependency
Without this, it is possible that Interpreter.cpp is being built before
clang/Driver/Options.inc is generated.

Observed only infrequently, serial builds and ext4 manifest the problem
much more often than parallel builds and btrfs.

https://reviews.llvm.org/rG06487b010d48c36c7714ee083ed38dff65711812
is a very similar case.

Patch by t184256!

Differential revision: https://reviews.llvm.org/D115827
2022-06-26 13:51:21 +00:00
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
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
Lang Hames
16dcbb53dc [ORC] Return ExecutorAddrs rather than JITEvaluatedSymbols from LLJIT::lookup.
Clients don't care about linkage, and ExecutorAddr is much more ergonomic.
2022-05-05 13:56:00 -07:00
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
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
d1b127b5b7 [clang] Remove unused forward declarations (NFC) 2022-01-08 11:56:40 -08:00
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
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
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
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