Fixes#123300
What is seen
```
clang-repl> int x = 42;
clang-repl> auto capture = [&]() { return x * 2; };
In file included from <<< inputs >>>:1:
input_line_4:1:17: error: non-local lambda expression cannot have a capture-default
1 | auto capture = [&]() { return x * 2; };
| ^
zsh: segmentation fault clang-repl --Xcc="-v"
(lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x8)
* frame #0: 0x0000000107b4f8b8 libclang-cpp.19.1.dylib`clang::IncrementalParser::CleanUpPTU(clang::PartialTranslationUnit&) + 988
frame #1: 0x0000000107b4f1b4 libclang-cpp.19.1.dylib`clang::IncrementalParser::ParseOrWrapTopLevelDecl() + 416
frame #2: 0x0000000107b4fb94 libclang-cpp.19.1.dylib`clang::IncrementalParser::Parse(llvm::StringRef) + 612
frame #3: 0x0000000107b52fec libclang-cpp.19.1.dylib`clang::Interpreter::ParseAndExecute(llvm::StringRef, clang::Value*) + 180
frame #4: 0x0000000100003498 clang-repl`main + 3560
frame #5: 0x000000018d39a0e0 dyld`start + 2360
```
Though the error is justified, we shouldn't be interested in exiting
through a segfault in such cases.
The issue is that empty named decls weren't being taken care of
resulting into this assert
c1a2292526/clang/include/clang/AST/DeclarationName.h (L503)
Can also be seen when the example is attempted through xeus-cpp-lite.
For constexpr function templates, we immediately instantiate them upon
reference. However, if the function isn't defined at the time of
instantiation, even though it might be defined later, the instantiation
would forever fail.
This patch corrects the behavior by popping up failed instantiations
through PendingInstantiations, so that we are able to instantiate them
again in the future (e.g. at the end of TU.)
Fixes https://github.com/llvm/llvm-project/issues/125747
This patch improves the design of the IncrementalParser and Interpreter
classes. Now the incremental parser is only responsible for building the
partial translation unit declaration and the AST, while the Interpreter
fills in the lower level llvm::Module and other JIT-related
infrastructure. Finally the Interpreter class now orchestrates the AST
and the LLVM IR with the IncrementalParser and IncrementalExecutor
classes.
The design improvement allows us to rework some of the logic that
extracts an interpreter value into the clang::Value object. The new
implementation simplifies use-cases which are used for out-of-process
execution by allowing interpreter to be inherited or customized with an
clang::ASTConsumer.
This change will enable completing the pretty printing work which is in
llvm/llvm-project#84769
When BPF object files are linked with bpftool, every symbol must be
accompanied by BTF info. Ensure that extern functions referenced by
global variable initializers are included in BTF.
The primary motivation is "static" initialization of PROG maps:
```c
extern int elsewhere(struct xdp_md *);
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 1);
__type(key, int);
__type(value, int);
__array(values, int (struct xdp_md *));
} prog_map SEC(".maps") = { .values = { elsewhere } };
```
BPF backend needs debug info to produce BTF. Debug info is not
normally generated for external variables and functions. Previously, it
was solved differently for variables (collecting variable declarations
in ExternalDeclarations vector) and functions (logic invoked during
codegen in CGExpr.cpp).
This patch generalises ExternalDefclarations to include both function
and variable declarations. This change ensures that function references
are not missed no matter the context. Previously external functions
referenced in constant expressions lacked debug info.
Original commit message:"
[clang-repl] Extend the C support. (#89804)
The IdResolver chain is the main way for C to implement lookup rules. Every new
partial translation unit caused clang to exit the top-most scope which in turn
cleaned up the IdResolver chain. That was not an issue for C++ because its
lookup is implemented on the level of declaration contexts.
This patch keeps the IdResolver chain across partial translation units
maintaining proper C-style lookup infrastructure.
"
It was reverted in dfdf1c5fe45a82b9c578306f3d7627fd251d63f8 because it broke the
bots of lldb. This failure was subtle to debug but the current model does not
work well with ObjectiveC support in lldb. This patch does cleans up the
partial translation units in ObjectiveC. In future if we want to support
ObjectiveC we need to understand what exactly lldb is doing when recovering from
errors...
The IdResolver chain is the main way for C to implement lookup rules.
Every new partial translation unit caused clang to exit the top-most
scope which in turn cleaned up the IdResolver chain. That was not an
issue for C++ because its lookup is implemented on the level of
declaration contexts.
This patch keeps the IdResolver chain across partial translation units
maintaining proper C-style lookup infrastructure.
Original commit message: "
Clang's CodeGen is designed to work with a single llvm::Module. In many cases
for convenience various CodeGen parts have a reference to the llvm::Module
(TheModule or Module) which does not change when a new module is pushed.
However, the execution engine wants to take ownership of the module which does
not map well to CodeGen's design. To work this around we clone the module and
pass it down.
With some effort it is possible to teach CodeGen to ask the CodeGenModule for
its current module and that would have an overall positive impact on CodeGen
improving the encapsulation of various parts but that's not resilient to future
regression.
This patch takes a more conservative approach and keeps the first llvm::Module
empty intentionally and does not pass it to the Jit. That's also not bullet
proof because we have to guarantee that CodeGen does not write on the
blueprint. However, we have inserted some assertions to catch accidental
additions to that canary module.
This change will fixes a long-standing invalid memory access reported by
valgrind when we enable the TBAA optimization passes. It also unblock progress
on https://github.com/llvm/llvm-project/pull/84758.
"
This patch reverts adc4f6233df734fbe3793118ecc89d3584e0c90f and removes
the check of `named_metadata_empty` of the first llvm::Module because on darwin
clang inserts some harmless metadata which we can ignore.
Clang's CodeGen is designed to work with a single llvm::Module. In many
cases
for convenience various CodeGen parts have a reference to the
llvm::Module
(TheModule or Module) which does not change when a new module is pushed.
However, the execution engine wants to take ownership of the module
which does
not map well to CodeGen's design. To work this around we clone the
module and
pass it down.
With some effort it is possible to teach CodeGen to ask the
CodeGenModule for
its current module and that would have an overall positive impact on
CodeGen
improving the encapsulation of various parts but that's not resilient to
future
regression.
This patch takes a more conservative approach and keeps the first
llvm::Module
empty intentionally and does not pass it to the Jit. That's also not
bullet
proof because we have to guarantee that CodeGen does not write on the
blueprint. However, we have inserted some assertions to catch accidental
additions to that canary module.
This change will fixes a long-standing invalid memory access reported by
valgrind when we enable the TBAA optimization passes. It also unblock
progress
on https://github.com/llvm/llvm-project/pull/84758.
Using remove() on DeclContext::lookup_result list invalidates iterators.
This assertion failure was one (fortunate) symptom:
```
clang/include/clang/AST/DeclBase.h:1337: reference clang::DeclListNode::iterator::operator*() const: Assertion `Ptr && "dereferencing end() iterator"' failed.
```
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
and upload the missing files.
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.
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
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
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
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>
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>
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
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
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
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>
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
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
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
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
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
Original commit message:
[clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
This reverts commit 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
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
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
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
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
