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| //===-- ASTResultSynthesizer.h ----------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef liblldb_ASTResultSynthesizer_h_
#define liblldb_ASTResultSynthesizer_h_
#include "lldb/Core/ClangForward.h"
#include "lldb/Target/Target.h"
#include "clang/Sema/SemaConsumer.h"
namespace lldb_private {
/// \class ASTResultSynthesizer ASTResultSynthesizer.h
/// "lldb/Expression/ASTResultSynthesizer.h" Adds a result variable
/// declaration to the ASTs for an expression.
///
/// Users expect the expression "i + 3" to return a result, even if a result
/// variable wasn't specifically declared. To fulfil this requirement, LLDB
/// adds a result variable to the expression, transforming it to "int
/// $__lldb_expr_result = i + 3." The IR transformers ensure that the
/// resulting variable is mapped to the right piece of memory.
/// ASTResultSynthesizer's job is to add the variable and its initialization
/// to the ASTs for the expression, and it does so by acting as a SemaConsumer
/// for Clang.
class ASTResultSynthesizer : public clang::SemaConsumer {
public:
/// Constructor
///
/// \param[in] passthrough
/// Since the ASTs must typically go through to the Clang code generator
/// in order to produce LLVM IR, this SemaConsumer must allow them to
/// pass to the next step in the chain after processing. Passthrough is
/// the next ASTConsumer, or NULL if none is required.
///
/// \param[in] top_level
/// If true, register all top-level Decls and don't try to handle the
/// main function.
///
/// \param[in] target
/// The target, which contains the persistent variable store and the
/// AST importer.
ASTResultSynthesizer(clang::ASTConsumer *passthrough, bool top_level,
Target &target);
/// Destructor
~ASTResultSynthesizer() override;
/// Link this consumer with a particular AST context
///
/// \param[in] Context
/// This AST context will be used for types and identifiers, and also
/// forwarded to the passthrough consumer, if one exists.
void Initialize(clang::ASTContext &Context) override;
/// Examine a list of Decls to find the function $__lldb_expr and transform
/// its code
///
/// \param[in] D
/// The list of Decls to search. These may contain LinkageSpecDecls,
/// which need to be searched recursively. That job falls to
/// TransformTopLevelDecl.
bool HandleTopLevelDecl(clang::DeclGroupRef D) override;
/// Passthrough stub
void HandleTranslationUnit(clang::ASTContext &Ctx) override;
/// Passthrough stub
void HandleTagDeclDefinition(clang::TagDecl *D) override;
/// Passthrough stub
void CompleteTentativeDefinition(clang::VarDecl *D) override;
/// Passthrough stub
void HandleVTable(clang::CXXRecordDecl *RD) override;
/// Passthrough stub
void PrintStats() override;
/// Set the Sema object to use when performing transforms, and pass it on
///
/// \param[in] S
/// The Sema to use. Because Sema isn't externally visible, this class
/// casts it to an Action for actual use.
void InitializeSema(clang::Sema &S) override;
/// Reset the Sema to NULL now that transformations are done
void ForgetSema() override;
/// The parse has succeeded, so record its persistent decls
void CommitPersistentDecls();
private:
/// Hunt the given Decl for FunctionDecls named $__lldb_expr, recursing as
/// necessary through LinkageSpecDecls, and calling SynthesizeResult on
/// anything that was found
///
/// \param[in] D
/// The Decl to hunt.
void TransformTopLevelDecl(clang::Decl *D);
/// Process an Objective-C method and produce the result variable and
/// initialization
///
/// \param[in] MethodDecl
/// The method to process.
bool SynthesizeObjCMethodResult(clang::ObjCMethodDecl *MethodDecl);
/// Process a function and produce the result variable and initialization
///
/// \param[in] FunDecl
/// The function to process.
bool SynthesizeFunctionResult(clang::FunctionDecl *FunDecl);
/// Process a function body and produce the result variable and
/// initialization
///
/// \param[in] Body
/// The body of the function.
///
/// \param[in] DC
/// The DeclContext of the function, into which the result variable
/// is inserted.
bool SynthesizeBodyResult(clang::CompoundStmt *Body, clang::DeclContext *DC);
/// Given a DeclContext for a function or method, find all types declared in
/// the context and record any persistent types found.
///
/// \param[in] FunDeclCtx
/// The context for the function to process.
void RecordPersistentTypes(clang::DeclContext *FunDeclCtx);
/// Given a TypeDecl, if it declares a type whose name starts with a dollar
/// sign, register it as a pointer type in the target's scratch
/// AST context.
///
/// \param[in] Body
/// The body of the function.
void MaybeRecordPersistentType(clang::TypeDecl *D);
/// Given a NamedDecl, register it as a pointer type in the target's scratch
/// AST context.
///
/// \param[in] Body
/// The body of the function.
void RecordPersistentDecl(clang::NamedDecl *D);
clang::ASTContext
*m_ast_context; ///< The AST context to use for identifiers and types.
clang::ASTConsumer *m_passthrough; ///< The ASTConsumer down the chain, for
///passthrough. NULL if it's a
///SemaConsumer.
clang::SemaConsumer *m_passthrough_sema; ///< The SemaConsumer down the chain,
///for passthrough. NULL if it's an
///ASTConsumer.
std::vector<clang::NamedDecl *> m_decls; ///< Persistent declarations to
///register assuming the expression
///succeeds.
Target &m_target; ///< The target, which contains the persistent variable
///store and the
clang::Sema *m_sema; ///< The Sema to use.
bool m_top_level;
};
} // namespace lldb_private
#endif // liblldb_ASTResultSynthesizer_h_
|