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//===-- ClangExpressionDeclMap.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 LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONDECLMAP_H
#define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONDECLMAP_H
#include <signal.h>
#include <stdint.h>
#include <vector>
#include "ClangASTSource.h"
#include "ClangExpressionVariable.h"
#include "lldb/Core/Value.h"
#include "lldb/Expression/Materializer.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/TaggedASTType.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/lldb-public.h"
#include "clang/AST/Decl.h"
#include "llvm/ADT/DenseMap.h"
namespace lldb_private {
class ClangPersistentVariables;
/// \class ClangExpressionDeclMap ClangExpressionDeclMap.h
/// "lldb/Expression/ClangExpressionDeclMap.h" Manages named entities that are
/// defined in LLDB's debug information.
///
/// The Clang parser uses the ClangASTSource as an interface to request named
/// entities from outside an expression. The ClangASTSource reports back,
/// listing all possible objects corresponding to a particular name. But it
/// in turn relies on ClangExpressionDeclMap, which performs several important
/// functions.
///
/// First, it records what variables and functions were looked up and what
/// Decls were returned for them.
///
/// Second, it constructs a struct on behalf of IRForTarget, recording which
/// variables should be placed where and relaying this information back so
/// that IRForTarget can generate context-independent code.
///
/// Third, it "materializes" this struct on behalf of the expression command,
/// finding the current values of each variable and placing them into the
/// struct so that it can be passed to the JITted version of the IR.
///
/// Fourth and finally, it "dematerializes" the struct after the JITted code
/// has has executed, placing the new values back where it found the old ones.
class ClangExpressionDeclMap : public ClangASTSource {
public:
/// Constructor
///
/// Initializes class variables.
///
/// \param[in] keep_result_in_memory
/// If true, inhibits the normal deallocation of the memory for
/// the result persistent variable, and instead marks the variable
/// as persisting.
///
/// \param[in] result_delegate
/// If non-NULL, use this delegate to report result values. This
/// allows the client ClangUserExpression to report a result.
///
/// \param[in] target
/// The target to use when parsing.
///
/// \param[in] importer
/// The ClangASTImporter to use when parsing.
///
/// \param[in] ctx_obj
/// If not empty, then expression is evaluated in context of this object.
/// See the comment to `UserExpression::Evaluate` for details.
ClangExpressionDeclMap(
bool keep_result_in_memory,
Materializer::PersistentVariableDelegate *result_delegate,
const lldb::TargetSP &target,
const std::shared_ptr<ClangASTImporter> &importer, ValueObject *ctx_obj);
/// Destructor
~ClangExpressionDeclMap() override;
/// Enable the state needed for parsing and IR transformation.
///
/// \param[in] exe_ctx
/// The execution context to use when finding types for variables.
/// Also used to find a "scratch" AST context to store result types.
///
/// \param[in] materializer
/// If non-NULL, the materializer to populate with information about
/// the variables to use
///
/// \return
/// True if parsing is possible; false if it is unsafe to continue.
bool WillParse(ExecutionContext &exe_ctx, Materializer *materializer);
void InstallCodeGenerator(clang::ASTConsumer *code_gen);
void InstallDiagnosticManager(DiagnosticManager &diag_manager);
/// Disable the state needed for parsing and IR transformation.
void DidParse();
/// [Used by IRForTarget] Add a variable to the list of persistent
/// variables for the process.
///
/// \param[in] decl
/// The Clang declaration for the persistent variable, used for
/// lookup during parsing.
///
/// \param[in] name
/// The name of the persistent variable, usually $something.
///
/// \param[in] type
/// The type of the variable, in the Clang parser's context.
///
/// \return
/// True on success; false otherwise.
bool AddPersistentVariable(const clang::NamedDecl *decl,
ConstString name, TypeFromParser type,
bool is_result, bool is_lvalue);
/// [Used by IRForTarget] Add a variable to the struct that needs to
/// be materialized each time the expression runs.
///
/// \param[in] decl
/// The Clang declaration for the variable.
///
/// \param[in] name
/// The name of the variable.
///
/// \param[in] value
/// The LLVM IR value for this variable.
///
/// \param[in] size
/// The size of the variable in bytes.
///
/// \param[in] alignment
/// The required alignment of the variable in bytes.
///
/// \return
/// True on success; false otherwise.
bool AddValueToStruct(const clang::NamedDecl *decl, ConstString name,
llvm::Value *value, size_t size,
lldb::offset_t alignment);
/// [Used by IRForTarget] Finalize the struct, laying out the position of
/// each object in it.
///
/// \return
/// True on success; false otherwise.
bool DoStructLayout();
/// [Used by IRForTarget] Get general information about the laid-out struct
/// after DoStructLayout() has been called.
///
/// \param[out] num_elements
/// The number of elements in the struct.
///
/// \param[out] size
/// The size of the struct, in bytes.
///
/// \param[out] alignment
/// The alignment of the struct, in bytes.
///
/// \return
/// True if the information could be retrieved; false otherwise.
bool GetStructInfo(uint32_t &num_elements, size_t &size,
lldb::offset_t &alignment);
/// [Used by IRForTarget] Get specific information about one field of the
/// laid-out struct after DoStructLayout() has been called.
///
/// \param[out] decl
/// The parsed Decl for the field, as generated by ClangASTSource
/// on ClangExpressionDeclMap's behalf. In the case of the result
/// value, this will have the name $__lldb_result even if the
/// result value ends up having the name $1. This is an
/// implementation detail of IRForTarget.
///
/// \param[out] value
/// The IR value for the field (usually a GlobalVariable). In
/// the case of the result value, this will have the correct
/// name ($1, for instance). This is an implementation detail
/// of IRForTarget.
///
/// \param[out] offset
/// The offset of the field from the beginning of the struct.
/// As long as the struct is aligned according to its required
/// alignment, this offset will align the field correctly.
///
/// \param[out] name
/// The name of the field as used in materialization.
///
/// \param[in] index
/// The index of the field about which information is requested.
///
/// \return
/// True if the information could be retrieved; false otherwise.
bool GetStructElement(const clang::NamedDecl *&decl, llvm::Value *&value,
lldb::offset_t &offset, ConstString &name,
uint32_t index);
/// [Used by IRForTarget] Get information about a function given its Decl.
///
/// \param[in] decl
/// The parsed Decl for the Function, as generated by ClangASTSource
/// on ClangExpressionDeclMap's behalf.
///
/// \param[out] ptr
/// The absolute address of the function in the target.
///
/// \return
/// True if the information could be retrieved; false otherwise.
bool GetFunctionInfo(const clang::NamedDecl *decl, uint64_t &ptr);
/// [Used by IRForTarget] Get the address of a symbol given nothing but its
/// name.
///
/// \param[in] target
/// The target to find the symbol in. If not provided,
/// then the current parsing context's Target.
///
/// \param[in] process
/// The process to use. For Objective-C symbols, the process's
/// Objective-C language runtime may be queried if the process
/// is non-NULL.
///
/// \param[in] name
/// The name of the symbol.
///
/// \param[in] module
/// The module to limit the search to. This can be NULL
///
/// \return
/// Valid load address for the symbol
lldb::addr_t GetSymbolAddress(Target &target, Process *process,
ConstString name, lldb::SymbolType symbol_type,
Module *module = nullptr);
lldb::addr_t GetSymbolAddress(ConstString name,
lldb::SymbolType symbol_type);
struct TargetInfo {
lldb::ByteOrder byte_order;
size_t address_byte_size;
TargetInfo() : byte_order(lldb::eByteOrderInvalid), address_byte_size(0) {}
bool IsValid() {
return (byte_order != lldb::eByteOrderInvalid && address_byte_size != 0);
}
};
TargetInfo GetTargetInfo();
/// [Used by ClangASTSource] Find all entities matching a given name, using
/// a NameSearchContext to make Decls for them.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
void FindExternalVisibleDecls(NameSearchContext &context) override;
/// Find all entities matching a given name in a given module/namespace,
/// using a NameSearchContext to make Decls for them.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
///
/// \param[in] module
/// If non-NULL, the module to query.
///
/// \param[in] namespace_decl
/// If valid and module is non-NULL, the parent namespace.
void FindExternalVisibleDecls(NameSearchContext &context,
lldb::ModuleSP module,
const CompilerDeclContext &namespace_decl);
protected:
/// Retrieves the declaration with the given name from the storage of
/// persistent declarations.
///
/// \return
/// A persistent decl with the given name or a nullptr.
virtual clang::NamedDecl *GetPersistentDecl(ConstString name);
private:
ExpressionVariableList
m_found_entities; ///< All entities that were looked up for the parser.
ExpressionVariableList
m_struct_members; ///< All entities that need to be placed in the struct.
bool m_keep_result_in_memory; ///< True if result persistent variables
///generated by this expression should stay in
///memory.
Materializer::PersistentVariableDelegate
*m_result_delegate; ///< If non-NULL, used to report expression results to
///ClangUserExpression.
ValueObject *m_ctx_obj; ///< If not empty, then expression is
///evaluated in context of this object.
///For details see the comment to
///`UserExpression::Evaluate`.
/// The following values should not live beyond parsing
class ParserVars {
public:
ParserVars() {}
Target *GetTarget() {
if (m_exe_ctx.GetTargetPtr())
return m_exe_ctx.GetTargetPtr();
else if (m_sym_ctx.target_sp)
return m_sym_ctx.target_sp.get();
return nullptr;
}
ExecutionContext m_exe_ctx; ///< The execution context to use when parsing.
SymbolContext m_sym_ctx; ///< The symbol context to use in finding variables
///and types.
ClangPersistentVariables *m_persistent_vars =
nullptr; ///< The persistent variables for the process.
bool m_enable_lookups = false; ///< Set to true during parsing if we have
///found the first "$__lldb" name.
TargetInfo m_target_info; ///< Basic information about the target.
Materializer *m_materializer = nullptr; ///< If non-NULL, the materializer
///to use when reporting used
///variables.
clang::ASTConsumer *m_code_gen = nullptr; ///< If non-NULL, a code generator
///that receives new top-level
///functions.
DiagnosticManager *m_diagnostics = nullptr;
private:
ParserVars(const ParserVars &) = delete;
const ParserVars &operator=(const ParserVars &) = delete;
};
std::unique_ptr<ParserVars> m_parser_vars;
/// Activate parser-specific variables
void EnableParserVars() {
if (!m_parser_vars.get())
m_parser_vars = std::make_unique<ParserVars>();
}
/// Deallocate parser-specific variables
void DisableParserVars() { m_parser_vars.reset(); }
/// The following values contain layout information for the materialized
/// struct, but are not specific to a single materialization
struct StructVars {
StructVars()
: m_struct_alignment(0), m_struct_size(0), m_struct_laid_out(false),
m_result_name(), m_object_pointer_type(nullptr, nullptr) {}
lldb::offset_t
m_struct_alignment; ///< The alignment of the struct in bytes.
size_t m_struct_size; ///< The size of the struct in bytes.
bool m_struct_laid_out; ///< True if the struct has been laid out and the
///layout is valid (that is, no new fields have been
///added since).
ConstString
m_result_name; ///< The name of the result variable ($1, for example)
TypeFromUser m_object_pointer_type; ///< The type of the "this" variable, if
///one exists
};
std::unique_ptr<StructVars> m_struct_vars;
/// Activate struct variables
void EnableStructVars() {
if (!m_struct_vars.get())
m_struct_vars.reset(new struct StructVars);
}
/// Deallocate struct variables
void DisableStructVars() { m_struct_vars.reset(); }
/// Get this parser's ID for use in extracting parser- and JIT-specific data
/// from persistent variables.
uint64_t GetParserID() { return (uint64_t) this; }
/// Should be called on all copied functions.
void MaybeRegisterFunctionBody(clang::FunctionDecl *copied_function_decl);
/// Searches the persistent decls of the target for entities with the
/// given name.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
///
/// \param[in] name
/// The name of the entities that need to be found.
void SearchPersistenDecls(NameSearchContext &context, const ConstString name);
/// Handles looking up $__lldb_class which requires special treatment.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
void LookUpLldbClass(NameSearchContext &context);
/// Handles looking up $__lldb_objc_class which requires special treatment.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
void LookUpLldbObjCClass(NameSearchContext &context);
/// Handles looking up the synthetic namespace that contains our local
/// variables for the current frame.
///
/// \param[in] sym_ctx
/// The current SymbolContext of this frame.
///
/// \param[in] name_context
/// The NameSearchContext that can construct Decls for this name.
void LookupLocalVarNamespace(SymbolContext &sym_ctx,
NameSearchContext &name_context);
/// Lookup entities in the ClangModulesDeclVendor.
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
///
/// \param[in] name
/// The name of the entities that need to be found.
void LookupInModulesDeclVendor(NameSearchContext &context, ConstString name);
/// Looks up a local variable.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
///
/// \param[in] name
/// The name of the entities that need to be found.
///
/// \param[in] sym_ctx
/// The current SymbolContext of this frame.
///
/// \param[in] namespace_decl
/// The parent namespace if there is one.
///
/// \return
/// True iff a local variable was found.
bool LookupLocalVariable(NameSearchContext &context, ConstString name,
SymbolContext &sym_ctx,
const CompilerDeclContext &namespace_decl);
/// Searches for functions in the given SymbolContextList.
///
/// \param[in] sc_list
/// The SymbolContextList to search.
///
/// \param[in] frame_decl_context
/// The current DeclContext of the current frame.
///
/// \return
/// A SymbolContextList with any found functions in the front and
/// any unknown SymbolContexts which are not functions in the back.
/// The SymbolContexts for the functions are ordered by how close they are
/// to the DeclContext for the given frame DeclContext.
SymbolContextList SearchFunctionsInSymbolContexts(
const SymbolContextList &sc_list,
const CompilerDeclContext &frame_decl_context);
/// Looks up a function.
///
/// \param[in] context
/// The NameSearchContext that can construct Decls for this name.
///
/// \param[in] module_sp
/// If non-NULL, the module to query.
///
/// \param[in] name
/// The name of the function that should be find.
///
/// \param[in] namespace_decl
/// If valid and module is non-NULL, the parent namespace.
void LookupFunction(NameSearchContext &context, lldb::ModuleSP module_sp,
ConstString name,
const CompilerDeclContext &namespace_decl);
/// Given a target, find a variable that matches the given name and type.
///
/// \param[in] target
/// The target to use as a basis for finding the variable.
///
/// \param[in] module
/// If non-NULL, the module to search.
///
/// \param[in] name
/// The name as a plain C string.
///
/// \param[in] namespace_decl
/// If non-NULL and module is non-NULL, the parent namespace.
///
/// \return
/// The LLDB Variable found, or NULL if none was found.
lldb::VariableSP
FindGlobalVariable(Target &target, lldb::ModuleSP &module, ConstString name,
const CompilerDeclContext &namespace_decl);
/// Get the value of a variable in a given execution context and return the
/// associated Types if needed.
///
/// \param[in] var
/// The variable to evaluate.
///
/// \param[out] var_location
/// The variable location value to fill in
///
/// \param[out] found_type
/// The type of the found value, as it was found in the user process.
/// This is only useful when the variable is being inspected on behalf
/// of the parser, hence the default.
///
/// \param[out] parser_type
/// The type of the found value, as it was copied into the parser's
/// AST context. This is only useful when the variable is being
/// inspected on behalf of the parser, hence the default.
///
/// \return
/// Return true if the value was successfully filled in.
bool GetVariableValue(lldb::VariableSP &var,
lldb_private::Value &var_location,
TypeFromUser *found_type = nullptr,
TypeFromParser *parser_type = nullptr);
/// Use the NameSearchContext to generate a Decl for the given LLDB
/// Variable, and put it in the Tuple list.
///
/// \param[in] context
/// The NameSearchContext to use when constructing the Decl.
///
/// \param[in] var
/// The LLDB Variable that needs a Decl.
///
/// \param[in] valobj
/// The LLDB ValueObject for that variable.
void AddOneVariable(NameSearchContext &context, lldb::VariableSP var,
lldb::ValueObjectSP valobj);
/// Use the NameSearchContext to generate a Decl for the given persistent
/// variable, and put it in the list of found entities.
///
/// \param[in] context
/// The NameSearchContext to use when constructing the Decl.
///
/// \param[in] pvar_sp
/// The persistent variable that needs a Decl.
void AddOneVariable(NameSearchContext &context,
lldb::ExpressionVariableSP &pvar_sp);
/// Use the NameSearchContext to generate a Decl for the given LLDB symbol
/// (treated as a variable), and put it in the list of found entities.
void AddOneGenericVariable(NameSearchContext &context, const Symbol &symbol);
/// Use the NameSearchContext to generate a Decl for the given function.
/// (Functions are not placed in the Tuple list.) Can handle both fully
/// typed functions and generic functions.
///
/// \param[in] context
/// The NameSearchContext to use when constructing the Decl.
///
/// \param[in] fun
/// The Function that needs to be created. If non-NULL, this is
/// a fully-typed function.
///
/// \param[in] sym
/// The Symbol that corresponds to a function that needs to be
/// created with generic type (unitptr_t foo(...)).
void AddOneFunction(NameSearchContext &context, Function *fun, Symbol *sym);
/// Use the NameSearchContext to generate a Decl for the given register.
///
/// \param[in] context
/// The NameSearchContext to use when constructing the Decl.
///
/// \param[in] reg_info
/// The information corresponding to that register.
void AddOneRegister(NameSearchContext &context, const RegisterInfo *reg_info);
/// Use the NameSearchContext to generate a Decl for the given type. (Types
/// are not placed in the Tuple list.)
///
/// \param[in] context
/// The NameSearchContext to use when constructing the Decl.
///
/// \param[in] type
/// The type that needs to be created.
void AddOneType(NameSearchContext &context, const TypeFromUser &type);
/// Adds the class in which the expression is evaluated to the lookup and
/// prepares the class to be used as a context for expression evaluation (for
/// example, it creates a fake member function that will contain the
/// expression LLDB is trying to evaluate).
///
/// \param[in] context
/// The NameSearchContext to which the class should be added as a lookup
/// result.
///
/// \param[in] type
/// The type of the class that serves as the evaluation context.
void AddContextClassType(NameSearchContext &context,
const TypeFromUser &type);
/// Move a type out of the current ASTContext into another, but make sure to
/// export all components of the type also.
///
/// \param[in] target
/// The TypeSystemClang to move to.
/// \param[in] source
/// The TypeSystemClang to move from. This is assumed to be going away.
/// \param[in] parser_type
/// The type as it appears in the source context.
///
/// \return
/// Returns the moved type, or an empty type if there was a problem.
TypeFromUser DeportType(TypeSystemClang &target, TypeSystemClang &source,
TypeFromParser parser_type);
TypeSystemClang *GetTypeSystemClang();
};
} // namespace lldb_private
#endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_CLANGEXPRESSIONDECLMAP_H