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1//===-- ASTStructExtractor.h ------------------------------------*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_ASTSTRUCTEXTRACTOR_H10#define LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_ASTSTRUCTEXTRACTOR_H11 12#include "ClangExpressionVariable.h"13#include "ClangFunctionCaller.h"14 15#include "clang/Sema/SemaConsumer.h"16 17namespace lldb_private {18 19/// \class ASTStructExtractor ASTStructExtractor.h20/// "lldb/Expression/ASTStructExtractor.h" Extracts and describes the argument21/// structure for a wrapped function.22///23/// This pass integrates with ClangFunctionCaller, which calls functions with24/// custom sets of arguments. To avoid having to implement the full calling25/// convention for the target's architecture, ClangFunctionCaller writes a26/// simple wrapper function that takes a pointer to an argument structure that27/// contains room for the address of the function to be called, the values of28/// all its arguments, and room for the function's return value.29///30/// The definition of this struct is itself in the body of the wrapper31/// function, so Clang does the structure layout itself. ASTStructExtractor32/// reads through the AST for the wrapper function and finds the struct.33class ASTStructExtractor : public clang::SemaConsumer {34public:35 /// Constructor36 ///37 /// \param[in] passthrough38 /// Since the ASTs must typically go through to the Clang code generator39 /// in order to produce LLVM IR, this SemaConsumer must allow them to40 /// pass to the next step in the chain after processing. Passthrough is41 /// the next ASTConsumer, or NULL if none is required.42 ///43 /// \param[in] struct_name44 /// The name of the structure to extract from the wrapper function.45 ///46 /// \param[in] function47 /// The caller object whose members should be populated with information48 /// about the argument struct. ClangFunctionCaller friends49 /// ASTStructExtractor50 /// for this purpose.51 ASTStructExtractor(clang::ASTConsumer *passthrough, const char *struct_name,52 ClangFunctionCaller &function);53 54 /// Destructor55 ~ASTStructExtractor() override;56 57 /// Link this consumer with a particular AST context58 ///59 /// \param[in] Context60 /// This AST context will be used for types and identifiers, and also61 /// forwarded to the passthrough consumer, if one exists.62 void Initialize(clang::ASTContext &Context) override;63 64 /// Examine a list of Decls to find the function $__lldb_expr and transform65 /// its code66 ///67 /// \param[in] D68 /// The list of Decls to search. These may contain LinkageSpecDecls,69 /// which need to be searched recursively. That job falls to70 /// TransformTopLevelDecl.71 bool HandleTopLevelDecl(clang::DeclGroupRef D) override;72 73 /// Passthrough stub74 void HandleTranslationUnit(clang::ASTContext &Ctx) override;75 76 /// Passthrough stub77 void HandleTagDeclDefinition(clang::TagDecl *D) override;78 79 /// Passthrough stub80 void CompleteTentativeDefinition(clang::VarDecl *D) override;81 82 /// Passthrough stub83 void HandleVTable(clang::CXXRecordDecl *RD) override;84 85 /// Passthrough stub86 void PrintStats() override;87 88 /// Set the Sema object to use when performing transforms, and pass it on89 ///90 /// \param[in] S91 /// The Sema to use. Because Sema isn't externally visible, this class92 /// casts it to an Action for actual use.93 void InitializeSema(clang::Sema &S) override;94 95 /// Reset the Sema to NULL now that transformations are done96 void ForgetSema() override;97 98private:99 /// Hunt the given FunctionDecl for the argument struct and place100 /// information about it into m_function101 ///102 /// \param[in] F103 /// The FunctionDecl to hunt.104 void ExtractFromFunctionDecl(clang::FunctionDecl *F);105 106 /// Hunt the given Decl for FunctionDecls named the same as the wrapper107 /// function name, recursing as necessary through LinkageSpecDecls, and108 /// calling ExtractFromFunctionDecl on anything that was found109 ///110 /// \param[in] D111 /// The Decl to hunt.112 void ExtractFromTopLevelDecl(clang::Decl *D);113 114 clang::ASTContext115 *m_ast_context; ///< The AST context to use for identifiers and types.116 clang::ASTConsumer *m_passthrough; ///< The ASTConsumer down the chain, for117 ///passthrough. NULL if it's a118 ///SemaConsumer.119 clang::SemaConsumer *m_passthrough_sema; ///< The SemaConsumer down the chain,120 ///for passthrough. NULL if it's an121 ///ASTConsumer.122 clang::Sema *m_sema; ///< The Sema to use.123 124 ClangFunctionCaller &m_function; ///< The function to populate with125 ///information about the argument structure.126 std::string m_struct_name; ///< The name of the structure to extract.127};128 129} // namespace lldb_private130 131#endif // LLDB_SOURCE_PLUGINS_EXPRESSIONPARSER_CLANG_ASTSTRUCTEXTRACTOR_H132