//===-- ClangExpressionSourceCode.cpp -------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "ClangExpressionSourceCode.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"
#include "llvm/ADT/StringRef.h"
#include "Plugins/ExpressionParser/Clang/ClangModulesDeclVendor.h"
#include "Plugins/ExpressionParser/Clang/ClangPersistentVariables.h"
#include "lldb/Symbol/Block.h"
#include "lldb/Symbol/CompileUnit.h"
#include "lldb/Symbol/DebugMacros.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Language.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/StreamString.h"
using namespace lldb_private;
#define PREFIX_NAME "<lldb wrapper prefix>"
const llvm::StringRef ClangExpressionSourceCode::g_prefix_file_name = PREFIX_NAME;
const char *ClangExpressionSourceCode::g_expression_prefix =
"#line 1 \"" PREFIX_NAME R"("
#ifndef offsetof
#define offsetof(t, d) __builtin_offsetof(t, d)
#endif
#ifndef NULL
#define NULL (__null)
#endif
#ifndef Nil
#define Nil (__null)
#endif
#ifndef nil
#define nil (__null)
#endif
#ifndef YES
#define YES ((BOOL)1)
#endif
#ifndef NO
#define NO ((BOOL)0)
#endif
typedef __INT8_TYPE__ int8_t;
typedef __UINT8_TYPE__ uint8_t;
typedef __INT16_TYPE__ int16_t;
typedef __UINT16_TYPE__ uint16_t;
typedef __INT32_TYPE__ int32_t;
typedef __UINT32_TYPE__ uint32_t;
typedef __INT64_TYPE__ int64_t;
typedef __UINT64_TYPE__ uint64_t;
typedef __INTPTR_TYPE__ intptr_t;
typedef __UINTPTR_TYPE__ uintptr_t;
typedef __SIZE_TYPE__ size_t;
typedef __PTRDIFF_TYPE__ ptrdiff_t;
typedef unsigned short unichar;
extern "C"
{
int printf(const char * __restrict, ...);
}
)";
namespace {
class AddMacroState {
enum State {
CURRENT_FILE_NOT_YET_PUSHED,
CURRENT_FILE_PUSHED,
CURRENT_FILE_POPPED
};
public:
AddMacroState(const FileSpec ¤t_file, const uint32_t current_file_line)
: m_state(CURRENT_FILE_NOT_YET_PUSHED), m_current_file(current_file),
m_current_file_line(current_file_line) {}
void StartFile(const FileSpec &file) {
m_file_stack.push_back(file);
if (file == m_current_file)
m_state = CURRENT_FILE_PUSHED;
}
void EndFile() {
if (m_file_stack.size() == 0)
return;
FileSpec old_top = m_file_stack.back();
m_file_stack.pop_back();
if (old_top == m_current_file)
m_state = CURRENT_FILE_POPPED;
}
// An entry is valid if it occurs before the current line in the current
// file.
bool IsValidEntry(uint32_t line) {
switch (m_state) {
case CURRENT_FILE_NOT_YET_PUSHED:
return true;
case CURRENT_FILE_PUSHED:
// If we are in file included in the current file, the entry should be
// added.
if (m_file_stack.back() != m_current_file)
return true;
return line < m_current_file_line;
default:
return false;
}
}
private:
std::vector<FileSpec> m_file_stack;
State m_state;
FileSpec m_current_file;
uint32_t m_current_file_line;
};
} // anonymous namespace
static void AddMacros(const DebugMacros *dm, CompileUnit *comp_unit,
AddMacroState &state, StreamString &stream) {
if (dm == nullptr)
return;
for (size_t i = 0; i < dm->GetNumMacroEntries(); i++) {
const DebugMacroEntry &entry = dm->GetMacroEntryAtIndex(i);
uint32_t line;
switch (entry.GetType()) {
case DebugMacroEntry::DEFINE:
if (state.IsValidEntry(entry.GetLineNumber()))
stream.Printf("#define %s\n", entry.GetMacroString().AsCString());
else
return;
break;
case DebugMacroEntry::UNDEF:
if (state.IsValidEntry(entry.GetLineNumber()))
stream.Printf("#undef %s\n", entry.GetMacroString().AsCString());
else
return;
break;
case DebugMacroEntry::START_FILE:
line = entry.GetLineNumber();
if (state.IsValidEntry(line))
state.StartFile(entry.GetFileSpec(comp_unit));
else
return;
break;
case DebugMacroEntry::END_FILE:
state.EndFile();
break;
case DebugMacroEntry::INDIRECT:
AddMacros(entry.GetIndirectDebugMacros(), comp_unit, state, stream);
break;
default:
// This is an unknown/invalid entry. Ignore.
break;
}
}
}
lldb_private::ClangExpressionSourceCode::ClangExpressionSourceCode(
llvm::StringRef filename, llvm::StringRef name, llvm::StringRef prefix,
llvm::StringRef body, Wrapping wrap, WrapKind wrap_kind)
: ExpressionSourceCode(name, prefix, body, wrap), m_wrap_kind(wrap_kind) {
// Use #line markers to pretend that we have a single-line source file
// containing only the user expression. This will hide our wrapper code
// from the user when we render diagnostics with Clang.
m_start_marker = "#line 1 \"" + filename.str() + "\"\n";
m_end_marker = "\n;\n#line 1 \"<lldb wrapper suffix>\"\n";
}
namespace {
/// Allows checking if a token is contained in a given expression.
class TokenVerifier {
/// The tokens we found in the expression.
llvm::StringSet<> m_tokens;
public:
TokenVerifier(std::string body);
/// Returns true iff the given expression body contained a token with the
/// given content.
bool hasToken(llvm::StringRef token) const {
return m_tokens.find(token) != m_tokens.end();
}
};
} // namespace
TokenVerifier::TokenVerifier(std::string body) {
using namespace clang;
// We only care about tokens and not their original source locations. If we
// move the whole expression to only be in one line we can simplify the
// following code that extracts the token contents.
std::replace(body.begin(), body.end(), '\n', ' ');
std::replace(body.begin(), body.end(), '\r', ' ');
FileSystemOptions file_opts;
FileManager file_mgr(file_opts,
FileSystem::Instance().GetVirtualFileSystem());
// Let's build the actual source code Clang needs and setup some utility
// objects.
llvm::IntrusiveRefCntPtr<DiagnosticIDs> diag_ids(new DiagnosticIDs());
llvm::IntrusiveRefCntPtr<DiagnosticOptions> diags_opts(
new DiagnosticOptions());
DiagnosticsEngine diags(diag_ids, diags_opts);
clang::SourceManager SM(diags, file_mgr);
auto buf = llvm::MemoryBuffer::getMemBuffer(body);
FileID FID = SM.createFileID(clang::SourceManager::Unowned, buf.get());
// Let's just enable the latest ObjC and C++ which should get most tokens
// right.
LangOptions Opts;
Opts.ObjC = true;
Opts.DollarIdents = true;
Opts.CPlusPlus17 = true;
Opts.LineComment = true;
Lexer lex(FID, buf.get(), SM, Opts);
Token token;
bool exit = false;
while (!exit) {
// Returns true if this is the last token we get from the lexer.
exit = lex.LexFromRawLexer(token);
// Extract the column number which we need to extract the token content.
// Our expression is just one line, so we don't need to handle any line
// numbers here.
bool invalid = false;
unsigned start = SM.getSpellingColumnNumber(token.getLocation(), &invalid);
if (invalid)
continue;
// Column numbers start at 1, but indexes in our string start at 0.
--start;
// Annotations don't have a length, so let's skip them.
if (token.isAnnotation())
continue;
// Extract the token string from our source code and store it.
std::string token_str = body.substr(start, token.getLength());
if (token_str.empty())
continue;
m_tokens.insert(token_str);
}
}
void ClangExpressionSourceCode::AddLocalVariableDecls(
const lldb::VariableListSP &var_list_sp, StreamString &stream,
const std::string &expr) const {
TokenVerifier tokens(expr);
for (size_t i = 0; i < var_list_sp->GetSize(); i++) {
lldb::VariableSP var_sp = var_list_sp->GetVariableAtIndex(i);
ConstString var_name = var_sp->GetName();
// We can check for .block_descriptor w/o checking for langauge since this
// is not a valid identifier in either C or C++.
if (!var_name || var_name == ".block_descriptor")
continue;
if (!expr.empty() && !tokens.hasToken(var_name.GetStringRef()))
continue;
const bool is_objc = m_wrap_kind == WrapKind::ObjCInstanceMethod ||
m_wrap_kind == WrapKind::ObjCStaticMethod;
if ((var_name == "self" || var_name == "_cmd") && is_objc)
continue;
if (var_name == "this" && m_wrap_kind == WrapKind::CppMemberFunction)
continue;
stream.Printf("using $__lldb_local_vars::%s;\n", var_name.AsCString());
}
}
bool ClangExpressionSourceCode::GetText(
std::string &text, ExecutionContext &exe_ctx, bool add_locals,
bool force_add_all_locals, llvm::ArrayRef<std::string> modules) const {
const char *target_specific_defines = "typedef signed char BOOL;\n";
std::string module_macros;
Target *target = exe_ctx.GetTargetPtr();
if (target) {
if (target->GetArchitecture().GetMachine() == llvm::Triple::aarch64 ||
target->GetArchitecture().GetMachine() == llvm::Triple::aarch64_32) {
target_specific_defines = "typedef bool BOOL;\n";
}
if (target->GetArchitecture().GetMachine() == llvm::Triple::x86_64) {
if (lldb::PlatformSP platform_sp = target->GetPlatform()) {
static ConstString g_platform_ios_simulator("ios-simulator");
if (platform_sp->GetPluginName() == g_platform_ios_simulator) {
target_specific_defines = "typedef bool BOOL;\n";
}
}
}
ClangModulesDeclVendor *decl_vendor = target->GetClangModulesDeclVendor();
auto *persistent_vars = llvm::cast<ClangPersistentVariables>(
target->GetPersistentExpressionStateForLanguage(lldb::eLanguageTypeC));
if (decl_vendor && persistent_vars) {
const ClangModulesDeclVendor::ModuleVector &hand_imported_modules =
persistent_vars->GetHandLoadedClangModules();
ClangModulesDeclVendor::ModuleVector modules_for_macros;
for (ClangModulesDeclVendor::ModuleID module : hand_imported_modules) {
modules_for_macros.push_back(module);
}
if (target->GetEnableAutoImportClangModules()) {
if (StackFrame *frame = exe_ctx.GetFramePtr()) {
if (Block *block = frame->GetFrameBlock()) {
SymbolContext sc;
block->CalculateSymbolContext(&sc);
if (sc.comp_unit) {
StreamString error_stream;
decl_vendor->AddModulesForCompileUnit(
*sc.comp_unit, modules_for_macros, error_stream);
}
}
}
}
decl_vendor->ForEachMacro(
modules_for_macros,
[&module_macros](const std::string &expansion) -> bool {
module_macros.append(expansion);
module_macros.append("\n");
return false;
});
}
}
StreamString debug_macros_stream;
StreamString lldb_local_var_decls;
if (StackFrame *frame = exe_ctx.GetFramePtr()) {
const SymbolContext &sc = frame->GetSymbolContext(
lldb::eSymbolContextCompUnit | lldb::eSymbolContextLineEntry);
if (sc.comp_unit && sc.line_entry.IsValid()) {
DebugMacros *dm = sc.comp_unit->GetDebugMacros();
if (dm) {
AddMacroState state(sc.line_entry.file, sc.line_entry.line);
AddMacros(dm, sc.comp_unit, state, debug_macros_stream);
}
}
if (add_locals)
if (target->GetInjectLocalVariables(&exe_ctx)) {
lldb::VariableListSP var_list_sp =
frame->GetInScopeVariableList(false, true);
AddLocalVariableDecls(var_list_sp, lldb_local_var_decls,
force_add_all_locals ? "" : m_body);
}
}
if (m_wrap) {
// Generate a list of @import statements that will import the specified
// module into our expression.
std::string module_imports;
for (const std::string &module : modules) {
module_imports.append("@import ");
module_imports.append(module);
module_imports.append(";\n");
}
StreamString wrap_stream;
wrap_stream.Printf("%s\n%s\n%s\n%s\n%s\n", module_macros.c_str(),
debug_macros_stream.GetData(), g_expression_prefix,
target_specific_defines, m_prefix.c_str());
// First construct a tagged form of the user expression so we can find it
// later:
std::string tagged_body;
tagged_body.append(m_start_marker);
tagged_body.append(m_body);
tagged_body.append(m_end_marker);
switch (m_wrap_kind) {
case WrapKind::Function:
wrap_stream.Printf("%s"
"void \n"
"%s(void *$__lldb_arg) \n"
"{ \n"
" %s; \n"
"%s"
"} \n",
module_imports.c_str(), m_name.c_str(),
lldb_local_var_decls.GetData(), tagged_body.c_str());
break;
case WrapKind::CppMemberFunction:
wrap_stream.Printf("%s"
"void \n"
"$__lldb_class::%s(void *$__lldb_arg) \n"
"{ \n"
" %s; \n"
"%s"
"} \n",
module_imports.c_str(), m_name.c_str(),
lldb_local_var_decls.GetData(), tagged_body.c_str());
break;
case WrapKind::ObjCInstanceMethod:
wrap_stream.Printf(
"%s"
"@interface $__lldb_objc_class ($__lldb_category) \n"
"-(void)%s:(void *)$__lldb_arg; \n"
"@end \n"
"@implementation $__lldb_objc_class ($__lldb_category) \n"
"-(void)%s:(void *)$__lldb_arg \n"
"{ \n"
" %s; \n"
"%s"
"} \n"
"@end \n",
module_imports.c_str(), m_name.c_str(), m_name.c_str(),
lldb_local_var_decls.GetData(), tagged_body.c_str());
break;
case WrapKind::ObjCStaticMethod:
wrap_stream.Printf(
"%s"
"@interface $__lldb_objc_class ($__lldb_category) \n"
"+(void)%s:(void *)$__lldb_arg; \n"
"@end \n"
"@implementation $__lldb_objc_class ($__lldb_category) \n"
"+(void)%s:(void *)$__lldb_arg \n"
"{ \n"
" %s; \n"
"%s"
"} \n"
"@end \n",
module_imports.c_str(), m_name.c_str(), m_name.c_str(),
lldb_local_var_decls.GetData(), tagged_body.c_str());
break;
}
text = std::string(wrap_stream.GetString());
} else {
text.append(m_body);
}
return true;
}
bool ClangExpressionSourceCode::GetOriginalBodyBounds(
std::string transformed_text, size_t &start_loc, size_t &end_loc) {
start_loc = transformed_text.find(m_start_marker);
if (start_loc == std::string::npos)
return false;
start_loc += m_start_marker.size();
end_loc = transformed_text.find(m_end_marker);
return end_loc != std::string::npos;
}