================
@@ -0,0 +1,276 @@
+//===-- DILParser.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
+//
+// This implements the recursive descent parser for the Data Inspection
+// Language (DIL), and its helper functions, which will eventually underlie the
+// 'frame variable' command. The language that this parser recognizes is
+// described in lldb/docs/dil-expr-lang.ebnf
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/ValueObject/DILParser.h"
+#include "lldb/Target/ExecutionContextScope.h"
+#include "lldb/Utility/DiagnosticsRendering.h"
+#include "lldb/ValueObject/DILAST.h"
+#include "lldb/ValueObject/DILEval.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/FormatAdapters.h"
+#include <cstdlib>
+#include <limits.h>
+#include <memory>
+#include <sstream>
+#include <string>
+
+namespace lldb_private::dil {
+
+DILDiagnosticError::DILDiagnosticError(ErrorCode ec, llvm::StringRef expr,
+ const std::string &message, uint32_t
loc,
+ uint16_t err_len)
+ : // ErrorInfo(ec) {
+ ErrorInfo(std::error_code(EINVAL, std::generic_category())) {
+ DiagnosticDetail::SourceLocation sloc = {
+ FileSpec{}, /*line=*/1, static_cast<uint16_t>(loc + 1),
+ err_len, false, /*in_user_input=*/true};
+ std::string rendered_msg =
+ llvm::formatv("<user expression 0>:1:{0}: {1}\n 1 | {2}\n | ^",
+ loc + 1, message, expr);
+ DiagnosticDetail detail;
+ detail.source_location = sloc;
+ detail.severity = lldb::eSeverityError;
+ detail.message = message;
+ detail.rendered = rendered_msg;
+ m_details.push_back(detail);
+}
+
+llvm::Expected<ASTNodeUP>
+DILParser::Parse(llvm::StringRef dil_input_expr, DILLexer lexer,
+ std::shared_ptr<StackFrame> frame_sp,
+ lldb::DynamicValueType use_dynamic, bool use_synthetic,
+ bool fragile_ivar, bool check_ptr_vs_member) {
+ Status error;
+ DILParser parser(dil_input_expr, lexer, frame_sp, use_dynamic, use_synthetic,
+ fragile_ivar, check_ptr_vs_member, error);
+ return parser.Run();
+}
+
+DILParser::DILParser(llvm::StringRef dil_input_expr, DILLexer lexer,
+ std::shared_ptr<StackFrame> frame_sp,
+ lldb::DynamicValueType use_dynamic, bool use_synthetic,
+ bool fragile_ivar, bool check_ptr_vs_member, Status
&error)
+ : m_ctx_scope(frame_sp), m_input_expr(dil_input_expr), m_dil_lexer(lexer),
+ m_error(error), m_use_dynamic(use_dynamic),
+ m_use_synthetic(use_synthetic), m_fragile_ivar(fragile_ivar),
+ m_check_ptr_vs_member(check_ptr_vs_member) {}
+
+llvm::Expected<ASTNodeUP> DILParser::Run() {
+ ASTNodeUP expr = ParseExpression();
+
+ Expect(Token::Kind::eof);
+
+ if (m_error.Fail())
+ return m_error.ToError();
+
+ return expr;
+}
+
+// Parse an expression.
+//
+// expression:
+// primary_expression
+//
+ASTNodeUP DILParser::ParseExpression() { return ParsePrimaryExpression(); }
+
+// Parse a primary_expression.
+//
+// primary_expression:
+// id_expression
+// "(" expression ")"
+//
+ASTNodeUP DILParser::ParsePrimaryExpression() {
+ if (CurToken().IsOneOf({Token::coloncolon, Token::identifier})) {
+ // Save the source location for the diagnostics message.
+ uint32_t loc = CurToken().GetLocation();
+ auto identifier = ParseIdExpression();
+
+ return std::make_unique<IdentifierNode>(loc, identifier, m_use_dynamic,
+ m_ctx_scope);
+ } else if (CurToken().Is(Token::l_paren)) {
+ m_dil_lexer.Advance();
+ auto expr = ParseExpression();
+ Expect(Token::r_paren);
+ m_dil_lexer.Advance();
+ return expr;
+ }
+
+ BailOut(ErrorCode::kInvalidExpressionSyntax,
+ llvm::formatv("Unexpected token: {0}", CurToken()),
+ CurToken().GetLocation());
+ return std::make_unique<ErrorNode>();
+}
+
+// Parse nested_name_specifier.
+//
+// nested_name_specifier:
+// type_name "::"
+// namespace_name "::"
+// nested_name_specifier identifier "::"
+//
+std::string DILParser::ParseNestedNameSpecifier() {
+ // The first token in nested_name_specifier is always an identifier, or
+ // '(anonymous namespace)'.
+ if (CurToken().IsNot(Token::identifier) && CurToken().IsNot(Token::l_paren))
{
+ return "";
+ }
+
+ // Anonymous namespaces need to be treated specially: They are represented
+ // the the string '(anonymous namespace)', which has a space in it (throwing
+ // off normal parsing) and is not actually proper C++> Check to see if we're
+ // looking at '(anonymous namespace)::...'
+ if (CurToken().Is(Token::l_paren)) {
+ // Look for all the pieces, in order:
+ // l_paren 'anonymous' 'namespace' r_paren coloncolon
+ if (m_dil_lexer.LookAhead(1).Is(Token::identifier) &&
+ (m_dil_lexer.LookAhead(1).GetSpelling() == "anonymous") &&
+ m_dil_lexer.LookAhead(2).Is(Token::identifier) &&
+ (m_dil_lexer.LookAhead(2).GetSpelling() == "namespace") &&
+ m_dil_lexer.LookAhead(3).Is(Token::r_paren) &&
+ m_dil_lexer.LookAhead(4).Is(Token::coloncolon)) {
+ m_dil_lexer.Advance(4);
+
+ assert(
+ (CurToken().Is(Token::identifier) || CurToken().Is(Token::l_paren))
&&
+ "Expected an identifier or anonymous namespace, but not found.");
+ // Continue parsing the nested_namespace_specifier.
+ std::string identifier2 = ParseNestedNameSpecifier();
+ if (identifier2.empty()) {
+ Expect(Token::identifier);
+ identifier2 = CurToken().GetSpelling();
+ m_dil_lexer.Advance();
+ }
+ return "(anonymous namespace)::" + identifier2;
+ }
+
+ return "";
+ } // end of special handling for '(anonymous namespace)'
+
+ // If the next token is scope ("::"), then this is indeed a
+ // nested_name_specifier
+ if (m_dil_lexer.LookAhead(1).Is(Token::coloncolon)) {
+ // This nested_name_specifier is a single identifier.
+ std::string identifier = CurToken().GetSpelling();
+ m_dil_lexer.Advance(1);
+ Expect(Token::coloncolon);
+ m_dil_lexer.Advance();
+ // Continue parsing the nested_name_specifier.
+ return identifier + "::" + ParseNestedNameSpecifier();
+ }
+
+ return "";
+}
+
+// Parse an id_expression.
+//
+// id_expression:
+// unqualified_id
+// qualified_id
+//
+// qualified_id:
+// ["::"] [nested_name_specifier] unqualified_id
+// ["::"] identifier
+//
+// identifier:
+// ? Token::identifier ?
+//
+std::string DILParser::ParseIdExpression() {
+ // Try parsing optional global scope operator.
+ bool global_scope = false;
+ if (CurToken().Is(Token::coloncolon)) {
+ global_scope = true;
+ m_dil_lexer.Advance();
+ }
+
+ // Try parsing optional nested_name_specifier.
+ auto nested_name_specifier = ParseNestedNameSpecifier();
+
+ // If nested_name_specifier is present, then it's qualified_id production.
+ // Follow the first production rule.
+ if (!nested_name_specifier.empty()) {
+ // Parse unqualified_id and construct a fully qualified id expression.
+ auto unqualified_id = ParseUnqualifiedId();
+
+ return llvm::formatv("{0}{1}{2}", global_scope ? "::" : "",
+ nested_name_specifier, unqualified_id);
+ }
+
+ // No nested_name_specifier, but with global scope -- this is also a
+ // qualified_id production. Follow the second production rule.
+ else if (global_scope) {
+ Expect(Token::identifier);
+ std::string identifier = CurToken().GetSpelling();
+ m_dil_lexer.Advance();
+ return llvm::formatv("{0}{1}", global_scope ? "::" : "", identifier);
+ }
+
+ // This is unqualified_id production.
+ return ParseUnqualifiedId();
+}
+
+// Parse an unqualified_id.
+//
+// unqualified_id:
+// identifier
+//
+// identifier:
+// ? Token::identifier ?
+//
+std::string DILParser::ParseUnqualifiedId() {
+ Expect(Token::identifier);
+ std::string identifier = CurToken().GetSpelling();
+ m_dil_lexer.Advance();
+ return identifier;
+}
+
+// Must somehow convert the DILDiagnosticError to a lldb::Status, since *that*
+// is was must be returned to the place where CommandObjectFrame::DoExecute
+// calls GetVariableValueForExpressionPath (at the moment).
+Status GetStatusError(DILDiagnosticError dil_error) {
+ return Status(dil_error.GetDetails()[0].message);
+}
+
+void DILParser::BailOut(ErrorCode code, const std::string &error,
+ uint32_t loc) {
+ if (m_error.Fail()) {
+ // If error is already set, then the parser is in the "bail-out" mode.
Don't
+ // do anything and keep the original error.
+ return;
+ }
+
+ m_error = GetStatusError(DILDiagnosticError(
+ code, m_input_expr, error, loc, CurToken().GetSpelling().length()));
----------------
labath wrote:
```suggestion
if (m_error) {
// If error is already set, then the parser is in the "bail-out" mode. Don't
// do anything and keep the original error.
return;
}
m_error = llvm::make_error<DILDiagnosticError>(
code, m_input_expr, error, loc, CurToken().GetSpelling().length()));
```
(This assumes other changes I suggested in the previous round)
https://github.com/llvm/llvm-project/pull/120971
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