Introduce experimental analysis basic infrastructure

liblangutil/Scanner.cpp

@@ -1019,15 +1019,28 @@ std::tuple<Token, unsigned, unsigned> Scanner::scanIdentifierOrKeyword()
 	while (isIdentifierPart(m_char) || (m_char == '.' && m_kind == ScannerKind::Yul))
 		addLiteralCharAndAdvance();
 	literal.complete();
+
 	auto const token = TokenTraits::fromIdentifierOrKeyword(m_tokens[NextNext].literal);
-	if (m_kind == ScannerKind::Yul)
+	switch (m_kind)
 	{
+	case ScannerKind::Solidity:
+		// Turn experimental Solidity keywords that are not keywords in legacy Solidity into identifiers.
+		if (TokenTraits::isExperimentalSolidityOnlyKeyword(std::get<0>(token)))
+			return std::make_tuple(Token::Identifier, 0, 0);
+		break;
+	case ScannerKind::Yul:
 		// Turn Solidity identifier into a Yul keyword
 		if (m_tokens[NextNext].literal == "leave")
 			return std::make_tuple(Token::Leave, 0, 0);
 		// Turn non-Yul keywords into identifiers.
 		if (!TokenTraits::isYulKeyword(std::get<0>(token)))
 			return std::make_tuple(Token::Identifier, 0, 0);
+		break;
+	case ScannerKind::ExperimentalSolidity:
+		// Turn legacy Solidity keywords that are not keywords in experimental Solidity into identifiers.
+		if (!TokenTraits::isExperimentalSolidityKeyword(std::get<0>(token)))
+			return std::make_tuple(Token::Identifier, 0, 0);
+		break;
 	}
 	return token;
 }

liblangutil/Scanner.h

@@ -69,7 +69,8 @@ class ParserRecorder;
 enum class ScannerKind
 {
 	Solidity,
-	Yul
+	Yul,
+	ExperimentalSolidity
 };
 
 enum class ScannerError

liblangutil/Token.h

@@ -268,6 +268,8 @@ namespace solidity::langutil
 	/* Yul-specific tokens, but not keywords. */                       \
 	T(Leave, "leave", 0)                                               \
 	\
+	T(NonExperimentalEnd, nullptr, 0) /* used as non-experimental enum end marker */ \
+	T(ExperimentalEnd, nullptr, 0) /* used as experimental enum end marker */ \
 	/* Illegal token - not able to scan. */                            \
 	T(Illegal, "ILLEGAL", 0)                                           \
 	\
@@ -323,6 +325,39 @@ namespace TokenTraits
 			tok == Token::TrueLiteral || tok == Token::FalseLiteral || tok == Token::HexStringLiteral || tok == Token::Hex;
 	}
 
+	constexpr bool isExperimentalSolidityKeyword(Token token)
+	{
+		return
+			token == Token::Assembly ||
+			token == Token::Contract ||
+			token == Token::External ||
+			token == Token::Fallback ||
+			token == Token::Pragma ||
+			token == Token::Import ||
+			token == Token::As ||
+			token == Token::Function ||
+			token == Token::Let ||
+			token == Token::Return ||
+			token == Token::Type ||
+			token == Token::If ||
+			token == Token::Else ||
+			token == Token::Do ||
+			token == Token::While ||
+			token == Token::For ||
+			token == Token::Continue ||
+			token == Token::Break;
+			// TODO: see isExperimentalSolidityKeyword below
+			// || (token > Token::NonExperimentalEnd && token < Token::ExperimentalEnd);
+	}
+
+	constexpr bool isExperimentalSolidityOnlyKeyword(Token)
+	{
+		// TODO: use token > Token::NonExperimentalEnd && token < Token::ExperimentalEnd
+		// as soon as other experimental tokens are added. For now the comparison generates
+		// a warning from clang because it is always false.
+		return false;
+	}
+
 	bool isYulKeyword(std::string const& _literal);
 
 	Token AssignmentToBinaryOp(Token op);

libsolidity/CMakeLists.txt

@@ -101,6 +101,8 @@ set(sources
 	codegen/ir/IRLValue.h
 	codegen/ir/IRVariable.cpp
 	codegen/ir/IRVariable.h
+	experimental/analysis/Analysis.cpp
+	experimental/analysis/Analysis.h
 	formal/ArraySlicePredicate.cpp
 	formal/ArraySlicePredicate.h
 	formal/BMC.cpp
@@ -186,4 +188,3 @@ set(sources
 
 add_library(solidity ${sources})
 target_link_libraries(solidity PUBLIC yul evmasm langutil smtutil solutil Boost::boost fmt::fmt-header-only Threads::Threads)
-

libsolidity/experimental/analysis/Analysis.cpp

@@ -0,0 +1,34 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// SPDX-License-Identifier: GPL-3.0
+#include <libsolidity/experimental/analysis/Analysis.h>
+
+#include <liblangutil/ErrorReporter.h>
+
+using namespace solidity::langutil;
+using namespace solidity::frontend::experimental;
+
+bool Analysis::check(std::vector<std::shared_ptr<SourceUnit const>> const&)
+{
+	m_errorReporter.error(
+		6547_error,
+		Error::Type::UnimplementedFeatureError,
+		SourceLocation{},
+		"Experimental Analysis is not implemented yet."
+	);
+	return false;
+}

libsolidity/experimental/analysis/Analysis.h

@@ -0,0 +1,49 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+// SPDX-License-Identifier: GPL-3.0
+#pragma once
+
+#include <vector>
+#include <memory>
+
+namespace solidity::frontend
+{
+class SourceUnit;
+}
+
+namespace solidity::langutil
+{
+class ErrorReporter;
+}
+
+namespace solidity::frontend::experimental
+{
+
+class Analysis
+{
+public:
+	Analysis(langutil::ErrorReporter& _errorReporter):
+		m_errorReporter(_errorReporter)
+	{}
+
+	bool check(std::vector<std::shared_ptr<SourceUnit const>> const& _sourceUnits);
+
+private:
+	langutil::ErrorReporter& m_errorReporter;
+};
+
+}

libsolidity/interface/CompilerStack.cpp

@@ -56,6 +56,8 @@
 #include <libsolidity/interface/Version.h>
 #include <libsolidity/parsing/Parser.h>
 
+#include <libsolidity/experimental/analysis/Analysis.h>
+
 #include <libsolidity/codegen/ir/Common.h>
 #include <libsolidity/codegen/ir/IRGenerator.h>
 
@@ -325,6 +327,7 @@ void CompilerStack::reset(bool _keepSettings)
 		m_metadataHash = MetadataHash::IPFS;
 		m_stopAfter = State::CompilationSuccessful;
 	}
+	m_experimentalAnalysis.reset();
 	m_globalContext.reset();
 	m_sourceOrder.clear();
 	m_contracts.clear();
@@ -449,6 +452,8 @@ bool CompilerStack::analyze()
 
 	try
 	{
+		bool experimentalSolidity = !m_sourceOrder.empty() && m_sourceOrder.front()->ast->experimentalSolidity();
+
 		SyntaxChecker syntaxChecker(m_errorReporter, m_optimiserSettings.runYulOptimiser);
 		for (Source const* source: m_sourceOrder)
 			if (source->ast && !syntaxChecker.checkSyntax(*source->ast))
@@ -480,12 +485,40 @@ bool CompilerStack::analyze()
 			if (source->ast && !resolver.resolveNamesAndTypes(*source->ast))
 				return false;
 
+		if (experimentalSolidity)
+		{
+			if (!analyzeExperimental())
+				noErrors = false;
+		}
+		else if (!analyzeLegacy(noErrors))
+			noErrors = false;
+	}
+	catch (FatalError const&)
+	{
+		if (m_errorReporter.errors().empty())
+			throw; // Something is weird here, rather throw again.
+		noErrors = false;
+	}
+
+	if (!noErrors)
+		return false;
+
+	m_stackState = AnalysisSuccessful;
+	return true;
+}
+
+
+bool CompilerStack::analyzeLegacy(bool _noErrorsSoFar)
+{
+	bool noErrors = _noErrorsSoFar;
+
 	DeclarationTypeChecker declarationTypeChecker(m_errorReporter, m_evmVersion);
 	for (Source const* source: m_sourceOrder)
 		if (source->ast && !declarationTypeChecker.check(*source->ast))
 			return false;
 
 	// Requires DeclarationTypeChecker to have run
+	DocStringTagParser docStringTagParser(m_errorReporter);
 	for (Source const* source: m_sourceOrder)
 		if (source->ast && !docStringTagParser.validateDocStringsUsingTypes(*source->ast))
 			noErrors = false;
@@ -615,19 +648,19 @@ bool CompilerStack::analyze()
 				modelChecker.analyze(*source->ast);
 		m_unhandledSMTLib2Queries += modelChecker.unhandledQueries();
 	}
+
+	return noErrors;
 }
-	catch (FatalError const&)
+
+bool CompilerStack::analyzeExperimental()
 {
-		if (m_errorReporter.errors().empty())
-			throw; // Something is weird here, rather throw again.
-		noErrors = false;
-	}
-
-	if (!noErrors)
-		return false;
-
-	m_stackState = AnalysisSuccessful;
-	return true;
+	solAssert(!m_experimentalAnalysis);
+	m_experimentalAnalysis = std::make_unique<experimental::Analysis>(m_errorReporter);
+	std::vector<std::shared_ptr<SourceUnit const>> sourceAsts;
+	for (Source const* source: m_sourceOrder)
+		if (source->ast)
+			sourceAsts.emplace_back(source->ast);
+	return m_experimentalAnalysis->check(sourceAsts);
 }
 
 bool CompilerStack::parseAndAnalyze(State _stopAfter)
@@ -694,9 +727,13 @@ bool CompilerStack::compile(State _stopAfter)
 							if (m_viaIR)
 								generateEVMFromIR(*contract);
 							else
+							{
+								if (m_experimentalAnalysis)
+									solThrow(CompilerError, "Legacy codegen after experimental analysis is unsupported.");
 								compileContract(*contract, otherCompilers);
 							}
 						}
+					}
 					catch (Error const& _error)
 					{
 						if (_error.type() != Error::Type::CodeGenerationError)
@@ -1429,6 +1466,9 @@ void CompilerStack::generateIR(ContractDefinition const& _contract)
 {
 	solAssert(m_stackState >= AnalysisSuccessful, "");
 
+	if (m_experimentalAnalysis)
+		solThrow(CompilerError, "IR codegen after experimental analysis is unsupported.");
+
 	Contract& compiledContract = m_contracts.at(_contract.fullyQualifiedName());
 	if (!compiledContract.yulIR.empty())
 		return;

libsolidity/interface/CompilerStack.h

@@ -81,6 +81,10 @@ class Compiler;
 class GlobalContext;
 class Natspec;
 class DeclarationContainer;
+namespace experimental
+{
+class Analysis;
+}
 
 /**
  * Easy to use and self-contained Solidity compiler with as few header dependencies as possible.
@@ -407,6 +411,14 @@ private:
 	/// @returns true if the contract is requested to be compiled.
 	bool isRequestedContract(ContractDefinition const& _contract) const;
 
+	/// Perform the analysis steps of legacy language mode.
+	/// @returns false on error.
+	bool analyzeLegacy(bool _noErrorsSoFar);
+
+	/// Perform the analysis steps of experimental language mode.
+	/// @returns false on error.
+	bool analyzeExperimental();
+
 	/// Assembles the contract.
 	/// This function should only be internally called by compileContract and generateEVMFromIR.
 	void assembleYul(
@@ -500,6 +512,7 @@ private:
 
 	langutil::ErrorList m_errorList;
 	langutil::ErrorReporter m_errorReporter;
+	std::unique_ptr<experimental::Analysis> m_experimentalAnalysis;
 	bool m_metadataLiteralSources = false;
 	MetadataHash m_metadataHash = MetadataHash::IPFS;
 	langutil::DebugInfoSelection m_debugInfoSelection = langutil::DebugInfoSelection::Default();

libyul/AsmParser.cpp

@@ -115,8 +115,9 @@ std::unique_ptr<Block> Parser::parseInline(std::shared_ptr<Scanner> const& _scan
 {
 	m_recursionDepth = 0;
 
+	auto previousScannerKind = _scanner->scannerKind();
 	_scanner->setScannerMode(ScannerKind::Yul);
-	ScopeGuard resetScanner([&]{ _scanner->setScannerMode(ScannerKind::Solidity); });
+	ScopeGuard resetScanner([&]{ _scanner->setScannerMode(previousScannerKind); });
 
 	try
 	{

test/libsolidity/ASTJSON/pragma_experimental_solidity.json

@@ -1,21 +0,0 @@
-{
-  "absolutePath": "a",
-  "experimentalSolidity": true,
-  "exportedSymbols": {},
-  "id": 2,
-  "nodeType": "SourceUnit",
-  "nodes":
-  [
-    {
-      "id": 1,
-      "literals":
-      [
-        "experimental",
-        "solidity"
-      ],
-      "nodeType": "PragmaDirective",
-      "src": "0:29:1"
-    }
-  ],
-  "src": "0:70:1"
-}

test/libsolidity/ASTJSON/pragma_experimental_solidity.sol

@@ -2,3 +2,4 @@ pragma experimental solidity;
 // ====
 // EVMVersion: >=constantinople
 // ----
+// failAfter: Parsed

test/libsolidity/syntaxTests/experimental/parsing_stdlib_import_1.sol

@@ -6,3 +6,4 @@ import std.stub;
 // ----
 // Warning 2264: (std.stub:63-92): Experimental features are turned on. Do not use experimental features on live deployments.
 // Warning 2264: (0-29): Experimental features are turned on. Do not use experimental features on live deployments.
+// UnimplementedFeatureError 6547: Experimental Analysis is not implemented yet.

test/libsolidity/syntaxTests/experimental/parsing_stdlib_import_2.sol

@@ -6,3 +6,4 @@ import std.stub as stub;
 // ----
 // Warning 2264: (std.stub:63-92): Experimental features are turned on. Do not use experimental features on live deployments.
 // Warning 2264: (0-29): Experimental features are turned on. Do not use experimental features on live deployments.
+// UnimplementedFeatureError 6547: Experimental Analysis is not implemented yet.

test/libsolidity/syntaxTests/experimental/parsing_stdlib_import_3.sol

@@ -6,3 +6,4 @@ import { identity } from std.stub;
 // ----
 // Warning 2264: (std.stub:63-92): Experimental features are turned on. Do not use experimental features on live deployments.
 // Warning 2264: (0-29): Experimental features are turned on. Do not use experimental features on live deployments.
+// UnimplementedFeatureError 6547: Experimental Analysis is not implemented yet.

test/libsolidity/syntaxTests/experimental/parsing_stdlib_import_4.sol

@@ -6,3 +6,4 @@ import * as stub from std.stub;
 // ----
 // Warning 2264: (std.stub:63-92): Experimental features are turned on. Do not use experimental features on live deployments.
 // Warning 2264: (0-29): Experimental features are turned on. Do not use experimental features on live deployments.
+// UnimplementedFeatureError 6547: Experimental Analysis is not implemented yet.

test/libsolidity/syntaxTests/pragma/experimental_solidity.sol

@@ -3,3 +3,4 @@ pragma experimental solidity;
 // EVMVersion: >=constantinople
 // ----
 // Warning 2264: (0-29): Experimental features are turned on. Do not use experimental features on live deployments.
+// UnimplementedFeatureError 6547: Experimental Analysis is not implemented yet.