Merge pull request #7961 from ethereum/error-recovery-ast-segfault

Fix segfault on empty contract compiled w/ --error-recovery

libsolidity/interface/CompilerStack.cpp

@@ -281,30 +281,31 @@ bool CompilerStack::analyze()
 	{
 		SyntaxChecker syntaxChecker(m_errorReporter, m_optimiserSettings.runYulOptimiser);
 		for (Source const* source: m_sourceOrder)
-			if (!syntaxChecker.checkSyntax(*source->ast))
+			if (source->ast && !syntaxChecker.checkSyntax(*source->ast))
 				noErrors = false;
 
 		DocStringAnalyser docStringAnalyser(m_errorReporter);
 		for (Source const* source: m_sourceOrder)
-			if (!docStringAnalyser.analyseDocStrings(*source->ast))
+			if (source->ast && !docStringAnalyser.analyseDocStrings(*source->ast))
 				noErrors = false;
 
 		m_globalContext = make_shared<GlobalContext>();
 		NameAndTypeResolver resolver(*m_globalContext, m_evmVersion, m_scopes, m_errorReporter);
 		for (Source const* source: m_sourceOrder)
-			if (!resolver.registerDeclarations(*source->ast))
+			if (source->ast && !resolver.registerDeclarations(*source->ast))
 				return false;
 
 		map<string, SourceUnit const*> sourceUnitsByName;
 		for (auto& source: m_sources)
 			sourceUnitsByName[source.first] = source.second.ast.get();
 		for (Source const* source: m_sourceOrder)
-			if (!resolver.performImports(*source->ast, sourceUnitsByName))
+			if (source->ast && !resolver.performImports(*source->ast, sourceUnitsByName))
 				return false;
 
 		// This is the main name and type resolution loop. Needs to be run for every contract, because
 		// the special variables "this" and "super" must be set appropriately.
 		for (Source const* source: m_sourceOrder)
+			if (source->ast)
 				for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 				{
 					if (!resolver.resolveNamesAndTypes(*node))
@@ -324,6 +325,7 @@ bool CompilerStack::analyze()
 		// type checker.
 		ContractLevelChecker contractLevelChecker(m_errorReporter);
 		for (Source const* source: m_sourceOrder)
+			if (source->ast)
 				for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 					if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
 						if (!contractLevelChecker.check(*contract))
@@ -338,6 +340,7 @@ bool CompilerStack::analyze()
 		// which is only done one step later.
 		TypeChecker typeChecker(m_evmVersion, m_errorReporter);
 		for (Source const* source: m_sourceOrder)
+			if (source->ast)
 				for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 					if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
 						if (!typeChecker.checkTypeRequirements(*contract))
@@ -348,7 +351,7 @@ bool CompilerStack::analyze()
 			// Checks that can only be done when all types of all AST nodes are known.
 			PostTypeChecker postTypeChecker(m_errorReporter);
 			for (Source const* source: m_sourceOrder)
-				if (!postTypeChecker.check(*source->ast))
+				if (source->ast && !postTypeChecker.check(*source->ast))
 					noErrors = false;
 		}
 
@@ -358,14 +361,14 @@ bool CompilerStack::analyze()
 			// variable is used before it is assigned to.
 			CFG cfg(m_errorReporter);
 			for (Source const* source: m_sourceOrder)
-				if (!cfg.constructFlow(*source->ast))
+				if (source->ast && !cfg.constructFlow(*source->ast))
 					noErrors = false;
 
 			if (noErrors)
 			{
 				ControlFlowAnalyzer controlFlowAnalyzer(cfg, m_errorReporter);
 				for (Source const* source: m_sourceOrder)
-					if (!controlFlowAnalyzer.analyze(*source->ast))
+					if (source->ast && !controlFlowAnalyzer.analyze(*source->ast))
 						noErrors = false;
 			}
 		}
@@ -375,7 +378,7 @@ bool CompilerStack::analyze()
 			// Checks for common mistakes. Only generates warnings.
 			StaticAnalyzer staticAnalyzer(m_errorReporter);
 			for (Source const* source: m_sourceOrder)
-				if (!staticAnalyzer.analyze(*source->ast))
+				if (source->ast && !staticAnalyzer.analyze(*source->ast))
 					noErrors = false;
 		}
 
@@ -384,6 +387,7 @@ bool CompilerStack::analyze()
 			// Check for state mutability in every function.
 			vector<ASTPointer<ASTNode>> ast;
 			for (Source const* source: m_sourceOrder)
+				if (source->ast)
 					ast.push_back(source->ast);
 
 			if (!ViewPureChecker(ast, m_errorReporter).check())
@@ -394,6 +398,7 @@ bool CompilerStack::analyze()
 		{
 			ModelChecker modelChecker(m_errorReporter, m_smtlib2Responses, m_readFile, m_enabledSMTSolvers);
 			for (Source const* source: m_sourceOrder)
+				if (source->ast)
 					modelChecker.analyze(*source->ast);
 			m_unhandledSMTLib2Queries += modelChecker.unhandledQueries();
 		}

test/cmdlineTests/recovery_ast_empty_contract/args

@@ -0,0 +1 @@
+--error-recovery

test/cmdlineTests/recovery_ast_empty_contract/err

@@ -0,0 +1,8 @@
+Error: Expected pragma, import directive or contract/interface/library/struct/enum definition.
+ --> recovery_ast_empty_contract/input.sol:2:1:
+  |
+2 | c
+  | ^
+
+
+Compilation halted after AST generation due to errors.

test/cmdlineTests/recovery_ast_empty_contract/input.sol

@@ -0,0 +1,2 @@
+pragma 0.5.11;
+c