Use all referenced errors.

libsolidity/CMakeLists.txt

@@ -30,6 +30,8 @@ set(sources
 	analysis/OverrideChecker.h
 	analysis/PostTypeChecker.cpp
 	analysis/PostTypeChecker.h
+	analysis/PostTypeContractLevelChecker.cpp
+	analysis/PostTypeContractLevelChecker.h
 	analysis/ReferencesResolver.cpp
 	analysis/ReferencesResolver.h
 	analysis/Scoper.cpp

libsolidity/analysis/ContractLevelChecker.cpp

@@ -433,24 +433,6 @@ void ContractLevelChecker::checkHashCollisions(ContractDefinition const& _contra
 			);
 		hashes.insert(hash);
 	}
-
-	map<uint32_t, SourceLocation> errorHashes;
-	for (ErrorDefinition const* error: _contract.interfaceErrors())
-	{
-		if (!error->functionType(true)->interfaceFunctionType())
-			// This will result in an error later on, so we can ignore it here.
-			continue;
-		uint32_t hash = selectorFromSignature32(error->functionType(true)->externalSignature());
-		if (errorHashes.count(hash))
-			m_errorReporter.typeError(
-				4883_error,
-				_contract.location(),
-				SecondarySourceLocation{}.append("This error has the same selector: "s, errorHashes[hash]),
-				"Error signature hash collision for " + error->functionType(true)->externalSignature()
-			);
-		else
-			errorHashes[hash] = error->location();
-	}
 }
 
 void ContractLevelChecker::checkLibraryRequirements(ContractDefinition const& _contract)

libsolidity/analysis/FunctionCallGraph.cpp

@@ -125,6 +125,8 @@ bool FunctionCallGraphBuilder::visit(FunctionCall const& _functionCall)
 		// change at runtime). All we can do is to add an edge to the dispatch which in turn has
 		// edges to all functions could possibly be called.
 		add(m_currentNode, CallGraph::SpecialNode::InternalDispatch);
+	else if (functionType->kind() == FunctionType::Kind::Error)
+		m_graph.usedErrors.insert(&dynamic_cast<ErrorDefinition const&>(functionType->declaration()));
 
 	return true;
 }

libsolidity/analysis/FunctionCallGraph.h

@@ -65,8 +65,8 @@ public:
 
 private:
 	FunctionCallGraphBuilder(ContractDefinition const& _contract):
-		m_contract(_contract),
+		m_contract(_contract)
-		m_graph{{}, {}, {}} {}
+	{}
 
 	bool visit(FunctionCall const& _functionCall) override;
 	bool visit(EmitStatement const& _emitStatement) override;

libsolidity/analysis/PostTypeContractLevelChecker.cpp

@@ -0,0 +1,72 @@
+/*
+	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
+/**
+ * Component that verifies overloads, abstract contracts, function clashes and others
+ * checks at contract or function level.
+ */
+
+#include <libsolidity/analysis/PostTypeContractLevelChecker.h>
+
+#include <libsolidity/ast/AST.h>
+#include <libsolutil/FunctionSelector.h>
+#include <liblangutil/ErrorReporter.h>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::langutil;
+using namespace solidity::frontend;
+
+bool PostTypeContractLevelChecker::check(SourceUnit const& _sourceUnit)
+{
+	bool noErrors = true;
+	for (auto* contract: ASTNode::filteredNodes<ContractDefinition>(_sourceUnit.nodes()))
+		if (!check(*contract))
+			noErrors = false;
+	return noErrors;
+}
+
+bool PostTypeContractLevelChecker::check(ContractDefinition const& _contract)
+{
+	solAssert(
+		_contract.annotation().creationCallGraph.set() &&
+		_contract.annotation().deployedCallGraph.set(),
+		""
+	);
+
+	map<uint32_t, map<string, SourceLocation>> errorHashes;
+	for (ErrorDefinition const* error: _contract.interfaceErrors())
+	{
+		string signature = error->functionType(true)->externalSignature();
+		uint32_t hash = selectorFromSignature32(signature);
+		// Fail if there is a different signature for the same hash.
+		if (!errorHashes[hash].empty() && !errorHashes[hash].count(signature))
+		{
+			SourceLocation& otherLocation = errorHashes[hash].begin()->second;
+			m_errorReporter.typeError(
+				4883_error,
+				error->nameLocation(),
+				SecondarySourceLocation{}.append("This error has a different signature but the same hash: ", otherLocation),
+				"Error signature hash collision for " + error->functionType(true)->externalSignature()
+			);
+		}
+		else
+			errorHashes[hash][signature] = error->location();
+	}
+
+	return Error::containsOnlyWarnings(m_errorReporter.errors());
+}

libsolidity/analysis/PostTypeContractLevelChecker.h

@@ -0,0 +1,56 @@
+/*
+	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
+/**
+ * Component that verifies properties at contract level, after the type checker has run.
+ */
+
+#pragma once
+
+#include <libsolidity/ast/ASTForward.h>
+
+namespace solidity::langutil
+{
+class ErrorReporter;
+}
+
+namespace solidity::frontend
+{
+
+/**
+ * Component that verifies properties at contract level, after the type checker has run.
+ */
+class PostTypeContractLevelChecker
+{
+public:
+	explicit PostTypeContractLevelChecker(langutil::ErrorReporter& _errorReporter):
+		m_errorReporter(_errorReporter)
+	{}
+
+	/// Performs checks on the given source ast.
+	/// @returns true iff all checks passed. Note even if all checks passed, errors() can still contain warnings
+	bool check(SourceUnit const& _sourceUnit);
+
+private:
+	/// Performs checks on the given contract.
+	/// @returns true iff all checks passed. Note even if all checks passed, errors() can still contain warnings
+	bool check(ContractDefinition const& _contract);
+
+	langutil::ErrorReporter& m_errorReporter;
+};
+
+}

libsolidity/ast/AST.cpp

@@ -23,6 +23,7 @@
 
 #include <libsolidity/ast/AST.h>
 
+#include <libsolidity/ast/CallGraph.h>
 #include <libsolidity/ast/ASTVisitor.h>
 #include <libsolidity/ast/AST_accept.h>
 #include <libsolidity/ast/TypeProvider.h>
@@ -174,12 +175,19 @@ vector<EventDefinition const*> const& ContractDefinition::interfaceEvents() cons
 	});
 }
 
-vector<ErrorDefinition const*> ContractDefinition::interfaceErrors() const
+vector<ErrorDefinition const*> ContractDefinition::interfaceErrors(bool _requireCallGraph) const
 {
 	set<ErrorDefinition const*, CompareByID> result;
-	// TODO add all referenced errors
 	for (ContractDefinition const* contract: annotation().linearizedBaseContracts)
 		result += filteredNodes<ErrorDefinition>(contract->m_subNodes);
+	solAssert(annotation().creationCallGraph.set() == annotation().deployedCallGraph.set(), "");
+	if (_requireCallGraph)
+		solAssert(annotation().creationCallGraph.set(), "");
+	if (annotation().creationCallGraph.set())
+	{
+		result += (*annotation().creationCallGraph)->usedErrors;
+		result += (*annotation().deployedCallGraph)->usedErrors;
+	}
 	return convertContainer<vector<ErrorDefinition const*>>(move(result));
 }
 

libsolidity/ast/AST.h

@@ -515,7 +515,8 @@ public:
 	std::vector<EventDefinition const*> const& interfaceEvents() const;
 	/// @returns all errors defined in this contract or any base contract
 	/// and all errors referenced during execution.
-	std::vector<ErrorDefinition const*> interfaceErrors() const;
+	/// @param _requireCallGraph if false, do not fail if the call graph has not been computed yet.
+	std::vector<ErrorDefinition const*> interfaceErrors(bool _requireCallGraph = true) const;
 	bool isInterface() const { return m_contractKind == ContractKind::Interface; }
 	bool isLibrary() const { return m_contractKind == ContractKind::Library; }
 

libsolidity/ast/CallGraph.h

@@ -67,6 +67,9 @@ struct CallGraph
 
 	/// Events that may get emitted by functions present in the graph.
 	std::set<EventDefinition const*, ASTNode::CompareByID> emittedEvents;
+
+	/// Errors that are used by functions present in the graph.
+	std::set<ErrorDefinition const*, ASTNode::CompareByID> usedErrors;
 };
 
 }

libsolidity/interface/CompilerStack.cpp

@@ -34,6 +34,7 @@
 #include <libsolidity/analysis/GlobalContext.h>
 #include <libsolidity/analysis/NameAndTypeResolver.h>
 #include <libsolidity/analysis/PostTypeChecker.h>
+#include <libsolidity/analysis/PostTypeContractLevelChecker.h>
 #include <libsolidity/analysis/StaticAnalyzer.h>
 #include <libsolidity/analysis/SyntaxChecker.h>
 #include <libsolidity/analysis/Scoper.h>
@@ -433,6 +434,11 @@ bool CompilerStack::analyze()
 				noErrors = false;
 		}
 
+		if (noErrors)
+			for (Source const* source: m_sourceOrder)
+				if (source->ast && !PostTypeContractLevelChecker{m_errorReporter}.check(*source->ast))
+					noErrors = false;
+
 		// Check that immutable variables are never read in c'tors and assigned
 		// exactly once
 		if (noErrors)

test/libsolidity/syntaxTests/errors/hash_collision.sol

@@ -3,4 +3,4 @@ contract test {
     error tgeo();
 }
 // ----
-// TypeError 4883: (0-52): Error signature hash collision for tgeo()
+// TypeError 4883: (43-47): Error signature hash collision for tgeo()

test/libsolidity/syntaxTests/errors/hash_collision_external.sol

@@ -0,0 +1,14 @@
+library L {
+    error gsf();
+}
+contract test {
+    error tgeo();
+    function f(bool a) public {
+        if (a)
+            revert L.gsf();
+        else
+            revert tgeo();
+    }
+}
+// ----
+// TypeError 4883: (57-61): Error signature hash collision for tgeo()