From e3b0827721f114a371df57b7079205034683ed25 Mon Sep 17 00:00:00 2001
From: Rhett Aultman <roadriverrail@gmail.com>
Date: Sun, 11 Dec 2016 23:58:01 -0800
Subject: [PATCH] Push the error instead of throwing it

Throwing a CompilerError on multiple contract definition violates the
expectations of the test suite, which thinks that compile() will
return false if the code can't compile.  This brings contract
collision reporting in line with most of the other errors.
---
 libsolidity/interface/CompilerStack.cpp | 48 ++++++++++++++++++-------
 1 file changed, 36 insertions(+), 12 deletions(-)

diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 13cf7d6ce..7626406c0 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -186,13 +186,24 @@ bool CompilerStack::parse()
 				{
 					const ContractDefinition* existingContract = m_contracts.find(contract->fullyQualifiedName())->second.contract;
 					if (contract != existingContract)
-						BOOST_THROW_EXCEPTION(CompilerError() <<
+					{
+						auto err = make_shared<Error>(Error::Type::DeclarationError);
+						*err <<
 							errinfo_sourceLocation(contract->location()) <<
-							errinfo_comment(contract->name() + " is already defined.") <<
-															errinfo_secondarySourceLocation(
-																SecondarySourceLocation().append("Previous definition is here:", existingContract->location())));
+							errinfo_comment(
+								"Contract/Library \"" + contract->name() + "\" declared twice "
+							) <<
+							errinfo_secondarySourceLocation(SecondarySourceLocation().append(
+									"The other declaration is here:", existingContract->location()));
+
+						m_errors.push_back(err);
+						noErrors = false;
+					}
+				}
+				else
+				{
+					m_contracts[contract->fullyQualifiedName()].contract = contract;
 				}
-				m_contracts[contract->fullyQualifiedName()].contract = contract;
 			}
 
 	if (!checkLibraryNameClashes())
@@ -216,14 +227,27 @@ bool CompilerStack::parse()
 				if (m_contracts.find(contract->fullyQualifiedName()) != m_contracts.end())
 				{
 					const ContractDefinition* existingContract = m_contracts.find(contract->fullyQualifiedName())->second.contract;
-					if (contract != existingContract)
-						BOOST_THROW_EXCEPTION(CompilerError() <<
-							errinfo_sourceLocation(contract->location()) <<
-							errinfo_comment(contract->name() + " is already defined at "
-								+ *(existingContract->location().sourceName)));
-				}
 
-				m_contracts[contract->fullyQualifiedName()].contract = contract;
+					if (contract != existingContract)
+					{
+						auto err = make_shared<Error>(Error::Type::DeclarationError);
+						*err <<
+							errinfo_sourceLocation(contract->location()) <<
+							errinfo_comment(
+								"Contract/Library \"" + contract->name() + "\" declared twice "
+							) <<
+							errinfo_secondarySourceLocation(SecondarySourceLocation().append(
+									"The other declaration is here:", existingContract->location()));
+
+						m_errors.push_back(err);
+						noErrors = false;
+					}
+
+				}
+				else
+				{
+					m_contracts[contract->fullyQualifiedName()].contract = contract;
+				}
 			}
 
 	if (noErrors)