Merge pull request #5530 from ethereum/fix-ast-segfault

Fixes crash on empty runtime code.

2 files changed, 11 insertions, 6 deletions

diff --git a/Changelog.md b/Changelog.md
index 4defbbe4..7fd95566 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -16,6 +16,7 @@ Compiler Features:
 
 Bugfixes:
  * Assembly output: Do not mix in/out jump annotations with arguments.
+ * Commandline interface: Fix crash when using ``--ast`` on empty runtime code.
  * Code Generator: Annotate jump from calldata decoder to function as "jump in".
  * Type Checker: Properly detect different return types when overriding an external interface function with a public contract function.
  * Optimizer: Fix nondeterminism bug related to the boost version and constants representation. The bug only resulted in less optimal but still correct code because the generated routine is always verified to be correct.
diff --git a/solc/CommandLineInterface.cpp b/solc/CommandLineInterface.cpp
index 7f64d8ac..e2baca7f 100644
--- a/solc/CommandLineInterface.cpp
+++ b/solc/CommandLineInterface.cpp
@@ -1022,12 +1022,16 @@ void CommandLineInterface::handleAst(string const& _argStr)
 		map<ASTNode const*, eth::GasMeter::GasConsumption> gasCosts;
 		for (auto const& contract : m_compiler->contractNames())
 		{
-			auto ret = GasEstimator::breakToStatementLevel(
-				GasEstimator(m_evmVersion).structuralEstimation(*m_compiler->runtimeAssemblyItems(contract), asts),
-				asts
-			);
-			for (auto const& it: ret)
-				gasCosts[it.first] += it.second;
+			if (auto const* assemblyItems = m_compiler->runtimeAssemblyItems(contract))
+			{
+				auto ret = GasEstimator::breakToStatementLevel(
+					GasEstimator(m_evmVersion).structuralEstimation(*assemblyItems, asts),
+					asts
+				);
+				for (auto const& it: ret)
+					gasCosts[it.first] += it.second;
+			}
+
 		}
 
 		bool legacyFormat = !m_args.count(g_argAstCompactJson);