Warn for assembly labels too

3 files changed, 5 insertions, 2 deletions

diff --git a/Changelog.md b/Changelog.md
index fd256af8..248165bb 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,6 +1,7 @@
 ### 0.4.20 (unreleased)
 
 Features:
+ * Inline Assembly: Issue warning for using jump labels (already existed for jump instructions).
 
 Bugfixes:
 
diff --git a/libsolidity/inlineasm/AsmAnalysis.cpp b/libsolidity/inlineasm/AsmAnalysis.cpp
index 5c03342d..04b8417f 100644
--- a/libsolidity/inlineasm/AsmAnalysis.cpp
+++ b/libsolidity/inlineasm/AsmAnalysis.cpp
@@ -56,6 +56,7 @@ bool AsmAnalyzer::operator()(Label const& _label)
 {
 	solAssert(!m_julia, "");
 	m_info.stackHeightInfo[&_label] = m_stackHeight;
+	warnOnInstructions(solidity::Instruction::JUMPDEST, _label.location);
 	return true;
 }
 
@@ -523,10 +524,10 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 			"the Metropolis hard fork. Before that it acts as an invalid instruction."
 		);
 
-	if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI)
+	if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI || _instr == solidity::Instruction::JUMPDEST)
 		m_errorReporter.warning(
 			_location,
-			"Jump instructions are low-level EVM features that can lead to "
+			"Jump instructions and labels are low-level EVM features that can lead to "
 			"incorrect stack access. Because of that they are discouraged. "
 			"Please consider using \"switch\" or \"for\" statements instead."
 		);
diff --git a/test/libsolidity/InlineAssembly.cpp b/test/libsolidity/InlineAssembly.cpp
index e9fb8431..506721c1 100644
--- a/test/libsolidity/InlineAssembly.cpp
+++ b/test/libsolidity/InlineAssembly.cpp
@@ -714,6 +714,7 @@ BOOST_AUTO_TEST_CASE(jump_warning)
 	CHECK_PARSE_WARNING("{ 1 2 jumpi }", Warning, "Jump instructions");
 	CHECK_PARSE_WARNING("{ a: jump(a) }", Warning, "Jump instructions");
 	CHECK_PARSE_WARNING("{ a: jumpi(a, 2) }", Warning, "Jump instructions");
+	CHECK_PARSE_WARNING("{ a: }", Warning, "Jump instructions");
 }
 
 BOOST_AUTO_TEST_SUITE_END()