Perform stack height checks in assembly analysis phase.

1 files changed, 10 insertions, 3 deletions

diff --git a/libsolidity/inlineasm/AsmAnalysis.h b/libsolidity/inlineasm/AsmAnalysis.h
index c6d23227..cfc9b25a 100644
--- a/libsolidity/inlineasm/AsmAnalysis.h
+++ b/libsolidity/inlineasm/AsmAnalysis.h
@@ -53,7 +53,7 @@ struct Scope;
 /**
  * Performs the full analysis stage, calls the ScopeFiller internally, then resolves
  * references and performs other checks.
- * @todo Does not yet check for stack height issues.
+ * If all these checks pass, code generation should not throw errors.
  */
 class AsmAnalyzer: public boost::static_visitor<bool>
 {
@@ -63,7 +63,7 @@ public:
 
 	bool analyze(assembly::Block const& _block);
 
-	bool operator()(assembly::Instruction const&) { return true; }
+	bool operator()(assembly::Instruction const&);
 	bool operator()(assembly::Literal const& _literal);
 	bool operator()(assembly::Identifier const&);
 	bool operator()(assembly::FunctionalInstruction const& _functionalInstruction);
@@ -76,9 +76,16 @@ public:
 	bool operator()(assembly::Block const& _block);
 
 private:
-	bool checkAssignment(assembly::Identifier const& _assignment);
+	/// Verifies that a variable to be assigned to exists and has the same size
+	/// as the value, @a _valueSize, unless that is equal to -1.
+	bool checkAssignment(assembly::Identifier const& _assignment, size_t _valueSize = size_t(-1));
+	bool expectDeposit(int _deposit, int _oldHeight, SourceLocation const& _location);
 	Scope& scope(assembly::Block const* _block);
 
+	/// Number of excess stack slots generated by function arguments to take into account for
+	/// next block.
+	int m_virtualVariablesInNextBlock = 0;
+	int m_stackHeight = 0;
 	ExternalIdentifierAccess::Resolver const& m_resolver;
 	Scope* m_currentScope = nullptr;
 	Scopes& m_scopes;