Index access for calldata arrays.

1 files changed, 20 insertions, 5 deletions

diff --git a/LValue.h b/LValue.h
index 1ed0ae01..0ada4f88 100644
--- a/LValue.h
+++ b/LValue.h
@@ -46,8 +46,8 @@ protected:
 		m_context(_compilerContext), m_dataType(_dataType) {}
 
 public:
-	/// @returns true if this lvalue reference type occupies a slot on the stack.
-	virtual bool storesReferenceOnStack() const = 0;
+	/// @returns the number of stack slots occupied by the lvalue reference
+	virtual unsigned sizeOnStack() const { return 1; }
 	/// Copies the value of the current lvalue to the top of the stack and, if @a _remove is true,
 	/// also removes the reference from the stack.
 	/// @a _location source location of the current expression, used for error reporting.
@@ -76,7 +76,7 @@ class StackVariable: public LValue
 public:
 	StackVariable(CompilerContext& _compilerContext, Declaration const& _declaration);
 
-	virtual bool storesReferenceOnStack() const { return false; }
+	virtual unsigned sizeOnStack() const override { return 0; }
 	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
 	virtual void storeValue(Type const& _sourceType,
 		SourceLocation const& _location = SourceLocation(), bool _move = false) const override;
@@ -100,7 +100,6 @@ public:
 	StorageItem(CompilerContext& _compilerContext, Declaration const& _declaration);
 	/// Constructs the LValue and assumes that the storage reference is already on the stack.
 	StorageItem(CompilerContext& _compilerContext, Type const& _type);
-	virtual bool storesReferenceOnStack() const { return true; }
 	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
 	virtual void storeValue(Type const& _sourceType,
 		SourceLocation const& _location = SourceLocation(), bool _move = false) const override;
@@ -114,6 +113,23 @@ private:
 };
 
 /**
+ * Reference to a single byte inside a storage byte array.
+ * Stack: <storage_ref> <byte_number>
+ */
+class StorageByteArrayElement: public LValue
+{
+public:
+	/// Constructs the LValue and assumes that the storage reference is already on the stack.
+	StorageByteArrayElement(CompilerContext& _compilerContext);
+	virtual unsigned sizeOnStack() const override { return 2; }
+	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
+	virtual void storeValue(Type const& _sourceType,
+		SourceLocation const& _location = SourceLocation(), bool _move = false) const override;
+	virtual void setToZero(
+		SourceLocation const& _location = SourceLocation(), bool _removeReference = true) const override;
+};
+
+/**
  * Reference to the "length" member of a dynamically-sized array. This is an LValue with special
  * semantics since assignments to it might reduce its length and thus arrays members have to be
  * deleted.
@@ -123,7 +139,6 @@ class StorageArrayLength: public LValue
 public:
 	/// Constructs the LValue, assumes that the reference to the array head is already on the stack.
 	StorageArrayLength(CompilerContext& _compilerContext, ArrayType const& _arrayType);
-	virtual bool storesReferenceOnStack() const { return true; }
 	virtual void retrieveValue(SourceLocation const& _location, bool _remove = false) const override;
 	virtual void storeValue(Type const& _sourceType,
 		SourceLocation const& _location = SourceLocation(), bool _move = false) const override;