public static List<Statement> ExtractContractBlocks (List<Statement> blocks, int firstBlockIndex, int firstStmtIndex, int lastBlockIndex, int lastStmtIndex)
{
var result = new List<Statement> ();
var firstBlock = (Block) blocks [firstBlockIndex];
var block = new Block (new List<Statement> ());
if (firstBlock != null) {
int cnt = firstBlockIndex == lastBlockIndex ? lastStmtIndex + 1 : firstBlock.Statements.Count;
for (int i = firstStmtIndex; i < cnt; i++) {
Statement stmt = firstBlock.Statements [i];
block.Statements.Add (stmt);
if (stmt != null)
firstBlock.Statements [i] = null;
}
}
result.Add (block);
int nextIndex = firstBlockIndex + 1;
if (nextIndex > lastBlockIndex)
return result;
Block newLastBlock = null;
int lastFullBlockIndex = lastBlockIndex - 1;
var lastBlock = (Block) blocks [lastBlockIndex];
if (lastBlock != null && lastStmtIndex == lastBlock.Statements.Count - 1)
lastFullBlockIndex = lastBlockIndex;
else {
newLastBlock = new Block (new List<Statement> ());
if (block.Statements != null && block.Statements.Count > 0) {
var branch = block.Statements [block.Statements.Count - 1] as Branch;
if (branch != null && branch.Target != null && branch.Target == lastBlock)
branch.Target = newLastBlock;
}
}
for (; nextIndex < lastFullBlockIndex; ++nextIndex) {
var curBlock = (Block) blocks [nextIndex];
result.Add (curBlock);
if (curBlock != null) {
blocks [nextIndex] = null;
if (newLastBlock != null && curBlock.Statements != null && curBlock.Statements.Count > 0) {
var branch = curBlock.Statements [curBlock.Statements.Count - 1] as Branch;
if (branch != null && branch.Target != null && branch.Target == lastBlock)
branch.Target = newLastBlock;
}
}
}
if (newLastBlock != null) {
for (int i = 0; i < lastStmtIndex + 1; i++) {
newLastBlock.Statements.Add (lastBlock.Statements [i]);
lastBlock.Statements [i] = null;
}
result.Add (newLastBlock);
}
return result;
}
private bool ExtractPrePostConditionsFromContractSection (List<Statement> contractSection,
List<Requires> preconditions, List<Ensures> postconditions)
{
List<Statement> blocks = contractSection;
int firstBlockIndex = 0;
int blocksCount = blocks.Count;
int firstStmtIndex = HelperMethods.FindNextRealStatement (((Block) blocks [firstBlockIndex]).Statements, 0);
bool wasEndContractBlock = false;
for (int lastBlockIndex = firstBlockIndex; lastBlockIndex < blocksCount; ++lastBlockIndex) {
var block = (Block) blocks [lastBlockIndex];
if (block == null)
continue;
int cnt = block.Statements == null ? 0 : block.Statements.Count;
for (int lastStmtIndex = 0; lastStmtIndex < cnt; ++lastStmtIndex) {
Statement s = block.Statements [lastStmtIndex];
if (s == null)
continue;
Method calledMethod = HelperMethods.IsMethodCall (s);
if (!this.contract_nodes.IsContractMethod (calledMethod))
continue;
if (wasEndContractBlock) {
if (DebugOptions.Debug)
Console.WriteLine ("Contract call after prior ContractBlock");
break;
}
if (this.contract_nodes.IsEndContractBlock (calledMethod)) {
wasEndContractBlock = true;
continue;
}
//here we definitely know that s is ExpressionStatement of (MethodCall). see HelperMethods.IsMethodCall(s)
var methodCall = ((ExpressionStatement) s).Expression as MethodCall;
Expression assertionExpression = methodCall.Arguments [0];
Expression expression;
if (firstBlockIndex == lastBlockIndex && firstStmtIndex == lastStmtIndex)
expression = assertionExpression;
else {
block.Statements [lastStmtIndex] = new ExpressionStatement (assertionExpression);
List<Statement> contractBlocks = HelperMethods.ExtractContractBlocks (blocks, firstBlockIndex, firstStmtIndex,
lastBlockIndex, lastStmtIndex);
var b = new Block (contractBlocks);
expression = new BlockExpression (b);
}
MethodContractElement methodContractElement = null;
if (this.contract_nodes.IsPlainPrecondition (calledMethod)) {
var requires = new Requires (expression);
methodContractElement = requires;
} else if (this.contract_nodes.IsPostCondition (calledMethod))
methodContractElement = new Ensures (expression);
if (methodContractElement == null)
throw new InvalidOperationException ("Unrecognized contract method");
if (methodCall.Arguments.Count > 1) {
Expression userMessage = methodCall.Arguments [1];
methodContractElement.UserMessage = userMessage;
}
switch (methodContractElement.NodeType) {
case NodeType.Requires:
var requires = (Requires) methodContractElement;
preconditions.Add (requires);
break;
case NodeType.Ensures:
var ensures = (Ensures) methodContractElement;
postconditions.Add (ensures);
break;
}
}
}
return true;
}
public static Local ExtractPreamble (Method method, ContractNodes contractNodes, Block contractInitializer, out Block postPreamble)
{
postPreamble = null;
return null;
}
private Block GetOrCreateBlock (int address)
{
Block block;
if (!this.block_map.TryGetValue (address, out block)) {
this.block_map [address] = (block = new Block (new List<Statement> ()));
block.ILOffset = address;
}
return block;
}