/// <summary>
/// stloc obj(resourceExpression)
/// .try BlockContainer {
/// Block IL_0003(incoming: 1) {
/// call WriteLine(ldstr "using (null)")
/// leave IL_0003(nop)
/// }
/// } finally BlockContainer {
/// Block IL_0012(incoming: 1) {
/// if (comp(ldloc obj != ldnull)) Block IL_001a {
/// callvirt Dispose(ldnull)
/// }
/// leave IL_0012(nop)
/// }
/// }
/// leave IL_0000(nop)
/// =>
/// using (resourceExpression) {
/// BlockContainer {
/// Block IL_0003(incoming: 1) {
/// call WriteLine(ldstr "using (null)")
/// leave IL_0003(nop)
/// }
/// }
/// }
/// </summary>
bool TransformUsing(Block block, int i)
{
if (i < 1)
{
return(false);
}
if (!(block.Instructions[i] is TryFinally tryFinally) || !(block.Instructions[i - 1] is StLoc storeInst))
{
return(false);
}
if (!(storeInst.Value.MatchLdNull() || CheckResourceType(storeInst.Variable.Type)))
{
return(false);
}
if (storeInst.Variable.LoadInstructions.Any(ld => !ld.IsDescendantOf(tryFinally)))
{
return(false);
}
if (storeInst.Variable.AddressInstructions.Any(la => !la.IsDescendantOf(tryFinally) || (la.IsDescendantOf(tryFinally.TryBlock) && !ILInlining.IsUsedAsThisPointerInCall(la))))
{
return(false);
}
if (storeInst.Variable.StoreInstructions.Count > 1)
{
return(false);
}
if (!(tryFinally.FinallyBlock is BlockContainer container) || !MatchDisposeBlock(container, storeInst.Variable, storeInst.Value.MatchLdNull()))
{
return(false);
}
context.Step("UsingTransform", tryFinally);
storeInst.Variable.Kind = VariableKind.UsingLocal;
block.Instructions.RemoveAt(i);
block.Instructions[i - 1] = new UsingInstruction(storeInst.Variable, storeInst.Value, tryFinally.TryBlock)
{
ILRange = storeInst.ILRange
};
return(true);
}
/// <summary>
/// stloc obj(resourceExpression)
/// .try BlockContainer {
/// Block IL_0003(incoming: 1) {
/// call WriteLine(ldstr "using (null)")
/// leave IL_0003(nop)
/// }
/// } finally BlockContainer {
/// Block IL_0012(incoming: 1) {
/// if (comp(ldloc obj != ldnull)) Block IL_001a {
/// callvirt Dispose(ldnull)
/// }
/// leave IL_0012(nop)
/// }
/// }
/// leave IL_0000(nop)
/// =>
/// using (resourceExpression) {
/// BlockContainer {
/// Block IL_0003(incoming: 1) {
/// call WriteLine(ldstr "using (null)")
/// leave IL_0003(nop)
/// }
/// }
/// }
/// </summary>
bool TransformUsing(Block block, int i)
{
if (i + 1 >= block.Instructions.Count)
{
return(false);
}
if (!(block.Instructions[i + 1] is TryFinally tryFinally) || !(block.Instructions[i] is StLoc storeInst))
{
return(false);
}
if (!(storeInst.Value.MatchLdNull() || CheckResourceType(storeInst.Variable.Type)))
{
return(false);
}
if (storeInst.Variable.Kind != VariableKind.Local)
{
return(false);
}
if (storeInst.Variable.LoadInstructions.Any(ld => !ld.IsDescendantOf(tryFinally)))
{
return(false);
}
if (storeInst.Variable.AddressInstructions.Any(la => !la.IsDescendantOf(tryFinally) || (la.IsDescendantOf(tryFinally.TryBlock) && !ILInlining.IsUsedAsThisPointerInCall(la))))
{
return(false);
}
if (storeInst.Variable.StoreInstructions.Count > 1)
{
return(false);
}
if (!(tryFinally.FinallyBlock is BlockContainer container))
{
return(false);
}
if (!MatchDisposeBlock(container, storeInst.Variable, storeInst.Value.MatchLdNull()))
{
return(false);
}
context.Step("UsingTransform", tryFinally);
storeInst.Variable.Kind = VariableKind.UsingLocal;
block.Instructions.RemoveAt(i + 1);
block.Instructions[i] = new UsingInstruction(storeInst.Variable, storeInst.Value, tryFinally.TryBlock)
{
IsRefStruct = context.Settings.IntroduceRefModifiersOnStructs && storeInst.Variable.Type.Kind == TypeKind.Struct && storeInst.Variable.Type.IsByRefLike
}.WithILRange(storeInst);
return(true);
}
