private void GenerateFunctionHeader(AstFuncExpr function, bool forceEmitCode)
{
// Don't emit global functions that aren't even used
if (!forceEmitCode && dontEmitUnusedDeclarations && !function.IsUsed)
{
return;
}
if (function.IsMacroFunction)
{
return;
}
var name = "";
if (function.ImplBlock != null)
{
name += function.ImplBlock.TargetType + ".";
if (function.ImplBlock.Trait != null)
{
name += function.ImplBlock.Trait + ".";
}
}
name += function.Name;
if (function.PolymorphicTypes != null && function.PolymorphicTypes.Count > 0)
{
name += "." + string.Join(".", function.PolymorphicTypes.Select(p => $"{p.Key}.{p.Value}"));
}
if (function.ConstParameters != null && function.ConstParameters.Count > 0)
{
name += "." + string.Join(".", function.ConstParameters.Select(p => $"{p.Key}.{p.Value.type}.{p.Value.value}"));
}
if (function.Body != null)
{
name += ".che";
}
var linkname = function.GetDirective("linkname");
LLVMValueRef lfunc = new LLVMValueRef();
if (linkname != null)
{
name = linkname.Arguments[0].Value as string;
lfunc = module.GetNamedFunction(name);
}
LLVMTypeRef ltype = FuncTypeToLLVMType(function.FunctionType);
if (lfunc.Pointer.ToInt64() == 0)
{
lfunc = module.AddFunction(name, ltype);
}
// :temporary
if (function.Body != null)
{
lfunc.SetLinkage(LLVMLinkage.LLVMInternalLinkage);
}
if (function.HasDirective("extern"))
{
lfunc.SetLinkage(LLVMLinkage.LLVMExternalLinkage);
}
// TODO
if (function.HasDirective("noinline"))
{
lfunc.AddFunctionAttribute(context, LLVMAttributeKind.NoInline);
}
lfunc.AddFunctionAttribute(context, LLVMAttributeKind.NoUnwind);
var ccDir = function.GetDirective("stdcall");
if (ccDir != null)
{
LLVM.SetFunctionCallConv(lfunc, (int)LLVMCallConv.LLVMX86StdcallCallConv);
}
valueMap[function] = lfunc;
}
private void GenerateFunctionImplementation(AstFuncExpr function, bool forceEmitCode)
{
// Don't emit global functions that aren't even used
if (!forceEmitCode && dontEmitUnusedDeclarations && !function.IsUsed)
{
return;
}
if (function.Body == null || function.IsMacroFunction)
{
return;
}
currentFunction = function;
keepTrackOfStackTrace = !function.HasDirective("nostacktrace") && enableStackTrace;
var lfunc = valueMap[function];
currentLLVMFunction = lfunc;
// generate body
{
var builder = new IRBuilder();
this.builder = builder;
var bbParams = lfunc.AppendBasicBlock("locals");
//var bbTemps = lfunc.AppendBasicBlock("temps");
var bbBody = lfunc.AppendBasicBlock("body");
// allocate space for parameters and return values on stack
builder.PositionBuilderAtEnd(bbParams);
PushStackTrace(function);
for (int i = 0; i < function.Parameters.Count; i++)
{
var param = function.Parameters[i];
var p = lfunc.GetParam((uint)i);
var ptype = LLVM.TypeOf(p);
p = builder.CreateAlloca(ptype, $"p_{param.Name?.Name}");
valueMap[param] = p;
}
// @todo: do we still need this?
//foreach (var c in function.ConstScope.Symbols)
//{
// if (c.Value is ConstSymbol s && !s.Type.IsComptimeOnly)
// {
// var val = CheezValueToLLVMValue(s.Type, s.Value);
// var cnst = builder.CreateAlloca(CheezTypeToLLVMType(s.Type), $"c_");
// builder.CreateStore(val, cnst);
// valueMap[s] = cnst;
// }
//}
if (function.ReturnTypeExpr != null)
{
var ptype = CheezTypeToLLVMType(function.ReturnTypeExpr.Type);
var p = builder.CreateAlloca(ptype, $"ret_{function.ReturnTypeExpr.Name?.Name}");
valueMap[function.ReturnTypeExpr] = p;
}
// store params and rets in local variables
for (int i = 0; i < function.Parameters.Count; i++)
{
var param = function.Parameters[i];
var p = lfunc.GetParam((uint)i);
builder.CreateStore(p, valueMap[param]);
}
// temp values
//builder.PositionBuilderAtEnd(bbTemps);
builder.CreateBr(bbBody);
// body
builder.PositionBuilderAtEnd(bbBody);
GenerateExpression(function.Body, false);
// ret if void
if (function.ReturnTypeExpr == null && !function.Body.GetFlag(ExprFlags.Returns))
{
PopStackTrace();
builder.CreateRetVoid();
}
builder.Dispose();
}
// remove empty basic blocks
var bb = lfunc.GetFirstBasicBlock();
while (bb.Pointer.ToInt64() != 0)
{
var first = bb.GetFirstInstruction();
if (bb.GetBasicBlockTerminator().Pointer.ToInt64() == 0)
{
var b = new IRBuilder();
b.PositionBuilderAtEnd(bb);
b.CreateUnreachable();
b.Dispose();
}
bb = bb.GetNextBasicBlock();
}
// TODO
//if (lfunc.VerifyFunction(LLVMVerifierFailureAction.LLVMPrintMessageAction))
//{
// Console.Error.WriteLine($"in function {lfunc}");
//}
currentFunction = null;
}
