VuoCompilerBitcodeParser.cc

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#include "VuoCompilerBitcodeParser.hh"
 
 
VuoCompilerBitcodeParser::VuoCompilerBitcodeParser(Module *module)
{
    this->module = module;
}
 
uint64_t VuoCompilerBitcodeParser::getGlobalUInt(string name)
{
    GlobalValue *gv = module->getNamedValue(name);
    if((gv == NULL) || (gv->getValueID() != Value::GlobalVariableVal))
        return 0;
 
    Value *v = gv->getOperand(0);
    if(v->getValueID() != Value::ConstantIntVal)
        return 0;
 
    ConstantInt *ci = (ConstantInt *)v;
    return ci->getValue().getLimitedValue();
}
 
string VuoCompilerBitcodeParser::getGlobalString(string name)
{
    string s = resolveGlobalToConst(name);
    if(s=="")
        return "";
 
    return getGlobalValueConstString(s);
}
 
vector<string> VuoCompilerBitcodeParser::getStringsFromGlobalArray(string name)
{
    vector<string> globalConstStrings;
    GlobalValue *gv = module->getNamedValue(name);
 
    if((gv == NULL) || (gv->getValueID() != Value::GlobalVariableVal))
    {
        return globalConstStrings;
    }
    Value *v = gv->getOperand(0);
 
    if(v->getValueID() != Value::ConstantArrayVal)
    {
        return globalConstStrings;
    }
    ConstantArray *constantArray = (ConstantArray *)v;
    int numArrayElmts = constantArray->getNumOperands();
 
    for(int i = 0; i < numArrayElmts; i++)
    {
        Constant *arrayConstElmt = (Constant *)(constantArray->getOperand(i));
 
        if(arrayConstElmt->getValueID() == Value::ConstantExprVal)
        {
            ConstantExpr *ce = (ConstantExpr *)arrayConstElmt;
 
            if(ce->getOpcode() == Instruction::GetElementPtr)
            {
                // `ConstantExpr` operands: https://llvm.org/docs/LangRef.html#constantexprs
                Value *gv2 = ce->getOperand(0);
 
                if(gv2->getValueID() == Value::GlobalVariableVal)
                {
                    string constantName = gv2->getName().str();
                    string constantVal = getGlobalValueConstString(constantName);
                    globalConstStrings.push_back(constantVal);
                }
            }
        }
    }
    return globalConstStrings;
}
 
string VuoCompilerBitcodeParser::resolveGlobalToConst(string name)
{
    GlobalValue *gv = module->getNamedValue(name);
    if((gv == NULL) || (gv->getValueID() != Value::GlobalVariableVal))
        return "";
 
    Value *v = gv->getOperand(0);
    if(v->getValueID() != Value::ConstantExprVal)
        return "";
    ConstantExpr *ce = (ConstantExpr *)v;
    if(ce->getOpcode() != Instruction::GetElementPtr)
        return "";
 
    // `ConstantExpr` operands: https://llvm.org/docs/LangRef.html#constantexprs
    Value *gv2 = ce->getOperand(0);
 
    if(gv2->getValueID() != Value::GlobalVariableVal)
        return "";
 
    return gv2->getName().str();
}
 
string VuoCompilerBitcodeParser::getGlobalValueConstString(string name)
{
    GlobalValue *gv = module->getNamedValue(name);
 
    // assumption: the zeroth operand of a Value::GlobalVariableVal is the actual Value
    Value *v = gv->getOperand(0);
    if(v->getValueID() != Value::ConstantDataArrayVal)
        return "";  // if the string's value is "", v->getValueID() is Value::ConstantAggregateZeroVal
 
    ConstantDataArray *ca = (ConstantDataArray *)v;
    string caStr = ca->getAsCString().str();
    return caStr;
}
 
Function * VuoCompilerBitcodeParser::getFunction(string name)
{
    return module->getFunction(name);
}
 
string VuoCompilerBitcodeParser::getArgumentNameInSourceCode(string argumentNameInBitcode)
{
    return argumentNameInBitcode.substr(0, argumentNameInBitcode.find('.'));
}
 
vector<pair<Argument *, string> > VuoCompilerBitcodeParser::getAnnotatedArguments(Function *function)
{
    vector<pair<Argument *, string> > annotatedArguments;
 
    // assumption: @llvm.var.annotation calls are always in the function's entry block.
    BasicBlock *b = &function->getEntryBlock();
 
    // Run through the entry block to associate annotations with function parameters.
    BitCastInst *precedingBitCastInst = NULL;
    for(BasicBlock::iterator it = b->begin();it!=b->end();++it)
    {
        Instruction *inst = &(*it);
        if(! CallInst::classof(inst))
        {
            if (BitCastInst::classof(inst))
                precedingBitCastInst = static_cast<BitCastInst *>(inst);
            continue;
        }
 
        // assumption: Instruction::Call's operands are the function arguments, followed by the function name
        Value *calledFunction = inst->getOperand(inst->getNumOperands()-1);
        if(calledFunction->getName().str() != "llvm.var.annotation")
            continue;
 
        // Find an operand whose name has the same prefix as the corresponding function parameter's name.
        // The correct place to look for this operand depends on the data type of the parameter.
        // For a struct, it's the bitcast. For a bool, it's the llvm.var.annotation call.
        // For other data types, either works.
        Value *annotatedValue;
        if (precedingBitCastInst)
        {
            // `bitcast` operands: https://llvm.org/docs/LangRef.html#bitcast-to-instruction
            annotatedValue = precedingBitCastInst->getOperand(0);
            precedingBitCastInst = NULL;
        }
        else
        {
            // `llvm.var.annotation` operands: https://llvm.org/docs/LangRef.html#llvm-var-annotation-intrinsic
            annotatedValue = inst->getOperand(0);
        }
 
        // Find the first function parameter whose name matches the operand's name.
        // The function parameter and/or the operand may have a suffix that begins with ".", e.g. ".coerce" or ".addr1".
        Argument *argument = NULL;
        string annotationNamePrefix = getArgumentNameInSourceCode(annotatedValue->getName());
        for (Function::arg_iterator i = function->arg_begin(); i != function->arg_end(); ++i)
        {
            Argument *currArgument = i;
            string argNamePrefix = getArgumentNameInSourceCode(currArgument->getName());
            if (argNamePrefix == annotationNamePrefix)
            {
                argument = currArgument;
                break;
            }
        }
        if(!argument)
        {
            // Workaround for vuo.image.make.checkerboard2 center (https://b33p.net/kosada/node/15936)
            for (Function::arg_iterator i = function->arg_begin(); i != function->arg_end(); ++i)
            {
                Argument *currArgument = i;
                if (currArgument->getName().empty())
                {
                    argument = currArgument;
                    argument->setName(annotationNamePrefix + ".workaround");
                    break;
                }
            }
 
            continue;
        }
 
        Value *annotation = inst->getOperand(1);
        if(annotation->getValueID() != Value::ConstantExprVal)
            continue;
        ConstantExpr *ce = (ConstantExpr *)annotation;
        if(ce->getOpcode() != Instruction::GetElementPtr)
            continue;
 
        // `ConstantExpr` operands: https://llvm.org/docs/LangRef.html#constant-expressions
        Value *gv = ce->getOperand(0);
 
        if(gv->getValueID() != Value::GlobalVariableVal)
            continue;
 
        string annotationName = getGlobalValueConstString(gv->getName().str());
 
        annotatedArguments.push_back(pair<Argument *, string>(argument, annotationName));
    }
 
    return annotatedArguments;
}