Method handleUserFunctionCall

SPIRV/GlslangToSpv.cpp:7853–7959

}

spv::Id TGlslangToSpvTraverser::handleUserFunctionCall(const glslang::TIntermAggregate* node)
{
    // Grab the function's pointer from the previously created function
    spv::Function* function = functionMap[node->getName().c_str()];
    if (! function)
        return 0;

    const glslang::TIntermSequence& glslangArgs = node->getSequence();
    const glslang::TQualifierList& qualifiers = node->getQualifierList();

    //  See comments in makeFunctions() for details about the semantics for parameter passing.
    //
    // These imply we need a four step process:
    // 1. Evaluate the arguments
    // 2. Allocate and make copies of in, out, and inout arguments
    // 3. Make the call
    // 4. Copy back the results

    // 1. Evaluate the arguments and their types
    std::vector<spv::Builder::AccessChain> lValues;
    std::vector<spv::Id> rValues;
    std::vector<const glslang::TType*> argTypes;
    for (int a = 0; a < (int)glslangArgs.size(); ++a) {
        argTypes.push_back(&glslangArgs[a]->getAsTyped()->getType());
        // build l-value
        builder.clearAccessChain();
        glslangArgs[a]->traverse(this);
        // keep outputs and pass-by-originals as l-values, evaluate others as r-values
        if (originalParam(qualifiers[a], *argTypes[a], function->hasImplicitThis() && a == 0) ||
            writableParam(qualifiers[a])) {
            // save l-value
            lValues.push_back(builder.getAccessChain());
        } else {
            // process r-value
            rValues.push_back(accessChainLoad(*argTypes.back()));
        }
    }

    // Reset source location to the function call location after argument evaluation
    builder.setDebugSourceLocation(node->getLoc().line, node->getLoc().getFilename());

    // 2. Allocate space for anything needing a copy, and if it's "in" or "inout"
    // copy the original into that space.
    //
    // Also, build up the list of actual arguments to pass in for the call
    int lValueCount = 0;
    int rValueCount = 0;
    std::vector<spv::Id> spvArgs;
    for (int a = 0; a < (int)glslangArgs.size(); ++a) {
        spv::Id arg;
        if (originalParam(qualifiers[a], *argTypes[a], function->hasImplicitThis() && a == 0)) {
            builder.setAccessChain(lValues[lValueCount]);
            arg = builder.accessChainGetLValue();
            ++lValueCount;
        } else if (writableParam(qualifiers[a])) {
            // need space to hold the copy
            arg = builder.createVariable(function->getParamPrecision(a), spv::StorageClass::Function,
                builder.getContainedTypeId(function->getParamType(a)), "param");