ispc/decl.cpp

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*/

/** @file decl.cpp
    @brief Implementations of classes related to turning declarations into 
           symbols and types.
*/

#include "decl.h"
#include "util.h"
#include "sym.h"
#include "type.h"
#include "expr.h"
#include <stdio.h>

///////////////////////////////////////////////////////////////////////////
// DeclSpecs

DeclSpecs::DeclSpecs(const Type *t, StorageClass sc, int tq) {
    baseType = t;
    storageClass = sc;
    typeQualifier = tq;
    soaWidth = 0;
    vectorSize = 0;
}


void
DeclSpecs::Print() const {
    if (storageClass == SC_EXTERN)   printf("extern ");
    if (storageClass == SC_EXTERN_C) printf("extern \"C\" ");
    if (storageClass == SC_EXPORT)   printf("export ");
    if (storageClass == SC_STATIC)   printf("static ");
    if (storageClass == SC_TYPEDEF)  printf("typedef ");

    if (soaWidth > 0) printf("soa<%d> ", soaWidth);

    if (typeQualifier & TYPEQUAL_INLINE)    printf("inline ");
    if (typeQualifier & TYPEQUAL_CONST)     printf("const ");
    if (typeQualifier & TYPEQUAL_UNIFORM)   printf("uniform ");
    if (typeQualifier & TYPEQUAL_VARYING)   printf("varying ");
    if (typeQualifier & TYPEQUAL_TASK)      printf("task ");
    if (typeQualifier & TYPEQUAL_REFERENCE) printf("reference ");
    if (typeQualifier & TYPEQUAL_UNSIGNED)  printf("unsigned ");

    printf("%s", baseType->GetString().c_str());

    if (vectorSize > 0) printf("<%d>", vectorSize);
}


///////////////////////////////////////////////////////////////////////////
// Declarator

Declarator::Declarator(Symbol *s, SourcePos p) 
  : pos(p) { 
    sym = s;
    functionArgs = NULL;
    isFunction = false;
    initExpr = NULL;
}


void
Declarator::AddArrayDimension(int size) {
    assert(size > 0 || size == -1); // -1 -> unsized
    arraySize.push_back(size);
}


void
Declarator::InitFromDeclSpecs(DeclSpecs *ds) {
    sym->type = GetType(ds);

    if (ds->storageClass == SC_STATIC)
        sym->isStatic = true;
}


void
Declarator::Print() const {
    printf("%s", sym->name.c_str());
    if (initExpr != NULL) {
        printf(" = (");
        initExpr->Print();
        printf(")");
    }
    pos.Print();
}


static const Type *
lGetType(const Declarator *decl, DeclSpecs *ds, 
         std::vector<int>::const_iterator arrayIter) {
    if (arrayIter == decl->arraySize.end()) {
        // If we don't have an array (or have processed all of the array
        // dimensions in previous recursive calls), we can go ahead and
        // figure out the final non-array type we have here.
        const Type *type = ds->baseType;
        if (type == NULL) {
            Error(decl->pos, "Type not provided in variable declaration for variable \"%s\".",
                  decl->sym->name.c_str());
            return NULL;
        }

        // Account for 'unsigned' and 'const' qualifiers in the type
        if ((ds->typeQualifier & TYPEQUAL_UNSIGNED) != 0) {
            const Type *unsignedType = type->GetAsUnsignedType();
            if (unsignedType != NULL)
                type = unsignedType;
            else
                Error(decl->pos, "\"unsigned\" qualifier is illegal with \"%s\" type.",
                      type->GetString().c_str());
        }
        if ((ds->typeQualifier & TYPEQUAL_CONST) != 0)
            type = type->GetAsConstType();

        if (ds->vectorSize > 0) {
            const AtomicType *atomicType = dynamic_cast<const AtomicType *>(type);
            if (atomicType == NULL) {
                Error(decl->pos, "Only atomic types (int, float, ...) are legal for vector "
                      "types.");
                return NULL;
            }
            type = new VectorType(atomicType, ds->vectorSize);
        }

        // if uniform/varying is specified explicitly, then go with that
        if ((ds->typeQualifier & TYPEQUAL_UNIFORM) != 0)
            return type->GetAsUniformType();
        else if ((ds->typeQualifier & TYPEQUAL_VARYING) != 0)
            return type->GetAsVaryingType();
        else {
            // otherwise, structs are uniform by default and everything
            // else is varying by default
            if (dynamic_cast<const StructType *>(type) != NULL)
                return type->GetAsUniformType();
            else
                return type->GetAsVaryingType();
        }
    }
    else {
        // Peel off one dimension of the array
        int arraySize = *arrayIter;
        ++arrayIter;

        // Get the type, not including the arraySize dimension peeled off
        // above.
        const Type *childType = lGetType(decl, ds, arrayIter);

        int soaWidth = ds->soaWidth;
        if (soaWidth == 0)
            // If there's no "soa<n>" stuff going on, just return a regular
            // array with the appropriate size 
            return new ArrayType(childType, arraySize == -1 ? 0 : arraySize);
       else {
            // Make sure we actually have an array of structs ..
            const StructType *childStructType = 
                dynamic_cast<const StructType *>(childType);
            if (childStructType == NULL) {
                Error(decl->pos, "Illegal to provide soa<%d> qualifier with non-struct "
                      "type \"%s\".", soaWidth, childType->GetString().c_str());
                return new ArrayType(childType, arraySize == -1 ? 0 : arraySize);
            }
            else if ((soaWidth & (soaWidth - 1)) != 0) {
                Error(decl->pos, "soa<%d> width illegal.  Value must be power of two.",
                      soaWidth);
                return NULL;
            }
            else if (arraySize != -1 && (arraySize % soaWidth) != 0) {
                Error(decl->pos, "soa<%d> width must evenly divide array size %d.",
                      soaWidth, arraySize);
                return NULL;
            }
            return new SOAArrayType(childStructType, arraySize == -1 ? 0 : arraySize,
                                    soaWidth);
        }
    }
}


const Type *
Declarator::GetType(DeclSpecs *ds) const {
    bool hasUniformQual = ((ds->typeQualifier & TYPEQUAL_UNIFORM) != 0);
    bool hasVaryingQual = ((ds->typeQualifier & TYPEQUAL_VARYING) != 0);
    bool isTask =         ((ds->typeQualifier & TYPEQUAL_TASK) != 0);
    bool isReference =    ((ds->typeQualifier & TYPEQUAL_REFERENCE) != 0);

    if (hasUniformQual && hasVaryingQual) {
        Error(pos, "Can't provide both \"uniform\" and \"varying\" qualifiers.");
        return NULL;
    }

    if (isFunction) {
        std::vector<const Type *> args;
        std::vector<std::string> argNames;
        if (functionArgs) {
            // Loop over the function arguments and get names and types for
            // each one in the args and argNames arrays
            for (unsigned int i = 0; i < functionArgs->size(); ++i) {
                Declaration *d = (*functionArgs)[i];
                Symbol *sym;
                if (d->declarators.size() == 0) {
                    // function declaration like foo(float), w/o a name for
                    // the parameter
                    char buf[32];
                    sprintf(buf, "__anon_parameter_%d", i);
                    sym = new Symbol(buf, pos);
                    Declarator *declarator = new Declarator(sym, sym->pos);
                    sym->type = declarator->GetType(d->declSpecs);
                    d->declarators.push_back(declarator);
                }
                else {
                    assert(d->declarators.size() == 1);
                    sym = d->declarators[0]->sym;
                }

                // Arrays are passed by reference, so convert array
                // parameters to be references here.
                if (dynamic_cast<const ArrayType *>(sym->type) != NULL)
                    sym->type = new ReferenceType(sym->type, sym->type->IsConstType());

                args.push_back(sym->type);
                argNames.push_back(sym->name);
            }
        }

        if (ds->baseType == NULL) {
            Warning(pos, "No return type provided in declaration of function \"%s\". "
                    "Treating as \"void\".", sym->name.c_str());
            ds->baseType = AtomicType::Void;
        }

        if (isReference) {
            Error(pos, "Function return types can't be reference types.");
            return NULL;
        }

        const Type *returnType = lGetType(this, ds, arraySize.begin());
        if (returnType == NULL)
            return NULL;

        bool isExported = (ds->storageClass == SC_EXPORT);
        bool isExternC =  (ds->storageClass == SC_EXTERN_C);
        return new FunctionType(returnType, args, pos, &argNames, isTask, 
                                isExported, isExternC);
    }
    else {
        if (isTask)
            Error(pos, "\"task\" qualifier illegal in variable declaration \"%s\".",
                  sym->name.c_str());

        const Type *type = lGetType(this, ds, arraySize.begin());

        if (type != NULL && isReference) {
            bool hasConstQual = ((ds->typeQualifier & TYPEQUAL_CONST) != 0);
            type = new ReferenceType(type, hasConstQual);
        }

        return type;
    }
}

///////////////////////////////////////////////////////////////////////////
// Declaration

void
Declaration::AddSymbols(SymbolTable *st) const {
    assert(declSpecs->storageClass != SC_TYPEDEF);

    for (unsigned int i = 0; i < declarators.size(); ++i)
       if (declarators[i])
           st->AddVariable(declarators[i]->sym);
}


void
Declaration::Print() const {
    printf("Declaration: specs [");
    declSpecs->Print();
    printf("], declarators [");
    for (unsigned int i = 0 ; i < declarators.size(); ++i) {
        declarators[i]->Print();
        printf("%s", (i == declarators.size() - 1) ? "]" : ", ");
    }
}

///////////////////////////////////////////////////////////////////////////

void
GetStructTypesNamesPositions(const std::vector<StructDeclaration *> &sd,
                             std::vector<const Type *> *elementTypes,
                             std::vector<std::string> *elementNames,
                             std::vector<SourcePos> *elementPositions) {
    for (unsigned int i = 0; i < sd.size(); ++i) {
        const Type *type = sd[i]->type;
        // FIXME: making this fake little DeclSpecs here is really
        // disgusting
        DeclSpecs ds(type);
        if (type->IsUniformType()) 
            ds.typeQualifier |= TYPEQUAL_UNIFORM;
        else
            ds.typeQualifier |= TYPEQUAL_VARYING;

        for (unsigned int j = 0; j < sd[i]->declarators->size(); ++j) {
            Declarator *d = (*sd[i]->declarators)[j];
            d->InitFromDeclSpecs(&ds);

            // if it's an unsized array, make it a reference to an unsized
            // array, so the caller can pass a pointer...
            const ArrayType *at = dynamic_cast<const ArrayType *>(d->sym->type);
            if (at && at->GetElementCount() == 0)
                d->sym->type = new ReferenceType(d->sym->type, type->IsConstType());

            elementTypes->push_back(d->sym->type);
            elementNames->push_back(d->sym->name);
            elementPositions->push_back(d->sym->pos);
        }
    }
}