Method find_structsym

src/liboslcomp/ast.cpp:671–705

structnode is an AST node representing a struct. It could be a struct variable, or a field of a struct (which is itself a struct), or an array element of a struct. Whatever, here we figure out some vital information about it: the name of the symbol representing the struct, and its type.

/// vital information about it: the name of the symbol representing the
/// struct, and its type.
void
ASTstructselect::find_structsym (ASTNode *structnode, ustring &structname,
                                 TypeSpec &structtype)
{
    // This node selects a field from a struct. The purpose of this
    // method is to "flatten" the possibly-nested (struct in struct, and
    // or array of structs) down to a symbol that represents the
    // particular field.  In the process, we set structname and its
    // type structtype.
    ASSERT (structnode->typespec().is_structure() ||
            structnode->typespec().is_structure_array());
    if (structnode->nodetype() == variable_ref_node) {
        // The structnode is a top-level struct variable
        ASTvariable_ref *var = (ASTvariable_ref *) structnode;
        structname = var->name();
        structtype = var->typespec();
    }
    else if (structnode->nodetype() == structselect_node) {
        // The structnode is itself a field of another struct.
        ASTstructselect *thestruct = (ASTstructselect *) structnode;
        int structid, fieldid;
        Symbol *sym = thestruct->find_fieldsym (structid, fieldid);
        structname = sym->name();
        structtype = sym->typespec();
    }
    else if (structnode->nodetype() == index_node) {
        // The structnode is an element of an array of structs:
        ASTindex *arrayref = (ASTindex *) structnode;
        find_structsym (arrayref->lvalue().get(), structname, structtype);
        structtype.make_array (0);  // clear its arrayness
    }
    else {
        ASSERT (0 && "Malformed ASTstructselect");
    }
}