ASTfunction_declaration::ASTfunction_declaration (OSLCompilerImpl *comp,
TypeSpec type, ustring name,
ASTNode *form, ASTNode *stmts, ASTNode *meta)
: ASTNode (function_declaration_node, comp, 0, meta, form, stmts),
m_name(name), m_sym(NULL), m_is_builtin(false)
{
m_typespec = type;
Symbol *f = comp->symtab().clash (name);
if (f && f->symtype() != SymTypeFunction) {
error ("\"%s\" already declared in this scope as a ", name.c_str(),
f->typespec().string().c_str());
// FIXME -- print the file and line of the other definition
f = NULL;
}
// FIXME -- allow multiple function declarations, but only if they
// aren't the same polymorphic type.
if (name[0] == '_' && name[1] == '_' && name[2] == '_') {
error ("\"%s\" : sorry, can't start with three underscores",
name.c_str());
}
m_sym = new FunctionSymbol (name, type, this);
func()->nextpoly ((FunctionSymbol *)f);
std::string argcodes = oslcompiler->code_from_type (m_typespec);
for (ASTNode *arg = form; arg; arg = arg->nextptr()) {
const TypeSpec &t (arg->typespec());
if (t == TypeSpec() /* UNKNOWN */) {
m_typespec = TypeDesc::UNKNOWN;
return;
}
argcodes += oslcompiler->code_from_type (t);
ASSERT (arg->nodetype() == variable_declaration_node);
ASTvariable_declaration *v = (ASTvariable_declaration *)arg;
if (v->init())
v->error ("function parameter '%s' may not have a default initializer.",
v->name().c_str());
}
func()->argcodes (ustring (argcodes));
oslcompiler->symtab().insert (m_sym);
// Typecheck it right now, upon declaration
typecheck (typespec ());
}
void
ASTfunction_call::typecheck_builtin_specialcase ()
{
if (m_name == "transform") {
// Special case for transform: under the covers, it selects
// vector or normal special versions depending on its use.
if (typespec().simpletype() == TypeDesc::TypeVector)
m_name = ustring ("transformv");
else if (typespec().simpletype() == TypeDesc::TypeNormal)
m_name = ustring ("transformn");
}
// Void functions DO read their first arg, DON'T write it
if (typespec().is_void()) {
argread (0, true);
argwrite (0, false);
}
if (func()->readwrite_special_case()) {
if (m_name == "fresnel") {
// This function has some output args
argwriteonly (3);
argwriteonly (4);
argwriteonly (5);
argwriteonly (6);
} else if (m_name == "sincos") {
argwriteonly (1);
argwriteonly (2);
} else if (m_name == "getattribute" || m_name == "getmessage" ||
m_name == "gettextureinfo" || m_name == "dict_value") {
// these all write to their last argument
argwriteonly ((int)listlength(args()));
} else if (func()->texture_args()) {
// texture-like function, look out for "alpha"
std::vector<ASTNode::ref> argvec;
list_to_vec (args(), argvec);
// Find the beginning of the optional arguments -- it will be
// the first string argument AFTER the filename.
int nargs = (int) listlength(args());
int firstopt = 2;
while (firstopt < nargs &&
! argvec[firstopt]->typespec().is_string())
++firstopt;
// Loop through the optional args, look for "alpha"
for (int a = firstopt; a < (int)argvec.size()-1; a += 2) {
ASTNode *s = argvec[a].get();
if (s->typespec().is_string() &&
s->nodetype() == ASTNode::literal_node &&
! strcmp (((ASTliteral *)s)->strval(), "alpha")) {
// 'alpha' writes to the next arg!
if (a+2 < 32)
argwriteonly (a+2); // mark writeable
else {
// We can only designate the first 32 args
// writeable. So swap it with earlier optional args.
std::swap (argvec[firstopt], argvec[a]);
std::swap (argvec[firstopt+1], argvec[a+1]);
argwriteonly (firstopt+1);
firstopt += 2; // advance in case another is needed
}
}
}
m_children[0] = vec_to_list (argvec);
}
}
if (func()->takes_derivs()) {
// Special handling for the few functions that take derivatives
// of their arguments. Mark those with argtakesderivs.
// N.B. This counts arguments in the same way that opcodes do --
// assuming "arg 0" is the return value.
size_t nargs = listlength(args());
if (m_name == "area") {
argtakesderivs (1, true);
} else if (m_name == "aastep") {
// all but the 5-arg version take derivs of edge param
argtakesderivs (1, nargs<5);
// aastep(f,f) and aastep(f,f,str) take derivs of s param
if (nargs == 2 || list_nth(args(),2)->typespec().is_string())
argtakesderivs (2, true);
} else if (m_name == "bump" || m_name == "displace") {
// FIXME -- come back to this
} else if (m_name == "calculatenormal") {
argtakesderivs (1, true);
} else if (m_name == "Dx" || m_name == "Dy") {
argtakesderivs (1, true);
} else if (m_name == "texture") {
if (nargs == 3 || list_nth(args(),3)->typespec().is_string()) {
argtakesderivs (2, true);
argtakesderivs (3, true);
}
} else if (m_name == "texture3d") {
if (nargs == 2 || list_nth(args(),2)->typespec().is_string()) {
argtakesderivs (2, true);
}
} else if (m_name == "environment") {
if (nargs == 2 || list_nth(args(),2)->typespec().is_string()) {
argtakesderivs (2, true);
}
} else if (m_name == "trace") {
argtakesderivs (1, true);
argtakesderivs (2, true);
} else {
ASSERT (0 && "Missed a takes_derivs case!");
}
}
}