Function* Backend::compile(const Stmt& stmt, vector<ir::Var> output){
Environment env;
std::set<Var> externSet;
for (const Var& var : output) {
if (!util::contains(externSet, var)) { // Remove duplicates
externSet.insert(var);
env.addExtern(var);
}
}
return compile(stmt, env, Storage());
}
backend::Function* Backend::compile(const Stmt& stmt, const Environment& env,
const Storage& storage) {
Environment environment = env; // copy
// Add output and undefined variable in the stmt to the environment as externs
std::set<Var> globalsSet;
util::ScopedMap<Var,void*> definedVariables;
// Add all environment variables to defined variables
for (auto& var : environment.getConstants()) {
globalsSet.insert(var.first);
definedVariables.insert(var.first, nullptr);
}
for (auto& ext : environment.getExterns()) {
const Var& var = ext.getVar();
globalsSet.insert(var);
definedVariables.insert(var, nullptr);
}
for (auto& tmp : environment.getTemporaries()) {
globalsSet.insert(tmp);
definedVariables.insert(tmp, nullptr);
}
// Find all undefined variables and add them to the context as globals.
function<void(Var var)> addToGlobalsIfNotDefined = [&](Var var) {
if (!definedVariables.contains(var) && !util::contains(globalsSet, var)) {
environment.addExtern(var);
globalsSet.insert(var);
definedVariables.insert(var, nullptr);
}
};
match(stmt,
function<void(const VarExpr*)>([&](const VarExpr* op) {
addToGlobalsIfNotDefined(op->var);
})
,
function<void(const AssignStmt*)>([&](const AssignStmt* op) {
definedVariables.insert(op->var, nullptr);
})
,
function<void(const VarDecl*)>([&](const VarDecl* op) {
definedVariables.insert(op->var, nullptr);
})
,
function<void(const ForRange*,Matcher*)>([&](const ForRange* op, Matcher* ctx) {
ctx->match(op->start);
ctx->match(op->end);
definedVariables.insert(op->var, nullptr);
ctx->match(op->body);
})
,
function<void(const For*,Matcher*)>([&](const For* op, Matcher* ctx) {
definedVariables.insert(op->var, nullptr);
ctx->match(op->body);
})
,
function<void(const Scope*,Matcher*)>([&](const Scope* op, Matcher* ctx) {
definedVariables.scope();
ctx->match(op->scopedStmt);
definedVariables.unscope();
})
);
Func func("main", {}, {}, stmt, environment);
return pimpl->compile(func, storage);
}