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//
// __global__ void vadd(const float* A, const float* B, float* C, int n) {
// int i = blockIdx.x * blockDim.x + threadIdx.x;
// if (i < n) C[i] = A[i] + B[i];
// }
#include "kernel.h"
#include <cctype>
#include <cstdlib>
namespace unify::kernel {
const char* type_name(Type t) {
switch (t) {
case Type::Void: return "void";
case Type::Int: return "int";
case Type::Float: return "float";
case Type::IntPtr: return "int*";
case Type::FloatPtr: return "float*";
}
return "?";
}
namespace {
struct Token {
enum Kind { Ident, Int, Float, Punct, End } kind;
std::string text;
int line;
};
bool lex(const std::string& s, std::vector<Token>& out, std::string& err) {
int line = 1;
size_t i = 0;
static const char* two[] = {"<=", ">=", "==", "!=", "&&", "||", "+=", "-=", "*=", "/=", "++", "--"};
while (i < s.size()) {
char c = s[i];
if (c == '\n') { line++; i++; continue; }
if (std::isspace(uint8_t(c))) { i++; continue; }
if (c == '/' && i + 1 < s.size() && s[i + 1] == '/') { while (i < s.size() && s[i] != '\n') i++; continue; }
if (c == '/' && i + 1 < s.size() && s[i + 1] == '*') {
i += 2;
while (i + 1 < s.size() && !(s[i] == '*' && s[i + 1] == '/')) { if (s[i] == '\n') line++; i++; }
i += 2;
continue;
}
if (std::isalpha(uint8_t(c)) || c == '_') {
size_t j = i;
while (j < s.size() && (std::isalnum(uint8_t(s[j])) || s[j] == '_')) j++;
out.push_back({Token::Ident, s.substr(i, j - i), line});
i = j;
continue;
}
if (std::isdigit(uint8_t(c)) || (c == '.' && i + 1 < s.size() && std::isdigit(uint8_t(s[i + 1])))) {
size_t j = i;
bool is_float = false;
while (j < s.size() && (std::isdigit(uint8_t(s[j])) || s[j] == '.' || s[j] == 'e' || s[j] == 'E' ||
((s[j] == '-' || s[j] == '+') && (s[j - 1] == 'e' || s[j - 1] == 'E')))) {
if (s[j] == '.' || s[j] == 'e' || s[j] == 'E') is_float = true;
j++;
}
std::string num = s.substr(i, j - i);
if (j < s.size() && (s[j] == 'f' || s[j] == 'F')) { is_float = true; j++; }
out.push_back({is_float ? Token::Float : Token::Int, num, line});
i = j;
continue;
}
bool matched = false;
for (const char* t : two)
if (s.compare(i, 2, t) == 0) { out.push_back({Token::Punct, t, line}); i += 2; matched = true; break; }
if (matched) continue;
if (std::string("+-*/%<>=!(){}[];,.&").find(c) != std::string::npos) {
out.push_back({Token::Punct, std::string(1, c), line});
i++;
continue;
}
err = "line " + std::to_string(line) + ": unexpected character '" + std::string(1, c) + "'";
return false;
}
out.push_back({Token::End, "", line});
return true;
}
class Parser {
public:
explicit Parser(std::vector<Token> t) : t_(std::move(t)) {}
std::string err;
bool kernel(KernelAST& k) {
while (peek("__global__") || peek("extern") || peek("\"C\"")) next();
if (!expect("void")) return false;
if (!ident(k.name)) return false;
if (!expect("(")) return false;
if (!peek(")")) {
do {
Param p;
if (!type(p.type)) return false;
if (!ident(p.name)) return false;
k.params.push_back(p);
} while (accept(","));
}
if (!expect(")")) return false;
k.body = block();
if (!k.body) return false;
if (t_[pos_].kind != Token::End) return fail("unexpected tokens after kernel body");
return true;
}
private:
const Token& cur() const { return t_[pos_]; }
void next() { if (t_[pos_].kind != Token::End) pos_++; }
bool peek(const char* s) const { return cur().text == s && cur().kind != Token::End; }
bool accept(const char* s) { if (peek(s)) { next(); return true; } return false; }
bool fail(const std::string& m) { if (err.empty()) err = "line " + std::to_string(cur().line) + ": " + m; return false; }
bool expect(const char* s) { if (accept(s)) return true; return fail(std::string("expected '") + s + "' but found '" + cur().text + "'"); }
bool ident(std::string& out) {
if (cur().kind != Token::Ident) return fail("expected identifier but found '" + cur().text + "'");
out = cur().text;
next();
return true;
}
bool is_type_start() const { return peek("int") || peek("float") || peek("const") || peek("unsigned"); }
bool type(Type& t) {
accept("const");
if (accept("int")) t = Type::Int;
else if (accept("float")) t = Type::Float;
else return fail("expected a type (int or float) but found '" + cur().text + "'");
if (accept("*")) t = t == Type::Int ? Type::IntPtr : Type::FloatPtr;
accept("const");
accept("__restrict__");
return true;
}
StmtP block() {
auto s = std::make_unique<Stmt>();
s->kind = Stmt::Block;
s->line = cur().line;
if (!expect("{")) return nullptr;
while (!peek("}")) {
if (cur().kind == Token::End) { fail("unterminated block"); return nullptr; }
StmtP st = statement();
if (!st) return nullptr;
s->stmts.push_back(std::move(st));
}
next();
return s;
}
StmtP simple_statement() { // declaration or assignment, no trailing ';'
auto s = std::make_unique<Stmt>();
s->line = cur().line;
if (is_type_start()) {
s->kind = Stmt::Decl;
if (!type(s->decl_type) || !ident(s->name)) return nullptr;
if (accept("=")) { s->value = expr(); if (!s->value) return nullptr; }
return s;
}
s->kind = Stmt::Assign;
s->target = postfix();
if (!s->target) return nullptr;
if (accept("++") || accept("--")) {
std::string op = t_[pos_ - 1].text == "++" ? "+=" : "-=";
s->name = op;
auto one = std::make_unique<Expr>();
one->kind = Expr::IntLit; one->ival = 1; one->line = s->line;
s->value = std::move(one);
return s;
}
for (const char* op : {"=", "+=", "-=", "*=", "/="})
if (accept(op)) { s->name = op; s->value = expr(); return s->value ? std::move(s) : nullptr; }
fail("expected an assignment");
return nullptr;
}
StmtP statement() {
int line = cur().line;
if (peek("{")) return block();
if (accept("if")) {
auto s = std::make_unique<Stmt>();
s->kind = Stmt::If; s->line = line;
if (!expect("(")) return nullptr;
s->cond = expr();
if (!s->cond || !expect(")")) return nullptr;
s->then_s = statement();
if (!s->then_s) return nullptr;
if (accept("else")) { s->else_s = statement(); if (!s->else_s) return nullptr; }
return s;
}
if (accept("for")) {
auto s = std::make_unique<Stmt>();
s->kind = Stmt::For; s->line = line;
if (!expect("(")) return nullptr;
if (!peek(";")) { s->init = simple_statement(); if (!s->init) return nullptr; }
if (!expect(";")) return nullptr;
if (!peek(";")) { s->cond = expr(); if (!s->cond) return nullptr; }
if (!expect(";")) return nullptr;
if (!peek(")")) { s->step = simple_statement(); if (!s->step) return nullptr; }
if (!expect(")")) return nullptr;
s->body = statement();
return s->body ? std::move(s) : nullptr;
}
if (accept("while")) {
auto s = std::make_unique<Stmt>();
s->kind = Stmt::While; s->line = line;
if (!expect("(")) return nullptr;
s->cond = expr();
if (!s->cond || !expect(")")) return nullptr;
s->body = statement();
return s->body ? std::move(s) : nullptr;
}
for (auto [kw, kind] : {std::pair<const char*, Stmt::Kind>{"return", Stmt::Return}, {"break", Stmt::Break}, {"continue", Stmt::Continue}}) {
if (accept(kw)) {
auto s = std::make_unique<Stmt>();
s->kind = kind; s->line = line;
return expect(";") ? std::move(s) : nullptr;
}
}
StmtP s = simple_statement();
if (!s || !expect(";")) return nullptr;
return s;
}
// Precedence climbing: || && ==,!= <,<=,>,>= +,- *,/,%
ExprP expr() { return binary(0); }
int prec(const std::string& op) const {
if (op == "||") return 1;
if (op == "&&") return 2;
if (op == "==" || op == "!=") return 3;
if (op == "<" || op == "<=" || op == ">" || op == ">=") return 4;
if (op == "+" || op == "-") return 5;
if (op == "*" || op == "/" || op == "%") return 6;
return -1;
}
ExprP binary(int min_prec) {
ExprP lhs = unary();
if (!lhs) return nullptr;
while (cur().kind == Token::Punct && prec(cur().text) > min_prec) {
std::string op = cur().text;
int line = cur().line;
next();
ExprP rhs = binary(prec(op));
if (!rhs) return nullptr;
auto e = std::make_unique<Expr>();
e->kind = Expr::Binary; e->name = op; e->line = line;
e->args.push_back(std::move(lhs));
e->args.push_back(std::move(rhs));
lhs = std::move(e);
}
return lhs;
}
ExprP unary() {
int line = cur().line;
if (accept("-") || accept("!")) {
auto e = std::make_unique<Expr>();
e->kind = Expr::Unary; e->name = t_[pos_ - 1].text; e->line = line;
ExprP x = unary();
if (!x) return nullptr;
e->args.push_back(std::move(x));
return e;
}
// Cast: "(" type ")" unary
if (peek("(") && (t_[pos_ + 1].text == "int" || t_[pos_ + 1].text == "float")) {
next();
Type t;
if (!type(t) || !expect(")")) return nullptr;
auto e = std::make_unique<Expr>();
e->kind = Expr::Cast; e->cast_to = t; e->line = line;
ExprP x = unary();
if (!x) return nullptr;
e->args.push_back(std::move(x));
return e;
}
return postfix();
}
ExprP postfix() {
ExprP e = primary();
if (!e) return nullptr;
while (true) {
int line = cur().line;
if (accept("[")) {
auto ix = std::make_unique<Expr>();
ix->kind = Expr::Index; ix->line = line;
ix->args.push_back(std::move(e));
ExprP idx = expr();
if (!idx || !expect("]")) return nullptr;
ix->args.push_back(std::move(idx));
e = std::move(ix);
} else if (accept(".")) {
// Only builtin member access (threadIdx.x etc.) exists in this language.
std::string field;
if (!ident(field)) return nullptr;
if (e->kind != Expr::Var) { fail("member access is only valid on builtins"); return nullptr; }
e->name += "." + field;
} else {
return e;
}
}
}
ExprP primary() {
auto e = std::make_unique<Expr>();
e->line = cur().line;
if (cur().kind == Token::Int) { e->kind = Expr::IntLit; e->ival = int32_t(std::strtol(cur().text.c_str(), nullptr, 0)); next(); return e; }
if (cur().kind == Token::Float) { e->kind = Expr::FloatLit; e->fval = std::strtof(cur().text.c_str(), nullptr); next(); return e; }
if (cur().kind == Token::Ident) {
e->name = cur().text;
next();
if (accept("(")) {
e->kind = Expr::Call;
if (!peek(")")) {
do { ExprP a = expr(); if (!a) return nullptr; e->args.push_back(std::move(a)); } while (accept(","));
}
if (!expect(")")) return nullptr;
return e;
}
e->kind = Expr::Var;
return e;
}
if (accept("(")) {
ExprP inner = expr();
if (!inner || !expect(")")) return nullptr;
return inner;
}
fail("expected an expression but found '" + cur().text + "'");
return nullptr;
}
std::vector<Token> t_;
size_t pos_ = 0;
};
} // namespace
bool parse(const std::string& source, KernelAST& out, std::string& error) {
std::vector<Token> tokens;
if (!lex(source, tokens, error)) return false;
Parser p(std::move(tokens));
if (!p.kernel(out)) { error = p.err; return false; }
return true;
}
} // namespace unify::kernel
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