feat(furas): introduce global variables

furas/examples/ops.furas

@@ -1,22 +1,24 @@
 func println $u32 = native println
 
+allocate uwu
+
 public func main = #main
 main:
     push $u32 0
-    store %0
+    storeg %uwu
 loop_header:
-    load %0
+    loadg %uwu
     push $u32 10
     ge
     jnz #loop_end
 loop_body:
-    load %0
+    loadg %uwu
     call $u32 println
 
-    load %0
+    loadg %uwu
     push $u32 1
     add
-    store %0
+    storeg %uwu
 
     jmp #loop_header
 loop_end:

furas/include/furas/token.hpp

@@ -29,6 +29,7 @@ struct token {
         Import,   /**< `import` keyword for importing functions and types. */
         Public,   /**< `public` access specifier. */
         Private,  /**< `private` access specifier. */
+        Allocate, /**< `allocate` keyword for global variables. */
 
         // Instructions
         Push,
@@ -56,6 +57,8 @@ struct token {
         Lenof,
         Load,
         Store,
+        LoadGlobal,
+        StoreGlobal,
         Call,
         Jmp,
         Jnz,

furas/src/gen.cpp

@@ -47,6 +47,8 @@ std::unordered_map<enum token::type, furvm::instruction_t> instructions = {
     { token::Lenof, furvm::instruction_t::Lengthof },
     { token::Load, furvm::instruction_t::Load },
     { token::Store, furvm::instruction_t::Store },
+    { token::LoadGlobal, furvm::instruction_t::LoadGlobal },
+    { token::StoreGlobal, furvm::instruction_t::StoreGlobal },
     { token::Call, furvm::instruction_t::Call },
     { token::Jmp, furvm::instruction_t::Jump },
     { token::Jnz, furvm::instruction_t::JumpNotZero },
@@ -72,6 +74,7 @@ const char* token_type(enum token::type type) {
     case token::Import: return "import";
     case token::Public: return "public";
     case token::Private: return "private";
+    case token::Allocate: return "allocate";
     case token::Push: return "push";
     case token::Array: return "array";
     case token::Get: return "get";
@@ -97,6 +100,8 @@ const char* token_type(enum token::type type) {
     case token::Lenof: return "lenof";
     case token::Load: return "load";
     case token::Store: return "store";
+    case token::LoadGlobal: return "loadg";
+    case token::StoreGlobal: return "storeg";
     case token::Call: return "call";
     case token::Jmp: return "jmp";
     case token::Jnz: return "jnz";
@@ -128,6 +133,7 @@ struct mod_context {
             pair_hash<std::string, furvm::function_sig, std::hash<std::string>, furvm::detail::function_sig_hash>>
                                                        functions;
     std::unordered_map<std::string, furvm::mod_type_h> types;
+    std::unordered_map<std::string, std::uint16_t>     variables;
 
     std::unordered_map<std::string, label_context> labels;
 
@@ -214,6 +220,15 @@ struct mod_context {
             return { generator_error::Success };
         }
 
+        case token::Allocate: {
+            result = eat_token(lexer, token::Identifier);
+            if (!result) return result.error;
+            std::string name = std::string(result->value.string);
+            variables.emplace(name, variables.size());
+            mod.set_global_variable_count(variables.size());
+            return { generator_error::Success };
+        }
+
         case token::Func:
         case token::Type:
         case token::Public:
@@ -465,6 +480,16 @@ struct mod_context {
                 if (!result) return result.error;
                 instr.arg.u16 = result->value.uint;
             } break;
+            case furvm::instruction_argument::GlobalVariable: {
+                result = eat_token(lexer, token::Percent);
+                if (!result) return result.error;
+                result = eat_token(lexer, token::Identifier);
+                if (!result) return result.error;
+                if (auto it = variables.find(std::string(result->value.string)); it != variables.end())
+                    instr.arg.u16 = it->second;
+                else
+                    throw std::runtime_error("Unknown global variable");
+            } break;
             case furvm::instruction_argument::Function: {
                 furvm::function_sig signature;
                 while ((result = next_token(lexer)).error.type == generator_error::Success &&

furas/src/lexer.cpp

@@ -39,6 +39,7 @@ token_r lexer::next_token() {
         { "import", token::Import },
         { "public", token::Public },
         { "private", token::Private },
+        { "allocate", token::Allocate },
 
         { "push", token::Push },
         { "array", token::Array },
@@ -65,6 +66,8 @@ token_r lexer::next_token() {
         { "lenof", token::Lenof },
         { "load", token::Load },
         { "store", token::Store },
+        { "loadg", token::LoadGlobal },
+        { "storeg", token::StoreGlobal },
         { "call", token::Call },
         { "jmp", token::Jmp },
         { "jnz", token::Jnz },