From 308ec615b90cc260d03aac42537cc17a5f0a975a Mon Sep 17 00:00:00 2001
From: Danila Fedorin <danila.fedorin@gmail.com>
Date: Wed, 9 Sep 2020 13:00:06 -0700
Subject: [PATCH] Start using driver, and switch to file IO.

---
 code/compiler/13/main.cpp         | 19 ++++++++------
 code/compiler/13/parse_driver.hpp | 43 +++++++++++++++++++++++++++++++
 code/compiler/13/parser.y         | 18 ++++++++-----
 code/compiler/13/scanner.l        | 17 ++++++++++--
 4 files changed, 80 insertions(+), 17 deletions(-)
 create mode 100644 code/compiler/13/parse_driver.hpp

diff --git a/code/compiler/13/main.cpp b/code/compiler/13/main.cpp
index 5ab7ed3..238caea 100644
--- a/code/compiler/13/main.cpp
+++ b/code/compiler/13/main.cpp
@@ -8,6 +8,7 @@
 #include "parser.hpp"
 #include "error.hpp"
 #include "type.hpp"
+#include "parse_driver.hpp"
 #include "llvm/IR/LegacyPassManager.h"
 #include "llvm/IR/Verifier.h"
 #include "llvm/Support/TargetSelect.h"
@@ -21,8 +22,6 @@ void yy::parser::error(const yy::location& loc, const std::string& msg) {
     std::cout << "An error occured: " << msg << std::endl;
 }
 
-extern definition_group global_defs;
-
 void typecheck_program(
         definition_group& defs,
         type_mgr& mgr, type_env_ptr& env) {
@@ -131,13 +130,17 @@ void gen_llvm(global_scope& scope) {
     output_llvm(ctx, "program.o");
 }
 
-int main() {
-    yy::parser parser;
+int main(int argc, char** argv) {
+    if(argc != 2) {
+        std::cout << "please enter a file to compile." << std::endl;
+    }
+    parse_driver driver(argv[1]);
+    driver.run_parse();
+
     type_mgr mgr;
     type_env_ptr env(new type_env);
 
-    parser.parse();
-    for(auto& def_defn : global_defs.defs_defn) {
+    for(auto& def_defn : driver.global_defs.defs_defn) {
         std::cout << def_defn.second->name;
         for(auto& param : def_defn.second->params) std::cout << " " << param;
         std::cout << ":" << std::endl;
@@ -145,8 +148,8 @@ int main() {
         def_defn.second->body->print(1, std::cout);
     }
     try {
-        typecheck_program(global_defs, mgr, env);
-        global_scope scope = translate_program(global_defs);
+        typecheck_program(driver.global_defs, mgr, env);
+        global_scope scope = translate_program(driver.global_defs);
         scope.compile();
         gen_llvm(scope);
     } catch(unification_error& err) {
diff --git a/code/compiler/13/parse_driver.hpp b/code/compiler/13/parse_driver.hpp
new file mode 100644
index 0000000..a00c586
--- /dev/null
+++ b/code/compiler/13/parse_driver.hpp
@@ -0,0 +1,43 @@
+#pragma once
+#include <string>
+#include <fstream>
+#include "definition.hpp"
+#include "location.hh"
+#include "parser.hpp"
+
+struct parse_driver;
+
+void scanner_init(parse_driver* d, yyscan_t* scanner);
+void scanner_destroy(yyscan_t* scanner);
+
+struct parse_driver {
+    std::string file_name;
+    std::ifstream file_stream;
+
+    yy::location location;
+    size_t file_offset;
+
+    std::vector<size_t> line_offsets;
+    definition_group global_defs;
+
+    parse_driver(const std::string& file)
+        : file_name(file) {}
+
+    void run_parse() {
+        file_stream.open(file_name);
+        if(!file_stream.good()) throw 0;
+        yyscan_t scanner;
+        scanner_init(this, &scanner);
+        yy::parser parser(scanner, *this);
+        parser();
+        scanner_destroy(&scanner);
+    }
+
+    int get() {
+        return file_stream.get();
+    }
+};
+
+#define YY_DECL yy::parser::symbol_type yylex(yyscan_t yyscanner, parse_driver& drv)
+
+YY_DECL;
diff --git a/code/compiler/13/parser.y b/code/compiler/13/parser.y
index c4edbb3..3fefb28 100644
--- a/code/compiler/13/parser.y
+++ b/code/compiler/13/parser.y
@@ -1,17 +1,21 @@
-%{
+%code requires {
 #include <string>
-#include <iostream>
-#include <map>
+#include <vector>
 #include "ast.hpp"
 #include "definition.hpp"
 #include "parser.hpp"
 #include "parsed_type.hpp"
 
-definition_group global_defs;
+class parse_driver;
+using yyscan_t = void*;
+}
 
-extern yy::parser::symbol_type yylex();
+%param { yyscan_t scanner }
+%param { parse_driver& drv }
 
-%}
+%code {
+#include "parse_driver.hpp"
+}
 
 %token BACKSLASH
 %token PLUS
@@ -59,7 +63,7 @@ extern yy::parser::symbol_type yylex();
 %%
 
 program
-    : definitions { global_defs = std::move($1); global_defs.vis = visibility::global; }
+    : definitions { $1.vis = visibility::global; std::swap(drv.global_defs, $1); }
     ;
 
 definitions
diff --git a/code/compiler/13/scanner.l b/code/compiler/13/scanner.l
index c571910..e409014 100644
--- a/code/compiler/13/scanner.l
+++ b/code/compiler/13/scanner.l
@@ -1,16 +1,22 @@
 %option noyywrap
+%option reentrant
 
 %{
 #include <iostream>
 #include "ast.hpp"
 #include "definition.hpp"
+#include "parse_driver.hpp"
 #include "parser.hpp"
 
 yy::parser::location_type location;
 
-#define YY_DECL yy::parser::symbol_type yylex()
+#define YY_EXTRA_TYPE parse_driver*
 #define YY_USER_ACTION location.step(); location.columns(yyleng); 
-
+#define YY_INPUT(buf,result,max_size) \
+    { \
+    int c = yyextra->get(); \
+    result = (c == EOF) ? YY_NULL : (buf[0] = c, 1); \
+    }
 %}
 
 %%
@@ -41,3 +47,10 @@ in { return yy::parser::make_IN(location); }
 <<EOF>> { return yy::parser::make_YYEOF(location); }
 
 %%
+
+void scanner_init(parse_driver* d, yyscan_t* scanner) {
+    yylex_init_extra(d, scanner);
+}
+void scanner_destroy(yyscan_t* scanner) {
+    yylex_destroy(*scanner);
+}