Adds support for reading DATA from a file.

Currently only supported in the cross-compiler, as the Atari compiler
don't have the necessary logic to open new files from the parser.

This closes #30.

Author: dmsc

Makefile

@@ -280,6 +280,7 @@ COMPILER_SRC=\
 	atarifp.cc\
 	basic.cc\
 	codestat.cc\
+	ifile.cc\
 	looptype.cc\
 	main.cc\
 	parser.cc\

manual.md

@@ -1520,6 +1520,7 @@ General Statements
   Note that the array can be modified
   afterwards like a normal array.
 
+
   *Advanced Usage*
 
   Byte DATA arrays can be used to
@@ -1544,6 +1545,27 @@ General Statements
       DATA ad() B. = $AD,str,$A2,0,$60
       ? USR(ADR(ad)), str(0)
 
+
+  *Loading data from a file*
+
+  The cross-compiler also supports
+  loading data from a file directly into
+  the program, using the `BYTEFILE`
+  (abbreviated `BYTEF.`) and `WORDFILE`
+  (abbreviated `WORDF.` or simply `F.`)
+  types and a file name enclosed in
+  double quotes.
+
+  Example:
+
+      DATA img() bytefile "img.raw"
+      DATA pos() wordfile "pos.bin"
+
+  The compiler will search the file in
+  the same folder than the current
+  basic source.
+
+
 **Decrements variable by 1**  
 **DEC _var_ / DE.**
 

src/basic.syn

@@ -93,6 +93,10 @@ EXTERN {
  E_LABEL, E_LABEL_DEF
  E_PUSH_VAR, E_POP_VAR
 
+#@if EXTENDED
+ E_DATA_FILE
+#@endif
+
 #@if FASTBASIC_FP
  E_NUMBER_FP
 #@endif FASTBASIC_FP
@@ -568,6 +572,10 @@ DATA_BYTES: data byte
 DATA_TYPE: data type
         TYPE_BYTE EQUAL E_LABEL_SET_TYPE DATA_BYTES
         TYPE_WORD EQUAL E_LABEL_SET_TYPE E_NUMBER_WORD DATA_WORDS
+#@if EXTENDED
+        TYPE_BYTE "File" E_LABEL_SET_TYPE "\"" E_DATA_FILE
+        TYPE_WORD "File" E_LABEL_SET_TYPE "\"" E_DATA_FILE
+#@endif
 
 DATA_END:
         ","

src/compiler/ifile.cc

@@ -0,0 +1,60 @@
+/*
+ * FastBasic - Fast basic interpreter for the Atari 8-bit computers
+ * Copyright (C) 2017-2020 Daniel Serpell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+// ifile.cc: Opens included file
+
+#include "ifile.h"
+#include <fstream>
+
+static std::string get_path(std::string fname)
+{
+    // Get's path to file. This understands either '/' or '\' as path
+    // separators, to be compatible between Unix and Windows.
+    auto p = fname.find_last_of("/\\");
+    if( p != fname.npos )
+        return fname.substr(0, p);
+    else
+        return std::string();
+}
+
+
+std::unique_ptr<std::istream> open_include_file(std::string current_file, std::string fname)
+{
+    auto f = std::make_unique<std::ifstream>();
+
+    // Get path of current file
+    std::string path = get_path(current_file);
+
+    if( !path.empty() )
+        path = path + "/" + fname;
+    else
+        path = fname;
+
+    // Tries to open
+    f->open(path, std::ios::binary);
+    if( f->is_open() )
+        return f;
+
+    // Try again without path
+    f->open(fname, std::ios::binary);
+    if( f->is_open() )
+        return f;
+
+    f.reset();
+    return f;
+}

src/compiler/ifile.h

@@ -0,0 +1,27 @@
+/*
+ * FastBasic - Fast basic interpreter for the Atari 8-bit computers
+ * Copyright (C) 2017-2019 Daniel Serpell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+// ifile.h: Opens included file
+
+#pragma once
+
+#include <istream>
+#include <memory>
+
+// Opens "fname" searching first in the same path as the current file
+std::unique_ptr<std::istream> open_include_file(std::string current_file, std::string fname);

src/compiler/main.cc

@@ -164,6 +164,7 @@ int main(int argc, char **argv)
         return show_error("missing output file name");
 
     parse s;
+    s.set_input_file(iname);
     int ln = 1;
     while(1)
     {

src/compiler/parser.cc

@@ -19,6 +19,7 @@
 // parser.cc: C++ parser
 
 #include "parser.h"
+#include "ifile.h"
 #include "vartype.h"
 
 #include <algorithm>
@@ -125,15 +126,12 @@ bool SMB_E_NUMBER_BYTE(parse &s)
     return true;
 }
 
-bool SMB_E_CONST_STRING(parse &s)
+static bool get_const_string(parse &s, std::string &str)
 {
-    s.debug("E_CONST_STRING");
-    std::string str;
     while( !s.eos() )
     {
         if( s.expect('"') && !s.peek('"') )
         {
-            s.emit_str(str);
             return true;
         }
         char c = s.str[s.pos];
@@ -143,6 +141,15 @@ bool SMB_E_CONST_STRING(parse &s)
     return false;
 }
 
+bool SMB_E_CONST_STRING(parse &s)
+{
+    s.debug("E_CONST_STRING");
+    std::string str;
+    if( get_const_string(s, str) )
+        return s.emit_str(str);
+    return false;
+}
+
 bool SMB_E_REM(parse &s)
 {
     s.debug("E_REM");
@@ -508,3 +515,31 @@ bool SMB_E_LABEL_SET_TYPE(parse &s)
     return true;
 }
 
+// Reads a DATA array from a file
+bool SMB_E_DATA_FILE(parse &s)
+{
+    s.debug("E_DATA_FILE");
+    s.skipws();
+    // Get file name until the '"'
+    std::string fname;
+    if( !get_const_string(s, fname) )
+        return false;
+
+    auto f = open_include_file(s.in_fname, fname);
+    if( !f )
+    {
+        std::cerr << s.in_fname << ":" << s.linenum << ":" << s.pos
+                  << ": can't open data file '" << fname << "'";
+        return false;
+    }
+
+    // Read the file to a buffer of max 64k
+    for(unsigned i=0; i<65536; i++)
+    {
+        int c = f->get();
+        if( c < 0 || c > 255 )
+            break;
+        s.emit_byte( c );
+    }
+    return true;
+}

src/compiler/parser.h

@@ -45,6 +45,7 @@ class parse {
                 std::string label;
                 int linenum;
         };
+        std::string in_fname;
         int sto_var;
         int lvl, maxlvl;
         std::string str;
@@ -126,6 +127,11 @@ class parse {
             return "EXIT without loop";
         }
 
+        void set_input_file(std::string fn)
+        {
+            in_fname = fn;
+        }
+
         void new_line(std::string l, int ln)
         {
             pos = max_pos = 0;