Make funcfiftlib compilation compatible with modern compilers (#618)

* wip: make funcfiftlib compilation compatible with modern compilers

* wip: add methods needed for another compiler

* fix: tdutils port config if emscripten

* feat: func source and realpath callback

* fix: invalid fift compilation exceptions

---------

Co-authored-by: krigga <krigga7@gmail.com>

crypto/func/func-main.cpp

@@ -123,5 +123,7 @@ int main(int argc, char* const argv[]) {
     sources.push_back(std::string(argv[optind++]));
   }
 
+  funC::read_callback = funC::fs_read_callback;
+
   return funC::func_proceed(sources, *outs, std::cerr);
 }

crypto/func/func.cpp

@@ -30,6 +30,8 @@
 #include "parser/lexer.h"
 #include <getopt.h>
 #include "git.h"
+#include <fstream>
+#include "td/utils/port/path.h"
 
 namespace funC {
 
@@ -39,6 +41,28 @@ bool interactive = false;
 GlobalPragma pragma_allow_post_modification{"allow-post-modification"};
 GlobalPragma pragma_compute_asm_ltr{"compute-asm-ltr"};
 std::string generated_from, boc_output_filename;
+ReadCallback::Callback read_callback;
+
+td::Result<std::string> fs_read_callback(ReadCallback::Kind kind, const char* query) {
+  switch (kind) {
+    case ReadCallback::Kind::ReadFile: {
+      std::ifstream ifs{query};
+      if (ifs.fail()) {
+        auto msg = std::string{"cannot open source file `"} + query + "`";
+        return td::Status::Error(msg);
+      }
+      std::stringstream ss;
+      ss << ifs.rdbuf();
+      return ss.str();
+    }
+    case ReadCallback::Kind::Realpath: {
+      return td::realpath(td::CSlice(query));
+    }
+    default: {
+      return td::Status::Error("Unknown query kind");
+    }
+  }
+}
 
 /*
  *

crypto/func/func.h

@@ -30,6 +30,7 @@
 #include "parser/srcread.h"
 #include "parser/lexer.h"
 #include "parser/symtable.h"
+#include "td/utils/Status.h"
 
 namespace funC {
 
@@ -845,6 +846,35 @@ extern std::vector<SymDef*> glob_func, glob_vars;
  * 
  */
 
+class ReadCallback {
+public:
+  /// Noncopyable.
+  ReadCallback(ReadCallback const&) = delete;
+  ReadCallback& operator=(ReadCallback const&) = delete;
+
+  enum class Kind
+  {
+    ReadFile,
+    Realpath
+  };
+
+  static std::string kindString(Kind _kind)
+  {
+    switch (_kind)
+    {
+    case Kind::ReadFile:
+      return "source";
+    case Kind::Realpath:
+      return "realpath";
+    default:
+      throw ""; // todo ?
+    }
+  }
+
+  /// File reading or generic query callback.
+  using Callback = std::function<td::Result<std::string>(ReadCallback::Kind, const char*)>;
+};
+
 // defined in parse-func.cpp
 bool parse_source(std::istream* is, const src::FileDescr* fdescr);
 bool parse_source_file(const char* filename, src::Lexem lex = {}, bool is_main = false);
@@ -1691,6 +1721,9 @@ void define_builtins();
 extern int verbosity, indent, opt_level;
 extern bool stack_layout_comments, op_rewrite_comments, program_envelope, asm_preamble, interactive;
 extern std::string generated_from, boc_output_filename;
+extern ReadCallback::Callback read_callback;
+
+td::Result<std::string> fs_read_callback(ReadCallback::Kind kind, const char* query);
 
 class GlobalPragma {
  public:

crypto/func/parse-func.cpp

@@ -22,8 +22,6 @@
 #include "openssl/digest.hpp"
 #include "block/block.h"
 #include "block-parse.h"
-#include <fstream>
-#include "td/utils/port/path.h"
 
 namespace sym {
 
@@ -1757,7 +1755,7 @@ bool parse_source_file(const char* filename, src::Lexem lex, bool is_main) {
     }
   }
 
-  auto path_res = td::realpath(td::CSlice(filename));
+  auto path_res = read_callback(ReadCallback::Kind::Realpath, filename);
   if (path_res.is_error()) {
     auto error = path_res.move_as_error();
     lex.error(error.message().c_str());
@@ -1784,17 +1782,19 @@ bool parse_source_file(const char* filename, src::Lexem lex, bool is_main) {
   source_files[real_filename] = cur_source;
   cur_source->is_main = is_main;
   source_fdescr.push_back(cur_source);
-  std::ifstream ifs{filename};
-  if (ifs.fail()) {
-    auto msg = std::string{"cannot open source file `"} + filename + "`";
+  auto file_res = read_callback(ReadCallback::Kind::ReadFile, filename);
+  if (file_res.is_error()) {
+    auto msg = file_res.move_as_error().message().str();
     if (lex.tp) {
       lex.error(msg);
     } else {
       throw src::Fatal{msg};
     }
   }
+  auto file_str = file_res.move_as_ok();
+  std::stringstream ss{file_str};
   inclusion_locations.push(lex.loc);
-  bool res = parse_source(&ifs, cur_source);
+  bool res = parse_source(&ss, cur_source);
   inclusion_locations.pop();
   return res;
 }