compiler: drop semicolons in export data

    
    The export data, which is approximately readable and looks something
    like Go, was first implemented back when Go still used semicolons.
    Drop the semicolons, to make it look slightly more Go like and make it
    slightly smaller.
    
    This updates the compiler and the gccgoimporter package.
    
    This introduces a new version of the export data.  There are going to
    be more changes to the export data, so this version is still subject
    to change.
    
    Reviewed-on: https://go-review.googlesource.com/c/143018

From-SVN: r265284

7 files changed, 72 insertions, 34 deletions

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 76689a3..fa708bc 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-e32e9aaee598eeb43f9616cf6ca1d11acaa9d167
+0494dc5737f0c89ad6f45e04e8313e4161678861
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/export.cc b/gcc/go/gofrontend/export.cc
index 27b7680..db57ab5 100644
--- a/gcc/go/gofrontend/export.cc
+++ b/gcc/go/gofrontend/export.cc
@@ -26,14 +26,18 @@ const int Export::magic_len;
 // Current version magic string.
 const char Export::cur_magic[Export::magic_len] =
   {
-    'v', '2', ';', '\n'
+    'v', '3', ';', '\n'
   };
 
-// Magic string for previous version (still supported)
+// Magic strings for previous versions (still supported).
 const char Export::v1_magic[Export::magic_len] =
   {
     'v', '1', ';', '\n'
   };
+const char Export::v2_magic[Export::magic_len] =
+  {
+    'v', '2', ';', '\n'
+  };
 
 const int Export::checksum_len;
 
@@ -147,7 +151,7 @@ Export::export_globals(const std::string& package_name,
   // The package name.
   this->write_c_string("package ");
   this->write_string(package_name);
-  this->write_c_string(";\n");
+  this->write_c_string("\n");
 
   // The prefix or package path, used for all global symbols.
   if (prefix.empty())
@@ -161,7 +165,7 @@ Export::export_globals(const std::string& package_name,
       this->write_c_string("prefix ");
       this->write_string(prefix);
     }
-  this->write_c_string(";\n");
+  this->write_c_string("\n");
 
   this->write_packages(packages);
 
@@ -191,7 +195,7 @@ Export::export_globals(const std::string& package_name,
       dig = c & 0xf;
       s += dig < 10 ? '0' + dig : 'A' + dig - 10;
     }
-  s += ";\n";
+  s += "\n";
   this->stream_->write_checksum(s);
 }
 
@@ -233,7 +237,7 @@ Export::write_packages(const std::map<std::string, Package*>& packages)
       this->write_string((*p)->pkgpath());
       this->write_c_string(" ");
       this->write_string((*p)->pkgpath_symbol());
-      this->write_c_string(";\n");
+      this->write_c_string("\n");
     }
 }
 
@@ -271,7 +275,7 @@ Export::write_imports(const std::map<std::string, Package*>& imports)
       this->write_string(p->second->pkgpath());
       this->write_c_string(" \"");
       this->write_string(p->first);
-      this->write_c_string("\";\n");
+      this->write_c_string("\"\n");
 
       this->packages_.insert(p->second);
     }
@@ -347,7 +351,7 @@ Export::write_imported_init_fns(const std::string& package_name,
 
   if (imported_init_fns.empty())
     {
-      this->write_c_string(";\n");
+      this->write_c_string("\n");
       return;
     }
 
@@ -394,7 +398,7 @@ Export::write_imported_init_fns(const std::string& package_name,
 	    it->second.push_back(ii->init_name());
 	}
     }
-  this->write_c_string(";\n");
+  this->write_c_string("\n");
 
   // Create the init graph. Start by populating the graph with
   // all the edges we inherited from imported packages.
@@ -494,7 +498,7 @@ Export::write_imported_init_fns(const std::string& package_name,
 	  this->write_unsigned(sink);
 	}
     }
-  this->write_c_string(";\n");
+  this->write_c_string("\n");
 }
 
 // Write a name to the export stream.
diff --git a/gcc/go/gofrontend/export.h b/gcc/go/gofrontend/export.h
index 1365677..b08bf85 100644
--- a/gcc/go/gofrontend/export.h
+++ b/gcc/go/gofrontend/export.h
@@ -57,7 +57,8 @@ enum Export_data_version {
   EXPORT_FORMAT_UNKNOWN = 0,
   EXPORT_FORMAT_V1 = 1,
   EXPORT_FORMAT_V2 = 2,
-  EXPORT_FORMAT_CURRENT = EXPORT_FORMAT_V2
+  EXPORT_FORMAT_V3 = 3,
+  EXPORT_FORMAT_CURRENT = EXPORT_FORMAT_V3
 };
 
 // This class manages exporting Go declarations.  It handles the main
@@ -119,9 +120,10 @@ class Export : public String_dump
   // Size of export data magic string (which includes version number).
   static const int magic_len = 4;
 
-  // Magic strings (current version and older v1 version).
+  // Magic strings (current version and older versions).
   static const char cur_magic[magic_len];
   static const char v1_magic[magic_len];
+  static const char v2_magic[magic_len];
 
   // The length of the checksum string.
   static const int checksum_len = 20;
diff --git a/gcc/go/gofrontend/gogo.cc b/gcc/go/gofrontend/gogo.cc
index dd6733f..d07068d 100644
--- a/gcc/go/gofrontend/gogo.cc
+++ b/gcc/go/gofrontend/gogo.cc
@@ -5391,7 +5391,7 @@ Function::export_func_with_type(Export* exp, const std::string& name,
 	  exp->write_c_string(")");
 	}
     }
-  exp->write_c_string(";\n");
+  exp->write_c_string("\n");
 }
 
 // Import a function.
@@ -5498,7 +5498,8 @@ Function::import_func(Import* imp, std::string* pname,
 	  imp->require_c_string(")");
 	}
     }
-  imp->require_c_string(";\n");
+  imp->require_semicolon_if_old_version();
+  imp->require_c_string("\n");
   *presults = results;
 }
 
@@ -6885,7 +6886,7 @@ Variable::export_var(Export* exp, const std::string& name) const
   exp->write_string(name);
   exp->write_c_string(" ");
   exp->write_type(this->type());
-  exp->write_c_string(";\n");
+  exp->write_c_string("\n");
 }
 
 // Import a variable.
@@ -6897,7 +6898,8 @@ Variable::import_var(Import* imp, std::string* pname, Type** ptype)
   *pname = imp->read_identifier();
   imp->require_c_string(" ");
   *ptype = imp->read_type();
-  imp->require_c_string(";\n");
+  imp->require_semicolon_if_old_version();
+  imp->require_c_string("\n");
 }
 
 // Convert a variable to the backend representation.
@@ -7089,7 +7091,7 @@ Named_constant::export_const(Export* exp, const std::string& name) const
     }
   exp->write_c_string("= ");
   this->expr()->export_expression(exp);
-  exp->write_c_string(";\n");
+  exp->write_c_string("\n");
 }
 
 // Import a constant.
@@ -7110,7 +7112,8 @@ Named_constant::import_const(Import* imp, std::string* pname, Type** ptype,
     }
   imp->require_c_string("= ");
   *pexpr = Expression::import_expression(imp);
-  imp->require_c_string(";\n");
+  imp->require_semicolon_if_old_version();
+  imp->require_c_string("\n");
 }
 
 // Get the backend representation.
diff --git a/gcc/go/gofrontend/import.cc b/gcc/go/gofrontend/import.cc
index f9586ac..ad30e6e 100644
--- a/gcc/go/gofrontend/import.cc
+++ b/gcc/go/gofrontend/import.cc
@@ -241,8 +241,9 @@ Import::find_export_data(const std::string& filename, int fd, Location location)
     return NULL;
 
   // Check for a file containing nothing but Go export data.
-  if (memcmp(buf, Export::cur_magic, Export::magic_len) == 0 ||
-      memcmp(buf, Export::v1_magic, Export::magic_len) == 0)
+  if (memcmp(buf, Export::cur_magic, Export::magic_len) == 0
+      || memcmp(buf, Export::v1_magic, Export::magic_len) == 0
+      || memcmp(buf, Export::v2_magic, Export::magic_len) == 0)
     return new Stream_from_file(fd);
 
   // See if we can read this as an archive.
@@ -325,6 +326,12 @@ Import::import(Gogo* gogo, const std::string& local_name,
 	                        Export::magic_len);
 	  this->version_ = EXPORT_FORMAT_V1;
 	}
+      else if (stream->match_bytes(Export::v2_magic, Export::magic_len))
+	{
+	  stream->require_bytes(this->location_, Export::v2_magic,
+	                        Export::magic_len);
+	  this->version_ = EXPORT_FORMAT_V2;
+	}
       else
 	{
 	  go_error_at(this->location_,
@@ -335,7 +342,8 @@ Import::import(Gogo* gogo, const std::string& local_name,
 
       this->require_c_string("package ");
       std::string package_name = this->read_identifier();
-      this->require_c_string(";\n");
+      this->require_semicolon_if_old_version();
+      this->require_c_string("\n");
 
       std::string pkgpath;
       std::string pkgpath_symbol;
@@ -343,7 +351,8 @@ Import::import(Gogo* gogo, const std::string& local_name,
 	{
 	  this->advance(7);
 	  std::string unique_prefix = this->read_identifier();
-	  this->require_c_string(";\n");
+	  this->require_semicolon_if_old_version();
+	  this->require_c_string("\n");
 	  pkgpath = unique_prefix + '.' + package_name;
 	  pkgpath_symbol = (Gogo::pkgpath_for_symbol(unique_prefix) + '.'
 			    + Gogo::pkgpath_for_symbol(package_name));
@@ -352,10 +361,14 @@ Import::import(Gogo* gogo, const std::string& local_name,
 	{
 	  this->require_c_string("pkgpath ");
 	  pkgpath = this->read_identifier();
-	  this->require_c_string(";\n");
+	  this->require_semicolon_if_old_version();
+	  this->require_c_string("\n");
 	  pkgpath_symbol = Gogo::pkgpath_for_symbol(pkgpath);
 	}
 
+      if (stream->saw_error())
+	return NULL;
+
       this->package_ = gogo->add_imported_package(package_name, local_name,
 						  is_local_name_exported,
 						  pkgpath, pkgpath_symbol,
@@ -418,7 +431,8 @@ Import::import(Gogo* gogo, const std::string& local_name,
       // load time.
       this->require_c_string("checksum ");
       stream->advance(Export::checksum_len * 2);
-      this->require_c_string(";\n");
+      this->require_semicolon_if_old_version();
+      this->require_c_string("\n");
     }
 
   return this->package_;
@@ -436,7 +450,8 @@ Import::read_one_package()
   std::string pkgpath = this->read_identifier();
   this->require_c_string(" ");
   std::string pkgpath_symbol = this->read_identifier();
-  this->require_c_string(";\n");
+  this->require_semicolon_if_old_version();
+  this->require_c_string("\n");
 
   Package* p = this->gogo_->register_package(pkgpath, pkgpath_symbol,
 					     Linemap::unknown_location());
@@ -456,7 +471,9 @@ Import::read_one_import()
   Stream* stream = this->stream_;
   while (stream->peek_char() != '"')
     stream->advance(1);
-  this->require_c_string("\";\n");
+  this->require_c_string("\"");
+  this->require_semicolon_if_old_version();
+  this->require_c_string("\n");
 
   Package* p = this->gogo_->register_package(pkgpath, "",
 					     Linemap::unknown_location());
@@ -474,7 +491,7 @@ Import::read_import_init_fns(Gogo* gogo)
   // to read the init_graph section.
   std::map<std::string, unsigned> init_idx;
 
-  while (!this->match_c_string(";"))
+  while (!this->match_c_string("\n") && !this->match_c_string(";"))
     {
       int priority = -1;
 
@@ -499,7 +516,8 @@ Import::read_import_init_fns(Gogo* gogo)
       unsigned idx = init_idx.size();
       init_idx[init_name] = idx;
     }
-  this->require_c_string(";\n");
+  this->require_semicolon_if_old_version();
+  this->require_c_string("\n");
 
   if (this->match_c_string("init_graph"))
     {
@@ -524,7 +542,7 @@ Import::read_import_init_fns(Gogo* gogo)
       //
       // where src + sink are init functions indices.
 
-      while (!this->match_c_string(";"))
+      while (!this->match_c_string("\n") && !this->match_c_string(";"))
 	{
 	  this->require_c_string(" ");
 	  std::string src_string = this->read_identifier();
@@ -543,7 +561,8 @@ Import::read_import_init_fns(Gogo* gogo)
 
 	  ii_src->record_precursor_fcn(ii_sink->init_name());
 	}
-      this->require_c_string(";\n");
+      this->require_semicolon_if_old_version();
+      this->require_c_string("\n");
     }
 }
 
@@ -967,7 +986,7 @@ Import::read_identifier()
   while (true)
     {
       c = stream->peek_char();
-      if (c == -1 || c == ' ' || c == ';')
+      if (c == -1 || c == ' ' || c == '\n' || c == ';')
 	break;
       ret += c;
       stream->advance(1);
diff --git a/gcc/go/gofrontend/import.h b/gcc/go/gofrontend/import.h
index aab4b89..84f5fc7 100644
--- a/gcc/go/gofrontend/import.h
+++ b/gcc/go/gofrontend/import.h
@@ -184,6 +184,15 @@ class Import
   advance(size_t skip)
   { this->stream_->advance(skip); }
 
+  // Skip a semicolon if using an older version.
+  void
+  require_semicolon_if_old_version()
+  {
+    if (this->version_ == EXPORT_FORMAT_V1
+	|| this->version_ == EXPORT_FORMAT_V2)
+      this->require_c_string(";");
+  }
+
   // Read an identifier.
   std::string
   read_identifier();
diff --git a/gcc/go/gofrontend/types.cc b/gcc/go/gofrontend/types.cc
index 3768719..573011a 100644
--- a/gcc/go/gofrontend/types.cc
+++ b/gcc/go/gofrontend/types.cc
@@ -10892,7 +10892,7 @@ Named_type::export_named_type(Export* exp, const std::string&) const
   // be written by Export::write_type anyhow.
   exp->write_c_string("type ");
   exp->write_type(this);
-  exp->write_c_string(";\n");
+  exp->write_c_string("\n");
 }
 
 // Import a named type.
@@ -10904,7 +10904,8 @@ Named_type::import_named_type(Import* imp, Named_type** ptype)
   Type *type = imp->read_type();
   *ptype = type->named_type();
   go_assert(*ptype != NULL);
-  imp->require_c_string(";\n");
+  imp->require_semicolon_if_old_version();
+  imp->require_c_string("\n");
 }
 
 // Export the type when it is referenced by another type.  In this