Go patch committed: add escape analysis notes to export data

[Ian Lance Taylor <iant@golang.org>]

[-- Attachment #1: Type: text/plain, Size: 285 bytes --]

This patch by Chris Manghane changes the Go frontend to add escape
analysis notes to the export data, and to read them in when importing
a package.  Escape analysis is still not enabled by default.
Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
to mainline.

Ian

[-- Attachment #2: patch.txt --]
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Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE	(revision 238057)
+++ gcc/go/gofrontend/MERGE	(working copy)
@@ -1,4 +1,4 @@
-c8fdad389ce6f439a02fb654d231053b47ff4e02
+5ea5c078829ae83bccb598772fff7c1a04e23e65
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: gcc/go/gofrontend/export.cc
===================================================================
--- gcc/go/gofrontend/export.cc	(revision 236804)
+++ gcc/go/gofrontend/export.cc	(working copy)
@@ -436,6 +436,21 @@ Export::write_type(const Type* type)
     this->type_refs_[type] = index;
 }
 
+// Export escape note.
+
+void
+Export::write_escape(std::string* note)
+{
+  if (note != NULL && *note != "esc:0x0")
+    {
+      this->write_c_string(" ");
+      char buf[50];
+      go_assert(note->find("esc:") != std::string::npos);
+      snprintf(buf, sizeof buf, "<%s>", note->c_str());
+      this->write_c_string(buf);
+    }
+}
+
 // Add the builtin types to the export table.
 
 void
Index: gcc/go/gofrontend/export.h
===================================================================
--- gcc/go/gofrontend/export.h	(revision 236804)
+++ gcc/go/gofrontend/export.h	(working copy)
@@ -161,6 +161,11 @@ class Export : public String_dump
   void
   write_type(const Type*);
 
+  // Write the escape note to the export stream.  If NOTE is NULL, write
+  // nothing.
+  void
+  write_escape(std::string* note);
+
  private:
   Export(const Export&);
   Export& operator=(const Export&);
Index: gcc/go/gofrontend/gogo.cc
===================================================================
--- gcc/go/gofrontend/gogo.cc	(revision 236804)
+++ gcc/go/gofrontend/gogo.cc	(working copy)
@@ -4794,6 +4794,7 @@ Function::export_func_with_type(Export*
       exp->write_c_string("(");
       const Typed_identifier* receiver = fntype->receiver();
       exp->write_name(receiver->name());
+      exp->write_escape(receiver->note());
       exp->write_c_string(" ");
       exp->write_type(receiver->type());
       exp->write_c_string(") ");
@@ -4817,6 +4818,7 @@ Function::export_func_with_type(Export*
 	  else
 	    exp->write_c_string(", ");
 	  exp->write_name(p->name());
+	  exp->write_escape(p->note());
 	  exp->write_c_string(" ");
 	  if (!is_varargs || p + 1 != parameters->end())
 	    exp->write_type(p->type());
@@ -4850,6 +4852,7 @@ Function::export_func_with_type(Export*
 	      else
 		exp->write_c_string(", ");
 	      exp->write_name(p->name());
+	      exp->write_escape(p->note());
 	      exp->write_c_string(" ");
 	      exp->write_type(p->type());
 	    }
@@ -4875,9 +4878,11 @@ Function::import_func(Import* imp, std::
     {
       imp->require_c_string("(");
       std::string name = imp->read_name();
+      std::string escape_note = imp->read_escape();
       imp->require_c_string(" ");
       Type* rtype = imp->read_type();
       *preceiver = new Typed_identifier(name, rtype, imp->location());
+      (*preceiver)->set_note(escape_note);
       imp->require_c_string(") ");
     }
 
@@ -4894,6 +4899,7 @@ Function::import_func(Import* imp, std::
       while (true)
 	{
 	  std::string name = imp->read_name();
+	  std::string escape_note = imp->read_escape();
 	  imp->require_c_string(" ");
 
 	  if (imp->match_c_string("..."))
@@ -4905,8 +4911,9 @@ Function::import_func(Import* imp, std::
 	  Type* ptype = imp->read_type();
 	  if (*is_varargs)
 	    ptype = Type::make_array_type(ptype, NULL);
-	  parameters->push_back(Typed_identifier(name, ptype,
-						 imp->location()));
+	  Typed_identifier t = Typed_identifier(name, ptype, imp->location());
+	  t.set_note(escape_note);
+	  parameters->push_back(t);
 	  if (imp->peek_char() != ',')
 	    break;
 	  go_assert(!*is_varargs);
@@ -4934,10 +4941,13 @@ Function::import_func(Import* imp, std::
 	  while (true)
 	    {
 	      std::string name = imp->read_name();
+	      std::string note = imp->read_escape();
 	      imp->require_c_string(" ");
 	      Type* rtype = imp->read_type();
-	      results->push_back(Typed_identifier(name, rtype,
-						  imp->location()));
+	      Typed_identifier t = Typed_identifier(name, rtype,
+						    imp->location());
+	      t.set_note(note);
+	      results->push_back(t);
 	      if (imp->peek_char() != ',')
 		break;
 	      imp->require_c_string(", ");
Index: gcc/go/gofrontend/import.cc
===================================================================
--- gcc/go/gofrontend/import.cc	(revision 236804)
+++ gcc/go/gofrontend/import.cc	(working copy)
@@ -762,6 +762,42 @@ Import::read_type()
   return type;
 }
 
+// Read an escape note.
+
+std::string
+Import::read_escape()
+{
+  if (this->match_c_string(" <esc:"))
+    {
+      Stream* stream = this->stream_;
+      this->require_c_string(" <esc:");
+
+      std::string escape = "esc:";
+      int c;
+      while (true)
+	{
+	  c = stream->get_char();
+	  if (c != 'x' && !ISXDIGIT(c))
+	    break;
+	  escape += c;
+	}
+
+      if (c != '>')
+	{
+	  error_at(this->location(),
+		   "error in import data at %d: expect %< %> or %<>%>, got %c",
+		   stream->pos(), c);
+	  stream->set_saw_error();
+	  stream->advance(1);
+	  escape = Escape_note::make_tag(Node::ESCAPE_UNKNOWN);
+	}
+      return escape;
+    }
+  else
+    return Escape_note::make_tag(Node::ESCAPE_UNKNOWN);
+}
+
+
 // Register the builtin types.
 
 void
Index: gcc/go/gofrontend/import.h
===================================================================
--- gcc/go/gofrontend/import.h	(revision 236804)
+++ gcc/go/gofrontend/import.h	(working copy)
@@ -197,6 +197,10 @@ class Import
   Type*
   read_type();
 
+  // Read an escape note.
+  std::string
+  read_escape();
+
  private:
   static Stream*
   try_package_in_directory(const std::string&, Location);