compiler: edit error messages to avoid -Wformat-diag warnings

    
    GCC recently introduced -Wformat-diag to scrutinize GCC error messages.
    It reports a number of warnings about gofrontend code, such as:
    
    ../../trunk/gcc/go/gofrontend/import.cc: In member function ‘Type* Import::type_for_index(int, const string&, size_t, bool*)’:
    ../../trunk/gcc/go/gofrontend/import.cc:1129:48: warning: unquoted operator ‘>=’ in format [-Wformat-diag]
     1129 |         "error in %s at %lu: bad type index %d >= %d",
          |                                                ^~
    
    ../../trunk/gcc/go/gofrontend/ast-dump.cc: In member function ‘void Ast_dump_context::dump(Gogo*, const char*)’:
    ../../trunk/gcc/go/gofrontend/ast-dump.cc:203:25: warning: unquoted option name ‘-fgo-dump-ast’ in format [-Wformat-diag]
      203 |     "cannot open %s:%m, -fgo-dump-ast ignored", dumpname.c_str());
          |                         ^~~~~~~~~~~~~
    
    ../../trunk/gcc/go/gofrontend/expressions.cc: In static member function ‘static Bexpression* Func_expression::get_code_pointer(Gogo*, Named_object*, Location)’:
    ../../trunk/gcc/go/gofrontend/expressions.cc:1350:29: warning: misspelled term ‘builtin function’ in format; use ‘built-in function’ instead [-Wformat-diag]
     1350 |     "invalid use of special builtin function %qs; must be called",
          |                             ^~~~~~~~~~~~~~~~
    
    ../../trunk/gcc/go/gofrontend/gogo.cc: In member function ‘void Gogo::add_linkname(const string&, bool, const string&, Location)’:
    ../../trunk/gcc/go/gofrontend/gogo.cc:2527:4: warning: unquoted sequence of 2 consecutive punctuation characters ‘//’ in format [-Wformat-diag]
     2527 |   ("%s is not a function; "
          |   ~^~~~~~~~~~~~~~~~~~~~~~~~
     2528 |    "//go:linkname is only supported for functions"),
          |    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    This CL edits error messages to avoid these warnings.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/183497

	* go.test/test/blank1.go: Update for diagnostic message changes.

From-SVN: r272608

1 files changed, 11 insertions, 11 deletions

diff --git a/gcc/go/gofrontend/parse.cc b/gcc/go/gofrontend/parse.cc
index e611c70..52371b2 100644
--- a/gcc/go/gofrontend/parse.cc
+++ b/gcc/go/gofrontend/parse.cc
@@ -1359,7 +1359,7 @@ Parse::decl(void (Parse::*pfn)(void*, unsigned int), void* varg,
     {
       if (pragmas != 0)
 	go_warning_at(this->location(), 0,
-		      "ignoring magic //go:... comment before group");
+		      "ignoring magic %<//go:...%> comment before group");
       if (!this->advance_token()->is_op(OPERATOR_RPAREN))
 	{
 	  this->list(pfn, varg, true);
@@ -1605,7 +1605,7 @@ Parse::type_spec(void*, unsigned int pragmas)
 	    }
 	  if (pragmas != 0)
 	    go_warning_at(location, 0,
-			  "ignoring magic //go:... comment before type");
+			  "ignoring magic %<//go:...%> comment before type");
 	}
       else
 	{
@@ -1633,7 +1633,7 @@ Parse::var_spec(void*, unsigned int pragmas)
 {
   if (pragmas != 0)
     go_warning_at(this->location(), 0,
-		  "ignoring magic //go:... comment before var");
+		  "ignoring magic %<//go:...%> comment before var");
 
   // Get the variable names.
   Typed_identifier_list til;
@@ -2383,7 +2383,7 @@ Parse::function_decl(unsigned int pragmas)
 	      if (pragma_check[i].decl_ok)
 		continue;
 	      go_warning_at(location, 0,
-			    ("ignoring magic //go:%s comment "
+			    ("ignoring magic %<//go:%s%> comment "
 			     "before declaration"),
 			    pragma_check[i].name);
 	    }
@@ -2392,7 +2392,7 @@ Parse::function_decl(unsigned int pragmas)
 	      if (pragma_check[i].func_ok)
 		continue;
 	      go_warning_at(location, 0,
-			    ("ignoring magic //go:%s comment "
+			    ("ignoring magic %<//go:%s%> comment "
 			     "before function definition"),
 			    pragma_check[i].name);
 	    }
@@ -2401,7 +2401,7 @@ Parse::function_decl(unsigned int pragmas)
 	      if (pragma_check[i].method_ok)
 		continue;
 	      go_warning_at(location, 0,
-			    ("ignoring magic //go:%s comment "
+			    ("ignoring magic %<//go:%s%> comment "
 			     "before method definition"),
 			    pragma_check[i].name);
 	    }
@@ -2602,7 +2602,7 @@ Parse::operand(bool may_be_sink, bool* is_parenthesized)
 	      return Expression::make_sink(location);
 	    else
 	      {
-		go_error_at(location, "cannot use _ as value");
+		go_error_at(location, "cannot use %<_%> as value");
 		return Expression::make_error(location);
 	      }
 	  case Named_object::NAMED_OBJECT_FUNC:
@@ -4178,7 +4178,7 @@ Parse::tuple_assignment(Expression_list* lhs, bool may_be_composite_lit,
       if ((*pe)->is_error_expression())
 	return;
       if (op != OPERATOR_EQ && (*pe)->is_sink_expression())
-	go_error_at((*pe)->location(), "cannot use _ as value");
+	go_error_at((*pe)->location(), "cannot use %<_%> as value");
     }
   for (Expression_list::const_iterator pe = vals->begin();
        pe != vals->end();
@@ -5721,7 +5721,7 @@ Parse::package_clause()
 	  name = token->identifier();
 	  if (name == "_")
 	    {
-	      go_error_at(this->location(), "invalid package name _");
+	      go_error_at(this->location(), "invalid package name %<_%>");
 	      name = Gogo::erroneous_name();
 	    }
 	  this->advance_token();
@@ -5752,7 +5752,7 @@ Parse::import_spec(void*, unsigned int pragmas)
 {
   if (pragmas != 0)
     go_warning_at(this->location(), 0,
-		  "ignoring magic //go:... comment before import");
+		  "ignoring magic %<//go:...%> comment before import");
 
   const Token* token = this->peek_token();
   Location location = token->location();
@@ -5876,7 +5876,7 @@ Parse::verify_not_sink(Expression* expr)
 {
   if (expr->is_sink_expression())
     {
-      go_error_at(expr->location(), "cannot use _ as value");
+      go_error_at(expr->location(), "cannot use %<_%> as value");
       expr = Expression::make_error(expr->location());
     }