Merge remote-tracking branch 'origin/maint'

* origin/maint: (24 commits)
  tests: calc: modernize the use of locations
  tests: remove useless location initializations
  lalr1.cc: always initialize yylval.
  tests: check that C and C++ objects can be linked together.
  yacc.c: also disable -Wuninitialized.
  glr.cc, yacc.c: initialize yylloc properly
  yacc.c, glr.c: a better YY_LOCATION_PRINT
  yacc.c: simplify initialization
  doc: formatting changes
  c++: fix position operator signatures
  tests: remove useless location initialization.
  tests: fix locations in C
  tests: handle %parse-param in the generated yyerror
  tests: simplifications
  grammars: fix display of nul character in error message
  tests: sort
  tests: cosmetic changes
  comment changes
  autoconf: update
  gnulib: update
  ...

Conflicts:
	data/lalr1.cc
	gnulib
	src/scan-gram.l
	submodules/autoconf
	tests/calc.at

data/glr.cc

@@ -81,12 +81,17 @@ b4_locations_if([,
 ]b4_parse_param_use[]dnl
 [  yyparser.yy_symbol_print_ (yytype, yyvaluep]b4_locations_if([, yylocationp])[);
 }
-]])
+]])[
 
+# Hijack the initial action to initialize the locations.
+]b4_locations_if([b4_percent_define_ifdef([[api.location.type]], [],
+[m4_define([b4_initial_action],
+[yylloc.initialize ();]m4_ifdef([b4_initial_action], [
+m4_defn([b4_initial_action])]))])])[
 
 # Hijack the post prologue to insert early definition of YYLLOC_DEFAULT
 # and declaration of yyerror.
-m4_append([b4_post_prologue],
+]m4_append([b4_post_prologue],
 [b4_syncline([@oline@], [@ofile@])[
 ]b4_yylloc_default_define[
 #define YYRHSLOC(Rhs, K) ((Rhs)[K].yystate.yyloc)