diagnostics: factor and enhance messages about duplicate rule directives

[bison.git] / tests / actions.at

diff --git a/tests/actions.at b/tests/actions.at
index 302c1bbb1985a138eff817f94175838c630ccff0..3021c7a9a392f64da8e90dddf1fda6fa79e27843 100644 (file)
--- a/tests/actions.at
+++ b/tests/actions.at
@@ -64,6 +64,119 @@ AT_PARSER_CHECK([./input], 0,
 
 AT_CLEANUP
 
+## ----------------------- ##
+## Implicitly empty rule.  ##
+## ----------------------- ##
+
+AT_SETUP([Implicitly empty rule])
+
+AT_DATA_GRAMMAR([[1.y]],
+[[%%
+exp: a b;
+a: /* empty. */ {};
+// A mid-rule action does not count as an empty rule.
+b: {} {};
+]])
+
+AT_BISON_CHECK([-fcaret -Wempty-rule 1.y], [0], [],
+[[1.y:11.17-18: warning: empty rule without %empty [-Wempty-rule]
+ a: /* empty. */ {};
+                 ^^
+]])
+
+AT_DATA_GRAMMAR([[2.y]],
+[[%%
+exp: a b c;
+a: /* empty. */ {};
+b: %empty       {};
+c: /* empty. */ {};
+]])
+
+AT_BISON_CHECK([-fcaret 2.y], [0], [],
+[[2.y:11.17-18: warning: empty rule without %empty [-Wempty-rule]
+ a: /* empty. */ {};
+                 ^^
+2.y:13.17-18: warning: empty rule without %empty [-Wempty-rule]
+ c: /* empty. */ {};
+                 ^^
+]])
+
+AT_BISON_CHECK([-fcaret -Wno-empty-rule 2.y], [0])
+
+AT_CLEANUP
+
+## ------------------------ ##
+## Invalid uses of %empty.  ##
+## ------------------------ ##
+
+AT_SETUP([Invalid uses of %empty])
+
+AT_DATA_GRAMMAR([[one.y]],
+[[%%
+exp:
+  %empty {} %empty
+;
+]])
+
+AT_BISON_CHECK([-fcaret one.y], [1], [],
+[[one.y:11.13-18: error: only one %empty allowed per rule
+   %empty {} %empty
+             ^^^^^^
+one.y:11.3-8: previous declaration
+   %empty {} %empty
+   ^^^^^^
+]])
+
+AT_DATA_GRAMMAR([[two.y]],
+[[%%
+exp:
+  'a' %empty    {}
+| %empty 'a'    {}
+| %empty {}     {}
+;
+]])
+
+AT_BISON_CHECK([-fcaret two.y], [1], [],
+[[two.y:11.7-12: error: %empty on non-empty rule
+   'a' %empty    {}
+       ^^^^^^
+two.y:12.3-8: error: %empty on non-empty rule
+ | %empty 'a'    {}
+   ^^^^^^
+two.y:13.3-8: error: %empty on non-empty rule
+ | %empty {}     {}
+   ^^^^^^
+]])
+
+AT_CLEANUP
+
+## ---------------------- ##
+## Valid uses of %empty.  ##
+## ---------------------- ##
+
+AT_SETUP([Valid uses of %empty])
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[
+%debug
+%code
+{
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+%%
+exp: %empty {}
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+]AT_MAIN_DEFINE[
+]])
+
+AT_FULL_COMPILE([input])
+AT_PARSER_CHECK([./input])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
 
 ## ------------------ ##
 ## Initial location.  ##
@@ -192,7 +305,7 @@ AT_DATA_GRAMMAR([[input.y]],
 ]AT_YYLEX_DECLARE[
 }
 %%
-exp: /* empty */;
+exp: %empty;
 %%
 ]AT_YYERROR_DEFINE[
 ]AT_YYLEX_DEFINE[
@@ -415,7 +528,7 @@ AT_LALR1_CC_IF([typedef yy::location YYLTYPE;])[
 %%
 /*
    This grammar is made to exercise error recovery.
-   "Lines" starting with `(' support error recovery, with
+   "Lines" starting with '(' support error recovery, with
    ')' as synchronizing token.  Lines starting with 'x' can never
    be recovered from if in error.
 */
@@ -578,7 +691,7 @@ Successful parse.
 
 # Syntax errors caught by the parser
 # ----------------------------------
-# Exercise the discarding of stack top and input until `error'
+# Exercise the discarding of stack top and input until 'error'
 # can be reduced.
 #
 #     '(', 'x', 'x', 'x', 'x', 'x', ')',
@@ -1011,7 +1124,7 @@ AT_DATA_GRAMMAR([[input]]$1[[.y]],
 start: { $$ = 'S'; } ;
 
 %%
-#include <stdlib.h> // abort
+#include <stdlib.h> /* abort */
 static int
 yylex (void)
 {
@@ -1174,7 +1287,7 @@ AT_SETUP([Default %printer and %destructor are not for $accept])
 #   - The %printer and %destructor code generated for $accept would always be
 #     dead code because $accept is currently never shifted onto the stack.
 #   - $$ for $accept would always be of type YYSTYPE because it's not possible
-#     to declare `%type <field> $accept'.  (Also true for $undefined.)
+#     to declare '%type <field> $accept'.  (Also true for $undefined.)
 #   - Thus, the compiler might complain that the user code assumes the wrong
 #     type for $$ since the code might assume the type associated with a
 #     specific union field, which is especially reasonable in C++ since that
@@ -1637,7 +1750,7 @@ AT_DATA_GRAMMAR([input.y],
 // that has set yychar might not always return normally.  Instead,
 // skeletons must translate before every use of yytoken.
 start: 'a' accept { USE($1); } ;
-accept: /*empty*/ {
+accept: %empty {
   assert (yychar == YYEMPTY);
   yychar = 'b';
   YYACCEPT;