grammar: record used associativity and print useless ones

Record which symbol associativity is used, and display useless ones. * src/symtab.h, src/symtab.c (register_assoc, print_assoc_warnings): New * src/symtab.c (init_assoc, is_assoc_used): New * src/main.c: Use print_assoc_warnings * src/conflicts.c: Use register_assoc * tests/conflicts.at (Useless associativity warning): New. Due to the new warning, many tests had to be updated. * tests/conflicts.at tests/existing.at tests/regression.at: Add the associativity warning in the expected results. * tests/java.at: Fix the java calculator's grammar to remove a useless associativity. * doc/bison.texi (mfcalc example): Fix associativity to remove warning.
2026-03-09 12:23:04 +00:00 · 2013-01-29 16:27:04 +01:00
parent 284bc49c83
commit e8f7155d98
9 changed files with 275 additions and 9 deletions
--- a/doc/bison.texi
+++ b/doc/bison.texi
@@ -2411,7 +2411,7 @@ Here are the C and Bison declarations for the multi-function calculator.
 %type  <val>  exp

@group
-%right '='
+%precedence '='
 %left '-' '+'
 %left '*' '/'
 %precedence NEG /* negation--unary minus */
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -303,16 +303,19 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs)
              break;

            case right_assoc:
+              register_assoc (i, redrule->prec->number);
              log_resolution (redrule, i, right_resolution);
              flush_reduce (lookahead_tokens, i);
              break;

            case left_assoc:
+              register_assoc (i, redrule->prec->number);
              log_resolution (redrule, i, left_resolution);
              flush_shift (s, i);
              break;

            case non_assoc:
+              register_assoc (i, redrule->prec->number);
              log_resolution (redrule, i, nonassoc_resolution);
              flush_shift (s, i);
              flush_reduce (lookahead_tokens, i);
--- a/src/main.c
+++ b/src/main.c
@@ -146,6 +146,8 @@ main (int argc, char *argv[])

  print_precedence_warnings ();

+  print_assoc_warnings ();
+
  /* Output file names. */
  compute_output_file_names ();

--- a/src/symtab.c
+++ b/src/symtab.c
@@ -52,6 +52,12 @@ location startsymbol_location;

 static symgraph **prec_nodes;

+/*-----------------------------------.
+| Store which associativity is used. |
+`-----------------------------------*/
+
+bool *used_assoc = NULL;
+
 /*---------------------------------.
 | Create a new symbol, named TAG.  |
 `---------------------------------*/
@@ -1073,3 +1079,61 @@ print_precedence_warnings (void)
                  _("useless precedence for %s"), s->tag);
    }
 }
+
+/*---------------------------------------.
+| Initialize association tracking table. |
+`---------------------------------------*/
+
+static void
+init_assoc (void)
+{
+  graphid i;
+  used_assoc = xcalloc(nsyms, sizeof(*used_assoc));
+  for (i = 0; i < nsyms; ++i)
+    used_assoc[i] = false;
+}
+
+/*------------------------------------------------------------------.
+| Test if the associativity for the symbols is defined and useless. |
+`------------------------------------------------------------------*/
+
+static inline bool
+is_assoc_useless (symbol *s)
+{
+  return s
+      && s->assoc != undef_assoc
+      && s->assoc != precedence_assoc
+      && !used_assoc[s->number];
+}
+
+/*-------------------------------.
+| Register a used associativity. |
+`-------------------------------*/
+
+void
+register_assoc (graphid i, graphid j)
+{
+  if (!used_assoc)
+    init_assoc ();
+  used_assoc[i] = true;
+  used_assoc[j] = true;
+}
+
+/*------------------------------------------------------.
+| Print a warning for each unused symbol associativity. |
+`------------------------------------------------------*/
+
+void
+print_assoc_warnings (void)
+{
+  graphid i;
+  if (!used_assoc)
+    init_assoc ();
+  for (i = 0; i < nsyms; ++i)
+    {
+      symbol *s = symbols[i];
+      if (is_assoc_useless (s))
+        complain (&s->location, Wother,
+                  _("useless associativity for %s"), s->tag);
+    }
+}
--- a/src/symtab.h
+++ b/src/symtab.h
@@ -270,6 +270,14 @@ void register_precedence (graphid first, graphid snd);

 void print_precedence_warnings (void);

+/*----------------------.
+| Symbol associativity  |
+`----------------------*/
+
+void register_assoc (int i, int j);
+
+void print_assoc_warnings (void);
+
 /*-----------------.
 | Semantic types.  |
 `-----------------*/
--- a/tests/conflicts.at
+++ b/tests/conflicts.at
@@ -17,6 +17,38 @@

 AT_BANNER([[Conflicts.]])

+## ------------------------------ ##
+## Useless associativity warning. ##
+## ------------------------------ ##
+
+AT_SETUP([Useless associativity warning])
+
+AT_DATA([[input.y]],
+[[%token T
+%left A B
+%right C
+%nonassoc D
+%precedence E
+
+%%
+e: T A T
+ | T B T
+ | T C T
+ | T D T
+ | T E T
+;
+]])
+
+AT_BISON_CHECK([input.y], 0, [],
+[[input.y:5.13: warning: useless precedence for E [-Wother]
+input.y:2.7: warning: useless associativity for A [-Wother]
+input.y:2.9: warning: useless associativity for B [-Wother]
+input.y:3.8: warning: useless associativity for C [-Wother]
+input.y:4.11: warning: useless associativity for D [-Wother]
+]])
+
+AT_CLEANUP
+

 ## ------------------------ ##
 ## Token declaration order. ##
@@ -85,6 +117,19 @@ input.y:24.17: warning: useless precedence for T [-Wother]
 input.y:24.19: warning: useless precedence for U [-Wother]
 input.y:25.13: warning: useless precedence for V [-Wother]
 input.y:25.15: warning: useless precedence for W [-Wother]
+input.y:18.8: warning: useless associativity for E [-Wother]
+input.y:18.10: warning: useless associativity for F [-Wother]
+input.y:18.12: warning: useless associativity for G [-Wother]
+input.y:19.8: warning: useless associativity for H [-Wother]
+input.y:19.10: warning: useless associativity for I [-Wother]
+input.y:20.8: warning: useless associativity for J [-Wother]
+input.y:21.8: warning: useless associativity for K [-Wother]
+input.y:22.8: warning: useless associativity for L [-Wother]
+input.y:22.10: warning: useless associativity for M [-Wother]
+input.y:22.12: warning: useless associativity for N [-Wother]
+input.y:23.11: warning: useless associativity for O [-Wother]
+input.y:23.13: warning: useless associativity for P [-Wother]
+input.y:23.15: warning: useless associativity for Q [-Wother]
 ]])
 AT_COMPILE([input])

@@ -133,6 +178,15 @@ AT_BISON_CHECK([-fcaret -o input.c input.y], 0, [],
 [[input.y:2.13: warning: useless precedence for Z [-Wother]
 %precedence Z
             ^
+input.y:5.7: warning: useless associativity for W [-Wother]
+ %left W
+       ^
+input.y:6.8: warning: useless associativity for V [-Wother]
+ %right V
+        ^
+input.y:7.11: warning: useless associativity for U [-Wother]
+ %nonassoc U
+           ^
 ]])

 AT_CLEANUP
@@ -1144,6 +1198,8 @@ e:   e '+' e

 AT_BISON_CHECK([-o input.c input.y], 0, [],
 [[input.y: warning: 4 shift/reduce conflicts [-Wconflicts-sr]
+input.y:1.7-9: warning: useless associativity for '+' [-Wother]
+input.y:2.7-9: warning: useless associativity for '*' [-Wother]
 ]])
 AT_CLEANUP

--- a/tests/existing.at
+++ b/tests/existing.at
@@ -427,8 +427,44 @@ dnl don't like even `print $!4;'.

 dnl BISON-STDERR
 [AT_COND_CASE([[canonical LR]],
-[[input.y: warning: 265 shift/reduce conflicts [-Wconflicts-sr]]],
-[[input.y: warning: 65 shift/reduce conflicts [-Wconflicts-sr]]])[
+[[input.y: warning: 265 shift/reduce conflicts [-Wconflicts-sr]
+input.y:19.8-16: warning: useless associativity for FUNC_CALL [-Wother]
+input.y:21.8-14: warning: useless associativity for YNUMBER [-Wother]
+input.y:21.16-22: warning: useless associativity for YSTRING [-Wother]
+input.y:22.14-22: warning: useless associativity for APPEND_OP [-Wother]
+input.y:23.8-15: warning: useless associativity for ASSIGNOP [-Wother]
+input.y:23.33-41: warning: useless associativity for CONCAT_OP [-Wother]
+input.y:27.8-18: warning: useless associativity for LEX_GETLINE [-Wother]
+input.y:28.8-13: warning: useless associativity for LEX_IN [-Wother]
+input.y:29.23-31: warning: useless associativity for INCREMENT [-Wother]
+input.y:29.33-41: warning: useless associativity for DECREMENT [-Wother]
+input.y:30.8-18: warning: useless associativity for LEX_BUILTIN [-Wother]
+input.y:30.20-29: warning: useless associativity for LEX_LENGTH [-Wother]
+input.y:40.11-13: warning: useless associativity for ',' [-Wother]
+input.y:47.8-10: warning: useless associativity for '!' [-Wother]
+input.y:47.12-16: warning: useless associativity for UNARY [-Wother]
+input.y:50.7-9: warning: useless associativity for '$' [-Wother]
+input.y:51.7-9: warning: useless associativity for '(' [-Wother]
+input.y:51.11-13: warning: useless associativity for ')' [-Wother]]],
+[[input.y: warning: 65 shift/reduce conflicts [-Wconflicts-sr]
+input.y:19.8-16: warning: useless associativity for FUNC_CALL [-Wother]
+input.y:21.8-14: warning: useless associativity for YNUMBER [-Wother]
+input.y:21.16-22: warning: useless associativity for YSTRING [-Wother]
+input.y:22.14-22: warning: useless associativity for APPEND_OP [-Wother]
+input.y:23.8-15: warning: useless associativity for ASSIGNOP [-Wother]
+input.y:23.33-41: warning: useless associativity for CONCAT_OP [-Wother]
+input.y:27.8-18: warning: useless associativity for LEX_GETLINE [-Wother]
+input.y:28.8-13: warning: useless associativity for LEX_IN [-Wother]
+input.y:29.23-31: warning: useless associativity for INCREMENT [-Wother]
+input.y:29.33-41: warning: useless associativity for DECREMENT [-Wother]
+input.y:30.8-18: warning: useless associativity for LEX_BUILTIN [-Wother]
+input.y:30.20-29: warning: useless associativity for LEX_LENGTH [-Wother]
+input.y:40.11-13: warning: useless associativity for ',' [-Wother]
+input.y:47.8-10: warning: useless associativity for '!' [-Wother]
+input.y:47.12-16: warning: useless associativity for UNARY [-Wother]
+input.y:50.7-9: warning: useless associativity for '$' [-Wother]
+input.y:51.7-9: warning: useless associativity for '(' [-Wother]
+input.y:51.11-13: warning: useless associativity for ')' [-Wother]]])[
 ]],

 dnl LAST-STATE
@@ -1369,9 +1405,21 @@ dnl INPUT
 dnl BISON-STDERR
 [AT_COND_CASE([[canonical LR]],
 [[input.y: warning: 1876 shift/reduce conflicts [-Wconflicts-sr]
-input.y: warning: 144 reduce/reduce conflicts [-Wconflicts-rr]]],
+input.y: warning: 144 reduce/reduce conflicts [-Wconflicts-rr]
+input.y:32.9-12: warning: useless associativity for HQUA [-Wother]
+input.y:53.8-14: warning: useless associativity for HASSIGN [-Wother]
+input.y:54.9-15: warning: useless associativity for HORELSE [-Wother]
+input.y:55.9-16: warning: useless associativity for HANDTHEN [-Wother]
+input.y:61.9-12: warning: useless associativity for HNOT [-Wother]
+input.y:68.7-11: warning: useless associativity for UNEAR [-Wother]]],
 [[input.y: warning: 78 shift/reduce conflicts [-Wconflicts-sr]
-input.y: warning: 10 reduce/reduce conflicts [-Wconflicts-rr]]])[
+input.y: warning: 10 reduce/reduce conflicts [-Wconflicts-rr]
+input.y:32.9-12: warning: useless associativity for HQUA [-Wother]
+input.y:53.8-14: warning: useless associativity for HASSIGN [-Wother]
+input.y:54.9-15: warning: useless associativity for HORELSE [-Wother]
+input.y:55.9-16: warning: useless associativity for HANDTHEN [-Wother]
+input.y:61.9-12: warning: useless associativity for HNOT [-Wother]
+input.y:68.7-11: warning: useless associativity for UNEAR [-Wother]]])[
 ]],

 dnl LAST-STATE
@@ -1954,6 +2002,87 @@ dnl without being followed by "of".)

 dnl BISON-STDERR
 [[input.y:471.11-48: warning: rule useless in parser due to conflicts: path: ORDINAL LAST object_type relative_path [-Wother]
+input.y:19.8-12: warning: useless associativity for LABEL [-Wother]
+input.y:20.8-15: warning: useless associativity for VARIABLE [-Wother]
+input.y:21.8-13: warning: useless associativity for NUMBER [-Wother]
+input.y:22.8-11: warning: useless associativity for TEXT [-Wother]
+input.y:25.8-14: warning: useless associativity for ORDINAL [-Wother]
+input.y:30.8-11: warning: useless associativity for LAST [-Wother]
+input.y:31.8-9: warning: useless associativity for UP [-Wother]
+input.y:32.8-11: warning: useless associativity for DOWN [-Wother]
+input.y:35.8-10: warning: useless associativity for BOX [-Wother]
+input.y:36.8-13: warning: useless associativity for CIRCLE [-Wother]
+input.y:37.8-14: warning: useless associativity for ELLIPSE [-Wother]
+input.y:38.8-10: warning: useless associativity for ARC [-Wother]
+input.y:39.8-11: warning: useless associativity for LINE [-Wother]
+input.y:40.8-12: warning: useless associativity for ARROW [-Wother]
+input.y:42.8-13: warning: useless associativity for SPLINE [-Wother]
+input.y:43.8-13: warning: useless associativity for HEIGHT [-Wother]
+input.y:44.8-13: warning: useless associativity for RADIUS [-Wother]
+input.y:45.8-12: warning: useless associativity for WIDTH [-Wother]
+input.y:46.8-15: warning: useless associativity for DIAMETER [-Wother]
+input.y:47.8-11: warning: useless associativity for FROM [-Wother]
+input.y:48.8-9: warning: useless associativity for TO [-Wother]
+input.y:49.8-9: warning: useless associativity for AT [-Wother]
+input.y:53.8-12: warning: useless associativity for SOLID [-Wother]
+input.y:54.8-13: warning: useless associativity for DOTTED [-Wother]
+input.y:55.8-13: warning: useless associativity for DASHED [-Wother]
+input.y:56.8-11: warning: useless associativity for CHOP [-Wother]
+input.y:59.8-12: warning: useless associativity for LJUST [-Wother]
+input.y:60.8-12: warning: useless associativity for RJUST [-Wother]
+input.y:61.8-12: warning: useless associativity for ABOVE [-Wother]
+input.y:62.8-12: warning: useless associativity for BELOW [-Wother]
+input.y:63.8-9: warning: useless associativity for OF [-Wother]
+input.y:66.8-14: warning: useless associativity for BETWEEN [-Wother]
+input.y:67.8-10: warning: useless associativity for AND [-Wother]
+input.y:68.8-11: warning: useless associativity for HERE [-Wother]
+input.y:69.8-12: warning: useless associativity for DOT_N [-Wother]
+input.y:70.8-12: warning: useless associativity for DOT_E [-Wother]
+input.y:71.8-12: warning: useless associativity for DOT_W [-Wother]
+input.y:72.8-12: warning: useless associativity for DOT_S [-Wother]
+input.y:73.8-13: warning: useless associativity for DOT_NE [-Wother]
+input.y:74.8-13: warning: useless associativity for DOT_SE [-Wother]
+input.y:75.8-13: warning: useless associativity for DOT_NW [-Wother]
+input.y:76.8-13: warning: useless associativity for DOT_SW [-Wother]
+input.y:77.8-12: warning: useless associativity for DOT_C [-Wother]
+input.y:78.8-16: warning: useless associativity for DOT_START [-Wother]
+input.y:79.8-14: warning: useless associativity for DOT_END [-Wother]
+input.y:85.8-10: warning: useless associativity for SIN [-Wother]
+input.y:86.8-10: warning: useless associativity for COS [-Wother]
+input.y:87.8-12: warning: useless associativity for ATAN2 [-Wother]
+input.y:88.8-10: warning: useless associativity for LOG [-Wother]
+input.y:89.8-10: warning: useless associativity for EXP [-Wother]
+input.y:90.8-11: warning: useless associativity for SQRT [-Wother]
+input.y:91.8-12: warning: useless associativity for K_MAX [-Wother]
+input.y:92.8-12: warning: useless associativity for K_MIN [-Wother]
+input.y:93.8-10: warning: useless associativity for INT [-Wother]
+input.y:94.8-11: warning: useless associativity for RAND [-Wother]
+input.y:95.8-12: warning: useless associativity for SRAND [-Wother]
+input.y:98.8-10: warning: useless associativity for TOP [-Wother]
+input.y:99.8-13: warning: useless associativity for BOTTOM [-Wother]
+input.y:100.8-12: warning: useless associativity for UPPER [-Wother]
+input.y:101.8-12: warning: useless associativity for LOWER [-Wother]
+input.y:116.8-18: warning: useless associativity for LEFT_CORNER [-Wother]
+input.y:117.8-19: warning: useless associativity for RIGHT_CORNER [-Wother]
+input.y:118.8-12: warning: useless associativity for NORTH [-Wother]
+input.y:119.8-12: warning: useless associativity for SOUTH [-Wother]
+input.y:120.8-11: warning: useless associativity for EAST [-Wother]
+input.y:121.8-11: warning: useless associativity for WEST [-Wother]
+input.y:122.8-13: warning: useless associativity for CENTER [-Wother]
+input.y:123.8-10: warning: useless associativity for END [-Wother]
+input.y:124.8-12: warning: useless associativity for START [-Wother]
+input.y:127.8-11: warning: useless associativity for PLOT [-Wother]
+input.y:128.8-16: warning: useless associativity for THICKNESS [-Wother]
+input.y:129.8-11: warning: useless associativity for FILL [-Wother]
+input.y:130.8-14: warning: useless associativity for COLORED [-Wother]
+input.y:131.8-15: warning: useless associativity for OUTLINED [-Wother]
+input.y:134.8-14: warning: useless associativity for SPRINTF [-Wother]
+input.y:137.7-9: warning: useless associativity for '.' [-Wother]
+input.y:156.23-25: warning: useless associativity for '(' [-Wother]
+input.y:157.20-22: warning: useless associativity for '`' [-Wother]
+input.y:159.48-50: warning: useless associativity for '@<:@' [-Wother]
+input.y:170.7-9: warning: useless associativity for ',' [-Wother]
+input.y:181.8-10: warning: useless associativity for '!' [-Wother]
 ]],

 dnl LAST-STATE
--- a/tests/java.at
+++ b/tests/java.at
@@ -57,7 +57,7 @@ AT_DATA([Calc.y],
 %nonassoc '='       /* comparison            */
 %left '-' '+'
 %left '*' '/'
-%left NEG     /* negation--unary minus */
+%precedence NEG     /* negation--unary minus */
 %right '^'          /* exponentiation        */

 /* Grammar follows */
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -377,7 +377,10 @@ exp: ;
 %%
 ]])

-AT_BISON_CHECK([-v -o input.c input.y])
+AT_BISON_CHECK([-v -o input.c input.y], 0, [],
+[[input.y:1.29-32: warning: useless associativity for "||" [-Wother]
+input.y:2.29-32: warning: useless associativity for "<=" [-Wother]
+]])

 AT_CLEANUP

@@ -1147,6 +1150,7 @@ AT_BISON_OPTION_POPDEFS
 AT_BISON_CHECK([[-o input.c input.y]], [[0]],,
 [[input.y:24.5-19: warning: rule useless in parser due to conflicts: start: start [-Wother]
 input.y:28.5-19: warning: rule useless in parser due to conflicts: sr_conflict: TK2 "tok alias" [-Wother]
+input.y:18.7-9: warning: useless associativity for TK1 [-Wother]
 ]])
 AT_COMPILE([[input]])
 AT_PARSER_CHECK([[./input]])