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Re: %nterm directive incorrectly accepts character literals and quoted s
From: |
Akim Demaille |
Subject: |
Re: %nterm directive incorrectly accepts character literals and quoted strings |
Date: |
Tue, 27 Nov 2018 07:18:21 +0100 |
The following two patches make %nterm safe to use.
commit c4778646608e3aa6680639e1823479b2999d5c6c
Author: Akim Demaille <address@hidden>
Date: Sun Nov 25 14:01:10 2018 +0100
%nterm: do not accept numbers nor string alias
Reported by Rici Lake.
http://lists.gnu.org/archive/html/bug-bison/2018-10/msg00000.html
* src/parse-gram.y (symbol_def): Refuse string aliases and numbers
for non-terminals.
(prologue_declaration): Recover from errors ended with ';'.
* tests/input.at (Invalid %nterm uses): New.
diff --git a/src/parse-gram.y b/src/parse-gram.y
index 2d0fb460..73eda17b 100644
--- a/src/parse-gram.y
+++ b/src/parse-gram.y
@@ -317,6 +317,7 @@ prologue_declaration:
| "%token-table" { token_table_flag = true; }
| "%verbose" { report_flag |= report_states; }
| "%yacc" { yacc_flag = true; }
+| error ";" { yyerrok; }
| /*FIXME: Err? What is this horror doing here? */ ";"
;
@@ -495,7 +496,7 @@ tag:
| "<>" { $$ = uniqstr_new (""); }
;
-/* One token definition. */
+/* One symbol (token or nterm depending on current_class) definition. */
symbol_def:
TAG
{
@@ -509,18 +510,38 @@ symbol_def:
}
| id INT
{
+ if (current_class != token_sym)
+ {
+ gram_error (&@2,
+ "non-terminals cannot be given an explicit number");
+ YYERROR;
+ }
symbol_class_set ($1, current_class, @1, true);
symbol_type_set ($1, current_type, @1);
symbol_user_token_number_set ($1, $2, @2);
}
| id string_as_id
{
+ if (current_class != token_sym)
+ {
+ gram_error (&@2,
+ "non-terminals cannot be given a string alias");
+ YYERROR;
+ }
symbol_class_set ($1, current_class, @1, true);
symbol_type_set ($1, current_type, @1);
symbol_make_alias ($1, $2, @$);
}
| id INT string_as_id
{
+ if (current_class != token_sym)
+ {
+ gram_error (&@2,
+ "non-terminals cannot be given an explicit number");
+ gram_error (&@3,
+ "non-terminals cannot be given a string alias");
+ YYERROR;
+ }
symbol_class_set ($1, current_class, @1, true);
symbol_type_set ($1, current_type, @1);
symbol_user_token_number_set ($1, $2, @2);
diff --git a/tests/input.at b/tests/input.at
index 175928d0..84fd0944 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -130,6 +130,48 @@ AT_BISON_CHECK([input.y], [1], [],
AT_CLEANUP
+## --------------------- ##
+## Invalid %nterm uses. ##
+## --------------------- ##
+
+AT_SETUP([Invalid %nterm uses])
+
+AT_DATA([input.y],
+[[%nterm expr "expression";
+%nterm term 123;
+%nterm fact 124 "factor";
+%%
+expr: expr '+' term | term;
+term: term '*' fact | fact;
+fact: '0';
+]])
+
+AT_BISON_CHECK([-fcaret input.y], [1], [],
+[[input.y:1.1-6: warning: deprecated directive, use '%type' [-Wdeprecated]
+ %nterm expr "expression";
+ ^^^^^^
+input.y:1.13-24: error: non-terminals cannot be given a string alias
+ %nterm expr "expression";
+ ^^^^^^^^^^^^
+input.y:2.1-6: warning: deprecated directive, use '%type' [-Wdeprecated]
+ %nterm term 123;
+ ^^^^^^
+input.y:2.13-15: error: non-terminals cannot be given an explicit number
+ %nterm term 123;
+ ^^^
+input.y:3.1-6: warning: deprecated directive, use '%type' [-Wdeprecated]
+ %nterm fact 124 "factor";
+ ^^^^^^
+input.y:3.13-15: error: non-terminals cannot be given an explicit number
+ %nterm fact 124 "factor";
+ ^^^
+input.y:3.17-24: error: non-terminals cannot be given a string alias
+ %nterm fact 124 "factor";
+ ^^^^^^^^
+]])
+
+AT_CLEANUP
+
## ------------ ##
## Invalid $n. ##