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Implement the FIXME that ends an user action with a semicolon

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if it seems necessary.

* src/scan-code.l (flex rules section): Flag cpp directive from
any `#' to the first unescaped end-of-line.  Semicolon is not
needed after `;', `{', '}', or cpp directives and is needed after
any other token (whitespaces and comments have no effect).
* tests/actions.at (Fix user actions without a trailing semicolon):
New test.
* tests/input.at (AT_CHECK_UNUSED_VALUES): Add semicolons to
to make user actions complete statements.
Adjust column numbers in error messages.
* tests/regression.at (Fix user actions without a trailing semicolon):
Remove.  Covered by new test.
This commit is contained in:
Di-an Jan
2008-12-07 21:54:45 -08:00
parent ce9447fc6a
commit e8cd1ad655
5 changed files with 198 additions and 57 deletions
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64
src/scan-code.l
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@@ -81,6 +81,19 @@ splice (\\[ \f\t\v]*\n)*
/* Nesting level of the current code in braces. */
int braces_level = 0;
/* Whether a semicolon is probably needed.
The heuristic is that a semicolon is not needed after `{', `}', `;',
or a C preprocessor directive, and that whitespaces and comments
do not affect this flag.
Note that `{' does not need a semicolon because of `{}'.
A semicolon may be needed before a cpp direcive, but don't bother. */
bool need_semicolon = false;
/* Whether in a C preprocessor directive. Don't use a start condition
for this because, at the end of strings and comments, we still need
to know whether we're in a directive. */
bool in_cpp = false;
/* This scanner is special: it is invoked only once, henceforth
is expected to return only once. This initialization is
therefore done once per action to translate. */
@@ -135,10 +148,12 @@ splice (\\[ \f\t\v]*\n)*
"'" {
STRING_GROW;
BEGIN SC_CHARACTER;
need_semicolon = true;
}
"\"" {
STRING_GROW;
BEGIN SC_STRING;
need_semicolon = true;
}
"/"{splice}"*" {
STRING_GROW;
@@ -154,46 +169,63 @@ splice (\\[ \f\t\v]*\n)*
{
"$"("<"{tag}">")?(-?[0-9]+|"$") {
handle_action_dollar (self->rule, yytext, *loc);
need_semicolon = true;
}
"@"(-?[0-9]+|"$") {
handle_action_at (self->rule, yytext, *loc);
need_semicolon = true;
}
"$" {
warn_at (*loc, _("stray `$'"));
obstack_sgrow (&obstack_for_string, "$][");
need_semicolon = true;
}
"@" {
warn_at (*loc, _("stray `@'"));
obstack_sgrow (&obstack_for_string, "@@");
need_semicolon = true;
}
"[" {
obstack_sgrow (&obstack_for_string, "@{");
need_semicolon = true;
}
"]" {
obstack_sgrow (&obstack_for_string, "@}");
need_semicolon = true;
}
"{" STRING_GROW; ++braces_level;
";" STRING_GROW; need_semicolon = false;
"{" STRING_GROW; ++braces_level; need_semicolon = false;
"}" {
bool outer_brace = --braces_level == 0;
/* As an undocumented Bison extension, append `;' before the last
brace in braced code, so that the user code can omit trailing
`;'. But do not append `;' if emulating Yacc, since Yacc does
not append one. Also, some output languages (like Java) do not
accept an extra semicolon, so don't append if the user specified
a skeleton or language.
FIXME: Bison should warn if a semicolon seems to be necessary
here, and should omit the semicolon if it seems unnecessary
(e.g., after ';', '{', or '}', each followed by comments or
white space). Such a warning shouldn't depend on --yacc; it
should depend on a new --pedantic option, which would cause
Bison to warn if it detects an extension to POSIX. --pedantic
should also diagnose other Bison extensions like %yacc.
Perhaps there should also be a GCC-style --pedantic-errors
option, so that such warnings are diagnosed as errors. */
not append one. */
if (outer_brace && !yacc_flag && language_prio == default_prio
&& skeleton_prio == default_prio)
obstack_1grow (&obstack_for_string, ';');
&& skeleton_prio == default_prio && need_semicolon && ! in_cpp)
{
warn_at (*loc, _("a `;' might be needed at the end of action code"));
warn_at (*loc, _("future versions of Bison will not add the `;'"));
obstack_1grow (&obstack_for_string, ';');
}
STRING_GROW;
need_semicolon = false;
}
/* Preprocessing directives should only be recognized at the beginning
of lines, allowing whitespace including comments, but in C/C++,
`#' can only be the start of preprocessor directives or within
`#define' directives anyway, so don't bother with begin of line. */
"#" STRING_GROW; in_cpp = true;
{splice} STRING_GROW;
[\n\r] STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false;
[ \t\f] STRING_GROW;
. STRING_GROW; need_semicolon = true;
}
<SC_SYMBOL_ACTION>