On a grammar such as
exp: "num" | "num" | "num"
we currently report only one RR conflict, instead of two.
This bug is present since the origins of Bison
commit 08089d5d35
Author: David MacKenzie <djm@djmnet.org>
Date: Tue Apr 20 05:42:52 1993 +0000
Initial revision
and was preserved in
commit 676385e29c
Author: Paul Hilfinger <Hilfinger@CS.Berkeley.EDU>
Date: Fri Jun 28 02:26:44 2002 +0000
Initial check-in introducing experimental GLR parsing. See entry in
ChangeLog dated 2002-06-27 from Paul Hilfinger for details.
See
https://lists.gnu.org/archive/html/bison-patches/2018-11/msg00011.html
* src/conflicts.h, src/conflicts.c (count_state_rr_conflicts)
(count_rr_conflicts): Use only the correct count of conflicts.
* tests/glr-regression.at: Fix expectations.
* data/xslt/xml2dot.xsl (xsl:template match="rule"): Use a ` '
instead of a `\n'. That is, don't add escapes yet or they'll be doubly
escaped later.
(xsl:template name="output-node"): Use the new escape template instead
of the string-replace template directly.
(xsl:template name="output-edge"): Likewise.
(xsl:template name="escape"): New, escapes backslashes and newlines in
addition to quotation marks.
* src/graphviz.c (start_graph, output_node, output_edge): Add
whitespace to output for legibility.
Make xml2text.xsl and --report produce the same output, and remove the
XML "conflicts" element since a conflict summary is easily extracted
from the automaton.
* data/xslt/bison.xsl: New.
(xsl:template match="state" mode="bison:count-conflicts): New.
* data/xslt/xml2text.xsl: Import bison.xsl.
(xsl:template match="bison-xml-report"): Instead of styling the
"conflicts" element, style the "automaton" element with mode
"conflicts". Unlike the former, the latter lists S/R and R/R
conflicts for a state on the same line.
(xsl:template match="conflicts"): Remove.
(xsl:template match="conflict"): Remove.
(xsl:template match="terminal"): Line-wrap the list of rules in which
the terminal is used.
(xsl:template match="nonterminal"): Likewise for nonterminals.
(xsl:template match="automaton" mode="conflicts"): New.
(xsl:template match="state" mode="conflicts"): New.
(xsl:template name="line-wrap"): New.
(xsl:template name="ws-search"): New.
* data/xslt/xml2xhtml.xsl: Import bison.xsl.
(xsl:template match="bison-xml-report"): Instead of styling the
"conflicts" element, style the "automaton" element with mode
"conflicts."
(xsl:template match="conflicts"): Remove.
(xsl:template match="conflict"): Remove.
(xsl:template match="automaton" mode="conflicts"): New.
(xsl:template match="state" mode="conflicts): New.
* src/conflicts.c (conflicts_output_xml): Remove.
* src/conflicts.h (conflicts_output_xml): Remove prototype.
* src/print-xml.c (print_xml): Don't invoke conflicts_output_xml.
* src/print.c (print_grammar): Consistently wrap at the 66th column so
the corresponding XSLT is easier. Also, never wrap between a word and
the comma that follows it.
elsewhere.
* src/print-xml.c: Prefer "const" after types; that's more consistent.
(xml_printf): Indent just 1 space for level.
(e_char, xlate_char): Remove.
(xml_escape_string): Rewrite to avoid undefined behavior (used
storage that was freed from the stack).
(xml_escape_n): Don't bother checking for subscript error.
2007-09-21 Wojciech Polak <polak@gnu.org>
Add support for an -x option to generate an XML report.
It is not documented yet.
* src/print-xml.c: New file.
* src/print-xml.h: Likewise.
* lib/timevar.def (TV_XML): New var.
* src/Makefile.am (bison_SOURCES): Add print-xml.c, print-xml.h.
* src/conflicts.c: Include print-xml.h.
(solved_conflicts_xml_obstack): New var.
(log_resolution, conflicts_solve, conflicts_free):
Add support for XML report.
(conflicts_output_val): New function.
* src/conflicts.h (conflicts_output_val): New decl.
* src/files.c (spec_xml_file): New var.
(compute_output_file_names, output_file_names_free): Add XML support.
* src/files.h (spec_xml_file): New decl.
* src/getargs.c (xml_flag): New var.
(usage, short_options, long_options, getargs): Add XML support.
* src/getargs.h (xml_flag): New decl.
* src/gram.c: Include print-xml.h.
(rule_lhs_print_xml, rule_rhs_print_xml):
(grammar_rules_partial_print_xml, grammar_rules_print_xml):
New functions.
* src/gram.h: Declare external ones.
* src/main.c: Include print-xml.h.
(main): Add XML support.
* src/reduce.c: Include print-xml.h.
(reduce_xml): New function.
* src/reduce.h: Declare it.
* src/state.c: Include print-xml.h.
(state_new): Add XML support.
(state_rule_lookahead_tokens_print_xml): New function.
* src/state.h: Declare it.
(struct state): New member solved_conflicts_xml.
* src/symtab.c (symbol_class_get_string): New function.
* src/symtab.h: Declare it.
2007-09-21 Paul Eggert <eggert@cs.ucla.edu>
report rules that are then unused, and don't report conflicts in those
states.
* src/conflicts.c, src/conflicts.h (conflicts_update_state_numbers):
New global function.
* src/lalr.c, src/lalr.h (lalr_update_state_numbers): New global
function.
* src/main.c (main): After conflict resolution, remove the unreachable
states and update all data structures that reference states by number.
* src/state.c (state_new): Initialize each state's reachable member to
false.
(state_mark_reachable_states): New static function.
(state_remove_unreachable_states): New global function.
* src/state.h (struct state): Add member bool reachable.
(state_remove_unreachable_states): Prototype.
* tests/conflicts.at (Unreachable States After Conflict Resolution):
New test case.
* tests/existing.at (GNU pic Grammar): Update test case output now that
an unused rule is discovered.
`look_ahead'. Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2006-01/msg00049.html>
and then at
<http://lists.gnu.org/archive/html/bison-patches/2006-06/msg00017.html>.
* NEWS: For the next release, note the change to `--report'.
* TODO, doc/bison.1: Update English.
* doc/bison.texinfo: Update English.
(Understanding Your Parser, Bison Options): Document as
`--report=lookahead' rather than `--report=look-ahead'.
* src/conflicts.c: Update English in comments.
(lookahead_set): Rename from look_ahead_set.
(flush_reduce): Rename argument look_ahead_tokens to lookahead_tokens.
(resolve_sr_conflict): Rename local look_ahead_tokens to
lookahead_tokens, and update other uses.
(flush_shift, set_conflicts, conflicts_solve, count_sr_conflicts,
count_rr_conflicts, conflicts_free): Update uses.
* src/getargs.c (report_args): Move "lookahead" before alternate
spellings.
(report_types): Update uses.
(usage): For `--report' usage description, state `lookahead' spelling
rather than `look-ahead'.
* src/getargs.h (report.report_lookahead_tokens): Rename from
report_look_ahead_tokens.
* src/lalr.c: Update English in comments.
(compute_lookahead_tokens): Rename from compute_look_ahead_tokens.
(state_lookahead_tokens_count): Rename from
state_look_ahead_tokens_count.
Rename local n_look_ahead_tokens to n_lookahead_tokens.
(lookahead_tokens_print): Rename from look_ahead_tokens_print.
Rename local n_look_ahead_tokens to n_lookahead_tokens.
Update other uses.
Update English in output.
(add_lookback_edge, initialize_LA, lalr, lalr_free): Update uses.
* src/print.c: Update English in comments.
(lookahead_set): Rename from look_ahead_set.
(print_reduction): Rename argument lookahead_token from
look_ahead_token.
(print_core, state_default_rule, print_reductions, print_results):
Update uses.
* src/print_graph.c: Update English in comments.
(print_core): Update uses.
* src/state.c: Update English in comments.
(reductions_new): Update uses.
(state_rule_lookahead_tokens_print): Rename from
state_rule_look_ahead_tokens_print, and update other uses.
* src/state.h: Update English in comments.
(reductions.lookahead_tokens): Rename from look_ahead_tokens.
(state_rule_lookahead_tokens_print): Rename from
state_rule_look_ahead_tokens_print.
* src/tables.c: Update English in comments.
(conflict_row, action_row): Update uses.
* tests/glr-regression.at
(Incorrect lookahead during deterministic GLR,
Incorrect lookahead during nondeterministic GLR): Rename
print_look_ahead to print_lookahead.
* tests/torture.at: Update English in comments.
(AT_DATA_LOOKAHEAD_TOKENS_GRAMMAR): Rename from
AT_DATA_LOOK_AHEAD_TOKENS_GRAMMAR.
(Many lookahead tokens): Update uses.
* data/glr.c: Update English in comments.
* lalr1.cc: Likewise.
* yacc.c: Likewise.
* src/conflicts.h: Likewise.
* src/lalr.h: Likewise.
* src/main.c: Likewise.
* src/output.c: Likewise.
* src/parse-gram.c: Likewise.
* src/tables.h: Likewise.
* tests/calc.at: Likewise.
(declaration): Replace expected_conflicts with expected_sr_conflicts.
Add %expect-rr rule.
* src/scan-gram.l: Recognize %expect-rr.
* src/conflicts.h (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Declare.
* src/conflicts.c (expected_sr_conflicts): Rename from
expected_conflicts.
(expected_rr_conflicts): Define.
(conflicts_print): Check r/r conflicts against expected_rr_conflicts
for GLR parsers.
Use expected_sr_conflicts in place of expected_conflicts.
Warn if expected_rr_conflicts used in non-GLR parser.
* doc/bison.texinfo: Add documentation for %expect-rr.
* src/LR0.c (new_state): Set it to 0.
* src/conflicts.h, src/conflicts.c (print_conflicts)
(free_conflicts, solve_conflicts): Rename as...
(conflicts_print, conflicts_free, conflicts_solve): these.
Adjust callers.
* src/conflicts.c (enum conflict_resolution_e)
(solved_conflicts_obstack): New, used by...
(log_resolution): this.
Adjust to attach the conflict resolution to each state.
Complete the description with the precedence/associativity
information.
(resolve_sr_conflict): Adjust.
* src/print.c (print_state): Output its solved_conflicts.
* tests/conflicts.at (Unresolved SR Conflicts)
(Solved SR Conflicts): Exercise --report=all.
(resolve_sr_conflict, set_conflicts, solve_conflicts)
(count_sr_conflicts, count_rr_conflicts, conflicts_output)
(conflicts_print, print_reductions): Use a state_t instead of an
integer when referring to a state.
As much as possible, depend upon nlookaheads, instead of the
`lookaheadsp' member of the following state (since lookaheads of
successive states are successive, the difference between state n + 1
and n served as the number of lookaheads for state n).
* src/lalr.c (add_lookback_edge): Likewise.
* src/print.c (print_core, print_actions, print_state)
(print_results): Likewise.
* src/print_graph.c (print_core, print_actions, print_state)
(print_graph): Likewise.
* src/conflicts.h: Adjust.
