diff options
| -rw-r--r-- | THANKS | 1 | ||||
| -rw-r--r-- | src/lalr.c | 16 | ||||
| -rw-r--r-- | tests/sets.at | 43 |
3 files changed, 58 insertions, 2 deletions
@@ -176,6 +176,7 @@ Tommy Nordgren tommy.nordgren@chello.se Troy A. Johnson troyj@ecn.purdue.edu Tys Lefering gccbison@gmail.com Valentin Tolmer nitnelave1@gmail.com +wcventure wcventure@126.com Victor Khomenko victor.khomenko@newcastle.ac.uk Victor Zverovich victor.zverovich@gmail.com Vin Shelton acs@alumni.princeton.edu @@ -271,7 +271,7 @@ build_relations (void) int nedges = 0; for (rule **rulep = derives[var - ntokens]; *rulep; ++rulep) { - rule const* r = *rulep; + rule const *r = *rulep; state *s = states[src]; path[0] = s->number; @@ -295,7 +295,19 @@ build_relations (void) for (int p = length - 2; 0 <= p && ISVAR (r->rhs[p]); --p) { symbol_number sym = item_number_as_symbol_number (r->rhs[p]); - edge[nedges++] = map_goto (path[p], sym); + goto_number g = map_goto (path[p], sym); + /* Insert G if not already in EDGE. + FIXME: linear search. A bitset instead? */ + { + bool found = false; + for (int j = 0; !found && j < nedges; ++j) + found = edge[j] == g; + if (!found) + { + assert (nedges < ngotos + 1); + edge[nedges++] = map_goto (path[p], sym); + } + } if (!nullable[sym - ntokens]) break; } diff --git a/tests/sets.at b/tests/sets.at index 3ad1a855..60c32767 100644 --- a/tests/sets.at +++ b/tests/sets.at @@ -304,6 +304,49 @@ AT_CLEANUP ## ----------------- ## +## Build relations. ## +## ----------------- ## + +AT_SETUP([Build relations]) + +# The "includes" relation [DeRemer 1982] is between gotos, so of +# course, for a given goto, there cannot be more that ngotos (number +# of gotos) images. But we manipulate the set of images of a goto as +# a list, without checking that an image was not already introduced. +# So we can "register" way more images than ngotos, leading to a crash +# (heap buffer overflow). +# +# http://lists.gnu.org/archive/html/bug-bison/2019-03/msg00007.html + +AT_DATA([input.y], +[[%% +expr: term | term | term | term | term | term +term: 'n' +]]) + +AT_BISON_CHECK([[-fcaret input.y]], [], [], +[[input.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr] +input.y:2.14-17: warning: rule useless in parser due to conflicts [-Wother] + expr: term | term | term | term | term | term + ^~~~ +input.y:2.21-24: warning: rule useless in parser due to conflicts [-Wother] + expr: term | term | term | term | term | term + ^~~~ +input.y:2.28-31: warning: rule useless in parser due to conflicts [-Wother] + expr: term | term | term | term | term | term + ^~~~ +input.y:2.35-38: warning: rule useless in parser due to conflicts [-Wother] + expr: term | term | term | term | term | term + ^~~~ +input.y:2.42-45: warning: rule useless in parser due to conflicts [-Wother] + expr: term | term | term | term | term | term + ^~~~ +]]) + +AT_CLEANUP + + +## ----------------- ## ## Reduced Grammar. ## ## ----------------- ## |