ast.hh:24:7: error: 'Node' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit [-Werror,-Wweak-vtables]
class Node
^
ast.hh:57:7: error: 'Nterm' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit [-Werror,-Wweak-vtables]
class Nterm : public Node
^
ast.hh:102:7: error: 'Term' has no out-of-line virtual method definitions; its vtable will be emitted in every translation unit [-Werror,-Wweak-vtables]
class Term : public Node
^
* examples/c++/glr/ast.hh: Define the destructors out of the class
definition.
This does not change anything, it is still in the header, but that
does pacify clang.
When debugging these parsers, we really need debug traces.
Enable them, and bind them to $YYDEBUG.
* tests/glr-regression.at: Support the YYDEBUG envvar.
As a consequence, now that syntactic ambiguities are reported, adjust
the expected output.
(No users destructors if stack 0 deleted): Don't return 0 on memory
exhaustion, really return the parser's status, and adust expectations.
Currently the example really looks like C. Instead of a union of
structs to implement the AST, use a hierarchy. It would be nice to
feature a C++17 version with std variants.
* examples/c++/glr/c++-types.yy (Node, free_node, new_nterm)
(new_term): Move into...
* examples/c++/glr/ast.hh: here, a proper C++ hierarchy.
Amusingly enough, glr2.cc still had its core function, yyparse, being
a free function instead of a member function.
* data/skeletons/glr2.cc (yyparse): Remove this free function called
from yyparser::parse. Inline its body into...
(yyparser::parse): this member function.
This requires moving a bit the yychar, etc. macros.
Access to token can be simplified (the
b4_namespace_ref::b4_parser_class prefix is no longer needed).
Remove the useless conditional b4_pure_if: the skeleton is, of course,
pure (no global variables). Make glr2.cc intrinsically pure.
* data/skeletons/glr2.cc (b4_pure_if): Remove definition and uses.
(b4_lex): New.
Stolen from lalr1.cc to avoid needing to use the one from c.m4.
Currently, yycompressStack expects the free items to be states only.
That's not the case.
Fixes 712 and 730 pass. 748 still fails, but later and
differently (heap-use-after-free).
* data/skeletons/glr2.cc (glr_stack_item::setState): New.
(glr_stack_item::yycompressStack): Use it.
* tests/glr-regression.at: Adjust.
A glr_state keeps tracks of its predecessor using an offset relative
to itself (i.e., pointer subtraction). Unfortunately we sometimes
have to compute offsets for pointers that live in different
containers, in particular in yyfillin. In that case there is no
reason for the distance between the two objects to be a multiple of
the object size (0x40 on my machine), and the resulting ptrdiff_t may
be "wrong", i.e., it does allow to recover one from the other. We
cannot use "typed" pointer arithmetics here, the Euclidean division
has it wrong. So use "plain" char* pointers.
Fixes 718 (Duplicate representation of merged trees: glr2.cc) and
examples/c++/glr/c++-types.
Still XFAIL:
712: Improper handling of embedded actions and dollar(-N) in GLR parsers: glr2.cc
730: Incorrectly initialized location for empty right-hand side in GLR: glr2.cc
748: Incorrect lookahead during nondeterministic GLR: glr2.cc
* data/skeletons/glr2.cc (glr_state::as_pointer_): New.
(glr_state::pred): Use it.
* examples/c++/glr/c++-types.test: The test passes.
* tests/glr-regression.at (Duplicate representation of merged trees:
glr2.cc): Passes.
The use of YY_IGNORE_NULL_DEREFERENCE_BEGIN/END in `check_` is to
please GCC 10:
glr-regr8.cc: In member function 'YYRESULTTAG glr_stack::yyresolveValue(glr_state&)':
glr-regr8.cc:1433:21: error: potential null pointer dereference [-Werror=null-dereference]
1433 | YYASSERT (this->magic_ == MAGIC);
| ~~~~~~^~~~~~
glr-regr8.cc:905:40: note: in definition of macro 'YYASSERT'
905 | # define YYASSERT(Condition) ((void) ((Condition) || (abort (), 0)))
| ^~~~~~~~~
* data/skeletons/glr2.cc (glr_state::check_): New.
Use it in the member functions.
We obviously have broken pointer arithmetics that hands us
glr_stack_items that are not glr_stack_items. Have a simple check for
this, to have earlier failures.
* data/skeletons/glr2.cc (glr_stack_item::check_): New.
Use it.
(glr_stack_item::contents): Avoid the useless struct.
Fix minor stylistic issues.
When installed on master as of 2020-12-05 (on top of "glr2.cc: fix
when the stack is not expandable", almost all the GLR regression tests
fail (with a SEGV):
709: Badly Collapsed GLR States: glr2.cc FAILED (glr-regression.at:130)
712: Improper handling of embedded actions and dollar(-N) in GLR parsers: glr2.cc FAILED (glr-regression.at:275)
715: Improper merging of GLR delayed action sets: glr2.cc FAILED (glr-regression.at:404)
718: Duplicate representation of merged trees: glr2.cc FAILED (glr-regression.at:502)
721: User destructor for unresolved GLR semantic value: glr2.cc FAILED (glr-regression.at:566)
724: User destructor after an error during a split parse: glr2.cc FAILED (glr-regression.at:624)
727: Duplicated user destructor for lookahead: glr2.cc FAILED (glr-regression.at:724)
730: Incorrectly initialized location for empty right-hand side in GLR: glr2.cc FAILED (glr-regression.at:823)
733: No users destructors if stack 0 deleted: glr2.cc FAILED (glr-regression.at:911)
736: Corrupted semantic options if user action cuts parse: glr2.cc FAILED (glr-regression.at:974)
739: Undesirable destructors if user action cuts parse: glr2.cc FAILED (glr-regression.at:1042)
742: Leaked semantic values if user action cuts parse: glr2.cc FAILED (glr-regression.at:1173)
748: Incorrect lookahead during nondeterministic GLR: glr2.cc FAILED (glr-regression.at:1546)
751: Leaked semantic values when reporting ambiguity: glr2.cc FAILED (glr-regression.at:1639)
754: Leaked lookahead after nondeterministic parse syntax error: glr2.cc FAILED (glr-regression.at:1710)
757: Uninitialized location when reporting ambiguity: glr2.cc FAILED (glr-regression.at:1794)
766: Predicates: glr2.cc FAILED (glr-regression.at:2045)
These pass:
745: Incorrect lookahead during deterministic GLR: glr2.cc ok
760: Missed %merge type warnings when LHS type is declared later: glr2.cc ok
763: Ambiguity reports: glr2.cc ok
With Valentin Tolmer's "glr2.cc: Fix memory corruption bug" commit,
these test fail "gracefully":
712: Improper handling of embedded actions and dollar(-N) in GLR parsers: glr2.cc FAILED (glr-regression.at:268)
730: Incorrectly initialized location for empty right-hand side in GLR: glr2.cc FAILED (glr-regression.at:816)
748: Incorrect lookahead during nondeterministic GLR: glr2.cc FAILED (glr-regression.at:1539)
And these do not end:
709: Badly Collapsed GLR States: glr2.cc FAILED (glr-regression.at:123)
715: Improper merging of GLR delayed action sets: glr2.cc FAILED (glr-regression.at:397)
718: Duplicate representation of merged trees: glr2.cc FAILED (glr-regression.at:495)
751: Leaked semantic values when reporting ambiguity: glr2.cc FAILED (glr-regression.at:1632)
With "tests: glr2.cc: run the glr-regression tests", none loop, and
709, 715, and 751 pass. Only 718 still fails.
* tests/glr-regression.at: Run all the tests with glr2.cc.
* tests/local.at (AT_GLR2_CC_IF): New.
When "tests: glr2.cc: run the glr-regression tests" tests are run,
before this commit the following tests used to loop endlessly:
709: Badly Collapsed GLR States: glr2.cc FAILED (glr-regression.at:123)
715: Improper merging of GLR delayed action sets: glr2.cc FAILED (glr-regression.at:397)
718: Duplicate representation of merged trees: glr2.cc FAILED (glr-regression.at:495)
751: Leaked semantic values when reporting ambiguity: glr2.cc FAILED (glr-regression.at:1632)
After this commit, no test loops and 709, 715, and 751 pass. Only 718
still fails.
* data/skeletons/glr2.cc (yyresolveValue): Add missing incrementation
of the iteration variable.
* data/skeletons/glr2.cc: Use 'const' on variables and applicable
member functions.
Improve comments.
Use references where applicable.
Enforce names_like_this, notLikeThis.
Reduce scopes.
* tests/glr-regression.at: Adjust the tests to be more independent of
the language, and run them with glr.cc.
Some tests relied on yychar, yylval and yylloc being global variables:
pass arguments instead.
* tests/glr-regression.at: Instead of using AT_BISON_CHECK and
AT_COMPILE, use AT_FULL_COMPILE. This is shorter, and makes it easier
to add support for other programming languages.
* tests/glr-regression.at: Use %expect and %expect-rr in the grammar
files, rather than accepting diagnostics.
This will make it easier to support other programming languages.
When using glr.cc, the C function yyparse is an internal detail that
should not be exposed. Users might call it by accident (I did).
* data/skeletons/glr.c (yyparse): When used for glr.cc, rename as yy_parse_impl.
* data/skeletons/glr.cc: Adjust.
src/reader.c: In function 'grammar_start_symbols_add':
src/reader.c:67:24: error: declaration of 'dup' shadows a global declaration [-Werror=shadow]
* src/reader.c (grammar_start_symbols_add): Rename dup as dupl.
The yydefgoto table uses -1 as an invalid for an impossible case (we
never use yydefgoto[0], since it corresponds to the reduction to
$accept, which never happens). Since yydefgoto is a table of state
numbers, this -1 forces a signed type uselessly, which (1) might
trigger compiler warnings when storing a value from yydefgoto into a
state number (nonnegative), and (2) wastes bits which might result in
using a int16 where a uint8 suffices.
Reported by Jot Dot <jotdot@shaw.ca>.
https://lists.gnu.org/r/bug-bison/2020-11/msg00027.html
* src/tables.c (default_goto): Use 0 rather than -1 as invalid value.
* tests/regression.at: Adjust.
We were declaring foo_parse_expr but implementing yyparse_expr.
* data/skeletons/yacc.c (_b4_define_sub_yyparse): Use api.prefix for
the parse function name.
This avoids heap allocation and gives minimal costs for the
creation and destruction of the YYParser.Symbol struct if
the location tracking is active.
Suggested by H. S. Teoh.
* data/skeletons/lalr1.d: Here.
* doc/bison.texi: Document it.
* examples/d/calc/calc.y: Adjust.
* tests/calc.at: Test it.
The complete symbol approach was deemed to be the right approach for Dlang.
Now, the user can return from yylex() an instance of YYParser.Symbol structure,
which binds together the TokenKind, the semantic value and the location. Before,
the last two were reported separately to the parser.
Only the user API is changed, Bisons's internal structure is kept the same.
* data/skeletons/d.m4 (struct YYParser.Symbol): New.
* data/skeletons/lalr1.d: Change the return value.
* doc/bison.texi: Document it.
* examples/d/calc/calc.y, examples/d/simple/calc.y: Demonstrate it.
* tests/calc.at, tests/scanner.at: Test it.
When using lookahead correction, the method YYParser.Context.getExpectedTokens
is not annotated with const, because the method calls yylacCheck, which is not
const. Also, because of yylacStack and yylacEstablished, yylacCheck needs to
be called from the context of the parser class, which is sent as parameter to
the Context's constructor.
* data/skeletons/lalr1.d (yylacCheck, yylacEstablish, yylacDiscard,
yylacStack, yylacEstablished): New.
(Context): Use it.
* doc/bison.texi: Document it.
* tests/calc.at: Check it.
Changed from syntax_error to reportSyntaxError to be similar to the Java parser.
* data/skeletons/lalr1.d: Change the function name.
* doc/bison.texi: Document it.
* tests/local.at: Adjust.
