Now that symbols behaves properly, we can eliminate special routines
that are no longer needed.
* data/c++.m4, data/glr.cc, data/lalr1.cc, data/variant.hh:
Remove useless assignment operators and copy constructors.
As a consequence, remove useless includes for "abort".
The current approach was too adhoc: the symbols were not sufficiently
self-contained, in particular wrt memory management. The "new"
guideline is the one that should have been followed from the start:
let the symbols handle themslves, instead of leaving their users to
it. It was justified by the will to avoid gratuitious moves and
copies, but the current approach does not seem to be slower, yet it
will probably be simpler to adjust to support move semantics from
C++11.
The documentation says that the %parse-param are available from the
%destructor. In retrospect, that was a silly design decision, which
we can break for variants, as its a new feature. It should be phased
out for non-variants too.
* data/variant.hh: A variant never knows if it stores something or
not, it is up to its users to store this information.
Yet, in parse.assert mode, make sure the empty/filled variants
are properly used.
(b4_symbol_constructor_define_): Don't call directly the symbol
constructor, to save a useless temporary.
* data/stack.hh (push): Steal the pushed value instead of duplicating
it.
This will simplify the callers of push, who handled this "move"
approach themselves.
* data/c++.m4 (basic_symbol): Let -1, as kind, denote the fact that
a symbol is empty.
This is needed for instance when shifting the lookahead: yyla
is given as argument to "push", and its value is then moved on
the stack. But then yyla must be declared "empty" so that its
destructor won't be called.
(basic_symbol::move): New.
Move the responsibility of calling the destructor from yy_destroy
to ~basic_symbol in the case of variants.
* data/lalr1.cc (stack_symbol_type): Now a derived class from its
previous value, so that we can add a constructor from a symbol_type.
(by_state): State -1 means empty.
(yypush_): Factor, by calling one overload from the other one, and
using the new semantics of stack::push.
No longer reclaim by hand the memory from rhs symbols, since now
that we store objects with proper destructors, they will be reclaimed
automatically.
Conversely, be sure to delete yylhs.
* tests/c++.at (C++ Variant-based Symbols): New "unit" test for
symbols.
* data/variant.hh (variant, operator=): Make private.
* data/c++.m4 (operator=): New, to avoid needing a definition of that operator
for each class member (such as a possible variant).
* data/glr.cc, data/lalr.cc: Add the necessary include for the abort.
A "symbol" groups together the symbol type (INT, PLUS, etc.), its
possible semantic value, and its optional location. The type is
needed to access the value, as it is stored as a variant/union.
There are two kinds of symbols. "symbol_type" are "external symbols":
they have type, value and location, and are returned by yylex.
"stack_symbol_type" are "internal symbols", they group state number,
value and location, and are stored in the parser stack. The type of
the symbol is computed from the state number.
The class template symbol_base_type<Exact> factors the code common to
stack_symbol_type and symbol_type. It uses the Curiously Recurring
Template pattern so that we can always (static_) downcast to the exact
type. symbol_base_type features value and location, and delegates the
handling of the type to its parameter.
When trying to generalize the support for variant, a significant issue
was revealed: because stack_symbol_type and symbol_type _derive_ from
symbol_base_type, the type/state member is defined _after_ the value
and location. In C++ the order of the definition of the members
defines the order in which they are initialized, things go backward:
the value is initialized _before_ the type. This is wrong, since the
type is needed to access the value.
Therefore, we need another means to factor the common code, one that
ensures the order of the members.
The idea is simple: define two (base) classes that code the symbol
type ("by_type" codes it by its type, and "by_state" by the state
number). Define basic_symbol<Base> as the class template that
provides value and location support. Make it _derive_ from its
parameter, by_type or by_state. Then define stack_symbol_type and
symbol_type as basic_symbol<by_state>, basic_symbol<by_type>. The
name basic_symbol was chosen by similarity with basic_string and
basic_ostream.
* data/c++.m4 (symbol_base_type<Exact>): Remove, replace by...
(basic_symbol<Base>): which derives from its parameter, one of...
(by_state, by_type): which provide means to retrieve the actual type of
symbol.
(symbol_type): Is now basic_symbol<by_type>.
(stack_symbol_type): Is now basic_symbol<by_state>.
* data/lalr1.cc: Many adjustments.
The commit 38de4e570f underquoted the
content of the comments, which resulted in losing square brackets in
the comments. Besides, some other invocations were underquoting the
effective arguments.
* data/c.m4 (b4_comment_): Properly quote the comment.
(b4_comment_, b4_comment): Move to...
* data/c-like.m4: here, so that...
* data/java.m4: can use it instead of its own copy.
* data/bison.m4 (b4_integral_parser_tables_map): Fix some comments.
* data/lalr1.cc, data/lalr1.java, data/yacc.c: Comment fixes.
* data/lalr1.cc: Reorder a bit to factor some CPP directives.
The YYLEX existed only to support YYLEX_PARAM, which is now removed.
This macro was a nuisance, since incorrect yylex calls where pointed
the macro _use_, instead of its definition.
* data/c.m4 (b4_lex_formals, b4_lex): New.
* data/glr.c, data/yacc.c: Use it.
* data/lalr1.cc (b4_lex): New.
Use it.
squash! skeletons: no longer call yylex via a CPP macro
The "variant" structure provides a means to store, in a typeless way,
C++ objects. Manipulating it without provide the type of the stored
content is doomed to failure. So provide a means to copy in a type
safe way, and prohibit typeless assignments.
* data/c++.m4 (symbol_type::move): New.
* data/lalr1.cc: Use it.
* data/variant.hh (b4_variant_define): Provide variant::copy.
Let variant::operator= abort.
We cannot undefine it, yet, as it is still uses by the implicit
assigment in symbols, which must also be disabled.
Equip variants with more checking code. Provide a means to request
includes.
* data/variant.hh (b4_variant_includes): New.
* data/lalr1.cc: Use it.
* data/variant.hh (variant::built): Define at the end, as a private member.
(variant::tname): New.
Somewhat makes "built" useless, but let's keep both for a start, in
case using "typeinfo" is considered unacceptable in some environments.
Fix some formatting issues.
* origin/maint:
parser: accept #line NUM
m4: use a safer pattern to enable/disable output
tests: beware of gnulib's need for config.h
gnulib: update
yacc.c, glr.c: check and fix the display of locations
formatting changes
glr.c: remove stray macro
Conflicts:
data/c.m4
data/glr.cc
data/lalr1.cc
data/lalr1.java
data/location.cc
data/stack.hh
data/yacc.c
src/scan-gram.l
Work on some other areas of Bison revealed that some macros expanded
to be expanded only once were actually expanded several times. This
was due to the fact that changecom was not properly restored each
time, and macro names appearing in comments were then expanded.
Introduce begin/end macros which are easier to match that
changecom()/changecom(#).
* data/bison.m4 (b4_output_begin, b4_output_end): New.
* data/glr.c, data/glr.cc, data/lalr1.cc, data/lalr1.java,
* data/location.cc, data/stack.hh, data/yacc.c:
Use them.
* data/bison.m4 (b4_lex_symbol_if): Rename as...
(b4_token_ctor_if): this.
Depend upon api.token.constructor.
* data/c++.m4, data/lalr1.cc: Adjust.
* doc/bison.texi: Fix all the occurrences of lex_symbol.
* etc/bench.pl.in: Adjust.
* examples/variant.yy: Likewise.
* tests/local.at (AT_BISON_OPTION_PUSHDEFS, AT_BISON_OPTION_POPDEFS):
Handle AT_TOKEN_CTOR_IF.
* tests/c++.at: Adjust to using api.token.constructor and AT_TOKEN_CTOR_IF.
Simplify the test of both build call styles.
(AT_CHECK_VARIANTS): Rename as...
(AT_TEST): this.
And undef when done.
* origin/maint:
tests: check %no-lines
tests: minor simplification
graphs: stylistic changes.
graphs: minor style changes
graphs: show reductions
graphs: style: prefix state number with "state"
graphs: style: use left justification for states
graphs: style: prefix rules and change shapes
obstack: import obstack_finish0 from master
c++: api.location.type
muscles: a function for backward compatibility
maint: more macros
Conflicts:
data/glr.cc
data/java.m4
data/lalr1.cc
doc/bison.texi
src/muscle-tab.c
src/system.h
tests/calc.at
This feature was introduced in 95a2de5695
(which is part of 2.5), but not documented. Give it a proper name, and
make it public.
* data/c++.m4, data/lalr1.cc, data/glr.cc, data/java.m4: Use
api.location.type instead of location_type.
* src/muscle-tab.c (muscle_percent_variable_update): Map the latter to
the former.
* tests/local.at: Adjust.
* tests/calc.at: Use api.location.type.
Leave tests/java.at with location_type, at least for the time being,
to cover both names.
* doc/bison.texi: Document api.location.type.
(User Defined Location Type): New.
* NEWS: Update.
* tests/c++.at (Exception safety): Let the parser support the --debug
option.
On 'p', throw an exception from the %printer.
* data/lalr1.cc (yyparse): Do not display the values we discard, as it
uses %printer, which might have thrown the exception.
* data/lalr1.cc: Check size > 1, rather than size != 1, when cleaning
the stack, as at the beginning, size is 0.
* tests/c++.at (Exception safety): Check exception safety in
%initial-action.
lalr1.cc does not reclaim its memory when ended by an exception.
Reported by Oleksii Taran:
http://lists.gnu.org/archive/html/help-bison/2012-09/msg00000.html
* data/lalr1.cc (yyparse): Protect the whole yyparse by a try-catch
block that cleans the stack and the lookahead.
* data/lalr1.cc (YY_SYMBOL_PRINT, YY_REDUCE_PRINT, YY_STACK_PRINT):
Define to something so that, for instance, "if (foo) YY_SYMBOL_PRINT"
is valid even when !YYDEBUG.
There are still spurious spaces at the end of some lines. But this is
addressed in the master branch, and I am reluctant to try to backport
this.
* data/yacc.c, data/glr.c, data/lalr1.cc, data/glr.cc: here.
* tests/calc.at (AT_CHECK_SPACES): New.
Use it.
Be sure not to introduce trailing empty lines in the *.y files.
* NEWS: Doc it.
* cfg.mk (syntax-check): Remove the exception.
* data/location.cc (b4_position_define, b4_location_define): New.
(location.hh, position.hh): Generate only if %defines.
* data/lalr1.cc: therefore, define these classes when locations are
needed, but headers are not generated.
* tests/output.at: Check that these files are not generated.
* NEWS: Document.
* data/glr.cc: Use b4_locations_if where appropriate.
* data/lalr1.cc: M4 quotation changes to highlight code duplication
with glr.cc.
* tests/calc.at: Check glr.cc with and without %location.
While at it, fuse multiple %parse-params into one.
* tests/actions.at: Simplify.
* NEWS: Doc this.
Some other wording changes.
* origin/maint: (29 commits)
regen
synclines: remove spurious empty line
also support $<foo>$ in the %initial-action
skeletons: b4_dollar_pushdef and popdef to simpify complex definitions
regen
printer/destructor: translate only once
factor the handling of m4 escaping
news: schedule the removal of the ";" hack
style changes in the scanners
regen
support $<tag>$ in printers and destructors
scan-code: factor the handling of the type in $<TYPE>$
muscles: fix another occurrence of unescaped type name
glr.cc: fix the handling of yydebug
gnulib: update
formatting changes
tests: fix an assertion
tests: adjust to GCC 4.8, which displays caret errors
be sure to properly escape type names
obstack_quote: escape and quote for M4
muscles: shuffle responsabilities
muscles: make private functions static
muscles: rename private functions/macros
obstack_escape: escape M4 characters
remove dead macro
maint: style changes
doc: avoid problems with case insensitive file systems
configure: fix botched quoting
news: fix typo.
Conflicts:
NEWS
data/c.m4
data/glr.cc
data/lalr1.cc
examples/rpcalc/local.mk
src/muscle-tab.h
src/output.c
src/parse-gram.c
src/parse-gram.h
src/parse-gram.y
src/scan-code.l
src/symlist.c
src/symlist.h
src/symtab.h
tests/calc.at
scan-code.l is already passing argument to b4_dollar_dollar for the
initial acton, but its definition (of b4_dollar_dollar) does not use
this argument.
Generalize this definition, and use it for the %initial-action too.
* data/c.m4 (b4_dollar_dollar_, b4_dollar_pushdef, b4_dollar_popdef):
Instead of expecting a pointer, require a value, and use ".".
Since they are now generic enough, move to...
* data/c-like.m4: this new file.
* data/c.m4, data/java.m4: Load it.
* data/glr.c, data/lalr1.cc, data/lalr1.java, data/yacc.c: Use
b4_dollar_pushdef for the %initial-action.
* tests/actions.at: Check that.
* data/Makefile.am: Adjust.
* NEWS, doc/bison.texi: Document.
* data/glr.c, data/glr.cc, data/lalr1.cc, data/lalr1.java, data/yacc.c:
Since the previous commit, b4_tokens_define and the like no longer need
b4_tokens.
* src/output.c (token_definitions_output): Remove.
* origin/maint:
tests: headers.at: strengthen.
glr.cc: do not override C++ definitions by C macros.
YYLLOC_DEFAULT: factor, and don't export it in headers.
api.prefix: do not use #define to handle YYSTYPE_IS_TRIVIAL etc.
tests: portability fixes.
c++: fewer #includes in the headers.
glr.cc: formatting changes.
tests: more logs.
api.prefix: also rename YYDEBUG.
Conflicts:
data/c.m4
data/glr.c
data/glr.cc
data/lalr1.cc
data/yacc.c
* data/c++.m4, data/c.m4 (b4_yylloc_default_define): New.
* data/glr.c, data/glr.cc, data/lalr1.cc, data/yacc.c: Use it.
* data/glr.cc: Do not define YYLLOC_DEFAULT in the header file,
but in the implementation one.
The testsuite in master has shown weird errors for the "Mulitple
Parsers" tests: the caller of p5.parse() received some apparently
random value, while tracing p5.parse() showed that the function was
consistently returning 0.
It happens when mixing several parser headers, some generated without
%debug, others with. In particular the C++ parser was generated with
%debug, i.e., with:
#ifndef YYDEBUG
# define YYDEBUG 1
#endif
and compiled separatedly. Yet, its header was included after the one
of another parser, this time without %debug, i.e., with
#ifndef YYDEBUG
# define YYDEBUG 0
#endif
in its header. As a result, the parser was compiled with YYDEBUG set,
but its header was used without. Since the layout of the objects are
then completely different, boom.
Therefore, do not change the value of YYDEBUG. Rather, use it as a
default value for <API.PREFIX>DEBUG.
* data/c.m4 (b4_YYDEBUG_define): New.
(b4_declare_yydebug): Rename as...
(b4_yydebug_declare): this, for consistency.
* data/glr.c, data/glr.cc, data/lalr1.cc, data/yacc.c: Use it.
* NEWS: Document it.
