Some users rely on this sentence to know that the file can be ignored.
Reported by Alexandre Duret-Lutz.
* data/bison.m4 (b4_generated_by): New.
(b4_copyright): Use it.
* data/location.cc, data/stack.hh: Use it too, for the stub files
(position.hh and stack.hh).
* data/lalr1.cc: Fix oldish comment.
* data/stack.hh: Prefer typename for type names.
Use size() instead of duplicating it.
* examples/variant-11.yy, examples/variant.yy (yylex): Use int,
as this is the type of the semantic value.
The files stack.hh and position.hh are deprecated. Rather than
devoting specify %define variables to discard them (api.position.file
and api.stack.file), and rather than having to use special rules when
api.location.file is used, let's simply decide that from %require
"3.2" onwards, these files will not be generated.
The only noticeable thing here is that, in order to be able to check
the behavior of %require "3.2", to have this version (which is still
3.1-*) to accept %require "3.2".
* src/gram.h, src/gram.c (required_version): New.
* src/parse-gram.y (version_check): Set it.
* src/output.c (prepare): Pass it m4.
* data/bison.m4 (b4_required_version_if): Receive it and use it.
* data/location.cc, data/stack.hh: Replace the api.*.file with only
required version comparison.
* tests/input.at: No longer check api.stack.file and api.position.file.
* NEWS, doc/bison.texi: Don't mention them.
Document the %require 3.2 behavior.
* tests/output.at: Use %require 3.2 instead.
In the case a user wants to create location.hh elsewhere, it can be
helpful to define api.location.file to some possibly absolute path
such as -Dapi.location.file='"$(top_srcdir)/include/ast/location.hh"'.
Currently this does not work with `-o foo/parser.cc`, as we join foo/
and $(top_srcdir) together, the latter starting with slash.
We should not try to do that in m4, manipulating file names is quite
complex when you through Windows file name in. Let m4 delegate this
to gnulib.
* src/scan-skel.l (at_output): Accept up to two arguments.
* data/bison.m4 (b4_output): Adjust.
* tests/skeletons.at (Fatal errors but M4 continues producing output):
Adjust to keep the error.
* data/location.cc, data/stack.hh: Leave the concatenation to @output.
* tests/output.at: Exercise api.location.file with an absolute path.
Make it easier to have fewer files.
* data/stack.hh: Don't generate stack.hh when api.location.file is
specified.
* tests/calc++.at, tests/output.at: Adjust tests.
Let's put the definition of position into location.hh, there's no real
value in keeping them separate: they are small, and share the same
requirements.
To help users transition to this new model, still generate position.hh
by default, but as a simple include to location.hh.
* data/location.cc (api.position.file): Accept only 'none' as possible
value.
(position.hh): Make it a stub.
(location.hh): Adjust.
(b4_position_define): Merge into...
(b4_location_define): this.
* data/glr.cc, data/lalr1.cc, tests/input.at, tests/output.at: Adjust.
It was not a good idea to generate the file stack.hh. It never was.
But now we have to deal with backward compatibility: if we stop
generating it, the build system of some build system will probably
break.
So offer the user a means to (i) decide what the name of the output
file should be, and (ii) not generate this file at all (its content
will be inline where the parser is defined).
* data/lalr1.cc (b4_percent_define_check_file_complain)
(b4_percent_define_check_file): New.
* data/stack.hh: Generate the file only if api.stack.file is not
empty.
In that case, use it as file name.
* data/lalr1.cc: Adjust to include the right file, or to include
the definition of stack.
* tests/calc.at, tests/output.at: Exercise api.stack.file.
Modern C++ (i.e., C++11 and later) introduced "move only" types: types such
as std::unique_ptr<T> that can never be duplicated. They must never be
copied (by assignments and constructors), they must be "moved". The
implementation of lalr1.cc used to copy symbols (including their semantic
values). This commit ensures that values are only moved in modern C++, yet
remain compatible with C++98/C++03.
Suggested by Frank Heckenbach, who provided a full implementation on
top of C++17's std::variant.
See http://lists.gnu.org/archive/html/bug-bison/2018-03/msg00002.html,
and https://lists.gnu.org/archive/html/bison-patches/2018-04/msg00002.html.
Symbols (terminal/non terminal) are handled by several functions that used
to take const-refs, which resulted eventually in a copy pushed on the stack.
With modern C++ (C++11 and later) the callers must use std::move, and the
callees must take their arguments as rvalue refs (foo&&). In order to avoid
duplicating these functions to support both legacy C++ and modern C++, let's
introduce macros (YY_MOVE, YY_RVREF, etc.) that rely on copy-semantics for
C++98/03, and move-semantics for modern C++.
That's easy for inner types, when the parser's functions pass arguments to
each other. Functions facing the user (make_NUMBER, make_STRING, etc.)
should support both rvalue-refs (for instance to support move-only types:
make_INT (std::make_unique<int> (1))), and lvalue-refs (so that we can pass
a variable: make_INT (my_int)). To avoid the multiplication of the
signatures (there is also the location), let's take the argument by value.
See:
https://lists.gnu.org/archive/html/bison-patches/2018-09/msg00024.html.
* data/c++.m4 (b4_cxx_portability): New.
(basic_symbol): In C++11, replace copy-ctors with move-ctors.
In C++11, replace copies with moves.
* data/lalr1.cc (stack_symbol_type, yypush_): Likewise.
Use YY_MOVE to avoid useless copies.
* data/variant.hh (variant): Support move-semantics.
(make_SYMBOL): In C++11, in order to support both read-only lvalues,
and rvalues, take the argument as a copy.
* data/stack.hh (yypush_): Use rvalue-refs in C++11.
* tests/c++.at: Use move semantics.
* tests/headers.at: Adjust to the new macros (YY_MOVE, etc.).
* configure.ac (CXX98_CXXFLAGS, CXX11_CXXFLAGS, CXX14_CXXFLAGS)
(CXX17_CXXFLAGS, ENABLE_CXX11): New.
* tests/atlocal.in: Receive them.
* examples/variant.yy: Don't define things in std.
* examples/variant-11.test, examples/variant-11.yy: New.
Check the support of move-only types.
* examples/README, examples/local.mk: Adjust.
This style appears to be more traditional, at least in C++.
For instance in the standard, [facets.examples].
There are occurrences using "unsigned int" too though.
* data/lalr1.cc, data/location.cc, data/stack.hh: here.
This is consistent with what is done with yacc.c and glr.c. Because
it also avoids that the stack needs to be resized very soon, it should
help keeping tests about destructors more reliable.
Indeed, if the stack is created too small, very soon the C++ library
needs to enlarge it, which means creating a new one, copying the
elements from the initial one onto it, and then destroy the elements
of the initial stack: that would be a spurious call to a destructor.
Reported by Thomas Jahns.
http://lists.gnu.org/archive/html/bug-bison/2015-01/msg00059.html
* data/stack.hh (stack::stack): Reserve 200 slots.
* tests/c++.at: Remove traces of stack expansions.
* origin/maint:
glr.cc: fix a clang warning
maint: update copyright years
build: fix VPATH issue
build: avoid clang's colored diagnostics in the test suite
tests: please clang and use ".cc", not ".c", for C++ input
gnulib: update
skeletons: avoid empty switch constructs
lalr1.cc: fix compiler warnings
yacc.c: do not use __attribute__ unprotected
tests: style changes
Reported by Rob Conde.
http://lists.gnu.org/archive/html/bug-bison/2013-03/msg00003.html
* data/stack.hh (operator=, stack(const stack&)): Make this class
uncopyable, i.e., "undefine" these operators: make them private and
don't implement them.
(clear): New.
* data/lalr1.cc: Use it instead of an assignment.
(parser): Make this class uncopyable.
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.
* 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.
This change was made by applying emacs' untabify function to
nearly all files in Bison's repository. Required tabs in make
files, ChangeLog, regexps, and test code were manually skipped.
Other notable exceptions and changes are listed below.
* bootstrap: Skip because we sync this with gnulib.
* data/m4sugar/foreach.m4
* data/m4sugar/m4sugar.m4: Skip because we sync these with
Autoconf.
* djgpp: Skip because I don't know how to test djgpp properly, and
this code appears to be unmaintained anyway.
* README-hacking (Hacking): Specify that tabs should be avoided
where not required.
