In some casing, once we moved a stack symbol, we forget to mark the
source stack symbol as emptied. As a consequence, it may be destroyed
a second time.
This happens when the stack has to be resized.
* data/lalr1.cc (stack_symbol_type::stack_symbol_type): Record that
the source was emptied.
(stack_symbol_type::operator=): Likewise.
* tests/c++.at (C++ Variant-based Symbols Unit Tests): Force the stack
to be resized. Check its content.
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.
Currently, in C, the default semantic action is implemented by being
always run before running the actual user semantic action. As a
consequence, when the user action is run, $$ is already set as $1.
In C++ with variants, we don't do that, since we cannot manipulate the
semantic value without knowing its exact type. When variants are
enabled, the only guarantee is that $$ is default contructed and ready
to the used.
Some users still would like the default action to be run with
variants. Frank Heckenbach's parser in
C++17 (http://lists.gnu.org/archive/html/bug-bison/2018-04/msg00011.html)
provides this feature, but relying on std::variant's dynamic typing,
which we forbid in lalr1.cc.
The simplest seems to be actually generating the default semantic
action (in all languages/skeletons). This makes the pre-action (that
sets $$ to $1) useless. But... maybe some users depend on this, in
spite of the comments that clearly warn againt this. So let's not
turn this off just yet.
* src/reader.c (grammar_rule_check_and_complete): Rename as...
(grammar_rule_check_and_complete): this.
Install the default semantic action when applicable.
* examples/variant-11.yy, examples/variant.yy, tests/calc.at:
Exercise the default semantic action, even with variants.
Currently we use "<dir><api.location.file>" as \file argument, and as
base for the CPP guard. This is not nice when <dir> is absolute, in
which case it is expected that the user will use api.location.include
to get something nicer. If defined, use that name instead.
* data/location.cc (b4_location_path): New.
Use it.
* tests/c++.at (Shared locations): Check the guard and Doxygen doc.
Users may want to generate the location file elsewhere, say
$top_srcdir/include/ast/location.hh. Yet, we should not generate
`#include "$top_srcdir/include/ast/location.hh"` but probably
something like `#include <ast/location.hh>`, or `#include
"ast/location.hh", or `#include <location.hh>`. It entirely depends
on the compiler flags (-I/-isystem) that are used. Bison cannot guess
what is expected, so let's give the user a means to tell how the
location file should be included.
* data/location.cc (b4_location_file): New.
* data/glr.cc, data/lalr1.cc: Use it.
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.
* data/location.cc: Sort includes.
(b4_position_file, b4_location_file): New.
When there's a file for locations but not for positions, include the
definition of position in the location file.
* data/lalr1.cc (b4_shared_declarations): Include the
position/location file when it exists.
Otherwise, define the class.
* data/glr.cc: Likewise.
* tests/input.at (%define file variables): Check them.
* tests/output.at (C++ output): Check various cases with
api.position.file and api.location.file.
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.
They are not the same concept. It appears that we still consider that
api.prefix is the default for api.namespace. We should stop that.
* tests/local.at (AT_BISON_OPTION_PUSHDEFS, AT_BISON_OPTION_POPDEFS):
Separate namespace and prefix.
Adjust dependencies.
* src/getargs.c (getargs): Don't display any argv other that argv[0]
when reporting a missing argument.
* tests/bison.in: Neutralize path differences in stderr.
* tests/input.at (Invalid number of arguments): New.
This has been bugging me for while. I was hard to reproduce: it
worked only on GNU/Linux, probably because libc++ implements the small
string optimization, while libstdc++ did not and actually allocated on
the heap for this small string.
See https://lists.gnu.org/archive/html/bison-patches/2018-09/msg00110.html.
* tests/types.at (api.value.type): Do not provide a semantic value to
EOF.
The forthcoming automove feature, to be properly checked, will require
that we can rely on the value of a moved-from string, which is not
something the C++ standard guarantees. So introduce our own wrapper.
Suggested by Frank Heckenbach.
https://lists.gnu.org/archive/html/bison-patches/2018-09/msg00111.html
* tests/c++.at (Variants): Introduce and use a new 'string' class.
The 'Variants' tests are well suited to check support for move, and in
particular for the forthcoming automove feature. But the tests were
written to show the best practice in C++98, using swap:
list "," item { std::swap ($$, $1); $$.push_back ($3); }
This cannot work with std::move. So, make this example simpler, based
on regular assignment instead of swap, which is a regression for
C++98 (as the new traces show), but will be an improvement for modern
C++ with automove.
* tests/c++.at (Variants): Stop using swap.
We don't generate a header file, so remove the 'require' code section.
Adjust expectations.
Several types of failures. First, unable to pass the file name
properly to the linker.
./synclines.at:416: $CC $CFLAGS $CPPFLAGS $LDFLAGS -o \"\\\"\" \"\\\"\".c $LIBS
stderr:
ld: cannot open output file "/"": No such file or directory
stdout:
Unable to save under such a file name.
./synclines.at:421: $CXX $CXXFLAGS $CPPFLAGS -c $LDFLAGS -o \"\\\"\" \"\\\"\".cc $LIBS
stderr:
error: can't open file "/"" for write
compilation aborted for "\"".cc (code 1)
Spurious output because of warning flags is failed to reject as an
error during configure:
./headers.at:343: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS c-only.o cxx-only.o -o c-and-cxx ||
exit 77
--- /dev/null 2018-09-18 21:21:37.745649000 +0000
+++ /home/travis/build/akimd/bison/tests/testsuite.dir/at-groups/222/stderr 2018-09-18 21:28:17.291919519 +0000
@@ -0,0 +1,7 @@
+icpc: command line warning #10006: ignoring unknown option '-Wcast-align'
+icpc: command line warning #10006: ignoring unknown option '-fparse-all-comments'
+icpc: command line warning #10006: ignoring unknown option '-Wdocumentation'
+icpc: command line warning #10006: ignoring unknown option '-Wnull-dereference'
+icpc: command line warning #10006: ignoring unknown option '-Wnoexcept'
+icpc: command line warning #10006: ignoring unknown option '-fno-color-diagnostics'
+icpc: command line warning #10006: ignoring unknown option '-Wno-keyword-macro'
stdout:
* tests/local.at (AT_SKIP_IF_CANNOT_LINK_C_AND_CXX): Also ignore
stderr, as with ICC we get
* tests/synclines.at (syncline escapes): Don't link the output.
The code was already using midrule only, never mid_rule. This is
simpler to remember, and matches a similar change we made from
look-ahead to lookahead.
* NEWS, doc/bison.texi, src/reader.c, src/scan-code.h, src/scan-code.l
* tests/actions.at, tests/c++.at, tests/existing.at: here.
On the CI, we have this spurious failure with clang 3.9 with
-std=c++17:
In file included from list.y:23:
In file included from /usr/include/c++/4.8/iostream:39:
In file included from /usr/include/c++/4.8/ostream:38:
In file included from /usr/include/c++/4.8/ios:42:
In file included from /usr/include/c++/4.8/bits/ios_base.h:41:
In file included from /usr/include/c++/4.8/bits/locale_classes.h:40:
In file included from /usr/include/c++/4.8/string:52:
In file included from /usr/include/c++/4.8/bits/basic_string.h:2815:
In file included from /usr/include/c++/4.8/ext/string_conversions.h:43:
/usr/include/c++/4.8/cstdio:120:11: error: no member named 'gets' in the global namespace
using ::gets;
~~^
This shows that our test, based on gl_WARN_ADD, is a joke. We have to
really check for at least a bit of C++.
* m4/ax_check_compile_flag.m4, m4/bison-cxx-std.m4: New.
* configure.ac: Use them to make sure the compiler actually works.
In C++ pre C++11 it is standard practice to use 0 for the null pointer.
But GCC pre 8 -std=c++98 with -Wzero-as-null-pointer-constant warns about
this.
So disable -Wzero-as-null-pointer-constant when compiling C++ pre 11.
Let's do this in AT_DATA_SOURCE_PROLOGUE (which is pasted on top of
all the test grammar files). Unfortunately, that shifts all the
locations in the expected error messages, which would be too noisy.
Instead, let's introduce testsuite.h, which can vary in length, and
include it in AT_DATA_SOURCE_PROLOGUE.
* tests/testsuite.h: New.
Disable -Wzero-as-null-pointer-constant's warning with GCC pre 8,
C++ pre 11.
* tests/local.at (AT_DATA_SOURCE_PROLOGUE): Use it.
* tests/atlocal.in (CPPFLAGS): Find it.
* tests/local.mk: Ship it.
* data/c.m4 (YY_NULLPTR): Prefer ((void*)0) to 0 in C.
This is much of course more efficient than in the matrix of the CI (or
on our own machines), but a bit more tedious.
* configure.ac (CXX03_CXXFLAGS, CXX11_CXXFLAGS, CXX14_CXXFLAGS)
(CXX17_CXXFLAGS, CXX2A_CXXFLAGS, STDCXX_FLAGS): New.
* tests/atlocal.in: Receive them.
* tests/local.at (AT_FOR_EACH_CXX): New.
* tests/c++.at: Use AT_FOR_EACH_CXX.
Reported by Frank Heckenbach.
http://lists.gnu.org/archive/html/bug-bison/2018-03/msg00002.html
Actually the assignment operator should never be needed: the C++98
requirements for vector::push_back is CopyInsertable, which does not require
an assignment operator. However, libstdc++ shipped with GCC up to (and
including) 6 uses the assignment operator (which affects Clang on top of
libstdc++, but also ICC). So let's keep it for legacy C++.
See https://gcc.godbolt.org/z/q0XXmC.
* data/lalr1.cc (stack_symbol_type::operator=): Remove.
* data/c++.m4 (basic_symbol::operator=): Ditto.
* tests/c++.at (C++ Variant-based Symbols Unit Tests): Adjust.
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.
We have some maintainer-check-foo and some maintainer-foo-check. Keep
only the former.
* tests/local.mk (maintainer-push-check, maintainer-xml-check)
(maintainer-release-check): Rename as...
(maintainer-check-push, maintainer-check-xml)
(maintainer-check-release): these.
Most of our variables for C++ flags are named FOO_CXXFLAGS, not
CXXFLAGS_FOO.
* configure.ac, tests/atlocal.in, tests/calc.at
(NO_EXCEPTIONS_CXXFLAGS): Rename as...
(CXXFLAGS_NO_EXCEPTIONS): this.
Clang++ issues warnings when it's used to compile C. This make target
is precisely checking whether we can do that.
* configure.ac (NO_DEPRECATED_CXXFLAGS): New.
* tests/atlocal.in: Use it.
With GCC7 we have warnings (false positive):
x8.c: In function 'x8_parse':
x8.c:1233:16: error: 'yylval' may be used uninitialized in this function [-Werror=maybe-uninitialized]
yylval = *yypushed_val;
~~~~~~~^~~~~~~~~~~~~~~
x8.c: In function 'x8_pull_parse':
x8.c:1233:16: error: 'yylval' may be used uninitialized in this function [-Werror=maybe-uninitialized]
yylval = *yypushed_val;
~~~~~~~^~~~~~~~~~~~~~~
See also 9645a2b20e.
* tests/local.at (AT_PUSH_IF): New.
(AT_BISON_OPTION_POPDEFS): Pop it, and pop AT_PURE_IF.
* tests/headers.at (Several parsers, Several parsers): Disable these
warnings when in push parser.
The header generated for variants with assertions but without
locations, is not self-contained. Prepare a check for this.
* tests/headers.at (Sane headers): New, extracted from...
(Several parsers): here.
On these tests, at -O2 and above, GCC 8 complains that yylval may be
uninitialized. But it seems wrong: it is initialized. Rather than
turning off the warning in the skeleton (hence possibility hiding
relevant warnings of user parsers), let's turn it off in the tests
only.
163: parse.error=verbose and consistent errors: FAILED (conflicts.at:625)
165: parse.error=verbose and consistent errors: lr.default-reduction=consistent FAILED (conflicts.at:635)
166: parse.error=verbose and consistent errors: lr.default-reduction=accepting FAILED (conflicts.at:641)
167: parse.error=verbose and consistent errors: lr.type=canonical-lr FAILED (conflicts.at:645)
168: parse.error=verbose and consistent errors: parse.lac=full FAILED (conflicts.at:650)
169: parse.error=verbose and consistent errors: parse.lac=full lr.default-reduction=accepting FAILED (conflicts.at:655)
We get:
input.c: In function 'yyparse':
input.c:980:9: error: 'yylval' may be used uninitialized in this function [-Werror=maybe-uninitialized]
YYSTYPE yylval YY_INITIAL_VALUE (= yyval_default);
^~~~~~
cc1: all warnings being treated as errors
See https://lists.gnu.org/archive/html/bison-patches/2018-08/msg00063.html.
* tests/conflicts.at (AT_CONSISTENT_ERRORS_CHECK): Disable
-Wmaybe-uninitialized.
Reported by Brooks Moses <bmoses@google.com>
http://lists.gnu.org/archive/html/bison-patches/2018-02/msg00000.html
* data/lalr1.cc (YY_EXCEPTIONS): New.
Use it to disable try/catch clauses.
* doc/bison.texi (C++ Parser Interface): Document it.
* configure.ac (CXXFLAGS_NO_EXCEPTIONS): New.
* tests/atlocal.in: Receive it.
* tests/local.at (AT_FULL_COMPILE, AT_LANG_COMPILE):
Accept a new argument, extra compiler flags.
* tests/calc.at: Run the C++ calculator with exception support disabled.
Reported by Jannick.
http://lists.gnu.org/archive/html/bug-bison/2017-05/msg00001.html
"Amusingly" enough, we have the same problem with %defines when the
parser file name has backslashes or quotes: we generate #includes with
an incorrect C string.
* src/output.c (prepare_symbol_definitions): Escape properly the file
names before passing them to M4.
* data/bison.m4, data/lalr1.cc: Don't simply put the file name between
two quotes (that should have been strong enough a smell...), expect
the string to be properly quoted.
* tests/synclines.at: New tests to check this.
