On Wed, Sep 14, 2022 at 6:20 PM Thomas Schwinge <tho...@codesourcery.com> wrote:
>
> Hi!
>
> On 2022-09-14T15:39:47+0200, Richard Biener via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> > On Wed, Aug 24, 2022 at 2:13 PM <herron.phi...@googlemail.com> wrote:
> >>
> >> From: Philip Herron <philip.her...@embecosm.com>
> >>
> >> We have some rust specific langugage options note -fwrapv is enabled by
> >> default in the code. We are trying to respect options such as
> >> -Wunused-result which we get by porting over c++ no-discard for rust's
> >> must-use attribute, so we have enabled these by default directly here.
> >
> > LGTM
>
> Actually, NACK. ;-)
>
> See <https://gcc.gnu.org/PR105914>
> "gccrs setting warn_unused_variable breaks thousands of non-Rust tests".
> The 'Init(1)' in 'gcc/rust/lang.opt' are in conflict with any (default)
> 'Init(0)' in other '*.opt' files -- remember that all '*.opt' files are
> processed together by GCC's "options machinery", and thus
> 'gcc/rust/lang.opt' may (and here, does) affect non-Rust front end code.
Ah, I wondered about the duplicates adding to the list of supported FEs, I guess
that the awk script should check for obvious mismatches in other settings?
> I do have a patch series adding a 'LangInit(@var{language}, @var{value})'
> option property, and patches to use this in a lot of places (here and in
> other front ends' '*.opt' files), where currently we implement such logic
> in '*.cc' files; '[...]_init_options_struct' functions via
> 'LANG_HOOKS_INIT_OPTIONS_STRUCT' (those then largely become empty and may
> be removed). I assume this idea to be uncontroversial; I "just" need to
> get it polished and submitted...
>
>
> Grüße
> Thomas
>
>
> >> gcc/rust/lang.opt | 118 ++++++++++++++++++++++++++++++++++++++++++++++
> >> 1 file changed, 118 insertions(+)
> >> create mode 100644 gcc/rust/lang.opt
> >>
> >> diff --git a/gcc/rust/lang.opt b/gcc/rust/lang.opt
> >> new file mode 100644
> >> index 00000000000..1f6855ede1d
> >> --- /dev/null
> >> +++ b/gcc/rust/lang.opt
> >> @@ -0,0 +1,118 @@
> >> +; Options for the Rust front end.
> >> +; Copyright (C) 2003-2022 Free Software Foundation, Inc.
> >> +;
> >> +; This file is part of GCC.
> >> +;
> >> +; GCC is free software; you can redistribute it and/or modify it under
> >> +; the terms of the GNU General Public License as published by the Free
> >> +; Software Foundation; either version 3, or (at your option) any later
> >> +; version.
> >> +;
> >> +; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
> >> +; WARRANTY; without even the implied warranty of MERCHANTABILITY or
> >> +; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
> >> +; for more details.
> >> +;
> >> +; You should have received a copy of the GNU General Public License
> >> +; along with GCC; see the file COPYING3. If not see
> >> +; <http://www.gnu.org/licenses/>.
> >> +
> >> +; See the GCC internals manual for a description of this file's format.
> >> +
> >> +; Please try to keep this file in ASCII collating order.
> >> +
> >> +; Describes command-line options used by this frontend
> >> +
> >> +Language
> >> +Rust
> >> +
> >> +I
> >> +Rust Joined Separate
> >> +; Documented in c.opt
> >> +
> >> +L
> >> +Rust Joined Separate
> >> +; Not documented
> >> +
> >> +Wall
> >> +Rust
> >> +; Documented in c.opt
> >> +
> >> +Wunused-variable
> >> +Rust Var(warn_unused_variable) Init(1) Warning
> >> +; documented in common.opt
> >> +
> >> +Wunused-const-variable
> >> +Rust Warning Alias(Wunused-const-variable=, 2, 0)
> >> +Warn when a const variable is unused.
> >> +
> >> +Wunused-const-variable=
> >> +Rust Joined RejectNegative UInteger Var(warn_unused_const_variable)
> >> Init(1) Warning LangEnabledBy(Rust,Wunused-variable, 1, 0) IntegerRange(0,
> >> 2)
> >> +Warn when a const variable is unused.
> >> +
> >> +Wunused-result
> >> +Rust Var(warn_unused_result) Init(1) Warning
> >> +Warn if a caller of a function, marked with attribute warn_unused_result,
> >> does not use its return value.
> >> +
> >> +frust-crate=
> >> +Rust Joined RejectNegative
> >> +-frust-crate=<name> Set the crate name for the compilation
> >> +
> >> +frust-debug
> >> +Rust Var(flag_rust_debug)
> >> +Dump various Rust front end internals.
> >> +
> >> +frust-dump-
> >> +Rust Joined RejectNegative
> >> +-frust-dump-<type> Dump Rust frontend internal information.
> >> +
> >> +frust-max-recursion-depth=
> >> +Rust RejectNegative Type(int) Var(rust_max_recursion_depth) Init(64)
> >> +-frust-max-recursion-depth=integer
> >> +
> >> +frust-mangling=
> >> +Rust Joined RejectNegative Enum(frust_mangling) Var(flag_rust_mangling)
> >> +-frust-mangling=[legacy|v0] Choose which version to use for name
> >> mangling
> >> +
> >> +Enum
> >> +Name(frust_mangling) Type(int) UnknownError(unknown rust mangling option
> >> %qs)
> >> +
> >> +EnumValue
> >> +Enum(frust_mangling) String(legacy) Value(0)
> >> +
> >> +EnumValue
> >> +Enum(frust_mangling) String(v0) Value(1)
> >> +
> >> +frust-cfg=
> >> +Rust Joined RejectNegative
> >> +-frust-cfg=<name> Set a config expansion option
> >> +
> >> +frust-edition=
> >> +Rust Joined RejectNegative Enum(frust_edition) Var(flag_rust_edition)
> >> +-frust-edition=[2015|2018|2021] Choose which edition to use
> >> when compiling rust code
> >> +
> >> +Enum
> >> +Name(frust_edition) Type(int) UnknownError(unknown rust edition %qs)
> >> +
> >> +EnumValue
> >> +Enum(frust_edition) String(2015) Value(0)
> >> +
> >> +EnumValue
> >> +Enum(frust_edition) String(2018) Value(1)
> >> +
> >> +EnumValue
> >> +Enum(frust_edition) String(2021) Value(2)
> >> +
> >> +frust-embed-metadata
> >> +Rust Var(flag_rust_embed_metadata)
> >> +Flag to enable embeding metadata directly into object files
> >> +
> >> +frust-metadata-output=
> >> +Rust Joined RejectNegative
> >> +-frust-metadata-output=<path.rox> Path to output crate metadata
> >> +
> >> +o
> >> +Rust Joined Separate
> >> +; Documented in common.opt
> >> +
> >> +; This comment is to ensure we retain the blank line above.
> >> --
> >> 2.25.1
> >>
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