Support `_Noreturn`, `[[noreturn]]`, `attribute((noreturn))` #2094

ojeda · 2021-08-24T20:05:11Z

Input C/C++ Header

C11:

_Noreturn void f(void);

C++11 (and potentially C2x with N2764):

[[noreturn]] void f();

GCC & Clang:

__attribute__((noreturn)) void f(void);

Actual Results

extern "C" {
    pub fn f();
}

Expected Results

extern "C" {
    pub fn f() -> !;
}

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Reported-by: Josh Poimboeuf <jpoimboe@kernel.org> Closes: https://lore.kernel.org/rust-for-linux/20230606215212.r7if2gsynajugf6j@treble/ Reported-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: Rust-for-Linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reword, add Josh's report and update Quick Start guide. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: #1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: #1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: #1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: #1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2284 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Link: rust-lang/rust-bindgen#2094 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: #1013 Tested-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2284 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Link: rust-lang/rust-bindgen#2094 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: Rust-for-Linux#1013 Tested-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2284 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Link: rust-lang/rust-bindgen#2094 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: Rust-for-Linux#1013 Tested-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2284 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Link: rust-lang/rust-bindgen#2094 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: Rust-for-Linux#1013 Tested-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

* Rationale: Upgrades bindgen to code-generation for anonymous unions, structs, and enums [7] for LLVM-16 based toolchains. The following upgrade also incorporates `noreturn` support from bindgen allowing us to remove useless `loop` calls which was placed as a workaround. * Truncated build logs on using bindgen `v0.56.0` prior to LLVM-16 toolchain: ``` $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... ``` * LLVM-16 Changes: API changes [1] were introduced such that libclang would emit names like "(unnamed union at compiler_types.h:146:2)" for unnamed unions, structs, and enums whereas it previously returned an empty string. * Bindgen Changes: Bindgen `v0.56.0` on LLVM-16 based toolchains hence was unable to process the anonymous union in `include/linux/compiler_types` `struct ftrace_branch_data` and caused subsequent panics as the new `libclang` API emitted name was not being handled. The following issue was fixed in Bindgen `v0.62.0` [2]. Bindgen `v0.58.0` changed the flags `--whitelist-*` and `--blacklist-*` to `--allowlist-*` and `--blocklist-*` respectively [3]. Bindgen `v0.61.0` added support for `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))` [4], hence the empty `loop`s used to circumvent bindgen returning `!` in place of `()` for noreturn attributes have been removed completely. Bindgen `v0.61.0` also changed default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` [5] flag to not bind `size_t` as `usize`. Bindgen `v0.65.0` removed `--size_t-is-usize` flag [6]. Link: llvm/llvm-project@19e984e [1] Link: rust-lang/rust-bindgen#2319 [2] Link: rust-lang/rust-bindgen#1990 [3] Link: rust-lang/rust-bindgen#2094 [4] Link: rust-lang/rust-bindgen@cc78b6f [5] Link: rust-lang/rust-bindgen#2408 [6] Closes: Rust-for-Linux/linux#1013 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Ariel Miculas <amiculas@cisco.com> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [boqun: resolve conflicts because of Rust version bump] Signed-off-by: Boqun Feng <boqun.feng@gmail.com>

This was referenced Aug 24, 2021

rust: generate bindings for helpers Rust-for-Linux/linux#359

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bindgen wanted features & bugfixes Rust-for-Linux/linux#353

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pvdrz mentioned this issue Aug 31, 2022

Handle no return attributes #2259

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emilio closed this as completed in #2259 Sep 23, 2022

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Support `_Noreturn`, `[[noreturn]]`, `attribute((noreturn))` #2094

Support `_Noreturn`, `[[noreturn]]`, `attribute((noreturn))` #2094

ojeda commented Aug 24, 2021

Support _Noreturn, [[noreturn]], __attribute__((noreturn)) #2094

Support _Noreturn, [[noreturn]], __attribute__((noreturn)) #2094

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ojeda commented Aug 24, 2021

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Support `_Noreturn`, `[[noreturn]]`, `attribute((noreturn))` #2094

Support `_Noreturn`, `[[noreturn]]`, `attribute((noreturn))` #2094