rust/tests/run-make/wasm-custom-section/bar.rs

#![crate_type = "cdylib"]
#![deny(warnings)]

extern crate foo;

#[link_section = "foo"]
pub static A: [u8; 2] = [5, 6];

#[link_section = "baz"]
pub static B: [u8; 2] = [7, 8];

#[no_mangle]
pub extern fn foo() {}
rustc: Add a `#[wasm_custom_section]` attribute This commit is an implementation of adding custom sections to wasm artifacts in rustc. The intention here is to expose the ability of the wasm binary format to contain custom sections with arbitrary user-defined data. Currently neither our version of LLVM nor LLD supports this so the implementation is currently custom to rustc itself. The implementation here is to attach a `#[wasm_custom_section = "foo"]` attribute to any `const` which has a type like `[u8; N]`. Other types of constants aren't supported yet but may be added one day! This should hopefully be enough to get off the ground with some custom section support. The current semantics are that any constant tagged with `#[wasm_custom_section]` section will be appended to the corresponding section in the final output wasm artifact (and this affects dependencies linked in as well, not just the final crate). This means that whatever is interpreting the contents must be able to interpret binary-concatenated sections (or each constant needs to be in its own custom section). To test this change the existing `run-make` test suite was moved to a `run-make-fulldeps` folder and a new `run-make` test suite was added which applies to all targets by default. This test suite currently only has one test which only runs for the wasm target (using a node.js script to use `WebAssembly` in JS to parse the wasm output). 2018-03-09 11:26:15 -06:00			`#![crate_type = "cdylib"]`
			`#![deny(warnings)]`
rustc: Tweak funclet cleanups of ffi functions This commit is targeted at addressing #48251 by specifically fixing a case where a longjmp over Rust frames on MSVC runs cleanups, accidentally running the "abort the program" cleanup as well. Added in #46833 `extern` ABI functions in Rust will abort the process if Rust panics, and currently this is modeled as a normal cleanup like all other destructors. Unfortunately it turns out that `longjmp` on MSVC is implemented with SEH, the same mechanism used to implement panics in Rust. This means that `longjmp` over Rust frames will run Rust cleanups (even though we don't necessarily want it to). Notably this means that if you `longjmp` over a Rust stack frame then that probably means you'll abort the program because one of the cleanups will abort the process. After some discussion on IRC it turns out that `longjmp` doesn't run cleanups for caught exceptions, it only runs cleanups for cleanup pads. Using this information this commit tweaks the codegen for an `extern` function to a catch-all clause for exceptions instead of a cleanup block. This catch-all is equivalent to the C++ code: try { foo(); } catch (...) { bar(); } and in fact our codegen here is designed to match exactly what clang emits for that C++ code! With this tweak a longjmp over Rust code will no longer abort the process. A longjmp will continue to "accidentally" run Rust cleanups (destructors) on MSVC. Other non-MSVC platforms will not rust destructors with a longjmp, so we'll probably still recommend "don't have destructors on the stack", but in any case this is a more surgical fix than #48567 and should help us stick to standard personality functions a bit longer. 2018-02-26 20:59:47 -06:00
rustc: Add a `#[wasm_custom_section]` attribute This commit is an implementation of adding custom sections to wasm artifacts in rustc. The intention here is to expose the ability of the wasm binary format to contain custom sections with arbitrary user-defined data. Currently neither our version of LLVM nor LLD supports this so the implementation is currently custom to rustc itself. The implementation here is to attach a `#[wasm_custom_section = "foo"]` attribute to any `const` which has a type like `[u8; N]`. Other types of constants aren't supported yet but may be added one day! This should hopefully be enough to get off the ground with some custom section support. The current semantics are that any constant tagged with `#[wasm_custom_section]` section will be appended to the corresponding section in the final output wasm artifact (and this affects dependencies linked in as well, not just the final crate). This means that whatever is interpreting the contents must be able to interpret binary-concatenated sections (or each constant needs to be in its own custom section). To test this change the existing `run-make` test suite was moved to a `run-make-fulldeps` folder and a new `run-make` test suite was added which applies to all targets by default. This test suite currently only has one test which only runs for the wasm target (using a node.js script to use `WebAssembly` in JS to parse the wasm output). 2018-03-09 11:26:15 -06:00			`extern crate foo;`
rustc: Tweak funclet cleanups of ffi functions This commit is targeted at addressing #48251 by specifically fixing a case where a longjmp over Rust frames on MSVC runs cleanups, accidentally running the "abort the program" cleanup as well. Added in #46833 `extern` ABI functions in Rust will abort the process if Rust panics, and currently this is modeled as a normal cleanup like all other destructors. Unfortunately it turns out that `longjmp` on MSVC is implemented with SEH, the same mechanism used to implement panics in Rust. This means that `longjmp` over Rust frames will run Rust cleanups (even though we don't necessarily want it to). Notably this means that if you `longjmp` over a Rust stack frame then that probably means you'll abort the program because one of the cleanups will abort the process. After some discussion on IRC it turns out that `longjmp` doesn't run cleanups for caught exceptions, it only runs cleanups for cleanup pads. Using this information this commit tweaks the codegen for an `extern` function to a catch-all clause for exceptions instead of a cleanup block. This catch-all is equivalent to the C++ code: try { foo(); } catch (...) { bar(); } and in fact our codegen here is designed to match exactly what clang emits for that C++ code! With this tweak a longjmp over Rust code will no longer abort the process. A longjmp will continue to "accidentally" run Rust cleanups (destructors) on MSVC. Other non-MSVC platforms will not rust destructors with a longjmp, so we'll probably still recommend "don't have destructors on the stack", but in any case this is a more surgical fix than #48567 and should help us stick to standard personality functions a bit longer. 2018-02-26 20:59:47 -06:00
rustc: Use link_section, not wasm_custom_section This commit transitions definitions of custom sections on the wasm target from the unstable `#[wasm_custom_section]` attribute to the already-stable-for-other-targets `#[link_section]` attribute. Mostly the same restrictions apply as before, except that this now applies only to statics. Closes #51088 2018-07-13 13:30:47 -05:00			`#[link_section = "foo"]`
			`pub static A: [u8; 2] = [5, 6];`
rustc: Tweak funclet cleanups of ffi functions This commit is targeted at addressing #48251 by specifically fixing a case where a longjmp over Rust frames on MSVC runs cleanups, accidentally running the "abort the program" cleanup as well. Added in #46833 `extern` ABI functions in Rust will abort the process if Rust panics, and currently this is modeled as a normal cleanup like all other destructors. Unfortunately it turns out that `longjmp` on MSVC is implemented with SEH, the same mechanism used to implement panics in Rust. This means that `longjmp` over Rust frames will run Rust cleanups (even though we don't necessarily want it to). Notably this means that if you `longjmp` over a Rust stack frame then that probably means you'll abort the program because one of the cleanups will abort the process. After some discussion on IRC it turns out that `longjmp` doesn't run cleanups for caught exceptions, it only runs cleanups for cleanup pads. Using this information this commit tweaks the codegen for an `extern` function to a catch-all clause for exceptions instead of a cleanup block. This catch-all is equivalent to the C++ code: try { foo(); } catch (...) { bar(); } and in fact our codegen here is designed to match exactly what clang emits for that C++ code! With this tweak a longjmp over Rust code will no longer abort the process. A longjmp will continue to "accidentally" run Rust cleanups (destructors) on MSVC. Other non-MSVC platforms will not rust destructors with a longjmp, so we'll probably still recommend "don't have destructors on the stack", but in any case this is a more surgical fix than #48567 and should help us stick to standard personality functions a bit longer. 2018-02-26 20:59:47 -06:00
rustc: Use link_section, not wasm_custom_section This commit transitions definitions of custom sections on the wasm target from the unstable `#[wasm_custom_section]` attribute to the already-stable-for-other-targets `#[link_section]` attribute. Mostly the same restrictions apply as before, except that this now applies only to statics. Closes #51088 2018-07-13 13:30:47 -05:00			`#[link_section = "baz"]`
			`pub static B: [u8; 2] = [7, 8];`
rustc: Tweak funclet cleanups of ffi functions This commit is targeted at addressing #48251 by specifically fixing a case where a longjmp over Rust frames on MSVC runs cleanups, accidentally running the "abort the program" cleanup as well. Added in #46833 `extern` ABI functions in Rust will abort the process if Rust panics, and currently this is modeled as a normal cleanup like all other destructors. Unfortunately it turns out that `longjmp` on MSVC is implemented with SEH, the same mechanism used to implement panics in Rust. This means that `longjmp` over Rust frames will run Rust cleanups (even though we don't necessarily want it to). Notably this means that if you `longjmp` over a Rust stack frame then that probably means you'll abort the program because one of the cleanups will abort the process. After some discussion on IRC it turns out that `longjmp` doesn't run cleanups for caught exceptions, it only runs cleanups for cleanup pads. Using this information this commit tweaks the codegen for an `extern` function to a catch-all clause for exceptions instead of a cleanup block. This catch-all is equivalent to the C++ code: try { foo(); } catch (...) { bar(); } and in fact our codegen here is designed to match exactly what clang emits for that C++ code! With this tweak a longjmp over Rust code will no longer abort the process. A longjmp will continue to "accidentally" run Rust cleanups (destructors) on MSVC. Other non-MSVC platforms will not rust destructors with a longjmp, so we'll probably still recommend "don't have destructors on the stack", but in any case this is a more surgical fix than #48567 and should help us stick to standard personality functions a bit longer. 2018-02-26 20:59:47 -06:00
rustc: Add a `#[wasm_custom_section]` attribute This commit is an implementation of adding custom sections to wasm artifacts in rustc. The intention here is to expose the ability of the wasm binary format to contain custom sections with arbitrary user-defined data. Currently neither our version of LLVM nor LLD supports this so the implementation is currently custom to rustc itself. The implementation here is to attach a `#[wasm_custom_section = "foo"]` attribute to any `const` which has a type like `[u8; N]`. Other types of constants aren't supported yet but may be added one day! This should hopefully be enough to get off the ground with some custom section support. The current semantics are that any constant tagged with `#[wasm_custom_section]` section will be appended to the corresponding section in the final output wasm artifact (and this affects dependencies linked in as well, not just the final crate). This means that whatever is interpreting the contents must be able to interpret binary-concatenated sections (or each constant needs to be in its own custom section). To test this change the existing `run-make` test suite was moved to a `run-make-fulldeps` folder and a new `run-make` test suite was added which applies to all targets by default. This test suite currently only has one test which only runs for the wasm target (using a node.js script to use `WebAssembly` in JS to parse the wasm output). 2018-03-09 11:26:15 -06:00			`#[no_mangle]`
			`pub extern fn foo() {}`