Matthias Krüger 7d78885a8e Rollup merge of #111891 - rustbox:feat/riscv-isr-cconv, r=jackh726 ... feat: `riscv-interrupt-{m,s}` calling conventions Similar to prior support added for the mips430, avr, and x86 targets this change implements the rough equivalent of clang's [`__attribute__((interrupt))`][clang-attr] for riscv targets, enabling e.g. ```rust static mut CNT: usize = 0; pub extern "riscv-interrupt-m" fn isr_m() { unsafe { CNT += 1; } } ``` to produce highly effective assembly like: ```asm pub extern "riscv-interrupt-m" fn isr_m() { 420003a0: 1141 addi sp,sp,-16 unsafe { CNT += 1; 420003a2: c62a sw a0,12(sp) 420003a4: c42e sw a1,8(sp) 420003a6: 3fc80537 lui a0,0x3fc80 420003aa: 63c52583 lw a1,1596(a0) # 3fc8063c <_ZN12esp_riscv_rt3CNT17hcec3e3a214887d53E.0> 420003ae: 0585 addi a1,a1,1 420003b0: 62b52e23 sw a1,1596(a0) } } 420003b4: 4532 lw a0,12(sp) 420003b6: 45a2 lw a1,8(sp) 420003b8: 0141 addi sp,sp,16 420003ba: 30200073 mret ``` (disassembly via `riscv64-unknown-elf-objdump -C -S --disassemble ./esp32c3-hal/target/riscv32imc-unknown-none-elf/release/examples/gpio_interrupt`) This outcome is superior to hand-coded interrupt routines which, lacking visibility into any non-assembly body of the interrupt handler, have to be very conservative and save the [entire CPU state to the stack frame][full-frame-save]. By instead asking LLVM to only save the registers that it uses, we defer the decision to the tool with the best context: it can more accurately account for the cost of spills if it knows that every additional register used is already at the cost of an implicit spill. At the LLVM level, this is apparently [implemented by] marking every register as "[callee-save]," matching the semantics of an interrupt handler nicely (it has to leave the CPU state just as it found it after its `{m|s}ret`). This approach is not suitable for every interrupt handler, as it makes no attempt to e.g. save the state in a user-accessible stack frame. For a full discussion of those challenges and tradeoffs, please refer to [the interrupt calling conventions RFC][rfc]. Inside rustc, this implementation differs from prior art because LLVM does not expose the "all-saved" function flavor as a calling convention directly, instead preferring to use an attribute that allows for differentiating between "machine-mode" and "superivsor-mode" interrupts. Finally, some effort has been made to guide those who may not yet be aware of the differences between machine-mode and supervisor-mode interrupts as to why no `riscv-interrupt` calling convention is exposed through rustc, and similarly for why `riscv-interrupt-u` makes no appearance (as it would complicate future LLVM upgrades). [clang-attr]: https://clang.llvm.org/docs/AttributeReference.html#interrupt-risc-v [full-frame-save]: 9281af2ecf/src/lib.rs (L440-L469) [implemented by]: b7fb2a3fec/llvm/lib/Target/RISCV/RISCVRegisterInfo.cpp (L61-L67) [callee-save]: 973f1fe7a8/llvm/lib/Target/RISCV/RISCVCallingConv.td (L30-L37) [rfc]: https://github.com/rust-lang/rfcs/pull/3246		2023-08-09 22:59:58 +02:00
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auxiliary	fix proc-macro test added here to solely be exercised as a build product for the host.	2023-08-08 11:40:35 -04:00
debug
outer	Add some reasons why tests are ignored.	2023-04-15 16:11:42 -07:00
pretty-print-hack	Add some reasons why tests are ignored.	2023-04-15 16:11:42 -07:00
add-impl.rs
allowed-attr-stmt-expr.rs
allowed-attr-stmt-expr.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
allowed-signatures.rs
ambiguous-builtin-attrs-test.rs
ambiguous-builtin-attrs-test.stderr
ambiguous-builtin-attrs.rs
ambiguous-builtin-attrs.stderr
amputate-span.fixed
amputate-span.rs
amputate-span.stderr	Special-case item attributes in the suggestion output	2023-04-12 22:50:10 +00:00
append-impl.rs
attr-args.rs
attr-cfg.rs
attr-complex-fn.rs
attr-complex-fn.stdout
attr-invalid-exprs.rs
attr-invalid-exprs.stderr
attr-on-trait.rs
attr-stmt-expr-rpass.rs
attr-stmt-expr.rs
attr-stmt-expr.stderr
attr-stmt-expr.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
attribute-after-derive.rs
attribute-after-derive.stdout
attribute-spans-preserved.rs
attribute-spans-preserved.stderr
attribute-spans-preserved.stdout
attribute-with-error.rs
attribute-with-error.stderr
attribute.rs
attribute.stderr
attributes-included.rs
attributes-included.stderr
attributes-on-definitions.rs
attributes-on-definitions.stderr
attributes-on-modules-fail.rs
attributes-on-modules-fail.stderr	Special-case item attributes in the suggestion output	2023-04-12 22:50:10 +00:00
attributes-on-modules.rs
bad-projection.rs
bad-projection.stderr
bang-macro.rs
break-token-spans.rs
break-token-spans.stderr
call-deprecated.rs
call-deprecated.stderr
call-site.rs
capture-macro-rules-invoke.rs
capture-macro-rules-invoke.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
capture-unglued-token.rs
capture-unglued-token.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
cfg-eval-fail.rs
cfg-eval-fail.stderr
cfg-eval-inner.rs
cfg-eval-inner.stdout
cfg-eval.rs
cfg-eval.stdout
count_compound_ops.rs
crate-attrs-multiple.rs
crate-var.rs
crt-static.rs	add support for needs-dynamic-linking	2023-06-20 17:20:57 +02:00
custom-attr-only-one-derive.rs
define-two.rs
define-two.stderr
derive-attr-cfg.rs
derive-b.rs
derive-bad.rs	Fix typos in compiler	2023-04-10 22:02:52 +02:00
derive-bad.stderr	Fix typos in compiler	2023-04-10 22:02:52 +02:00
derive-expand-order.rs
derive-expand-order.stdout
derive-helper-configured.rs
derive-helper-legacy-limits.rs
derive-helper-legacy-limits.stderr
derive-helper-legacy-spurious.rs
derive-helper-legacy-spurious.stderr
derive-helper-shadowed.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
derive-helper-shadowing-2.rs
derive-helper-shadowing.rs	resolve: Remove artificial import ambiguity errors	2023-06-29 13:42:58 +03:00
derive-helper-shadowing.stderr	resolve: Remove artificial import ambiguity errors	2023-06-29 13:42:58 +03:00
derive-helper-vs-legacy.rs
derive-in-mod.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
derive-multiple-with-packed.rs
derive-same-struct.rs
derive-same-struct.stdout
derive-still-gated.rs
derive-still-gated.stderr
derive-test.rs
derive-two-attrs.rs
derive-union.rs
disappearing-resolution.rs
disappearing-resolution.stderr
doc-comment-preserved.rs
doc-comment-preserved.stdout
dollar-crate-issue-57089.rs
dollar-crate-issue-57089.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
dollar-crate-issue-62325.rs
dollar-crate-issue-62325.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
dollar-crate-issue-101211.rs
dollar-crate.rs
dollar-crate.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
edition-imports-2018.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
empty-crate.rs
empty-where-clause.rs
empty-where-clause.stderr
expand-expr.rs
expand-expr.stderr
expand-to-derive.rs
expand-to-derive.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
expand-to-unstable.rs
expand-to-unstable.stderr
expand-with-a-macro.rs
export-macro.rs
export-macro.stderr
exports.rs
exports.stderr
expr-stmt-nonterminal-tokens.rs
expr-stmt-nonterminal-tokens.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
extern-prelude-extern-crate-proc-macro.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
gen-lifetime-token.rs
gen-macro-rules-hygiene.rs
gen-macro-rules-hygiene.stderr
gen-macro-rules.rs
generate-dollar-ident.rs
generate-mod.rs
generate-mod.stderr
helper-attr-blocked-by-import-ambig.rs
helper-attr-blocked-by-import-ambig.stderr
helper-attr-blocked-by-import.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
hygiene_example.rs
illegal-proc-macro-derive-use.rs
illegal-proc-macro-derive-use.stderr
import.rs
import.stderr
inert-attribute-order.rs
inert-attribute-order.stdout
inner-attr-non-inline-mod.rs
inner-attr-non-inline-mod.stderr
inner-attr-non-inline-mod.stdout
inner-attrs.rs
inner-attrs.stderr
inner-attrs.stdout
input-interpolated.rs
input-interpolated.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
invalid-attributes.rs
invalid-attributes.stderr
invalid-punct-ident-1.rs
invalid-punct-ident-1.stderr
invalid-punct-ident-2.rs
invalid-punct-ident-2.stderr
invalid-punct-ident-3.rs
invalid-punct-ident-3.stderr
invalid-punct-ident-4.rs
invalid-punct-ident-4.stderr
is-available.rs
issue-36935.rs
issue-36935.stderr
issue-37788.rs
issue-37788.stderr
issue-38586.rs
issue-38586.stderr
issue-39889.rs
issue-42708.rs
issue-50061.rs
issue-50493.rs
issue-50493.stderr
issue-53481.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
issue-59191-replace-root-with-fn.rs
issue-59191-replace-root-with-fn.stderr
issue-66286.rs
issue-66286.stderr
issue-73933-procedural-masquerade.rs
issue-73933-procedural-masquerade.stdout
issue-75734-pp-paren.rs
issue-75734-pp-paren.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
issue-75801.rs
issue-75801.stderr
issue-75930-derive-cfg.rs
issue-75930-derive-cfg.stderr
issue-75930-derive-cfg.stdout
issue-76182-leading-vert-pat.rs
issue-76182-leading-vert-pat.stdout
issue-76270-panic-in-libproc-macro.rs
issue-76270-panic-in-libproc-macro.stderr
issue-78675-captured-inner-attrs.rs
issue-78675-captured-inner-attrs.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
issue-79148.rs
issue-79148.stderr
issue-79242-slow-retokenize-check.rs
issue-79825.rs
issue-80760-empty-stmt.rs
issue-80760-empty-stmt.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
issue-81007-item-attrs.rs
issue-81007-item-attrs.stdout
issue-81543-item-parse-err.rs
issue-81543-item-parse-err.stderr
issue-81555.rs
issue-83469-global-alloc-invalid-stmt.rs
issue-83469-global-alloc-invalid-stmt.stderr
issue-83510.rs
issue-83510.stderr
issue-86781-bad-inner-doc.fixed
issue-86781-bad-inner-doc.rs
issue-86781-bad-inner-doc.stderr
issue-91800.rs	Fix typos in compiler	2023-04-10 22:02:52 +02:00
issue-91800.stderr	Fix typos in compiler	2023-04-10 22:02:52 +02:00
issue-104884-trait-impl-sugg-err.rs
issue-104884-trait-impl-sugg-err.stderr
issue-107113-wrap.rs	Fix #107113, avoid suggest for macro attributes	2023-08-02 14:54:37 +08:00
issue-107113-wrap.stderr	Fix #107113, avoid suggest for macro attributes	2023-08-02 14:54:37 +08:00
item-error.rs
item-error.stderr
keep-expr-tokens.rs
keep-expr-tokens.stderr
keep-expr-tokens.stdout
lifetimes-rpass.rs
lifetimes.rs
lifetimes.stderr
lints_in_proc_macros.rs
lints_in_proc_macros.stderr
load-panic-backtrace.rs
load-panic-backtrace.stderr	Change default panic handler message format.	2023-07-29 11:42:50 +02:00
load-panic.rs
load-panic.stderr
load-two.rs
macro-brackets.rs
macro-brackets.stderr
macro-crate-multi-decorator.rs
macro-namespace-reserved-2.rs
macro-namespace-reserved-2.stderr	Rewrite added diagnostics as translatable	2023-04-07 08:33:56 +01:00
macro-namespace-reserved.rs
macro-namespace-reserved.stderr
macro-quote-cond.rs
macro-rules-derive-cfg.rs
macro-rules-derive-cfg.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
macro-rules-derive.rs
macro-rules-derive.stderr
macro-use-attr.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
macro-use-bang.rs	tests/ui/proc-macro/*: Migrate FIXMEs to check-pass	2023-07-27 10:37:31 +02:00
macros-in-extern-derive.rs
macros-in-extern-derive.stderr
macros-in-extern.rs
macros-in-type.rs
meta-delim.rs
meta-macro-hygiene.rs	fix(test): improve sensitivity of hygene tests	2023-08-08 18:09:56 -07:00
meta-macro-hygiene.stdout	fix(test): improve sensitivity of hygene tests	2023-08-08 18:09:56 -07:00
meta-macro.rs
meta-macro.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
mixed-site-span.rs
mixed-site-span.stderr
modify-ast.rs
module_with_attrs.rs	Add some reasons why tests are ignored.	2023-04-15 16:11:42 -07:00
module.rs	Add some reasons why tests are ignored.	2023-04-15 16:11:42 -07:00
multispan.rs
multispan.stderr
negative-token.rs
nested-derive-cfg.rs
nested-derive-cfg.stdout
nested-item-spans.rs
nested-item-spans.stderr
nested-macro-rules.rs
nested-macro-rules.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
nested-nonterminal-tokens.rs
nested-nonterminal-tokens.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
no-macro-use-attr.rs
no-macro-use-attr.stderr
no-mangle-in-proc-macro-issue-111888.rs	fix proc-macro test added here to solely be exercised as a build product for the host.	2023-08-08 11:40:35 -04:00
no-missing-docs.rs
nodelim-groups.rs
nodelim-groups.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
non-root.rs
non-root.stderr
nonterminal-expansion.rs
nonterminal-expansion.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
nonterminal-recollect-attr.rs
nonterminal-recollect-attr.stdout	Hide compiler_builtins in the prelude	2023-07-14 16:53:36 +01:00
nonterminal-token-hygiene.rs	fix(test): improve sensitivity of hygene tests	2023-08-08 18:09:56 -07:00
nonterminal-token-hygiene.stdout	fix(test): improve sensitivity of hygene tests	2023-08-08 18:09:56 -07:00
not-joint.rs
out-of-line-mod.rs
panic-abort.rs
panic-abort.stderr
parent-source-spans.rs
parent-source-spans.stderr
pretty-print-hack-hide.rs
pretty-print-hack-hide.stdout
pretty-print-hack-show.local.stderr
pretty-print-hack-show.local.stdout
pretty-print-hack-show.remapped.stderr
pretty-print-hack-show.remapped.stdout
pretty-print-hack-show.rs
pretty-print-tts.rs
pretty-print-tts.stdout
proc-macro-abi.rs
proc-macro-abi.stderr
proc-macro-attributes.rs
proc-macro-attributes.stderr
proc-macro-deprecated-attr.rs
proc-macro-gates2.rs
proc-macro-gates2.stderr
proc-macro-gates.rs
proc-macro-gates.stderr
pub-at-crate-root.rs
pub-at-crate-root.stderr
quote-debug.rs
quote-debug.stdout
raw-ident.rs
raw-ident.stderr
reserved-macro-names.rs
reserved-macro-names.stderr
resolve-error.rs
resolve-error.stderr
resolved-located-at.rs
resolved-located-at.stderr
shadow.rs
shadow.stderr
signature-proc-macro-attribute.rs
signature-proc-macro-attribute.stderr	Tighter spans	2023-03-14 19:12:42 +00:00
signature-proc-macro-derive.rs
signature-proc-macro-derive.stderr	Tighter spans	2023-03-14 19:12:42 +00:00
signature-proc-macro.rs
signature-proc-macro.stderr	Tighter spans	2023-03-14 19:12:42 +00:00
signature.rs
signature.stderr
smoke.rs
span-absolute-posititions.rs
span-absolute-posititions.stderr
span-api-tests.rs	remove invalid ignore-pretty	2023-04-03 09:24:11 +02:00
span-from-proc-macro.rs
span-from-proc-macro.stderr
span-preservation.rs
span-preservation.stderr	Don't mention already set fields	2023-06-05 21:00:08 +00:00
struct-field-macro.rs
subspan.rs
subspan.stderr
test-same-crate.rs	Suggest using integration tests for proc-macros	2023-04-17 13:01:03 +01:00
test-same-crate.stderr	Suggest using integration tests for proc-macros	2023-04-17 13:01:03 +01:00
test.rs
three-equals.rs
three-equals.stderr
trailing-plus.rs
trailing-plus.stdout
trait-fn-args-2015.rs
two-crate-types-1.rs
two-crate-types-1.stderr
two-crate-types-2.rs
two-crate-types-2.stderr
unsafe-foreign-mod.rs
unsafe-mod.rs
visibility-path.rs
visibility-path.stderr
weird-braces.rs
weird-braces.stdout
weird-hygiene.rs
weird-hygiene.stderr