diff options
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/attributes.rs | 9 | ||||
| -rw-r--r-- | compiler/rustc_interface/src/tests.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_session/src/options.rs | 2 | ||||
| -rw-r--r-- | src/test/assembly/x86_64-no-jump-tables.rs | 34 | ||||
| -rw-r--r-- | src/test/codegen/no-jump-tables.rs | 22 | ||||
| -rw-r--r-- | src/test/rustdoc-ui/z-help.stdout | 1 |
6 files changed, 69 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs index f3bdacf6085..487eead22b8 100644 --- a/compiler/rustc_codegen_llvm/src/attributes.rs +++ b/compiler/rustc_codegen_llvm/src/attributes.rs @@ -137,6 +137,14 @@ fn instrument_function_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribu } } +fn nojumptables_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { + if !cx.sess().opts.unstable_opts.no_jump_tables { + return None; + } + + Some(llvm::CreateAttrStringValue(cx.llcx, "no-jump-tables", "true")) +} + fn probestack_attr<'ll>(cx: &CodegenCx<'ll, '_>) -> Option<&'ll Attribute> { // Currently stack probes seem somewhat incompatible with the address // sanitizer and thread sanitizer. With asan we're already protected from @@ -293,6 +301,7 @@ pub fn from_fn_attrs<'ll, 'tcx>( // FIXME: none of these three functions interact with source level attributes. to_add.extend(frame_pointer_type_attr(cx)); to_add.extend(instrument_function_attr(cx)); + to_add.extend(nojumptables_attr(cx)); to_add.extend(probestack_attr(cx)); to_add.extend(stackprotector_attr(cx)); diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs index e903cb86dd2..ff2196d5857 100644 --- a/compiler/rustc_interface/src/tests.rs +++ b/compiler/rustc_interface/src/tests.rs @@ -754,6 +754,7 @@ fn test_unstable_options_tracking_hash() { tracked!(move_size_limit, Some(4096)); tracked!(mutable_noalias, Some(true)); tracked!(no_generate_arange_section, true); + tracked!(no_jump_tables, true); tracked!(no_link, true); tracked!(no_profiler_runtime, true); tracked!(no_unique_section_names, true); diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index 9e130287104..40bc669707a 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -1421,6 +1421,8 @@ options! { "run all passes except codegen; no output"), no_generate_arange_section: bool = (false, parse_no_flag, [TRACKED], "omit DWARF address ranges that give faster lookups"), + no_jump_tables: bool = (false, parse_no_flag, [TRACKED], + "disable the jump tables and lookup tables that can be generated from a switch case lowering"), no_leak_check: bool = (false, parse_no_flag, [UNTRACKED], "disable the 'leak check' for subtyping; unsound, but useful for tests"), no_link: bool = (false, parse_no_flag, [TRACKED], diff --git a/src/test/assembly/x86_64-no-jump-tables.rs b/src/test/assembly/x86_64-no-jump-tables.rs new file mode 100644 index 00000000000..007c3591a4a --- /dev/null +++ b/src/test/assembly/x86_64-no-jump-tables.rs @@ -0,0 +1,34 @@ +// Test that jump tables are (not) emitted when the `-Zno-jump-tables` +// flag is (not) set. + +// revisions: unset set +// assembly-output: emit-asm +// compile-flags: -O +// [set] compile-flags: -Zno-jump-tables +// only-x86_64 + +#![crate_type = "lib"] + +extern "C" { + fn bar1(); + fn bar2(); + fn bar3(); + fn bar4(); + fn bar5(); + fn bar6(); +} + +// CHECK-LABEL: foo: +#[no_mangle] +pub unsafe fn foo(x: i32) { + // unset: LJTI0_0 + // set-NOT: LJTI0_0 + match x { + 1 => bar1(), + 2 => bar2(), + 3 => bar3(), + 4 => bar4(), + 5 => bar5(), + _ => bar6(), + } +} diff --git a/src/test/codegen/no-jump-tables.rs b/src/test/codegen/no-jump-tables.rs new file mode 100644 index 00000000000..8e2cb47566e --- /dev/null +++ b/src/test/codegen/no-jump-tables.rs @@ -0,0 +1,22 @@ +// Test that the `no-jump-tables` function attribute are (not) emitted when +// the `-Zno-jump-tables` flag is (not) set. + +// revisions: unset set +// needs-llvm-components: x86 +// compile-flags: --target x86_64-unknown-linux-gnu +// [set] compile-flags: -Zno-jump-tables + +#![crate_type = "lib"] +#![feature(no_core, lang_items)] +#![no_core] + +#[lang = "sized"] +trait Sized {} + +#[no_mangle] +pub fn foo() { + // CHECK: @foo() unnamed_addr #0 + + // unset-NOT: attributes #0 = { {{.*}}"no-jump-tables"="true"{{.*}} } + // set: attributes #0 = { {{.*}}"no-jump-tables"="true"{{.*}} } +} diff --git a/src/test/rustdoc-ui/z-help.stdout b/src/test/rustdoc-ui/z-help.stdout index 3537e669608..53677b18377 100644 --- a/src/test/rustdoc-ui/z-help.stdout +++ b/src/test/rustdoc-ui/z-help.stdout @@ -92,6 +92,7 @@ -Z no-analysis=val -- parse and expand the source, but run no analysis -Z no-codegen=val -- run all passes except codegen; no output -Z no-generate-arange-section=val -- omit DWARF address ranges that give faster lookups + -Z no-jump-tables=val -- disable the jump tables and lookup tables that can be generated from a switch case lowering -Z no-leak-check=val -- disable the 'leak check' for subtyping; unsound, but useful for tests -Z no-link=val -- compile without linking -Z no-parallel-llvm=val -- run LLVM in non-parallel mode (while keeping codegen-units and ThinLTO) |