diff options
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/back/write.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp | 5 | ||||
| -rw-r--r-- | src/test/codegen/panic-in-drop-abort.rs | 15 |
3 files changed, 17 insertions, 8 deletions
diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs index 791604a1827..92199f611ba 100644 --- a/compiler/rustc_codegen_llvm/src/back/write.rs +++ b/compiler/rustc_codegen_llvm/src/back/write.rs @@ -370,8 +370,9 @@ fn get_pgo_use_path(config: &ModuleConfig) -> Option<CString> { } pub(crate) fn should_use_new_llvm_pass_manager(config: &ModuleConfig) -> bool { - // The new pass manager is disabled by default. - config.new_llvm_pass_manager.unwrap_or(false) + // The new pass manager is enabled by default for LLVM >= 13. + // This matches Clang, which also enables it since Clang 13. + config.new_llvm_pass_manager.unwrap_or_else(|| llvm_util::get_version() >= (13, 0, 0)) } pub(crate) unsafe fn optimize_with_new_llvm_pass_manager( diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp index 1a0cfd58885..48eb50953a9 100644 --- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp @@ -1004,7 +1004,10 @@ LLVMRustOptimizeWithNewPassManager( #endif bool NeedThinLTOBufferPasses = UseThinLTOBuffers; if (!NoPrepopulatePasses) { - if (OptLevel == OptimizationLevel::O0) { + // The pre-link pipelines don't support O0 and require using budilO0DefaultPipeline() instead. + // At the same time, the LTO pipelines do support O0 and using them is required. + bool IsLTO = OptStage == LLVMRustOptStage::ThinLTO || OptStage == LLVMRustOptStage::FatLTO; + if (OptLevel == OptimizationLevel::O0 && !IsLTO) { #if LLVM_VERSION_GE(12, 0) for (const auto &C : PipelineStartEPCallbacks) PB.registerPipelineStartEPCallback(C); diff --git a/src/test/codegen/panic-in-drop-abort.rs b/src/test/codegen/panic-in-drop-abort.rs index 62d093507dd..39f73c4e396 100644 --- a/src/test/codegen/panic-in-drop-abort.rs +++ b/src/test/codegen/panic-in-drop-abort.rs @@ -1,8 +1,17 @@ -// compile-flags: -Z panic-in-drop=abort -O +// compile-flags: -Z panic-in-drop=abort -O -Z new-llvm-pass-manager=no // Ensure that unwinding code paths are eliminated from the output after // optimization. +// This test uses -Z new-llvm-pass-manager=no, because the expected optimization does not happen +// on targets using SEH exceptions (i.e. MSVC) anymore. The core issue is that Rust promises that +// the drop_in_place() function can't unwind, but implements it in a way that *can*, because we +// currently go out of our way to allow longjmps, which also use the unwinding mechanism on MSVC +// targets. We should either forbid longjmps, or not assume nounwind, making this optimization +// incompatible with the current behavior of running cleanuppads on longjmp unwinding. + +// CHECK-NOT: {{(call|invoke).*}}should_not_appear_in_output + #![crate_type = "lib"] use std::any::Any; use std::mem::forget; @@ -35,8 +44,6 @@ impl Drop for AssertNeverDrop { } } -// CHECK-LABEL: normal_drop -// CHECK-NOT: should_not_appear_in_output #[no_mangle] pub fn normal_drop(x: ExternDrop) { let guard = AssertNeverDrop; @@ -44,8 +51,6 @@ pub fn normal_drop(x: ExternDrop) { forget(guard); } -// CHECK-LABEL: indirect_drop -// CHECK-NOT: should_not_appear_in_output #[no_mangle] pub fn indirect_drop(x: Box<dyn Any>) { let guard = AssertNeverDrop; |