Drop support for legacy PM with LLVM 15

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -625,7 +625,7 @@ pub(crate) fn run_pass_manager(
             if thin {
                 llvm::LLVMRustPassManagerBuilderPopulateThinLTOPassManager(b, pm);
             } else {
-                llvm::LLVMPassManagerBuilderPopulateLTOPassManager(
+                llvm::LLVMRustPassManagerBuilderPopulateLTOPassManager(
                     b, pm, /* Internalize = */ False, /* RunInliner = */ True,
                 );
             }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -523,6 +523,12 @@ pub(crate) unsafe fn optimize(
     let module_name = module.name.clone();
     let module_name = Some(&module_name[..]);
 
+    if let Some(false) = config.new_llvm_pass_manager && llvm_util::get_version() >= (15, 0, 0) {
+        diag_handler.warn(
+            "ignoring `-Z new-llvm-pass-manager=no`, which is no longer supported with LLVM 15",
+        );
+    }
+
     if config.emit_no_opt_bc {
         let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
         let out = path_to_c_string(&out);
@@ -628,8 +634,8 @@ pub(crate) unsafe fn optimize(
                         extra_passes.as_ptr(),
                         extra_passes.len() as size_t,
                     );
-                    llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
-                    llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
+                    llvm::LLVMRustPassManagerBuilderPopulateFunctionPassManager(b, fpm);
+                    llvm::LLVMRustPassManagerBuilderPopulateModulePassManager(b, mpm);
                 });
 
                 have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
@@ -1085,7 +1091,7 @@ pub unsafe fn with_llvm_pmb(
     // Create the PassManagerBuilder for LLVM. We configure it with
     // reasonable defaults and prepare it to actually populate the pass
     // manager.
-    let builder = llvm::LLVMPassManagerBuilderCreate();
+    let builder = llvm::LLVMRustPassManagerBuilderCreate();
     let opt_size = config.opt_size.map_or(llvm::CodeGenOptSizeNone, |x| to_llvm_opt_settings(x).1);
     let inline_threshold = config.inline_threshold;
     let pgo_gen_path = get_pgo_gen_path(config);
@@ -1102,14 +1108,9 @@ pub unsafe fn with_llvm_pmb(
         pgo_gen_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
         pgo_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
         pgo_sample_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
+        opt_size as c_int,
     );
 
-    llvm::LLVMPassManagerBuilderSetSizeLevel(builder, opt_size as u32);
-
-    if opt_size != llvm::CodeGenOptSizeNone {
-        llvm::LLVMPassManagerBuilderSetDisableUnrollLoops(builder, 1);
-    }
-
     llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
 
     // Here we match what clang does (kinda). For O0 we only inline
@@ -1118,16 +1119,16 @@ pub unsafe fn with_llvm_pmb(
     // thresholds copied from clang.
     match (opt_level, opt_size, inline_threshold) {
         (.., Some(t)) => {
-            llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, t);
+            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, t);
         }
         (llvm::CodeGenOptLevel::Aggressive, ..) => {
-            llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 275);
+            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 275);
         }
         (_, llvm::CodeGenOptSizeDefault, _) => {
-            llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 75);
+            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 75);
         }
         (_, llvm::CodeGenOptSizeAggressive, _) => {
-            llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 25);
+            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 25);
         }
         (llvm::CodeGenOptLevel::None, ..) => {
             llvm::LLVMRustAddAlwaysInlinePass(builder, config.emit_lifetime_markers);
@@ -1136,12 +1137,12 @@ pub unsafe fn with_llvm_pmb(
             llvm::LLVMRustAddAlwaysInlinePass(builder, config.emit_lifetime_markers);
         }
         (llvm::CodeGenOptLevel::Default, ..) => {
-            llvm::LLVMPassManagerBuilderUseInlinerWithThreshold(builder, 225);
+            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 225);
         }
     }
 
     f(builder);
-    llvm::LLVMPassManagerBuilderDispose(builder);
+    llvm::LLVMRustPassManagerBuilderDispose(builder);
 }
 
 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -1825,24 +1825,22 @@ extern "C" {
 
     pub fn LLVMAddAnalysisPasses<'a>(T: &'a TargetMachine, PM: &PassManager<'a>);
 
-    pub fn LLVMPassManagerBuilderCreate() -> &'static mut PassManagerBuilder;
-    pub fn LLVMPassManagerBuilderDispose(PMB: &'static mut PassManagerBuilder);
-    pub fn LLVMPassManagerBuilderSetSizeLevel(PMB: &PassManagerBuilder, Value: Bool);
-    pub fn LLVMPassManagerBuilderSetDisableUnrollLoops(PMB: &PassManagerBuilder, Value: Bool);
-    pub fn LLVMPassManagerBuilderUseInlinerWithThreshold(
+    pub fn LLVMRustPassManagerBuilderCreate() -> &'static mut PassManagerBuilder;
+    pub fn LLVMRustPassManagerBuilderDispose(PMB: &'static mut PassManagerBuilder);
+    pub fn LLVMRustPassManagerBuilderUseInlinerWithThreshold(
         PMB: &PassManagerBuilder,
         threshold: c_uint,
     );
-    pub fn LLVMPassManagerBuilderPopulateModulePassManager(
+    pub fn LLVMRustPassManagerBuilderPopulateModulePassManager(
         PMB: &PassManagerBuilder,
         PM: &PassManager<'_>,
     );
 
-    pub fn LLVMPassManagerBuilderPopulateFunctionPassManager(
+    pub fn LLVMRustPassManagerBuilderPopulateFunctionPassManager(
         PMB: &PassManagerBuilder,
         PM: &PassManager<'_>,
     );
-    pub fn LLVMPassManagerBuilderPopulateLTOPassManager(
+    pub fn LLVMRustPassManagerBuilderPopulateLTOPassManager(
         PMB: &PassManagerBuilder,
         PM: &PassManager<'_>,
         Internalize: Bool,
@@ -2308,6 +2306,7 @@ extern "C" {
         PGOGenPath: *const c_char,
         PGOUsePath: *const c_char,
         PGOSampleUsePath: *const c_char,
+        SizeLevel: c_int,
     );
     pub fn LLVMRustAddLibraryInfo<'a>(
         PM: &PassManager<'a>,

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -542,6 +542,11 @@ pub(crate) fn should_use_new_llvm_pass_manager(user_opt: &Option<bool>, target_a
     // The new pass manager is enabled by default for LLVM >= 13.
     // This matches Clang, which also enables it since Clang 13.
 
+    // Since LLVM 15, the legacy pass manager is no longer supported.
+    if llvm_util::get_version() >= (15, 0, 0) {
+        return true;
+    }
+
     // There are some perf issues with the new pass manager when targeting
     // s390x with LLVM 13, so enable the new pass manager only with LLVM 14.
     // See https://github.com/rust-lang/rust/issues/89609.

compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp

@@ -107,6 +107,7 @@ static LLVMRustPassKind toRust(PassKind Kind) {
 }
 
 extern "C" LLVMPassRef LLVMRustFindAndCreatePass(const char *PassName) {
+#if LLVM_VERSION_LT(15, 0)
   StringRef SR(PassName);
   PassRegistry *PR = PassRegistry::getPassRegistry();
 
@@ -115,36 +116,59 @@ extern "C" LLVMPassRef LLVMRustFindAndCreatePass(const char *PassName) {
     return wrap(PI->createPass());
   }
   return nullptr;
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateAddressSanitizerFunctionPass(bool Recover) {
+#if LLVM_VERSION_LT(15, 0)
   const bool CompileKernel = false;
   const bool UseAfterScope = true;
 
   return wrap(createAddressSanitizerFunctionPass(CompileKernel, Recover, UseAfterScope));
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateModuleAddressSanitizerPass(bool Recover) {
+#if LLVM_VERSION_LT(15, 0)
   const bool CompileKernel = false;
 
   return wrap(createModuleAddressSanitizerLegacyPassPass(CompileKernel, Recover));
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateMemorySanitizerPass(int TrackOrigins, bool Recover) {
+#if LLVM_VERSION_LT(15, 0)
   const bool CompileKernel = false;
 
   return wrap(createMemorySanitizerLegacyPassPass(
       MemorySanitizerOptions{TrackOrigins, Recover, CompileKernel}));
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateThreadSanitizerPass() {
+#if LLVM_VERSION_LT(15, 0)
   return wrap(createThreadSanitizerLegacyPassPass());
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMPassRef LLVMRustCreateHWAddressSanitizerPass(bool Recover) {
+#if LLVM_VERSION_LT(15, 0)
   const bool CompileKernel = false;
 
   return wrap(createHWAddressSanitizerLegacyPassPass(CompileKernel, Recover));
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C" LLVMRustPassKind LLVMRustPassKind(LLVMPassRef RustPass) {
@@ -154,23 +178,84 @@ extern "C" LLVMRustPassKind LLVMRustPassKind(LLVMPassRef RustPass) {
 }
 
 extern "C" void LLVMRustAddPass(LLVMPassManagerRef PMR, LLVMPassRef RustPass) {
+#if LLVM_VERSION_LT(15, 0)
   assert(RustPass);
   Pass *Pass = unwrap(RustPass);
   PassManagerBase *PMB = unwrap(PMR);
   PMB->add(Pass);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" LLVMPassManagerBuilderRef LLVMRustPassManagerBuilderCreate() {
+#if LLVM_VERSION_LT(15, 0)
+  return LLVMPassManagerBuilderCreate();
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" void LLVMRustPassManagerBuilderDispose(LLVMPassManagerBuilderRef PMB) {
+#if LLVM_VERSION_LT(15, 0)
+  LLVMPassManagerBuilderDispose(PMB);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" void LLVMRustPassManagerBuilderPopulateFunctionPassManager(
+  LLVMPassManagerBuilderRef PMB, LLVMPassManagerRef PM) {
+#if LLVM_VERSION_LT(15, 0)
+  LLVMPassManagerBuilderPopulateFunctionPassManager(PMB, PM);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" void LLVMRustPassManagerBuilderPopulateModulePassManager(
+  LLVMPassManagerBuilderRef PMB, LLVMPassManagerRef PM) {
+#if LLVM_VERSION_LT(15, 0)
+  LLVMPassManagerBuilderPopulateModulePassManager(PMB, PM);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" void LLVMRustPassManagerBuilderPopulateLTOPassManager(
+  LLVMPassManagerBuilderRef PMB, LLVMPassManagerRef PM, bool Internalize, bool RunInliner) {
+#if LLVM_VERSION_LT(15, 0)
+  LLVMPassManagerBuilderPopulateLTOPassManager(PMB, PM, Internalize, RunInliner);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C"
 void LLVMRustPassManagerBuilderPopulateThinLTOPassManager(
   LLVMPassManagerBuilderRef PMBR,
   LLVMPassManagerRef PMR
 ) {
+#if LLVM_VERSION_LT(15, 0)
   unwrap(PMBR)->populateThinLTOPassManager(*unwrap(PMR));
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
+}
+
+extern "C" void LLVMRustPassManagerBuilderUseInlinerWithThreshold(
+  LLVMPassManagerBuilderRef PMB, unsigned Threshold) {
+#if LLVM_VERSION_LT(15, 0)
+  LLVMPassManagerBuilderUseInlinerWithThreshold(PMB, Threshold);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 extern "C"
 void LLVMRustAddLastExtensionPasses(
     LLVMPassManagerBuilderRef PMBR, LLVMPassRef *Passes, size_t NumPasses) {
+#if LLVM_VERSION_LT(15, 0)
   auto AddExtensionPasses = [Passes, NumPasses](
       const PassManagerBuilder &Builder, PassManagerBase &PM) {
     for (size_t I = 0; I < NumPasses; I++) {
@@ -183,6 +268,9 @@ void LLVMRustAddLastExtensionPasses(
                              AddExtensionPasses);
   unwrap(PMBR)->addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
                              AddExtensionPasses);
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 #ifdef LLVM_COMPONENT_X86
@@ -533,12 +621,16 @@ extern "C" void LLVMRustDisposeTargetMachine(LLVMTargetMachineRef TM) {
 extern "C" void LLVMRustConfigurePassManagerBuilder(
     LLVMPassManagerBuilderRef PMBR, LLVMRustCodeGenOptLevel OptLevel,
     bool MergeFunctions, bool SLPVectorize, bool LoopVectorize, bool PrepareForThinLTO,
-    const char* PGOGenPath, const char* PGOUsePath, const char* PGOSampleUsePath) {
+    const char* PGOGenPath, const char* PGOUsePath, const char* PGOSampleUsePath,
+    int SizeLevel) {
+#if LLVM_VERSION_LT(15, 0)
   unwrap(PMBR)->MergeFunctions = MergeFunctions;
   unwrap(PMBR)->SLPVectorize = SLPVectorize;
   unwrap(PMBR)->OptLevel = fromRust(OptLevel);
   unwrap(PMBR)->LoopVectorize = LoopVectorize;
   unwrap(PMBR)->PrepareForThinLTO = PrepareForThinLTO;
+  unwrap(PMBR)->SizeLevel = SizeLevel;
+  unwrap(PMBR)->DisableUnrollLoops = SizeLevel != 0;
 
   if (PGOGenPath) {
     assert(!PGOUsePath && !PGOSampleUsePath);
@@ -550,6 +642,9 @@ extern "C" void LLVMRustConfigurePassManagerBuilder(
   } else if (PGOSampleUsePath) {
     unwrap(PMBR)->PGOSampleUse = PGOSampleUsePath;
   }
+#else
+  report_fatal_error("Legacy PM not supported with LLVM 15");
+#endif
 }
 
 // Unfortunately, the LLVM C API doesn't provide a way to set the `LibraryInfo`

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -6,6 +6,7 @@
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Mangler.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/COFFImportFile.h"
 #include "llvm/Object/ObjectFile.h"

src/test/codegen/panic-in-drop-abort.rs

@@ -1,14 +1,12 @@
-// compile-flags: -Z panic-in-drop=abort -O -Z new-llvm-pass-manager=no
+// compile-flags: -Z panic-in-drop=abort -O
+// ignore-msvc
 
 // 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.
+// This test uses ignore-msvc, because the expected optimization does not happen on targets using
+// SEH exceptions with the new LLVM pass manager anymore, see
+// https://github.com/llvm/llvm-project/issues/51311.
 
 // CHECK-NOT: {{(call|invoke).*}}should_not_appear_in_output