Rollup merge of #96215 - nikic:legacy-pm-removal, r=nagisa

Drop support for legacy PM with LLVM 15

LLVM 15 already removes some of the legacy PM APIs we're using. This patch forces use of NewPM with LLVM 15 (with `-Z new-llvm-pass-manager=no` throwing a warning) and stubs out various FFI methods with a report_fatal_error on LLVM 15.

For LLVMPassManagerBuilderPopulateLTOPassManager() I went with adding our own wrapper, as the alternative would be to muck about with weak symbols, which seems to be non-trivial as far as cross-platform support is concerned (std has `weak!` for this purpose, but only as an internal utility.)

Fixes #96072.
Fixes #96362.

2 files changed, 97 insertions, 1 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index 71f21dc6666..38fddbdba54 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/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) {
@@ -154,10 +178,57 @@ 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"
@@ -165,12 +236,26 @@ 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`
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index 3ed4396d1e9..850b80e4280 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/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"