Auto merge of #114148 - cuviper:drop-llvm-14, r=nikic

Update the minimum external LLVM to 15

With this change, we'll have stable support for LLVM 15 through 17 (pending release).
For reference, the previous increase to LLVM 14 was #107573.

5 files changed, 28 insertions, 82 deletions

diff --git a/compiler/rustc_codegen_llvm/src/attributes.rs b/compiler/rustc_codegen_llvm/src/attributes.rs
index 4c69b9503a2..e4fce30e232 100644
--- a/compiler/rustc_codegen_llvm/src/attributes.rs
+++ b/compiler/rustc_codegen_llvm/src/attributes.rs
@@ -363,50 +363,44 @@ pub fn from_fn_attrs<'ll, 'tcx>(
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR)
         || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR_ZEROED)
     {
-        if llvm_util::get_version() >= (15, 0, 0) {
-            to_add.push(create_alloc_family_attr(cx.llcx));
-            // apply to argument place instead of function
-            let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx);
-            attributes::apply_to_llfn(llfn, AttributePlace::Argument(1), &[alloc_align]);
-            to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 0));
-            let mut flags = AllocKindFlags::Alloc | AllocKindFlags::Aligned;
-            if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) {
-                flags |= AllocKindFlags::Uninitialized;
-            } else {
-                flags |= AllocKindFlags::Zeroed;
-            }
-            to_add.push(llvm::CreateAllocKindAttr(cx.llcx, flags));
+        to_add.push(create_alloc_family_attr(cx.llcx));
+        // apply to argument place instead of function
+        let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx);
+        attributes::apply_to_llfn(llfn, AttributePlace::Argument(1), &[alloc_align]);
+        to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 0));
+        let mut flags = AllocKindFlags::Alloc | AllocKindFlags::Aligned;
+        if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR) {
+            flags |= AllocKindFlags::Uninitialized;
+        } else {
+            flags |= AllocKindFlags::Zeroed;
         }
+        to_add.push(llvm::CreateAllocKindAttr(cx.llcx, flags));
         // apply to return place instead of function (unlike all other attributes applied in this function)
         let no_alias = AttributeKind::NoAlias.create_attr(cx.llcx);
         attributes::apply_to_llfn(llfn, AttributePlace::ReturnValue, &[no_alias]);
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::REALLOCATOR) {
-        if llvm_util::get_version() >= (15, 0, 0) {
-            to_add.push(create_alloc_family_attr(cx.llcx));
-            to_add.push(llvm::CreateAllocKindAttr(
-                cx.llcx,
-                AllocKindFlags::Realloc | AllocKindFlags::Aligned,
-            ));
-            // applies to argument place instead of function place
-            let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx);
-            attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]);
-            // apply to argument place instead of function
-            let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx);
-            attributes::apply_to_llfn(llfn, AttributePlace::Argument(2), &[alloc_align]);
-            to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 3));
-        }
+        to_add.push(create_alloc_family_attr(cx.llcx));
+        to_add.push(llvm::CreateAllocKindAttr(
+            cx.llcx,
+            AllocKindFlags::Realloc | AllocKindFlags::Aligned,
+        ));
+        // applies to argument place instead of function place
+        let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx);
+        attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]);
+        // apply to argument place instead of function
+        let alloc_align = AttributeKind::AllocAlign.create_attr(cx.llcx);
+        attributes::apply_to_llfn(llfn, AttributePlace::Argument(2), &[alloc_align]);
+        to_add.push(llvm::CreateAllocSizeAttr(cx.llcx, 3));
         let no_alias = AttributeKind::NoAlias.create_attr(cx.llcx);
         attributes::apply_to_llfn(llfn, AttributePlace::ReturnValue, &[no_alias]);
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::DEALLOCATOR) {
-        if llvm_util::get_version() >= (15, 0, 0) {
-            to_add.push(create_alloc_family_attr(cx.llcx));
-            to_add.push(llvm::CreateAllocKindAttr(cx.llcx, AllocKindFlags::Free));
-            // applies to argument place instead of function place
-            let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx);
-            attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]);
-        }
+        to_add.push(create_alloc_family_attr(cx.llcx));
+        to_add.push(llvm::CreateAllocKindAttr(cx.llcx, AllocKindFlags::Free));
+        // applies to argument place instead of function place
+        let allocated_pointer = AttributeKind::AllocatedPointer.create_attr(cx.llcx);
+        attributes::apply_to_llfn(llfn, AttributePlace::Argument(0), &[allocated_pointer]);
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::CMSE_NONSECURE_ENTRY) {
         to_add.push(llvm::CreateAttrString(cx.llcx, "cmse_nonsecure_entry"));
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 4f20fbf2045..6ae738174bf 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -507,8 +507,6 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
             .features
             .split(',')
             .filter(|v| !v.is_empty() && backend_feature_name(v).is_some())
-            // Drop +atomics-32 feature introduced in LLVM 15.
-            .filter(|v| *v != "+atomics-32" || get_version() >= (15, 0, 0))
             .map(String::from),
     );
 
diff --git a/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h b/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h
index af6f4d5eaf9..ea045462845 100644
--- a/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h
+++ b/compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h
@@ -92,10 +92,8 @@ enum LLVMRustAttribute {
   NoCfCheck = 35,
   ShadowCallStack = 36,
   AllocSize = 37,
-#if LLVM_VERSION_GE(15, 0)
   AllocatedPointer = 38,
   AllocAlign = 39,
-#endif
   SanitizeSafeStack = 40,
 };
 
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index 71df17c9ce7..ebf8a50ae8b 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -801,9 +801,6 @@ LLVMRustOptimize(
       OptimizerLastEPCallbacks.push_back(
         [SanitizerOptions](ModulePassManager &MPM, OptimizationLevel Level) {
           auto CompileKernel = SanitizerOptions->SanitizeKernelAddress;
-#if LLVM_VERSION_LT(15, 0)
-          MPM.addPass(RequireAnalysisPass<ASanGlobalsMetadataAnalysis, Module>());
-#endif
           AddressSanitizerOptions opts = AddressSanitizerOptions{
             CompileKernel,
             SanitizerOptions->SanitizeAddressRecover
diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
index 870a2e02cba..f509e2911f3 100644
--- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp
@@ -277,12 +277,10 @@ static Attribute::AttrKind fromRust(LLVMRustAttribute Kind) {
     return Attribute::ShadowCallStack;
   case AllocSize:
     return Attribute::AllocSize;
-#if LLVM_VERSION_GE(15, 0)
   case AllocatedPointer:
     return Attribute::AllocatedPointer;
   case AllocAlign:
     return Attribute::AllocAlign;
-#endif
   case SanitizeSafeStack:
     return Attribute::SafeStack;
   }
@@ -340,20 +338,12 @@ extern "C" LLVMAttributeRef LLVMRustCreateStructRetAttr(LLVMContextRef C, LLVMTy
 }
 
 extern "C" LLVMAttributeRef LLVMRustCreateElementTypeAttr(LLVMContextRef C, LLVMTypeRef Ty) {
-#if LLVM_VERSION_GE(15, 0)
   return wrap(Attribute::get(*unwrap(C), Attribute::ElementType, unwrap(Ty)));
-#else
-  report_fatal_error("Should not be needed on LLVM < 15");
-#endif
 }
 
 extern "C" LLVMAttributeRef LLVMRustCreateUWTableAttr(LLVMContextRef C, bool Async) {
-#if LLVM_VERSION_LT(15, 0)
-  return wrap(Attribute::get(*unwrap(C), Attribute::UWTable));
-#else
   return wrap(Attribute::getWithUWTableKind(
       *unwrap(C), Async ? UWTableKind::Async : UWTableKind::Sync));
-#endif
 }
 
 extern "C" LLVMAttributeRef LLVMRustCreateAllocSizeAttr(LLVMContextRef C, uint32_t ElementSizeArg) {
@@ -366,8 +356,6 @@ extern "C" LLVMAttributeRef LLVMRustCreateAllocSizeAttr(LLVMContextRef C, uint32
                                               ));
 }
 
-#if LLVM_VERSION_GE(15, 0)
-
 // These values **must** match ffi::AllocKindFlags.
 // It _happens_ to match the LLVM values of llvm::AllocFnKind,
 // but that's happenstance and we do explicit conversions before
@@ -411,16 +399,10 @@ static llvm::AllocFnKind allocKindFromRust(LLVMRustAllocKindFlags F) {
   }
   return AFK;
 }
-#endif
 
 extern "C" LLVMAttributeRef LLVMRustCreateAllocKindAttr(LLVMContextRef C, uint64_t AllocKindArg) {
-#if LLVM_VERSION_GE(15, 0)
   return wrap(Attribute::get(*unwrap(C), Attribute::AllocKind,
       static_cast<uint64_t>(allocKindFromRust(static_cast<LLVMRustAllocKindFlags>(AllocKindArg)))));
-#else
-  report_fatal_error(
-      "allockind attributes are new in LLVM 15 and should not be used on older LLVMs");
-#endif
 }
 
 // Simplified representation of `MemoryEffects` across the FFI boundary.
@@ -517,14 +499,9 @@ LLVMRustInlineAsm(LLVMTypeRef Ty, char *AsmString, size_t AsmStringLen,
 
 extern "C" bool LLVMRustInlineAsmVerify(LLVMTypeRef Ty, char *Constraints,
                                         size_t ConstraintsLen) {
-#if LLVM_VERSION_LT(15, 0)
-  return InlineAsm::Verify(unwrap<FunctionType>(Ty),
-                           StringRef(Constraints, ConstraintsLen));
-#else
   // llvm::Error converts to true if it is an error.
   return !llvm::errorToBool(InlineAsm::verify(
       unwrap<FunctionType>(Ty), StringRef(Constraints, ConstraintsLen)));
-#endif
 }
 
 typedef DIBuilder *LLVMRustDIBuilderRef;
@@ -1649,19 +1626,11 @@ extern "C" bool LLVMRustConstInt128Get(LLVMValueRef CV, bool sext, uint64_t *hig
     auto C = unwrap<llvm::ConstantInt>(CV);
     if (C->getBitWidth() > 128) { return false; }
     APInt AP;
-#if LLVM_VERSION_GE(15, 0)
     if (sext) {
         AP = C->getValue().sext(128);
     } else {
         AP = C->getValue().zext(128);
     }
-#else
-    if (sext) {
-        AP = C->getValue().sextOrSelf(128);
-    } else {
-        AP = C->getValue().zextOrSelf(128);
-    }
-#endif
     *low = AP.getLoBits(64).getZExtValue();
     *high = AP.getHiBits(64).getZExtValue();
     return true;
@@ -2037,16 +2006,7 @@ extern "C" void LLVMRustGetMangledName(LLVMValueRef V, RustStringRef Str) {
   Mangler().getNameWithPrefix(OS, GV, true);
 }
 
-// LLVMGetAggregateElement was added in LLVM 15. For earlier LLVM versions just
-// use its implementation.
-#if LLVM_VERSION_LT(15, 0)
-extern "C" LLVMValueRef LLVMGetAggregateElement(LLVMValueRef C, unsigned Idx) {
-    return wrap(unwrap<Constant>(C)->getAggregateElement(Idx));
-}
-#endif
-
 extern "C" int32_t LLVMRustGetElementTypeArgIndex(LLVMValueRef CallSite) {
-#if LLVM_VERSION_GE(15, 0)
     auto *CB = unwrap<CallBase>(CallSite);
     switch (CB->getIntrinsicID()) {
         case Intrinsic::arm_ldrex:
@@ -2054,7 +2014,6 @@ extern "C" int32_t LLVMRustGetElementTypeArgIndex(LLVMValueRef CallSite) {
         case Intrinsic::arm_strex:
             return 1;
     }
-#endif
     return -1;
 }