Auto merge of #81451 - nikic:llvm-12, r=nagisa

Upgrade to LLVM 12

This implements the necessary adjustments to make rustc work with LLVM 12. I didn't encounter any major issues so far.

r? `@cuviper`

Author: bors

.gitmodules

@@ -37,7 +37,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/11.0-2021-01-05
+	branch = rustc/12.0-2021-02-03
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
 	url = https://github.com/rust-embedded/book.git

compiler/rustc_codegen_llvm/src/abi.rs

@@ -430,7 +430,13 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
                 assert!(!on_stack);
                 let i = apply(attrs);
-                llvm::Attribute::StructRet.apply_llfn(llvm::AttributePlace::Argument(i), llfn);
+                unsafe {
+                    llvm::LLVMRustAddStructRetAttr(
+                        llfn,
+                        llvm::AttributePlace::Argument(i).as_uint(),
+                        self.ret.layout.llvm_type(cx),
+                    );
+                }
             }
             _ => {}
         }
@@ -486,8 +492,13 @@ impl<'tcx> FnAbiLlvmExt<'tcx> for FnAbi<'tcx, Ty<'tcx>> {
             PassMode::Indirect { ref attrs, extra_attrs: _, on_stack } => {
                 assert!(!on_stack);
                 let i = apply(attrs);
-                llvm::Attribute::StructRet
-                    .apply_callsite(llvm::AttributePlace::Argument(i), callsite);
+                unsafe {
+                    llvm::LLVMRustAddStructRetCallSiteAttr(
+                        callsite,
+                        llvm::AttributePlace::Argument(i).as_uint(),
+                        self.ret.layout.llvm_type(bx),
+                    );
+                }
             }
             _ => {}
         }

compiler/rustc_codegen_llvm/src/asm.rs

@@ -304,6 +304,7 @@ impl AsmBuilderMethods<'tcx> for Builder<'a, 'll, 'tcx> {
             } else if options.contains(InlineAsmOptions::READONLY) {
                 llvm::Attribute::ReadOnly.apply_callsite(llvm::AttributePlace::Function, result);
             }
+            llvm::Attribute::WillReturn.apply_callsite(llvm::AttributePlace::Function, result);
         } else if options.contains(InlineAsmOptions::NOMEM) {
             llvm::Attribute::InaccessibleMemOnly
                 .apply_callsite(llvm::AttributePlace::Function, result);

compiler/rustc_codegen_llvm/src/context.rs

@@ -104,6 +104,10 @@ fn strip_x86_address_spaces(data_layout: String) -> String {
     data_layout.replace("-p270:32:32-p271:32:32-p272:64:64-", "-")
 }
 
+fn strip_powerpc64_vectors(data_layout: String) -> String {
+    data_layout.replace("-v256:256:256-v512:512:512", "")
+}
+
 pub unsafe fn create_module(
     tcx: TyCtxt<'_>,
     llcx: &'ll llvm::Context,
@@ -119,6 +123,9 @@ pub unsafe fn create_module(
     {
         target_data_layout = strip_x86_address_spaces(target_data_layout);
     }
+    if llvm_util::get_version() < (12, 0, 0) && sess.target.arch == "powerpc64" {
+        target_data_layout = strip_powerpc64_vectors(target_data_layout);
+    }
 
     // Ensure the data-layout values hardcoded remain the defaults.
     if sess.target.is_builtin {

compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs

@@ -162,7 +162,7 @@ pub(crate) fn write_filenames_section_to_buffer<'a>(
 pub(crate) fn write_mapping_to_buffer(
     virtual_file_mapping: Vec<u32>,
     expressions: Vec<CounterExpression>,
-    mut mapping_regions: Vec<CounterMappingRegion>,
+    mapping_regions: Vec<CounterMappingRegion>,
     buffer: &RustString,
 ) {
     unsafe {
@@ -171,7 +171,7 @@ pub(crate) fn write_mapping_to_buffer(
             virtual_file_mapping.len() as c_uint,
             expressions.as_ptr(),
             expressions.len() as c_uint,
-            mapping_regions.as_mut_ptr(),
+            mapping_regions.as_ptr(),
             mapping_regions.len() as c_uint,
             buffer,
         );

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -132,6 +132,7 @@ pub enum Attribute {
     ReadNone = 26,
     InaccessibleMemOnly = 27,
     SanitizeHWAddress = 28,
+    WillReturn = 29,
 }
 
 /// LLVMIntPredicate
@@ -239,6 +240,7 @@ pub enum TypeKind {
     Token = 16,
     ScalableVector = 17,
     BFloat = 18,
+    X86_AMX = 19,
 }
 
 impl TypeKind {
@@ -263,6 +265,7 @@ impl TypeKind {
             TypeKind::Token => rustc_codegen_ssa::common::TypeKind::Token,
             TypeKind::ScalableVector => rustc_codegen_ssa::common::TypeKind::ScalableVector,
             TypeKind::BFloat => rustc_codegen_ssa::common::TypeKind::BFloat,
+            TypeKind::X86_AMX => rustc_codegen_ssa::common::TypeKind::X86_AMX,
         }
     }
 }
@@ -674,9 +677,7 @@ pub mod coverageinfo {
     /// array", encoded separately), and source location (start and end positions of the represented
     /// code region).
     ///
-    /// Aligns with [llvm::coverage::CounterMappingRegion](https://github.com/rust-lang/llvm-project/blob/rustc/11.0-2020-10-12/llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h#L224-L227)
-    /// Important: The Rust struct layout (order and types of fields) must match its C++
-    /// counterpart.
+    /// Matches LLVMRustCounterMappingRegion.
     #[derive(Copy, Clone, Debug)]
     #[repr(C)]
     pub struct CounterMappingRegion {
@@ -1073,6 +1074,7 @@ extern "C" {
     pub fn LLVMRustAddDereferenceableAttr(Fn: &Value, index: c_uint, bytes: u64);
     pub fn LLVMRustAddDereferenceableOrNullAttr(Fn: &Value, index: c_uint, bytes: u64);
     pub fn LLVMRustAddByValAttr(Fn: &Value, index: c_uint, ty: &Type);
+    pub fn LLVMRustAddStructRetAttr(Fn: &Value, index: c_uint, ty: &Type);
     pub fn LLVMRustAddFunctionAttribute(Fn: &Value, index: c_uint, attr: Attribute);
     pub fn LLVMRustAddFunctionAttrStringValue(
         Fn: &Value,
@@ -1108,6 +1110,7 @@ extern "C" {
     pub fn LLVMRustAddDereferenceableCallSiteAttr(Instr: &Value, index: c_uint, bytes: u64);
     pub fn LLVMRustAddDereferenceableOrNullCallSiteAttr(Instr: &Value, index: c_uint, bytes: u64);
     pub fn LLVMRustAddByValCallSiteAttr(Instr: &Value, index: c_uint, ty: &Type);
+    pub fn LLVMRustAddStructRetCallSiteAttr(Instr: &Value, index: c_uint, ty: &Type);
 
     // Operations on load/store instructions (only)
     pub fn LLVMSetVolatile(MemoryAccessInst: &Value, volatile: Bool);
@@ -1792,7 +1795,7 @@ extern "C" {
         NumVirtualFileMappingIDs: c_uint,
         Expressions: *const coverage_map::CounterExpression,
         NumExpressions: c_uint,
-        MappingRegions: *mut coverageinfo::CounterMappingRegion,
+        MappingRegions: *const coverageinfo::CounterMappingRegion,
         NumMappingRegions: c_uint,
         BufferOut: &RustString,
     );

compiler/rustc_codegen_ssa/src/common.rs

@@ -95,6 +95,7 @@ pub enum TypeKind {
     Token,
     ScalableVector,
     BFloat,
+    X86_AMX,
 }
 
 // FIXME(mw): Anything that is produced via DepGraph::with_task() must implement

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -8,6 +8,17 @@
 
 using namespace llvm;
 
+struct LLVMRustCounterMappingRegion {
+  coverage::Counter Count;
+  uint32_t FileID;
+  uint32_t ExpandedFileID;
+  uint32_t LineStart;
+  uint32_t ColumnStart;
+  uint32_t LineEnd;
+  uint32_t ColumnEnd;
+  coverage::CounterMappingRegion::RegionKind Kind;
+};
+
 extern "C" void LLVMRustCoverageWriteFilenamesSectionToBuffer(
     const char* const Filenames[],
     size_t FilenamesLen,
@@ -27,13 +38,22 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
     unsigned NumVirtualFileMappingIDs,
     const coverage::CounterExpression *Expressions,
     unsigned NumExpressions,
-    coverage::CounterMappingRegion *MappingRegions,
+    LLVMRustCounterMappingRegion *RustMappingRegions,
     unsigned NumMappingRegions,
     RustStringRef BufferOut) {
+  // Convert from FFI representation to LLVM representation.
+  SmallVector<coverage::CounterMappingRegion, 0> MappingRegions;
+  MappingRegions.reserve(NumMappingRegions);
+  for (const auto &Region : makeArrayRef(RustMappingRegions, NumMappingRegions)) {
+    MappingRegions.emplace_back(
+        Region.Count, Region.FileID, Region.ExpandedFileID,
+        Region.LineStart, Region.ColumnStart, Region.LineEnd, Region.ColumnEnd,
+        Region.Kind);
+  }
   auto CoverageMappingWriter = coverage::CoverageMappingWriter(
       makeArrayRef(VirtualFileMappingIDs, NumVirtualFileMappingIDs),
       makeArrayRef(Expressions, NumExpressions),
-      makeMutableArrayRef(MappingRegions, NumMappingRegions));
+      MappingRegions);
   RawRustStringOstream OS(BufferOut);
   CoverageMappingWriter.write(OS);
 }

compiler/rustc_llvm/llvm-wrapper/LLVMWrapper.h

@@ -86,6 +86,7 @@ enum LLVMRustAttribute {
   ReadNone = 26,
   InaccessibleMemOnly = 27,
   SanitizeHWAddress = 28,
+  WillReturn = 29,
 };
 
 typedef struct OpaqueRustString *RustStringRef;