Auto merge of rust-lang#127513 - nikic:llvm-19, r=<try>

Update to LLVM 19

Related changes:
 * rust-lang#127605
 * rust-lang#127613
 * rust-lang#127654
 * rust-lang#128141
 * llvm/llvm-project#98933

try-job: dist-x86_64-apple
try-job: dist-apple-various
try-job: x86_64-apple-1
try-job: x86_64-apple-2
try-job: dist-aarch64-apple
try-job: aarch64-apple

Author: bors

Diff for: .gitmodules

@@ -32,8 +32,8 @@
 	shallow = true
 [submodule "src/llvm-project"]
 	path = src/llvm-project
-	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/18.1-2024-05-19
+	url = https://github.com/nikic/llvm-project.git
+	branch = rust-llvm-19
 	shallow = true
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book

Diff for: compiler/rustc_codegen_llvm/src/attributes.rs

@@ -4,7 +4,7 @@ use rustc_codegen_ssa::traits::*;
 use rustc_hir::def_id::DefId;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, PatchableFunctionEntry};
 use rustc_middle::ty::{self, TyCtxt};
-use rustc_session::config::{FunctionReturn, OptLevel};
+use rustc_session::config::{BranchProtection, FunctionReturn, OptLevel, PAuthKey, PacRet};
 use rustc_span::symbol::sym;
 use rustc_target::spec::{FramePointer, SanitizerSet, StackProbeType, StackProtector};
 use smallvec::SmallVec;
@@ -407,8 +407,33 @@ pub fn from_fn_attrs<'ll, 'tcx>(
         // And it is a module-level attribute, so the alternative is pulling naked functions into new LLVM modules.
         // Otherwise LLVM's "naked" functions come with endbr prefixes per https://github.com/rust-lang/rust/issues/98768
         to_add.push(AttributeKind::NoCfCheck.create_attr(cx.llcx));
-        // Need this for AArch64.
-        to_add.push(llvm::CreateAttrStringValue(cx.llcx, "branch-target-enforcement", "false"));
+        if llvm_util::get_version() < (19, 0, 0) {
+            // Prior to LLVM 19, branch-target-enforcement was disabled by setting the attribute to
+            // the string "false". Now it is disabled by absence of the attribute.
+            to_add.push(llvm::CreateAttrStringValue(cx.llcx, "branch-target-enforcement", "false"));
+        }
+    } else if llvm_util::get_version() >= (19, 0, 0) {
+        // For non-naked functions, set branch protection attributes on aarch64.
+        if let Some(BranchProtection { bti, pac_ret }) =
+            cx.sess().opts.unstable_opts.branch_protection
+        {
+            assert!(cx.sess().target.arch == "aarch64");
+            if bti {
+                to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement"));
+            }
+            if let Some(PacRet { leaf, key }) = pac_ret {
+                to_add.push(llvm::CreateAttrStringValue(
+                    cx.llcx,
+                    "sign-return-address",
+                    if leaf { "all" } else { "non-leaf" },
+                ));
+                to_add.push(llvm::CreateAttrStringValue(
+                    cx.llcx,
+                    "sign-return-address-key",
+                    if key == PAuthKey::A { "a_key" } else { "b_key" },
+                ));
+            }
+        }
     }
     if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR)
         || codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::ALLOCATOR_ZEROED)

Diff for: compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1557,11 +1557,12 @@ LLVMRustGetInstrProfMCDCTVBitmapUpdateIntrinsic(LLVMModuleRef M) {
 
 extern "C" LLVMValueRef
 LLVMRustGetInstrProfMCDCCondBitmapIntrinsic(LLVMModuleRef M) {
-#if LLVM_VERSION_GE(18, 0)
+#if LLVM_VERSION_GE(18, 0) && LLVM_VERSION_LT(19, 0)
   return wrap(llvm::Intrinsic::getDeclaration(
       unwrap(M), llvm::Intrinsic::instrprof_mcdc_condbitmap_update));
 #else
-  report_fatal_error("LLVM 18.0 is required for mcdc intrinsic functions");
+  report_fatal_error(
+      "The instrprof_mcdc_condbitmap_update only exists in LLVM 18");
 #endif
 }
 

Diff for: src/llvm-project

@@ -0,0 +1,45 @@
+// Test that the correct module flags are emitted with different branch protection flags.
+
+//@ revisions: BTI PACRET LEAF BKEY NONE
+//@ needs-llvm-components: aarch64
+//@ [BTI] compile-flags: -Z branch-protection=bti
+//@ [PACRET] compile-flags: -Z branch-protection=pac-ret
+//@ [LEAF] compile-flags: -Z branch-protection=pac-ret,leaf
+//@ [BKEY] compile-flags: -Z branch-protection=pac-ret,b-key
+//@ compile-flags: --target aarch64-unknown-linux-gnu
+//@ ignore-llvm-version: 19 - 99
+
+#![crate_type = "lib"]
+#![feature(no_core, lang_items)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+
+// A basic test function.
+pub fn test() {}
+
+// BTI: !"branch-target-enforcement", i32 1
+// BTI: !"sign-return-address", i32 0
+// BTI: !"sign-return-address-all", i32 0
+// BTI: !"sign-return-address-with-bkey", i32 0
+
+// PACRET: !"branch-target-enforcement", i32 0
+// PACRET: !"sign-return-address", i32 1
+// PACRET: !"sign-return-address-all", i32 0
+// PACRET: !"sign-return-address-with-bkey", i32 0
+
+// LEAF: !"branch-target-enforcement", i32 0
+// LEAF: !"sign-return-address", i32 1
+// LEAF: !"sign-return-address-all", i32 1
+// LEAF: !"sign-return-address-with-bkey", i32 0
+
+// BKEY: !"branch-target-enforcement", i32 0
+// BKEY: !"sign-return-address", i32 1
+// BKEY: !"sign-return-address-all", i32 0
+// BKEY: !"sign-return-address-with-bkey", i32 1
+
+// NONE-NOT: branch-target-enforcement
+// NONE-NOT: sign-return-address
+// NONE-NOT: sign-return-address-all
+// NONE-NOT: sign-return-address-with-bkey

Diff for: tests/codegen/branch-protection-old-llvm.rs

@@ -7,6 +7,7 @@
 //@ [LEAF] compile-flags: -Z branch-protection=pac-ret,leaf
 //@ [BKEY] compile-flags: -Z branch-protection=pac-ret,b-key
 //@ compile-flags: --target aarch64-unknown-linux-gnu
+//@ min-llvm-version: 19
 
 #![crate_type = "lib"]
 #![feature(no_core, lang_items)]
@@ -16,23 +17,32 @@
 trait Sized {}
 
 // A basic test function.
+// CHECK: @test(){{.*}} [[ATTR:#[0-9]+]] {
+#[no_mangle]
 pub fn test() {}
 
+// BTI: attributes [[ATTR]] = {{.*}} "branch-target-enforcement"
 // BTI: !"branch-target-enforcement", i32 1
 // BTI: !"sign-return-address", i32 0
 // BTI: !"sign-return-address-all", i32 0
 // BTI: !"sign-return-address-with-bkey", i32 0
 
+// PACRET: attributes [[ATTR]] = {{.*}} "sign-return-address"="non-leaf"
+// PACRET-SAME: "sign-return-address-key"="a_key"
 // PACRET: !"branch-target-enforcement", i32 0
 // PACRET: !"sign-return-address", i32 1
 // PACRET: !"sign-return-address-all", i32 0
 // PACRET: !"sign-return-address-with-bkey", i32 0
 
+// LEAF: attributes [[ATTR]] = {{.*}} "sign-return-address"="all"
+// LEAF-SAME: "sign-return-address-key"="a_key"
 // LEAF: !"branch-target-enforcement", i32 0
 // LEAF: !"sign-return-address", i32 1
 // LEAF: !"sign-return-address-all", i32 1
 // LEAF: !"sign-return-address-with-bkey", i32 0
 
+// BKEY: attributes [[ATTR]] = {{.*}} "sign-return-address"="non-leaf"
+// BKEY-SAME: "sign-return-address-key"="b_key"
 // BKEY: !"branch-target-enforcement", i32 0
 // BKEY: !"sign-return-address", i32 1
 // BKEY: !"sign-return-address-all", i32 0

Diff for: tests/codegen/branch-protection.rs

@@ -1,6 +1,7 @@
 #![feature(coverage_attribute)]
 //@ edition: 2021
 //@ min-llvm-version: 18
+//@ ignore-llvm-version: 19 - 99
 //@ compile-flags: -Zcoverage-options=mcdc
 //@ llvm-cov-flags: --show-branches=count --show-mcdc
 

Diff for: tests/coverage/mcdc/condition-limit.rs

@@ -1,6 +1,7 @@
 #![feature(coverage_attribute)]
 //@ edition: 2021
 //@ min-llvm-version: 18
+//@ ignore-llvm-version: 19 - 99
 //@ compile-flags: -Zcoverage-options=mcdc
 //@ llvm-cov-flags: --show-branches=count --show-mcdc
 

Diff for: tests/coverage/mcdc/if.rs

@@ -1,6 +1,7 @@
 #![feature(coverage_attribute)]
 //@ edition: 2021
 //@ min-llvm-version: 18
+//@ ignore-llvm-version: 19 - 99
 //@ compile-flags: -Zcoverage-options=mcdc -Copt-level=z -Cllvm-args=--inline-threshold=0
 //@ llvm-cov-flags: --show-branches=count --show-mcdc
 

Diff for: tests/coverage/mcdc/inlined_expressions.rs

@@ -1,6 +1,7 @@
 #![feature(coverage_attribute)]
 //@ edition: 2021
 //@ min-llvm-version: 18
+//@ ignore-llvm-version: 19 - 99
 //@ compile-flags: -Zcoverage-options=mcdc
 //@ llvm-cov-flags: --show-branches=count --show-mcdc
 

Diff for: tests/coverage/mcdc/nested_if.rs

@@ -1,6 +1,7 @@
 #![feature(coverage_attribute)]
 //@ edition: 2021
 //@ min-llvm-version: 18
+//@ ignore-llvm-version: 19 - 99
 //@ compile-flags: -Zcoverage-options=mcdc
 //@ llvm-cov-flags: --show-branches=count --show-mcdc
 

Diff for: tests/coverage/mcdc/non_control_flow.rs

@@ -1,11 +1,13 @@
-//@ known-bug: #121444
 //@ compile-flags: -Copt-level=0
-//@ edition:2021
 //@ only-x86_64
 //@ ignore-windows
+//@ min-llvm-version: 19
+//@ build-pass
+
 #[repr(align(536870912))]
 pub struct A(i64);
 
+#[allow(improper_ctypes_definitions)]
 pub extern "C" fn foo(x: A) {}
 
 fn main() {