Prepare for LLVM 21

.github/workflows/supported_llvm_versions.yml

@@ -19,6 +19,11 @@ jobs:
       fail-fast: false
       matrix:
         include:
+          - job_name: Ubuntu 24.04, LLVM 21, latest LDC beta
+            os: ubuntu-24.04
+            host_dc: ldc-beta
+            llvm_version: 21
+            cmake_flags: -DCMAKE_EXE_LINKER_FLAGS=-lcurl # work around libcurl dependency for ldc-profdata (LLVM apparently built with non-default LLVM_ENABLE_CURL=ON)
           - job_name: Ubuntu 24.04, LLVM 19, latest LDC beta
             os: ubuntu-24.04
             host_dc: ldc-beta
@@ -74,7 +79,14 @@ jobs:
         run: |
           set -eux
           sudo apt-get update
-          sudo apt-get install gdb lld-${{ matrix.llvm_version }} llvm-${{ matrix.llvm_version }}-dev libclang-common-${{ matrix.llvm_version }}-dev
+          version='${{ matrix.llvm_version }}'
+          if [[ "$version" -eq 21 ]]; then
+            curl -fL --retry 3 --max-time 30 -O https://apt.llvm.org/llvm.sh
+            sudo bash llvm.sh "$version"
+            sudo apt-get install gdb libcurl4-openssl-dev
+          else
+            sudo apt-get install gdb lld-${{ matrix.llvm_version }} llvm-${{ matrix.llvm_version }}-dev libclang-common-${{ matrix.llvm_version }}-dev
+          fi
 
       - name: 'macOS: Install a more recent GNU make'
         if: runner.os == 'macOS'

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 #### Big news
 - Frontend, druntime and Phobos are at version ~[2.112.0](https://dlang.org/changelog/2.112.0.html), incl. new command-line options `-extI`, `-dllimport=externalOnly` and `-edition`. (#4949, #4962, #4988, #5029)
+- Support for [LLVM 21](https://releases.llvm.org/21.1.0/docs/ReleaseNotes.html). Beware that patch versions before v21.1.8 seem to misoptimize `std.json`. (#4950, #5033)
 - **Breaking change for dcompute**: The special `@kernel` UDA is now a function and _**requires**_ parentheses as in `@kernel() void foo(){}`. Optionally you can provide launch dimensions, `@kernel([2,4,8])`, to specify to the compute runtime how the kernel is intended to be launched.
 - ldc2.conf can now be a directory. All the files inside it, ordered naturally, will be concatenated and treated like a big config. (#4954)
   - Running `ldc-build-runtime --installWithSuffix` now includes installing a target-specific .conf file to that directory. (#4978)
@@ -15,6 +16,7 @@
 - The prebuilt arm64/universal macOS packages additionally bundle the arm64 iOS-*simulator* libraries, for out-of-the-box cross-compilation support via e.g. `-mtriple=arm64-apple-ios12.0-simulator`. (#4974)
 
 #### Platform support
+- Supports LLVM 15 - 21.
 
 #### Bug fixes
 

cmake/Modules/FindLLVM.cmake

@@ -32,7 +32,8 @@
 # We also want an user-specified LLVM_ROOT_DIR to take precedence over the
 # system default locations such as /usr/local/bin. Executing find_program()
 # multiples times is the approach recommended in the docs.
-set(llvm_config_names llvm-config-20.1 llvm-config201 llvm-config-20
+set(llvm_config_names llvm-config-21.1 llvm-config211 llvm-config-21
+                      llvm-config-20.1 llvm-config201 llvm-config-20
                       llvm-config-19.1 llvm-config191 llvm-config-19
                       llvm-config-18.1 llvm-config181 llvm-config-18
                       llvm-config-17.0 llvm-config170 llvm-config-17
@@ -48,10 +49,12 @@ if(APPLE)
     # extra fallbacks for MacPorts & Homebrew
     find_program(LLVM_CONFIG
         NAMES ${llvm_config_names}
-        PATHS /opt/local/libexec/llvm-20/bin /opt/local/libexec/llvm-19/bin
+        PATHS /opt/local/libexec/llvm-21/bin
+              /opt/local/libexec/llvm-20/bin /opt/local/libexec/llvm-19/bin
               /opt/local/libexec/llvm-18/bin /opt/local/libexec/llvm-17/bin
               /opt/local/libexec/llvm-16/bin /opt/local/libexec/llvm-15/bin
               /opt/local/libexec/llvm/bin
+              /usr/local/opt/llvm@21/bin
               /usr/local/opt/llvm@20/bin /usr/local/opt/llvm@19/bin
               /usr/local/opt/llvm@18/bin /usr/local/opt/llvm@17/bin
               /usr/local/opt/llvm@16/bin /usr/local/opt/llvm@15/bin

gen/passes/GarbageCollect2Stack.cpp

@@ -746,18 +746,16 @@ bool isSafeToStackAllocate(BasicBlock::iterator Alloc, Value *V,
       for (auto A = B; A != E; ++A) {
         if (A->get() == V) {
 #if LDC_LLVM_VER >= 2100
-          if (CB->paramHasAttr(A - B, llvm::Attribute::AttrKind::Captures)) {
-            return capturesNothing(
-                        CB->getParamAttr(A - B, llvm::Attribute::AttrKind::Captures)
-                           .getCaptureInfo());
-          }
-
+          if (!(CB->paramHasAttr(A - B, llvm::Attribute::AttrKind::Captures) &&
+                capturesNothing(
+                    CB->getParamAttr(A - B, llvm::Attribute::AttrKind::Captures)
+                        .getCaptureInfo()))) {
 #else
           if (!CB->paramHasAttr(A - B, llvm::Attribute::AttrKind::NoCapture)) {
+#endif
             // The parameter is not marked 'nocapture' - captured.
             return false;
           }
-#endif
 
           if (auto call = dyn_cast<CallInst>(static_cast<Instruction *>(CB))) {
             if (call->isTailCall()) {

runtime/druntime/src/ldc/intrinsics.di

@@ -26,7 +26,7 @@ else version (LDC_LLVM_1800) enum LLVM_version = 1800;
 else version (LDC_LLVM_1801) enum LLVM_version = 1801;
 else version (LDC_LLVM_1901) enum LLVM_version = 1901;
 else version (LDC_LLVM_2001) enum LLVM_version = 2001;
-else version (LDC_LLVM_2100) enum LLVM_version = 2100;
+else version (LDC_LLVM_2101) enum LLVM_version = 2101;
 else version (LDC_LLVM_2200) enum LLVM_version = 2200;
 else static assert(false, "LDC LLVM version not supported");
 

tests/codegen/align.d

@@ -21,12 +21,12 @@ Outer passAndReturnOuterByVal(Outer arg) { return arg; }
 // CHECK-SAME: ptr {{noalias sret.*|inreg noalias}} align 32 %.sret_arg
 /* How the arg is passed by value is ABI-specific, but the pointer must be aligned.
  * When the argument is passed as a byte array and copied into a stack alloc, that stack alloca must be aligned. */
-// CHECK: {{(align 32 %arg|%arg = alloca %align.Outer, align 32)}}
+// CHECK: {{(align 32 %arg|%arg = alloca %align.Outer, align 32|call void @llvm.memcpy.* %.sret_arg,.* %arg)}}
 
 Inner passAndReturnInnerByVal(Inner arg) { return arg; }
 // CHECK: define{{.*}} void @{{.*}}_D5align23passAndReturnInnerByValFSQBh5InnerZQl
 // CHECK-SAME: ptr {{noalias sret.*|inreg noalias}} align 32 %.sret_arg
-// CHECK: {{(align 32 %arg|%arg = alloca %align.Inner, align 32)}}
+// CHECK: {{(align 32 %arg|%arg = alloca %align.Inner, align 32|call void @llvm.memcpy.* %.sret_arg,.* %arg)}}
 
 void main() {
   Outer outer;
@@ -61,11 +61,11 @@ void main() {
   // CHECK: call{{.*}} void @{{.*}}_D5align23passAndReturnOuterByValFSQBh5OuterZQl
   // CHECK-SAME: ptr {{noalias sret.*|inreg noalias}} align 32 %.sret_tmp
   // The argument is either passed by aligned (optimizer hint) pointer or as an array of i32/64 and copied into an aligned stack slot inside the callee.
-  // CHECK-SAME: {{(align 32 %|\[[0-9]+ x i..\])}}
+  // CHECK-SAME: {{(align 32 |\[[0-9]+ x i..\])}}
 
   inner = passAndReturnInnerByVal(inner);
   // CHECK: call{{.*}} void @{{.*}}_D5align23passAndReturnInnerByValFSQBh5InnerZQl
   // CHECK-SAME: ptr {{noalias sret.*|inreg noalias}} align 32 %.sret_tmp
   // The argument is either passed by aligned (optimizer hint) pointer or as an array of i32/64 and copied into an aligned stack slot inside the callee.
-  // CHECK-SAME: {{(align 32 %|\[[0-9]+ x i..\])}}
+  // CHECK-SAME: {{(align 32 |\[[0-9]+ x i..\])}}
 }

tests/codegen/dmd_style_asm_with_variable_and_offset_memory_reference.d

@@ -26,7 +26,7 @@ uint getHighHalfOfGlobal(ulong value)
 {
     asm
     {
-        // CHECK: movl    ((4+(-8))+_someGlobalVariable)+8, %eax
+        // CHECK: movl    {{\(?\(?4\+\(?-8\)?\)?\+_someGlobalVariable\)?\+8}}, %eax
         mov EAX, dword ptr [someGlobalVariable + 4];
     }
 }