From 812d365ca558c4d9b87b741f6f2bab569546f232 Mon Sep 17 00:00:00 2001
From: Nicholas Wilson <iamthewilsonator@hotmail.com>
Date: Sat, 6 Sep 2025 16:57:46 +0800
Subject: [PATCH] [LLVM 21] fix calls to `llvm.lifetime.start`

---
 gen/llvmhelpers.cpp                    | 25 +++++++++++--------------
 gen/variable_lifetime.cpp              | 21 ++++++++++++++++-----
 gen/variable_lifetime.h                |  5 +++--
 runtime/druntime/src/ldc/intrinsics.di |  1 +
 4 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/gen/llvmhelpers.cpp b/gen/llvmhelpers.cpp
index 7d24c08c339..882a3c953f3 100644
--- a/gen/llvmhelpers.cpp
+++ b/gen/llvmhelpers.cpp
@@ -897,30 +897,27 @@ void DtoVarDeclaration(VarDeclaration *vd) {
 
     // We also allocate a variable for zero-sized variables, because they are technically not `null` when loaded.
     // The x86_64 ABI "loads" zero-sized function arguments, and without an allocation ASan will report an error (Github #4816).
-    llvm::Value *allocainst;
-    bool isRealAlloca = false;
     LLType *lltype = DtoType(type); // void for noreturn
     if (lltype->isVoidTy()) {
-      allocainst = getNullPtr();
-    } else if (type != vd->type) {
+      irLocal->value = getNullPtr();
+      return;
+    }
+
+    llvm::AllocaInst *allocainst;
+
+    if (type != vd->type) {
       allocainst = DtoAlloca(type, vd->toChars());
-      isRealAlloca = true;
     } else {
       allocainst = DtoAlloca(vd, vd->toChars());
-      isRealAlloca = true;
     }
 
     irLocal->value = allocainst;
 
-    if (!lltype->isVoidTy())
-      gIR->DBuilder.EmitLocalVariable(allocainst, vd);
+    gIR->DBuilder.EmitLocalVariable(allocainst, vd);
 
-    // Lifetime annotation is only valid on alloca.
-    if (isRealAlloca) {
-      // The lifetime of a stack variable starts from the point it is declared
-      gIR->funcGen().localVariableLifetimeAnnotator.addLocalVariable(
-          allocainst, DtoConstUlong(size(type)));
-    }
+    // The lifetime of a stack variable starts from the point it is declared
+    gIR->funcGen().localVariableLifetimeAnnotator.addLocalVariable(
+        allocainst, DtoConstUlong(size(type)));
   }
 
   IF_LOG Logger::cout() << "llvm value for decl: " << *getIrLocal(vd)->value
diff --git a/gen/variable_lifetime.cpp b/gen/variable_lifetime.cpp
index cf21104de2f..a6659f6ec34 100644
--- a/gen/variable_lifetime.cpp
+++ b/gen/variable_lifetime.cpp
@@ -37,7 +37,7 @@ LocalVariableLifetimeAnnotator::LocalVariableLifetimeAnnotator(IRState &irs)
 
 void LocalVariableLifetimeAnnotator::pushScope() { scopes.emplace_back(); }
 
-void LocalVariableLifetimeAnnotator::addLocalVariable(llvm::Value *address,
+void LocalVariableLifetimeAnnotator::addLocalVariable(llvm::AllocaInst *address,
                                                       llvm::Value *size) {
   assert(address);
   assert(size);
@@ -52,8 +52,13 @@ void LocalVariableLifetimeAnnotator::addLocalVariable(llvm::Value *address,
   scopes.back().variables.emplace_back(size, address);
 
   // Emit lifetime start
-  irs.CreateCallOrInvoke(getLLVMLifetimeStartFn(), {size, address}, "",
-                         true /*nothrow*/);
+  irs.CreateCallOrInvoke(getLLVMLifetimeStartFn(),
+#if LDC_LLVM_VER >= 2100
+                         {address},
+#else
+                         {size, address},
+#endif
+                         "", true /*nothrow*/);
 }
 
 // Emits end-of-lifetime annotation for all variables in current scope.
@@ -67,8 +72,14 @@ void LocalVariableLifetimeAnnotator::popScope() {
 
     assert(address);
 
-    irs.CreateCallOrInvoke(getLLVMLifetimeEndFn(), {size, address}, "",
-                           true /*nothrow*/);
+    irs.CreateCallOrInvoke(getLLVMLifetimeEndFn(),
+#if LDC_LLVM_VER >= 2100
+                           {address},
+#else
+                           {size, address},
+#endif
+                           "", true /*nothrow*/);
+
   }
   scopes.pop_back();
 }
diff --git a/gen/variable_lifetime.h b/gen/variable_lifetime.h
index f482030c9ad..2dcf02090f2 100644
--- a/gen/variable_lifetime.h
+++ b/gen/variable_lifetime.h
@@ -21,12 +21,13 @@ namespace llvm {
 class Function;
 class Type;
 class Value;
+class AllocaInst;
 }
 struct IRState;
 
 struct LocalVariableLifetimeAnnotator {
   struct LocalVariableScope {
-    std::vector<std::pair<llvm::Value *, llvm::Value *>> variables;
+    std::vector<std::pair<llvm::Value *, llvm::AllocaInst *>> variables;
   };
   /// Stack of scopes, each scope can have multiple variables.
   std::vector<LocalVariableScope> scopes;
@@ -52,5 +53,5 @@ struct LocalVariableLifetimeAnnotator {
   void popScope();
 
   /// Register a new local variable for lifetime annotation.
-  void addLocalVariable(llvm::Value *address, llvm::Value *size);
+  void addLocalVariable(llvm::AllocaInst *address, llvm::Value *size);
 };
diff --git a/runtime/druntime/src/ldc/intrinsics.di b/runtime/druntime/src/ldc/intrinsics.di
index c0d88d8e2d7..e0f17e1488a 100644
--- a/runtime/druntime/src/ldc/intrinsics.di
+++ b/runtime/druntime/src/ldc/intrinsics.di
@@ -27,6 +27,7 @@ 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_2200) enum LLVM_version = 2200;
 else static assert(false, "LDC LLVM version not supported");
 
 enum LLVM_atleast(int major) = (LLVM_version >= major * 100);