Merge pull request swiftlang#18717 from adrian-prantl/43296089

Add initial support for debug info for coroutine allocas.

Author: adrian-prantl

lib/IRGen/IRGenDebugInfo.cpp

@@ -2003,21 +2003,25 @@ void IRGenDebugInfoImpl::emitDbgIntrinsic(
     return;
 
   // A dbg.declare is only meaningful if there is a single alloca for
-  // the variable that is live throughout the function. With SIL
-  // optimizations this is not guaranteed and a variable can end up in
-  // two allocas (for example, one function inlined twice).
+  // the variable that is live throughout the function.
   if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Storage)) {
     auto *ParentBB = Alloca->getParent();
     auto InsertBefore = std::next(Alloca->getIterator());
     if (InsertBefore != ParentBB->end())
       DBuilder.insertDeclare(Alloca, Var, Expr, DL, &*InsertBefore);
     else
       DBuilder.insertDeclare(Alloca, Var, Expr, DL, ParentBB);
-    return;
+  } else if (isa<llvm::IntrinsicInst>(Storage) &&
+             cast<llvm::IntrinsicInst>(Storage)->getIntrinsicID() ==
+                 llvm::Intrinsic::coro_alloca_get) {
+    // FIXME: The live range of a coroutine alloca within the function may be
+    // limited, so using a dbg.addr instead of a dbg.declare would be more
+    // appropriate.
+    DBuilder.insertDeclare(Storage, Var, Expr, DL, BB);
+  } else {
+    // Insert a dbg.value at the current insertion point.
+    DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL, BB);
   }
-
-  // Insert a dbg.value at the current insertion point.
-  DBuilder.insertDbgValueIntrinsic(Storage, Var, Expr, DL, BB);
 }
 
 void IRGenDebugInfoImpl::emitGlobalVariableDeclaration(

lib/IRGen/IRGenSIL.cpp

@@ -4001,9 +4001,15 @@ void IRGenSILFunction::emitDebugInfoForAllocStack(AllocStackInst *i,
   VarDecl *Decl = i->getDecl();
   // Describe the underlying alloca. This way an llvm.dbg.declare instrinsic
   // is used, which is valid for the entire lifetime of the alloca.
-  if (auto *BitCast = dyn_cast<llvm::BitCastInst>(addr))
-    if (auto *Alloca = dyn_cast<llvm::AllocaInst>(BitCast->getOperand(0)))
+  if (auto *BitCast = dyn_cast<llvm::BitCastInst>(addr)) {
+    auto *Op0 = BitCast->getOperand(0);
+    if (auto *Alloca = dyn_cast<llvm::AllocaInst>(Op0))
       addr = Alloca;
+    else if (auto *CoroAllocaGet = dyn_cast<llvm::IntrinsicInst>(Op0)) {
+      if (CoroAllocaGet->getIntrinsicID() == llvm::Intrinsic::coro_alloca_get)
+        addr = CoroAllocaGet;
+    }
+  }
 
   auto DS = i->getDebugScope();
   if (!DS)
@@ -4016,7 +4022,9 @@ void IRGenSILFunction::emitDebugInfoForAllocStack(AllocStackInst *i,
   StringRef Name = getVarName(i, IsAnonymous);
 
   // At this point addr must be an alloca or an undef.
-  assert(isa<llvm::AllocaInst>(addr) || isa<llvm::UndefValue>(addr));
+  assert(isa<llvm::AllocaInst>(addr) || isa<llvm::UndefValue>(addr) ||
+         isa<llvm::IntrinsicInst>(addr));
+
   auto Indirection = DirectValue;
   if (!IGM.IRGen.Opts.shouldOptimize())
     if (auto *Alloca = dyn_cast<llvm::AllocaInst>(addr))