[llvm] [Corosplit][DebugInfo] Don't add EntryValue ops in variadic DIExpressions (PR #67179)

[Felipe de Azevedo Piovezan via llvm-commits]

https://github.com/felipepiovezan created https://github.com/llvm/llvm-project/pull/67179

These are not supported by the backend.

The comment that got deleted was out of place, and it exists in the call sites of this function.

>From 75d7c83fd03c90a6964ccbb4265dc796baeb5a50 Mon Sep 17 00:00:00 2001
From: Felipe de Azevedo Piovezan <fpiovezan at apple.com>
Date: Fri, 22 Sep 2023 14:47:41 -0400
Subject: [PATCH] [Corosplit][DebugInfo] Don't add EntryValue ops in variadic
 DIExpressions

These are not supported by the backend.

The comment that got deleted was out of place, and it exists in the call sites
of this function.
---
 llvm/lib/Transforms/Coroutines/CoroFrame.cpp       | 7 +++----
 llvm/test/Transforms/Coroutines/swift-async-dbg.ll | 4 ++++
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
index 40b0650deda51e1..1de702c47fb0735 100644
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -2879,10 +2879,9 @@ void coro::salvageDebugInfo(
 
   // Swift async arguments are described by an entry value of the ABI-defined
   // register containing the coroutine context.
-  // For the EntryPoint funclet, don't use EntryValues. This funclet can be
-  // inlined, which would remove the guarantee that this intrinsic targets an
-  // Argument.
-  if (IsSwiftAsyncArg && UseEntryValue && !Expr->isEntryValue())
+  // Entry values in variadic expressions are not supported.
+  if (IsSwiftAsyncArg && UseEntryValue && !Expr->isEntryValue() &&
+      Expr->isSingleLocationExpression())
     Expr = DIExpression::prepend(Expr, DIExpression::EntryValue);
 
   // If the coroutine frame is an Argument, store it in an alloca to improve
diff --git a/llvm/test/Transforms/Coroutines/swift-async-dbg.ll b/llvm/test/Transforms/Coroutines/swift-async-dbg.ll
index acd077db440dfe8..af7d816c1286166 100644
--- a/llvm/test/Transforms/Coroutines/swift-async-dbg.ll
+++ b/llvm/test/Transforms/Coroutines/swift-async-dbg.ll
@@ -35,6 +35,7 @@ define swifttailcc void @coroutineA(ptr swiftasync %arg) !dbg !48 {
   call void @dont_optimize(ptr %var_with_dbg_value, ptr %var_with_dbg_declare)
   call void @llvm.dbg.value(metadata ptr %var_with_dbg_value, metadata !50, metadata !DIExpression(DW_OP_deref)), !dbg !54
   %i17 = load i32, ptr getelementptr inbounds (<{i32, i32}>, ptr @coroutineBTu, i64 0, i32 1), align 8, !dbg !54
+  call void @llvm.dbg.value(metadata !DIArgList(ptr %var_with_dbg_value, i32 %i17), metadata !501, metadata !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_deref)), !dbg !54
   %i18 = zext i32 %i17 to i64, !dbg !54
   %i19 = call swiftcc ptr @swift_task_alloc(i64 %i18), !dbg !54
 ; CHECK-NOT: define
@@ -44,6 +45,8 @@ define swifttailcc void @coroutineA(ptr swiftasync %arg) !dbg !48 {
 ; CHECK-SAME:                   DW_OP_LLVM_entry_value, 1, DW_OP_plus_uconst, 16, DW_OP_plus_uconst, 8)
 ; CHECK:      @llvm.dbg.value(metadata ptr %[[frame_ptr]], {{.*}} !DIExpression(
 ; CHECK-SAME:                 DW_OP_LLVM_entry_value, 1, DW_OP_plus_uconst, 16, DW_OP_deref)
+; CHECK:      @llvm.dbg.value(metadata !DIArgList(ptr %[[frame_ptr]], i32 %{{.*}}), {{.*}} !DIExpression(
+; CHECK-SAME:                 DW_OP_LLVM_arg, 0, DW_OP_plus_uconst, 16, DW_OP_LLVM_arg, 1, DW_OP_plus, DW_OP_deref)
 ; CHECK:      call {{.*}} @coroutineB
 
   %i23 = call ptr @llvm.coro.async.resume(), !dbg !54
@@ -139,6 +142,7 @@ declare { ptr } @llvm.coro.suspend.async.sl_p0s(i32, ptr, ptr, ...)
 
 !50 = !DILocalVariable(name: "k1", scope: !48, file: !17, line: 7, type: !53)
 !500 = !DILocalVariable(name: "k2", scope: !48, file: !17, line: 7, type: !53)
+!501 = !DILocalVariable(name: "k3", scope: !48, file: !17, line: 7, type: !53)
 !49 = !{!50, !500}
 
 !16 = distinct !DICompileUnit(language: DW_LANG_Swift, file: !17, producer: "", emissionKind: FullDebug)