[llvm] 8ae5e0b - Add missing nullptr check

[Adrian Prantl via llvm-commits]

Author: Adrian Prantl
Date: 2021-08-17T13:59:52-07:00
New Revision: 8ae5e0b154ae18a78f73c0aef58356002b8ff0d7

URL: https://github.com/llvm/llvm-project/commit/8ae5e0b154ae18a78f73c0aef58356002b8ff0d7
DIFF: https://github.com/llvm/llvm-project/commit/8ae5e0b154ae18a78f73c0aef58356002b8ff0d7.diff

LOG: Add missing nullptr check

Unfortunatley the IR Verifier doesn't reject debug intrinsics that
have nullptr as arguments, so coro::salvageDebugInfo for now also
needs to deal with them.

rdar://81979541

Added: 
    

Modified: 
    llvm/lib/Transforms/Coroutines/CoroFrame.cpp
    llvm/test/Transforms/Coroutines/coro-debug.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
index e4ef23c0094b..e213de2b73f4 100644
--- a/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroFrame.cpp
@@ -2514,7 +2514,7 @@ void coro::salvageDebugInfo(
   bool OutermostLoad = true;
   Value *Storage = DVI->getVariableLocationOp(0);
   Value *OriginalStorage = Storage;
-  while (auto *Inst = dyn_cast<Instruction>(Storage)) {
+  while (auto *Inst = dyn_cast_or_null<Instruction>(Storage)) {
     if (auto *LdInst = dyn_cast<LoadInst>(Inst)) {
       Storage = LdInst->getOperand(0);
       // FIXME: This is a heuristic that works around the fact that
@@ -2543,6 +2543,8 @@ void coro::salvageDebugInfo(
       Expr = DIExpression::appendOpsToArg(Expr, Ops, 0, /*StackValue*/ false);
     }
   }
+  if (!Storage)
+    return;
 
   // Store a pointer to the coroutine frame object in an alloca so it
   // is available throughout the function when producing unoptimized

diff  --git a/llvm/test/Transforms/Coroutines/coro-debug.ll b/llvm/test/Transforms/Coroutines/coro-debug.ll
index 1e86b656d62e..ec5924fc3ea9 100644
--- a/llvm/test/Transforms/Coroutines/coro-debug.ll
+++ b/llvm/test/Transforms/Coroutines/coro-debug.ll
@@ -34,8 +34,10 @@ sw.bb:                                            ; preds = %entry
   call void @llvm.dbg.declare(metadata i32 %direct, metadata !25, metadata !13), !dbg !14
   call void @llvm.dbg.declare(metadata i32* %x.addr, metadata !12, metadata !13), !dbg !14
   call void @llvm.dbg.declare(metadata i8** %coro_hdl, metadata !15, metadata !13), !dbg !16
-  call void @llvm.dbg.declare(metadata i8* null, metadata !28, metadata !13), !dbg !16
   call void @llvm.dbg.declare(metadata i32* %late_local, metadata !29, metadata !13), !dbg !16
+  ; don't crash when encountering nonsensical debug info, verfifier doesn't yet reject these
+  call void @llvm.dbg.declare(metadata i8* null, metadata !28, metadata !13), !dbg !16
+  call void @llvm.dbg.declare(metadata !{}, metadata !28, metadata !13), !dbg !16
   br label %next, !dbg !18
 
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