commit ebc3b25e187cb39a12dcb05ae1c44de23aa5696e
author Nicolas Geoffray <ngeoffray@google.com> Wed Jan 09 10:47:02 2019 +0000
committer Nicolas Geoffray <ngeoffray@google.com> Wed Jan 09 12:40:22 2019 +0000
tree 589f80a876f899a14608ee657b10fd4b821f463f
parent 458a948d4fc954d767103b5a95803a0a60be9f1c

Fix compiler bug when typing exceptions.

Handlers of different exception types can start at the same
bytecode address, so we should update the type in the compiler
to avoid wrongly typing the exception.

bug: 119944057
Test: 689-multi-catch
Change-Id: I66e43890634965ee7790436c8e5a718564c6040f

compiler/optimizing/block_builder.cc

diff --git a/compiler/optimizing/block_builder.cc b/compiler/optimizing/block_builder.cc
index 3672cce..a5f78ca 100644
--- a/compiler/optimizing/block_builder.cc
+++ b/compiler/optimizing/block_builder.cc
@@ -315,8 +315,16 @@
     CatchHandlerIterator iterator(handlers_ptr);
     for (; iterator.HasNext(); iterator.Next()) {
       uint32_t address = iterator.GetHandlerAddress();
-      if (catch_blocks.find(address) != catch_blocks.end()) {
+      auto existing = catch_blocks.find(address);
+      if (existing != catch_blocks.end()) {
         // Catch block already processed.
+        TryCatchInformation* info = existing->second->GetTryCatchInformation();
+        if (iterator.GetHandlerTypeIndex() != info->GetCatchTypeIndex()) {
+          // The handler is for multiple types. We could record all the types, but
+          // doing class resolution here isn't ideal, and it's unclear whether wasting
+          // the space in TryCatchInformation is worth it.
+          info->SetInvalidTypeIndex();
+        }
         continue;
       }
 
@@ -337,7 +345,7 @@
 
       catch_blocks.Put(address, catch_block);
       catch_block->SetTryCatchInformation(
-        new (allocator_) TryCatchInformation(iterator.GetHandlerTypeIndex(), *dex_file_));
+          new (allocator_) TryCatchInformation(iterator.GetHandlerTypeIndex(), *dex_file_));
     }
     handlers_ptr = iterator.EndDataPointer();
   }

compiler/optimizing/nodes.h

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 686a2de..48fb611 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -895,7 +895,7 @@
   explicit TryCatchInformation(const HTryBoundary& try_entry)
       : try_entry_(&try_entry),
         catch_dex_file_(nullptr),
-        catch_type_index_(DexFile::kDexNoIndex16) {
+        catch_type_index_(dex::TypeIndex::Invalid()) {
     DCHECK(try_entry_ != nullptr);
   }
 
@@ -914,9 +914,9 @@
 
   bool IsCatchBlock() const { return catch_dex_file_ != nullptr; }
 
-  bool IsCatchAllTypeIndex() const {
+  bool IsValidTypeIndex() const {
     DCHECK(IsCatchBlock());
-    return !catch_type_index_.IsValid();
+    return catch_type_index_.IsValid();
   }
 
   dex::TypeIndex GetCatchTypeIndex() const {
@@ -929,6 +929,10 @@
     return *catch_dex_file_;
   }
 
+  void SetInvalidTypeIndex() {
+    catch_type_index_ = dex::TypeIndex::Invalid();
+  }
+
  private:
   // One of possibly several TryBoundary instructions entering the block's try.
   // Only set for try blocks.
@@ -936,7 +940,7 @@
 
   // Exception type information. Only set for catch blocks.
   const DexFile* catch_dex_file_;
-  const dex::TypeIndex catch_type_index_;
+  dex::TypeIndex catch_type_index_;
 };
 
 static constexpr size_t kNoLifetime = -1;

compiler/optimizing/reference_type_propagation.cc

diff --git a/compiler/optimizing/reference_type_propagation.cc b/compiler/optimizing/reference_type_propagation.cc
index 61e7a60..4929e0a 100644
--- a/compiler/optimizing/reference_type_propagation.cc
+++ b/compiler/optimizing/reference_type_propagation.cc
@@ -699,14 +699,14 @@
   DCHECK(instr->GetBlock()->IsCatchBlock());
   TryCatchInformation* catch_info = instr->GetBlock()->GetTryCatchInformation();
 
-  if (catch_info->IsCatchAllTypeIndex()) {
-    instr->SetReferenceTypeInfo(
-        ReferenceTypeInfo::Create(handle_cache_->GetThrowableClassHandle(), /* is_exact= */ false));
-  } else {
+  if (catch_info->IsValidTypeIndex()) {
     UpdateReferenceTypeInfo(instr,
                             catch_info->GetCatchTypeIndex(),
                             catch_info->GetCatchDexFile(),
                             /* is_exact= */ false);
+  } else {
+    instr->SetReferenceTypeInfo(
+        ReferenceTypeInfo::Create(handle_cache_->GetThrowableClassHandle(), /* is_exact= */ false));
   }
 }