[vm/gardening] clang tidy fixes

https://github.com/dart-lang/sdk/issues/38196

Change-Id: I0a61eae20d8cfc1c2ada8d6a607d437d02136d33
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115609
Reviewed-by: Ben Konyi <bkonyi@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Aart Bik <ajcbik@google.com>

runtime/tools/run_clang_tidy.dart

@@ -38,6 +38,15 @@ final pool = new Pool(max(1, Platform.numberOfProcessors ~/ 2));
 // TODO(dartbug.com/38196): Ensure all VM sources are clang-tidy clean.
 final Set<String> migratedFiles = Set<String>.from([
   'runtime/vm/native_api_impl.cc',
+  'runtime/vm/compiler/backend/constant_propagator.cc',
+  'runtime/vm/compiler/backend/flow_graph.cc',
+  'runtime/vm/compiler/backend/flow_graph_checker.cc',
+  'runtime/vm/compiler/backend/il.cc',
+  'runtime/vm/compiler/backend/inliner.cc',
+  'runtime/vm/compiler/backend/linearscan.cc',
+  'runtime/vm/compiler/backend/loops.cc',
+  'runtime/vm/compiler/backend/loops_test.cc',
+  'runtime/vm/compiler/backend/range_analysis.cc',
 ]);
 
 main(List<String> files) async {

runtime/vm/compiler/backend/inliner.cc

@@ -1895,6 +1895,7 @@ TargetEntryInstr* PolymorphicInliner::BuildDecisionGraph() {
         // Unshared.  Graft the normal entry on after the check class
         // instruction.
         auto target = callee_entry->AsGraphEntry()->normal_entry();
+        ASSERT(cursor != nullptr);
         cursor->LinkTo(target->next());
         target->ReplaceAsPredecessorWith(current_block);
         // Unuse all inputs of the graph entry and the normal entry. They are
@@ -1955,6 +1956,7 @@ TargetEntryInstr* PolymorphicInliner::BuildDecisionGraph() {
             new TargetEntryInstr(AllocateBlockId(), try_idx, DeoptId::kNone);
         below_target->InheritDeoptTarget(zone(), call_);
         current_block->AddDominatedBlock(below_target);
+        ASSERT(cursor != nullptr);  // read before overwrite
         cursor = current_block = below_target;
         *branch_top->true_successor_address() = below_target;
 
@@ -1972,9 +1974,9 @@ TargetEntryInstr* PolymorphicInliner::BuildDecisionGraph() {
       }
 
       branch->InheritDeoptTarget(zone(), call_);
-      cursor = AppendInstruction(cursor, branch);
+      AppendInstruction(cursor, branch);
+      cursor = nullptr;
       current_block->set_last_instruction(branch);
-      cursor = NULL;
 
       // 2. Handle a match by linking to the inlined body.  There are three
       // cases (unshared, shared first predecessor, and shared subsequent
@@ -3369,7 +3371,7 @@ bool FlowGraphInliner::TryReplaceInstanceCallWithInline(
     }
     // Replace all uses of this definition with the result.
     if (call->HasUses()) {
-      ASSERT(result->HasSSATemp());
+      ASSERT(result != nullptr && result->HasSSATemp());
       call->ReplaceUsesWith(result);
     }
     // Finally insert the sequence other definition in place of this one in the

runtime/vm/compiler/backend/linearscan.cc

@@ -603,7 +603,8 @@ void FlowGraphAllocator::BuildLiveRanges() {
 
     // Check if any values live into the loop can be spilled for free.
     if (block->IsLoopHeader()) {
-      current_interference_set = NULL;
+      ASSERT(loop_info != nullptr);
+      current_interference_set = nullptr;
       for (BitVector::Iterator it(liveness_.GetLiveInSetAt(i)); !it.Done();
            it.Advance()) {
         LiveRange* range = GetLiveRange(it.Current());

runtime/vm/object.h

@@ -7395,8 +7395,8 @@ class Smi : public Integer {
   static intptr_t InstanceSize() { return 0; }
 
   static RawSmi* New(intptr_t value) {
-    RawSmi* raw_smi =
-        reinterpret_cast<RawSmi*>((value << kSmiTagShift) | kSmiTag);
+    RawSmi* raw_smi = reinterpret_cast<RawSmi*>(
+        (static_cast<uintptr_t>(value) << kSmiTagShift) | kSmiTag);
     ASSERT(ValueFromRawSmi(raw_smi) == value);
     return raw_smi;
   }

runtime/vm/zone.h

@@ -119,6 +119,7 @@ class Zone {
   void Free(ElementType* old_array, intptr_t len) {
 #ifdef DEBUG
     if (len > 0) {
+      ASSERT(old_array != nullptr);
       memset(old_array, kZapUninitializedByte, len * sizeof(ElementType));
     }
 #endif