Add MinidumpThreadListWriter::InitializeFromSnapshot()

snapshot/cpu_context_test.cc

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "snapshot/cpu_context.h"
 
 #include <stdint.h>
 #include <string.h>
 
+#include "base/basictypes.h"
 #include "gtest/gtest.h"
 
 namespace crashpad {
 namespace test {
 namespace {
 
 enum ExponentValue {
   kExponentAllZero = 0,
   kExponentAllOne,
   kExponentNormal,
@@ skipping 106 matching lines @@
   SetX87Register(&st_mm[0], kExponentNormal, true, kFractionAllZero);  // valid
   SetX87Register(&st_mm[1], kExponentAllZero, false, kFractionAllZero);  // zero
   SetX87Register(&st_mm[2], kExponentAllOne, true, kFractionAllZero);  // spec.
   SetX87Register(&st_mm[3], kExponentAllOne, true, kFractionNormal);  // spec.
   SetX87Register(&st_mm[4], kExponentAllZero, false, kFractionAllZero);
   SetX87Register(&st_mm[5], kExponentAllZero, false, kFractionAllZero);
   SetX87Register(&st_mm[6], kExponentAllZero, false, kFractionAllZero);
   SetX87Register(&st_mm[7], kExponentNormal, true, kFractionNormal);  // valid
   EXPECT_EQ(0xfe90,
             CPUContextX86::FxsaveToFsaveTagWord(fsw, fxsave_tag, st_mm));
+
+  // In this set, everything is valid.
+  fsw = 0 << 11;  // top = 0: logical 0-7 maps to physical 0-7
+  fxsave_tag = 0xff;  // nothing empty
+  for (size_t index = 0; index < arraysize(st_mm); ++index) {
+    SetX87Register(&st_mm[index], kExponentNormal, true, kFractionAllZero);
+  }
+  EXPECT_EQ(0, CPUContextX86::FxsaveToFsaveTagWord(fsw, fxsave_tag, st_mm));
+
+  // In this set, everything is empty. The registers shouldn’t be consulted at
+  // all, so they’re left alone from the previous set.
+  fsw = 0 << 11;  // top = 0: logical 0-7 maps to physical 0-7
+  fxsave_tag = 0;  // everything empty
+  EXPECT_EQ(0xffff,
+            CPUContextX86::FxsaveToFsaveTagWord(fsw, fxsave_tag, st_mm));
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace crashpad