Revert of Update Crashpad to 6da9708e7cc93e2e1772439d51646e47583cb225

third_party/crashpad/crashpad/snapshot/win/cpu_context_win.cc

 // Copyright 2015 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/win/cpu_context_win.h"
 
 #include <stdint.h>
 #include <string.h>
 
 #include "base/logging.h"
 #include "snapshot/cpu_context.h"
 
 namespace crashpad {
 
 namespace {
 
-// Validation for casts used with CPUContextX86::FsaveToFxsave().
-static_assert(sizeof(CPUContextX86::Fsave) ==
-                  offsetof(WOW64_FLOATING_SAVE_AREA, Cr0NpxState),
-              "WoW64 fsave types must be equivalent");
-#if defined(ARCH_CPU_X86)
-static_assert(sizeof(CPUContextX86::Fsave) ==
-                  offsetof(FLOATING_SAVE_AREA, Spare0),
-              "fsave types must be equivalent");
-#endif  // ARCH_CPU_X86
-
-template <typename T>
-bool HasContextPart(const T& context, uint32_t bits) {
-  return (context.ContextFlags & bits) == bits;
-}
-
 template <class T>
 void CommonInitializeX86Context(const T& context, CPUContextX86* out) {
-  // This function assumes that the WOW64_CONTEXT_* and x86 CONTEXT_* values
-  // for ContextFlags are identical. This can be tested when targeting 32-bit
-  // x86.
-#if defined(ARCH_CPU_X86)
-  static_assert(sizeof(CONTEXT) == sizeof(WOW64_CONTEXT),
-                "type mismatch: CONTEXT");
-#define ASSERT_WOW64_EQUIVALENT(x)                        \
-  do {                                                    \
-    static_assert(x == WOW64_##x, "value mismatch: " #x); \
-  } while (false)
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_i386);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_i486);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_CONTROL);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_INTEGER);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_SEGMENTS);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_FLOATING_POINT);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_DEBUG_REGISTERS);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_EXTENDED_REGISTERS);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_FULL);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_ALL);
-  ASSERT_WOW64_EQUIVALENT(CONTEXT_XSTATE);
-#undef ASSERT_WOW64_EQUIVALENT
-#endif  // ARCH_CPU_X86
-
+  LOG_IF(ERROR, !(context.ContextFlags & WOW64_CONTEXT_i386))
+      << "non-x86 context";
   memset(out, 0, sizeof(*out));
 
-  LOG_IF(ERROR, !HasContextPart(context, WOW64_CONTEXT_i386))
-      << "non-x86 context";
+  // We assume in this function that the WOW64_CONTEXT_* and x86 CONTEXT_*
+  // values for ContextFlags are identical.
 
-  if (HasContextPart(context, WOW64_CONTEXT_CONTROL)) {
+  if (context.ContextFlags & WOW64_CONTEXT_CONTROL) {
     out->ebp = context.Ebp;
     out->eip = context.Eip;
     out->cs = static_cast<uint16_t>(context.SegCs);
     out->eflags = context.EFlags;
     out->esp = context.Esp;
     out->ss = static_cast<uint16_t>(context.SegSs);
   }
 
-  if (HasContextPart(context, WOW64_CONTEXT_INTEGER)) {
+  if (context.ContextFlags & WOW64_CONTEXT_INTEGER) {
     out->eax = context.Eax;
     out->ebx = context.Ebx;
     out->ecx = context.Ecx;
     out->edx = context.Edx;
     out->edi = context.Edi;
     out->esi = context.Esi;
   }
 
-  if (HasContextPart(context, WOW64_CONTEXT_SEGMENTS)) {
+  if (context.ContextFlags & WOW64_CONTEXT_SEGMENTS) {
     out->ds = static_cast<uint16_t>(context.SegDs);
     out->es = static_cast<uint16_t>(context.SegEs);
     out->fs = static_cast<uint16_t>(context.SegFs);
     out->gs = static_cast<uint16_t>(context.SegGs);
   }
 
-  if (HasContextPart(context, WOW64_CONTEXT_DEBUG_REGISTERS)) {
+  if (context.ContextFlags & WOW64_CONTEXT_DEBUG_REGISTERS) {
     out->dr0 = context.Dr0;
     out->dr1 = context.Dr1;
     out->dr2 = context.Dr2;
     out->dr3 = context.Dr3;
-
     // DR4 and DR5 are obsolete synonyms for DR6 and DR7, see
     // https://en.wikipedia.org/wiki/X86_debug_register.
     out->dr4 = context.Dr6;
     out->dr5 = context.Dr7;
-
     out->dr6 = context.Dr6;
     out->dr7 = context.Dr7;
   }
 
-  if (HasContextPart(context, WOW64_CONTEXT_EXTENDED_REGISTERS)) {
+  if (context.ContextFlags & WOW64_CONTEXT_EXTENDED_REGISTERS) {
     static_assert(sizeof(out->fxsave) == sizeof(context.ExtendedRegisters),
-                  "fxsave types must be equivalent");
+                  "types must be equivalent");
     memcpy(&out->fxsave, &context.ExtendedRegisters, sizeof(out->fxsave));
-  } else if (HasContextPart(context, WOW64_CONTEXT_FLOATING_POINT)) {
-    // The static_assert that validates this cast can’t be here because it
-    // relies on field names that vary based on the template parameter.
-    CPUContextX86::FsaveToFxsave(
-        *reinterpret_cast<const CPUContextX86::Fsave*>(&context.FloatSave),
-        &out->fxsave);
+  } else if (context.ContextFlags & WOW64_CONTEXT_FLOATING_POINT) {
+    CHECK(false) << "TODO(scottmg): extract x87 data";
   }
 }
 
 }  // namespace
 
 #if defined(ARCH_CPU_64_BITS)
 
 void InitializeX86Context(const WOW64_CONTEXT& context, CPUContextX86* out) {
   CommonInitializeX86Context(context, out);
 }
 
 void InitializeX64Context(const CONTEXT& context, CPUContextX86_64* out) {
   memset(out, 0, sizeof(*out));
 
-  LOG_IF(ERROR, !HasContextPart(context, CONTEXT_AMD64)) << "non-x64 context";
+  LOG_IF(ERROR, !(context.ContextFlags & CONTEXT_AMD64)) << "non-x64 context";
 
-  if (HasContextPart(context, CONTEXT_CONTROL)) {
+  if (context.ContextFlags & CONTEXT_CONTROL) {
     out->cs = context.SegCs;
     out->rflags = context.EFlags;
     out->rip = context.Rip;
     out->rsp = context.Rsp;
     // SegSs ignored.
   }
 
-  if (HasContextPart(context, CONTEXT_INTEGER)) {
+  if (context.ContextFlags & CONTEXT_INTEGER) {
     out->rax = context.Rax;
     out->rbx = context.Rbx;
     out->rcx = context.Rcx;
     out->rdx = context.Rdx;
     out->rdi = context.Rdi;
     out->rsi = context.Rsi;
     out->rbp = context.Rbp;
     out->r8 = context.R8;
     out->r9 = context.R9;
     out->r10 = context.R10;
     out->r11 = context.R11;
     out->r12 = context.R12;
     out->r13 = context.R13;
     out->r14 = context.R14;
     out->r15 = context.R15;
   }
 
-  if (HasContextPart(context, CONTEXT_SEGMENTS)) {
+  if (context.ContextFlags & CONTEXT_SEGMENTS) {
     out->fs = context.SegFs;
     out->gs = context.SegGs;
     // SegDs ignored.
     // SegEs ignored.
   }
 
-  if (HasContextPart(context, CONTEXT_DEBUG_REGISTERS)) {
+  if (context.ContextFlags & CONTEXT_DEBUG_REGISTERS) {
     out->dr0 = context.Dr0;
     out->dr1 = context.Dr1;
     out->dr2 = context.Dr2;
     out->dr3 = context.Dr3;
-
     // DR4 and DR5 are obsolete synonyms for DR6 and DR7, see
     // https://en.wikipedia.org/wiki/X86_debug_register.
     out->dr4 = context.Dr6;
     out->dr5 = context.Dr7;
-
     out->dr6 = context.Dr6;
     out->dr7 = context.Dr7;
   }
 
-  if (HasContextPart(context, CONTEXT_FLOATING_POINT)) {
+  if (context.ContextFlags & CONTEXT_FLOATING_POINT) {
     static_assert(sizeof(out->fxsave) == sizeof(context.FltSave),
                   "types must be equivalent");
-    memcpy(&out->fxsave, &context.FltSave, sizeof(out->fxsave));
+    memcpy(&out->fxsave, &context.FltSave.ControlWord, sizeof(out->fxsave));
   }
 }
 
 #else  // ARCH_CPU_64_BITS
 
 void InitializeX86Context(const CONTEXT& context, CPUContextX86* out) {
   CommonInitializeX86Context(context, out);
 }
 
 #endif  // ARCH_CPU_64_BITS
 
 }  // namespace crashpad