crashpad/snapshot/cpu_context.cc
Mark Mentovai 6d2d31d2d1 Use base/macros.h instead of base/basictypes.h
This was done in Chromium’s local copy of Crashpad in 562827afb599. This
change is similar to that one, except more care was taken to avoid
including headers from a .cc or _test.cc when already included by the
associated .h. Rather than using <stddef.h> for size_t, Crashpad has
always used <sys/types.h>, so that’s used here as well.

This updates mini_chromium to 8a2363f486e3a0dc562a68884832d06d28d38dcc,
which removes base/basictypes.h.

e128dcf10122 Remove base/move.h; use std::move() instead of Pass()
8a2363f486e3 Move basictypes.h to macros.h

R=avi@chromium.org

Review URL: https://codereview.chromium.org/1566713002 .
2016-01-06 12:22:50 -05:00

101 lines
3.3 KiB
C++

// 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 "base/logging.h"
#include "util/misc/implicit_cast.h"
namespace crashpad {
// static
uint16_t CPUContextX86::FxsaveToFsaveTagWord(
uint16_t fsw,
uint8_t fxsave_tag,
const CPUContextX86::X87OrMMXRegister st_mm[8]) {
enum {
kX87TagValid = 0,
kX87TagZero,
kX87TagSpecial,
kX87TagEmpty,
};
// The x87 tag word (in both abridged and full form) identifies physical
// registers, but |st_mm| is arranged in logical stack order. In order to map
// physical tag word bits to the logical stack registers they correspond to,
// the “stack top” value from the x87 status word is necessary.
int stack_top = (fsw >> 11) & 0x7;
uint16_t fsave_tag = 0;
for (int physical_index = 0; physical_index < 8; ++physical_index) {
bool fxsave_bit = (fxsave_tag & (1 << physical_index)) != 0;
uint8_t fsave_bits;
if (fxsave_bit) {
int st_index = (physical_index + 8 - stack_top) % 8;
const CPUContextX86::X87Register& st = st_mm[st_index].st;
uint32_t exponent = ((st[9] & 0x7f) << 8) | st[8];
if (exponent == 0x7fff) {
// Infinity, NaN, pseudo-infinity, or pseudo-NaN. If it was important to
// distinguish between these, the J bit and the M bit (the most
// significant bit of |fraction|) could be consulted.
fsave_bits = kX87TagSpecial;
} else {
// The integer bit the “J bit”.
bool integer_bit = (st[7] & 0x80) != 0;
if (exponent == 0) {
uint64_t fraction = ((implicit_cast<uint64_t>(st[7]) & 0x7f) << 56) |
(implicit_cast<uint64_t>(st[6]) << 48) |
(implicit_cast<uint64_t>(st[5]) << 40) |
(implicit_cast<uint64_t>(st[4]) << 32) |
(implicit_cast<uint32_t>(st[3]) << 24) |
(st[2] << 16) | (st[1] << 8) | st[0];
if (!integer_bit && fraction == 0) {
fsave_bits = kX87TagZero;
} else {
// Denormal (if the J bit is clear) or pseudo-denormal.
fsave_bits = kX87TagSpecial;
}
} else if (integer_bit) {
fsave_bits = kX87TagValid;
} else {
// Unnormal.
fsave_bits = kX87TagSpecial;
}
}
} else {
fsave_bits = kX87TagEmpty;
}
fsave_tag |= (fsave_bits << (physical_index * 2));
}
return fsave_tag;
}
uint64_t CPUContext::InstructionPointer() const {
switch (architecture) {
case kCPUArchitectureX86:
return x86->eip;
case kCPUArchitectureX86_64:
return x86_64->rip;
default:
NOTREACHED();
return ~0ull;
}
}
} // namespace crashpad