cef/libcef_dll/base/cef_logging.cc

267 lines
9.1 KiB
C++

// Copyright (c) 2014 The Chromium Embedded Framework Authors.
// Portions copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "include/base/cef_logging.h"
#if defined(OS_WIN)
#include <windows.h>
#include <algorithm>
#include <sstream>
#elif defined(OS_POSIX)
#include <errno.h>
#include <stdio.h>
#include <string.h>
#endif
#include "include/internal/cef_string_types.h"
namespace cef {
namespace logging {
namespace {
#if defined(OS_POSIX)
// From base/posix/safe_strerror.cc
#if defined(__GLIBC__) || defined(OS_NACL)
#define USE_HISTORICAL_STRERRO_R 1
#else
#define USE_HISTORICAL_STRERRO_R 0
#endif
#if USE_HISTORICAL_STRERRO_R && defined(__GNUC__)
// GCC will complain about the unused second wrap function unless we tell it
// that we meant for them to be potentially unused, which is exactly what this
// attribute is for.
#define POSSIBLY_UNUSED __attribute__((unused))
#else
#define POSSIBLY_UNUSED
#endif
#if USE_HISTORICAL_STRERRO_R
// glibc has two strerror_r functions: a historical GNU-specific one that
// returns type char *, and a POSIX.1-2001 compliant one available since 2.3.4
// that returns int. This wraps the GNU-specific one.
static void POSSIBLY_UNUSED
wrap_posix_strerror_r(char* (*strerror_r_ptr)(int, char*, size_t),
int err,
char* buf,
size_t len) {
// GNU version.
char* rc = (*strerror_r_ptr)(err, buf, len);
if (rc != buf) {
// glibc did not use buf and returned a static string instead. Copy it
// into buf.
buf[0] = '\0';
strncat(buf, rc, len - 1);
}
// The GNU version never fails. Unknown errors get an "unknown error" message.
// The result is always null terminated.
}
#endif // USE_HISTORICAL_STRERRO_R
// Wrapper for strerror_r functions that implement the POSIX interface. POSIX
// does not define the behaviour for some of the edge cases, so we wrap it to
// guarantee that they are handled. This is compiled on all POSIX platforms, but
// it will only be used on Linux if the POSIX strerror_r implementation is
// being used (see below).
static void POSSIBLY_UNUSED wrap_posix_strerror_r(int (*strerror_r_ptr)(int,
char*,
size_t),
int err,
char* buf,
size_t len) {
int old_errno = errno;
// Have to cast since otherwise we get an error if this is the GNU version
// (but in such a scenario this function is never called). Sadly we can't use
// C++-style casts because the appropriate one is reinterpret_cast but it's
// considered illegal to reinterpret_cast a type to itself, so we get an
// error in the opposite case.
int result = (*strerror_r_ptr)(err, buf, len);
if (result == 0) {
// POSIX is vague about whether the string will be terminated, although
// it indirectly implies that typically ERANGE will be returned, instead
// of truncating the string. We play it safe by always terminating the
// string explicitly.
buf[len - 1] = '\0';
} else {
// Error. POSIX is vague about whether the return value is itself a system
// error code or something else. On Linux currently it is -1 and errno is
// set. On BSD-derived systems it is a system error and errno is unchanged.
// We try and detect which case it is so as to put as much useful info as
// we can into our message.
int strerror_error; // The error encountered in strerror
int new_errno = errno;
if (new_errno != old_errno) {
// errno was changed, so probably the return value is just -1 or something
// else that doesn't provide any info, and errno is the error.
strerror_error = new_errno;
} else {
// Either the error from strerror_r was the same as the previous value, or
// errno wasn't used. Assume the latter.
strerror_error = result;
}
// snprintf truncates and always null-terminates.
snprintf(buf, len, "Error %d while retrieving error %d", strerror_error,
err);
}
errno = old_errno;
}
void safe_strerror_r(int err, char* buf, size_t len) {
if (buf == NULL || len <= 0) {
return;
}
// If using glibc (i.e., Linux), the compiler will automatically select the
// appropriate overloaded function based on the function type of strerror_r.
// The other one will be elided from the translation unit since both are
// static.
wrap_posix_strerror_r(&strerror_r, err, buf, len);
}
std::string safe_strerror(int err) {
const int buffer_size = 256;
char buf[buffer_size];
safe_strerror_r(err, buf, sizeof(buf));
return std::string(buf);
}
#endif // defined(OS_POSIX)
} // namespace
// MSVC doesn't like complex extern templates and DLLs.
#if !defined(COMPILER_MSVC)
// Explicit instantiations for commonly used comparisons.
template std::string* MakeCheckOpString<int, int>(const int&,
const int&,
const char* names);
template std::string* MakeCheckOpString<unsigned long, unsigned long>(
const unsigned long&,
const unsigned long&,
const char* names);
template std::string* MakeCheckOpString<unsigned long, unsigned int>(
const unsigned long&,
const unsigned int&,
const char* names);
template std::string* MakeCheckOpString<unsigned int, unsigned long>(
const unsigned int&,
const unsigned long&,
const char* names);
template std::string* MakeCheckOpString<std::string, std::string>(
const std::string&,
const std::string&,
const char* name);
#endif
#if defined(OS_WIN)
LogMessage::SaveLastError::SaveLastError() : last_error_(::GetLastError()) {}
LogMessage::SaveLastError::~SaveLastError() {
::SetLastError(last_error_);
}
#endif // defined(OS_WIN)
LogMessage::LogMessage(const char* file, int line, LogSeverity severity)
: severity_(severity), file_(file), line_(line) {}
LogMessage::LogMessage(const char* file, int line, std::string* result)
: severity_(LOG_FATAL), file_(file), line_(line) {
stream_ << "Check failed: " << *result;
delete result;
}
LogMessage::LogMessage(const char* file,
int line,
LogSeverity severity,
std::string* result)
: severity_(severity), file_(file), line_(line) {
stream_ << "Check failed: " << *result;
delete result;
}
LogMessage::~LogMessage() {
stream_ << std::endl;
std::string str_newline(stream_.str());
cef_log(file_, line_, severity_, str_newline.c_str());
}
#if defined(OS_WIN)
// This has already been defined in the header, but defining it again as DWORD
// ensures that the type used in the header is equivalent to DWORD. If not,
// the redefinition is a compile error.
typedef DWORD SystemErrorCode;
#endif
SystemErrorCode GetLastSystemErrorCode() {
#if defined(OS_WIN)
return ::GetLastError();
#elif defined(OS_POSIX)
return errno;
#else
#error Not implemented
#endif
}
#if defined(OS_WIN)
std::string SystemErrorCodeToString(SystemErrorCode error_code) {
const int error_message_buffer_size = 256;
char msgbuf[error_message_buffer_size];
DWORD flags = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
DWORD len = FormatMessageA(flags, NULL, error_code, 0, msgbuf,
arraysize(msgbuf), NULL);
std::stringstream ss;
if (len) {
std::string s(msgbuf);
// Messages returned by system end with line breaks.
s.erase(std::remove_if(s.begin(), s.end(), ::isspace), s.end());
ss << s << " (0x" << std::hex << error_code << ")";
} else {
ss << "Error (0x" << std::hex << GetLastError()
<< ") while retrieving error. (0x" << error_code << ")";
}
return ss.str();
}
#elif defined(OS_POSIX)
std::string SystemErrorCodeToString(SystemErrorCode error_code) {
return safe_strerror(error_code);
}
#else
#error Not implemented
#endif
#if defined(OS_WIN)
Win32ErrorLogMessage::Win32ErrorLogMessage(const char* file,
int line,
LogSeverity severity,
SystemErrorCode err)
: err_(err), log_message_(file, line, severity) {}
Win32ErrorLogMessage::~Win32ErrorLogMessage() {
stream() << ": " << SystemErrorCodeToString(err_);
}
#elif defined(OS_POSIX)
ErrnoLogMessage::ErrnoLogMessage(const char* file,
int line,
LogSeverity severity,
SystemErrorCode err)
: err_(err), log_message_(file, line, severity) {}
ErrnoLogMessage::~ErrnoLogMessage() {
stream() << ": " << SystemErrorCodeToString(err_);
}
#endif // OS_WIN
std::ostream& operator<<(std::ostream& out, const wchar_t* wstr) {
cef_string_utf8_t str = {0};
std::wstring tmp_str(wstr);
cef_string_wide_to_utf8(wstr, tmp_str.size(), &str);
out << str.str;
cef_string_utf8_clear(&str);
return out;
}
} // namespace logging
} // namespace cef