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Exceptions store the message as reference counted string for

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compatibility to libstdc++. Move the implementation into a header for
easier sharing with libc++abi. Merge a number of improvements from that
version. Provide a POD definition for <stdexcept>'s public use to avoid
cast dances. Discussed with Marshall Clow.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@207695 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Joerg Sonnenberger
2014-04-30 19:54:11 +00:00
parent 5f64a2b3c3
commit 55622073f4
3 changed files with 163 additions and 112 deletions
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124
src/stdexcept.cpp
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@@ -7,124 +7,42 @@
//
//===----------------------------------------------------------------------===//
#include "__refstring"
#include "stdexcept"
#include "new"
#include "string"
#include <cstdlib>
#include <cstring>
#include <cstdint>
#include <cstddef>
#include "system_error"
#ifndef __has_include
#define __has_include(inc) 0
#endif
#ifdef __APPLE__
#include <cxxabi.h>
#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
/* For _LIBCPPABI_VERSION */
#if __has_include(<cxxabi.h>) || defined(__APPLE_) || defined(LIBCXXRT)
#include <cxxabi.h>
#endif
// Note: optimize for size
#if ! defined(_LIBCPP_MSVC)
#pragma GCC visibility push(hidden)
#endif
namespace
{
class __libcpp_nmstr
{
private:
const char* str_;
typedef std::size_t unused_t;
typedef std::ptrdiff_t count_t;
static const std::ptrdiff_t offset = static_cast<std::ptrdiff_t>(2*sizeof(unused_t) +
sizeof(count_t));
count_t& count() const _NOEXCEPT {return *const_cast<count_t *>(reinterpret_cast<const count_t *>(str_ - sizeof(count_t)));}
public:
explicit __libcpp_nmstr(const char* msg);
__libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT;
__libcpp_nmstr& operator=(const __libcpp_nmstr& s) _NOEXCEPT;
~__libcpp_nmstr();
const char* c_str() const _NOEXCEPT {return str_;}
};
__libcpp_nmstr::__libcpp_nmstr(const char* msg)
{
std::size_t len = strlen(msg);
str_ = new char[len + 1 + offset];
unused_t* c = reinterpret_cast<unused_t*>(const_cast<char *>(str_));
c[0] = c[1] = len;
str_ += offset;
count() = 0;
std::memcpy(const_cast<char*>(c_str()), msg, len + 1);
}
inline
__libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT
: str_(s.str_)
{
__sync_add_and_fetch(&count(), 1);
}
__libcpp_nmstr&
__libcpp_nmstr::operator=(const __libcpp_nmstr& s) _NOEXCEPT
{
const char* p = str_;
str_ = s.str_;
__sync_add_and_fetch(&count(), 1);
if (__sync_add_and_fetch(reinterpret_cast<count_t*>(const_cast<char*>(p)-sizeof(count_t)), count_t(-1)) < 0)
delete [] (p-offset);
return *this;
}
inline
__libcpp_nmstr::~__libcpp_nmstr()
{
if (__sync_add_and_fetch(&count(), count_t(-1)) < 0)
delete [] (str_ - offset);
}
}
#if ! defined(_LIBCPP_MSVC)
#pragma GCC visibility pop
#endif
static_assert(sizeof(std::__libcpp_refstring) == sizeof(const char *), "");
namespace std // purposefully not using versioning namespace
{
logic_error::logic_error(const string& msg)
logic_error::logic_error(const string& msg) : __imp_(msg.c_str())
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
::new(s) __libcpp_nmstr(msg.c_str());
}
logic_error::logic_error(const char* msg)
logic_error::logic_error(const char* msg) : __imp_(msg)
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
::new(s) __libcpp_nmstr(msg);
}
logic_error::logic_error(const logic_error& le) _NOEXCEPT
logic_error::logic_error(const logic_error& le) _NOEXCEPT : __imp_(le.__imp_)
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
const __libcpp_nmstr *s2 = reinterpret_cast<const __libcpp_nmstr *>(&le.__imp_);
::new(s) __libcpp_nmstr(*s2);
}
logic_error&
logic_error::operator=(const logic_error& le) _NOEXCEPT
{
__libcpp_nmstr *s1 = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
const __libcpp_nmstr *s2 = reinterpret_cast<const __libcpp_nmstr *>(&le.__imp_);
*s1 = *s2;
__imp_ = le.__imp_;
return *this;
}
@@ -132,44 +50,33 @@ logic_error::operator=(const logic_error& le) _NOEXCEPT
logic_error::~logic_error() _NOEXCEPT
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
s->~__libcpp_nmstr();
}
const char*
logic_error::what() const _NOEXCEPT
{
const __libcpp_nmstr *s = reinterpret_cast<const __libcpp_nmstr *>(&__imp_);
return s->c_str();
return __imp_.c_str();
}
#endif
runtime_error::runtime_error(const string& msg)
runtime_error::runtime_error(const string& msg) : __imp_(msg.c_str())
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
::new(s) __libcpp_nmstr(msg.c_str());
}
runtime_error::runtime_error(const char* msg)
runtime_error::runtime_error(const char* msg) : __imp_(msg)
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
::new(s) __libcpp_nmstr(msg);
}
runtime_error::runtime_error(const runtime_error& le) _NOEXCEPT
: __imp_(le.__imp_)
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
const __libcpp_nmstr *s2 = reinterpret_cast<const __libcpp_nmstr *>(&le.__imp_);
::new(s) __libcpp_nmstr(*s2);
}
runtime_error&
runtime_error::operator=(const runtime_error& le) _NOEXCEPT
{
__libcpp_nmstr *s1 = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
const __libcpp_nmstr *s2 = reinterpret_cast<const __libcpp_nmstr *>(&le.__imp_);
*s1 = *s2;
__imp_ = le.__imp_;
return *this;
}
@@ -177,15 +84,12 @@ runtime_error::operator=(const runtime_error& le) _NOEXCEPT
runtime_error::~runtime_error() _NOEXCEPT
{
__libcpp_nmstr *s = reinterpret_cast<__libcpp_nmstr *>(&__imp_);
s->~__libcpp_nmstr();
}
const char*
runtime_error::what() const _NOEXCEPT
{
const __libcpp_nmstr *s = reinterpret_cast<const __libcpp_nmstr *>(&__imp_);
return s->c_str();
return __imp_.c_str();
}
domain_error::~domain_error() _NOEXCEPT {}