Improve use of std::unique_ptr

* Use unique_ptr in place of shared_ptr in some cases
* unique_ptr for arrays does not require a custom deleter
* use std::make_unique (c++14) where possible
This commit is contained in:
Jay Berkenbilt 2022-02-05 08:15:07 -05:00
parent 88c3d556d5
commit 5f3f78822b
14 changed files with 54 additions and 23 deletions

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@ -1,3 +1,9 @@
2022-02-05 Jay Berkenbilt <ejb@ql.org>
* Add QUtil::make_unique_cstr to return a std::unique_ptr<char[]>
as an alternative to QUtil::copy_string and
QUtil::make_shared_cstr.
2022-02-04 Jay Berkenbilt <ejb@ql.org>
* New preprocessor symbols QPDF_MAJOR_VERSION, QPDF_MINOR_VERSION,

10
TODO
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@ -1,6 +1,9 @@
10.6
====
* Expose emptyPDF to the C API. Ensure that qpdf_get_qpdf_version is
always static.
* Consider doing one big commit to reformat the entire codebase using
clang-format or a similar tool. Consider using blame.ignoreRevsFile
or similar (or otherwise study git blame to see how to minimize the
@ -364,6 +367,13 @@ auto x_ph = std::make_shared<X>(); X* x = x_ph.get();
Derived* x = new Derived(); PointerHolder<Base> x_ph(x) -->
Derived* x = new Derived(); auto x_ph = std::shared_pointer<Base>(x);
Also remember
auto x = std::shared_ptr(new T[5], std::default_delete<T[]>())
vs.
auto x = std::make_unique<T[]>(5)
PointerHolder in public API:
QUtil::read_file_into_memory(

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@ -161,6 +161,10 @@ namespace QUtil
QPDF_DLL
std::shared_ptr<char> make_shared_cstr(std::string const&);
// Copy string as a unique_ptr to an array.
QPDF_DLL
std::unique_ptr<char[]> make_unique_cstr(std::string const&);
// Returns lower-case hex-encoded version of the string, treating
// each character in the input string as unsigned. The output
// string will be twice as long as the input string.

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@ -19,12 +19,8 @@ AES_PDF_native::AES_PDF_native(bool encrypt, unsigned char const* key,
nrounds(0)
{
size_t keybits = 8 * key_bytes;
this->key = std::unique_ptr<unsigned char[]>(
new unsigned char[key_bytes],
std::default_delete<unsigned char[]>());
this->rk = std::unique_ptr<uint32_t[]>(
new uint32_t[RKLENGTH(keybits)],
std::default_delete<uint32_t[]>());
this->key = std::make_unique<unsigned char[]>(key_bytes);
this->rk = std::make_unique<uint32_t[]>(RKLENGTH(keybits));
size_t rk_bytes = RKLENGTH(keybits) * sizeof(uint32_t);
std::memcpy(this->key.get(), key, key_bytes);
std::memset(this->rk.get(), 0, rk_bytes);

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@ -25,9 +25,7 @@ Pl_AES_PDF::Pl_AES_PDF(char const* identifier, Pipeline* next,
use_specified_iv(false),
disable_padding(false)
{
this->key = std::unique_ptr<unsigned char[]>(
new unsigned char[key_bytes],
std::default_delete<unsigned char[]>());
this->key = std::make_unique<unsigned char[]>(key_bytes);
std::memcpy(this->key.get(), key, key_bytes);
std::memset(this->inbuf, 0, this->buf_size);
std::memset(this->outbuf, 0, this->buf_size);

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@ -20,7 +20,7 @@ QPDFArgParser::Members::Members(
option_table(nullptr),
final_check_handler(nullptr)
{
auto tmp = QUtil::make_shared_cstr(argv[0]);
auto tmp = QUtil::make_unique_cstr(argv[0]);
char* p = QUtil::getWhoami(tmp.get());
// Remove prefix added by libtool for consistency during testing.
if (strncmp(p, "lt-", 3) == 0)

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@ -3379,7 +3379,7 @@ QPDFJob::setEncryptionOptions(QPDF& pdf, QPDFWriter& w)
static void parse_version(std::string const& full_version_string,
std::string& version, int& extension_level)
{
auto vp = QUtil::make_shared_cstr(full_version_string);
auto vp = QUtil::make_unique_cstr(full_version_string);
char* v = vp.get();
char* p1 = strchr(v, '.');
char* p2 = (p1 ? strchr(1 + p1, '.') : 0);

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@ -1919,7 +1919,7 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
}
else
{
auto tmp_ph = QUtil::make_shared_cstr(val);
auto tmp_ph = QUtil::make_unique_cstr(val);
char* tmp = tmp_ph.get();
size_t vlen = val.length();
RC4 rc4(QUtil::unsigned_char_pointer(this->m->cur_data_key),

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@ -1211,7 +1211,7 @@ QPDF::decryptString(std::string& str, int objid, int generation)
size_t vlen = str.length();
// Using PointerHolder guarantees that tmp will
// be freed even if rc4.process throws an exception.
auto tmp = QUtil::make_shared_cstr(str);
auto tmp = QUtil::make_unique_cstr(str);
RC4 rc4(QUtil::unsigned_char_pointer(key), toI(key.length()));
rc4.process(QUtil::unsigned_char_pointer(tmp.get()), vlen);
str = std::string(tmp.get(), vlen);

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@ -744,6 +744,16 @@ QUtil::make_shared_cstr(std::string const& str)
return result;
}
std::unique_ptr<char[]>
QUtil::make_unique_cstr(std::string const& str)
{
auto result = std::make_unique<char[]>(str.length() + 1);
// Use memcpy in case string contains nulls
result.get()[str.length()] = '\0';
memcpy(result.get(), str.c_str(), str.length());
return result;
}
std::string
QUtil::hex_encode(std::string const& input)
{
@ -2625,7 +2635,7 @@ call_main_from_wmain(bool, int argc, wchar_t const* const argv[],
// other systems. That way the rest of qpdf.cc can just act like
// arguments are UTF-8.
std::vector<std::shared_ptr<char>> utf8_argv;
std::vector<std::unique_ptr<char[]>> utf8_argv;
for (int i = 0; i < argc; ++i)
{
std::string utf16;
@ -2638,11 +2648,9 @@ call_main_from_wmain(bool, int argc, wchar_t const* const argv[],
QIntC::to_uchar(codepoint & 0xff)));
}
std::string utf8 = QUtil::utf16_to_utf8(utf16);
utf8_argv.push_back(QUtil::make_shared_cstr(utf8));
utf8_argv.push_back(QUtil::make_unique_cstr(utf8));
}
auto utf8_argv_sp =
std::shared_ptr<char*>(
new char*[1+utf8_argv.size()], std::default_delete<char*[]>());
auto utf8_argv_sp = std::make_unique<char*[]>(1+utf8_argv.size());
char** new_argv = utf8_argv_sp.get();
for (size_t i = 0; i < utf8_argv.size(); ++i)
{

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@ -9,7 +9,7 @@
int qpdfjob_run_from_argv(char const* const argv[])
{
auto whoami_p = QUtil::make_shared_cstr(argv[0]);
auto whoami_p = QUtil::make_unique_cstr(argv[0]);
auto whoami = QUtil::getWhoami(whoami_p.get());
QUtil::setLineBuf(stdout);

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@ -23,6 +23,7 @@ one
7
compare okay
compare okay
compare okay
-2147483648 to int: PASSED
2147483647 to int: PASSED
2147483648 to int threw (integer out of range converting 2147483648 from a 8-byte signed type to a 4-byte signed type): PASSED

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@ -150,7 +150,7 @@ void string_conversion_test()
std::cout << "compare failed" << std::endl;
}
delete [] tmp;
// Also test with make_shared_cstr
// Also test with make_shared_cstr and make_unique_cstr
auto tmp2 = QUtil::make_shared_cstr(embedded_null);
if (memcmp(tmp2.get(), embedded_null.c_str(), 7) == 0)
{
@ -160,6 +160,15 @@ void string_conversion_test()
{
std::cout << "compare failed" << std::endl;
}
auto tmp3 = QUtil::make_unique_cstr(embedded_null);
if (memcmp(tmp3.get(), embedded_null.c_str(), 7) == 0)
{
std::cout << "compare okay" << std::endl;
}
else
{
std::cout << "compare failed" << std::endl;
}
std::string int_max_str = QUtil::int_to_string(INT_MAX);
std::string int_min_str = QUtil::int_to_string(INT_MIN);
@ -417,7 +426,7 @@ void transcoding_test()
void print_whoami(char const* str)
{
auto dup = QUtil::make_shared_cstr(str);
auto dup = QUtil::make_unique_cstr(str);
std::cout << QUtil::getWhoami(dup.get()) << std::endl;
}

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@ -14,8 +14,7 @@ static void other_tests()
// Test cases not covered by the pipeline: string as key, convert
// in place
RC4 r(reinterpret_cast<unsigned char const*>("quack"));
auto data = std::unique_ptr<unsigned char[]>(
new unsigned char[6], std::default_delete<unsigned char[]>());
auto data = std::make_unique<unsigned char[]>(6);
memcpy(data.get(), "potato", 6);
r.process(data.get(), 6);
assert(memcmp(data.get(), "\xa5\x6f\xe7\x27\x2b\x5c", 6) == 0);