https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67209
Bug ID: 67209
Summary: G++ generates incorrect code for boost::filesystem
Product: gcc
Version: 5.2.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: bear at bears dot org
Target Milestone: ---
I have code which worked fine using boost::filesystem with gcc 4.8.2 but which
segfaults with 5.2.0. Here is a gdb session where it falls apart.
Breakpoint 1, FolderNotify::configure (this=0xd4b960 <externalLogsFolder>,
fname=..., mask=776) at common/FileNotify.cpp:116
116 bfs::create_directories(dirPath);
(gdb) print dirPath.m_pathname.size()
$40 = 20
(gdb) step
boost::filesystem::create_directories (p=...) at
/usr/local/include/boost/filesystem/operations.hpp:523
523 bool create_directories(const path& p) {return
detail::create_directories(p);}
(gdb) print p.m_pathname.size()
$41 = 20
(gdb) step
boost::filesystem::detail::create_directories (p=..., ec=0x0) at
libs/filesystem/src/operations.cpp:930
930 error_code local_ec;
(gdb) print p.m_pathname.size()
$42 = 15443128
As you can see, the value returned by p.m_pathname.size() goes haywire in the
handoff from the inline header to the actual cpp. Here is a printout of the
structure of p. The _M_string_length variable goes missing even though the
variables are all references to the same structure:
Breakpoint 1, FolderNotify::configure (this=0xd4b960 <externalLogsFolder>,
fname=..., mask=776) at common/FileNotify.cpp:116
116 bfs::create_directories(dirPath);
(gdb) print dirPath
$44 = {static preferred_separator = 47 '/', m_pathname = {static npos =
18446744073709551615,
_M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> =
{<No data fields>}, <No data fields>},
_M_p = 0xebea40 "/tmp/sacExternalLogs"}, _M_string_length = 20,
{_M_local_buf = "\036", '\000' <repeats 14 times>, _M_allocated_capacity =
30}}}
(gdb) step
boost::filesystem::create_directories (p=...) at
/usr/local/include/boost/filesystem/operations.hpp:523
523 bool create_directories(const path& p) {return
detail::create_directories(p);}
(gdb) print p
$45 = (const boost::filesystem::path &) @0xd4b990: {static preferred_separator
= 47 '/', m_pathname = {static npos = 18446744073709551615,
_M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> =
{<No data fields>}, <No data fields>},
_M_p = 0xebea40 "/tmp/sacExternalLogs"}, _M_string_length = 20,
{_M_local_buf = "\036", '\000' <repeats 14 times>, _M_allocated_capacity =
30}}}
(gdb) step
boost::filesystem::detail::create_directories (p=..., ec=0x0) at
libs/filesystem/src/operations.cpp:930
930 error_code local_ec;
(gdb) print p
$46 = (const boost::filesystem::path &) @0xd4b990: {static preferred_separator
= 47 '/', m_pathname = {static npos = <optimized out>,
_M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> =
{<No data fields>}, <No data fields>},
_M_p = 0xebea40 "/tmp/sacExternalLogs"}}}
