In one of my project's header file, the following line is included in a inline method
typedef boost::archive::iterators::transform_width<boost::archive::iterators::binary_from_base64< boost::archive::iterators::remove_whitespace<std::string::const_iterator>>, 8, 6> Base64ToBin;
When I compile this with gcc 4.8.2 I'm getting the following error:
error: ‘boost::archive::iterators::remove_whitespace<__gnu_cxx::__normal_iterator > >’ has a field ‘boost::archive::iterators::remove_whitespace<__gnu_cxx::__normal_iterator > >::’ whose type uses the anonymous namespace [-Werror]
I'm really hitting hard but could not resolve this issue, also from the link1 and link2 it looks like it is an issue with lower version of gcc. Can somebody suggests how to silence this warning or get over with that. I'm using -Werror flag compilation.
This looks like a correct warning. Because the code is in a header, it will be included from multiple files but the anonymous namespace is unique for every file. That means the type doesn't have the same definition everywhere.
Solution: move the relevant code to a .cpp file.
Related
I am trying to compile an application from source, FlyWithLua, which includes the sol2 library.
I am following the instructions but when I run cmake --build ./build I get the following error:
In file included from /home/jon/src/FlyWithLua/src/FloatingWindows
/FLWIntegration.cpp:10:
/home/jon/src/FlyWithLua/src/third_party/sol2/./upstream/sol.hpp: In lambda function:
/home/jon/src/FlyWithLua/src/third_party/sol2/./upstream/sol.hpp:7194:59:
error: ‘numeric_limits’ is not a member of ‘std’
7194 | std::size_t space = (std::numeric_limits<std::size_t>::max)();
There are several other errors on the same line after this, but I guess they might just go away if I can solve this one.
there are several similar issues with the solution to add the following includes to the .hpp file
#include <stdexcept>
#include <limits>
the sol.hpp file includes the following imports:
#include <stddef.h>
#include <limits.h>
https://sol2.readthedocs.io/en/latest/errors.html gives some hints about the why the compiler might not recognize these includes:
Compiler Errors / Warnings
A myriad of compiler errors can occur when something goes wrong. Here
is some basic advice about working with these types:
If there are a myriad of errors relating to std::index_sequence, type traits,
and other std:: members, it is likely you have not turned on your C++14 switch for
your compiler. Visual Studio 2015 turns these on by default, but g++ and clang++
do not have them as defaults and you should pass the flag --std=c++1y or
--std=c++14, or similar for your compiler.
the src/CMakeList.txt file has the following line:
set(CMAKE_CXX_STANDARD 17)
I'm only faintly familiar with C/C++ and this all seems very complicated to me, but I'm hoping that there might be an easily recognizable cause and solution to this to someone more skilled.
cat /etc/*-release gives
DISTRIB_RELEASE=21.10
DISTRIB_CODENAME=impish
DISTRIB_DESCRIPTION="Ubuntu 21.10"
$ g++ --version
g++ (Ubuntu 11.2.0-7ubuntu2) 11.2.0
/home/jon/src/FlyWithLua/src/third_party/sol2/./upstream/sol.hpp:7194:59:
error: ‘numeric_limits’ is not a member of ‘std’
7194 | std::size_t space = (std::numeric_limits<std::size_t>::max)();
This error message implies that src/third_party/sol2/./upstream/sol.hpp header uses std::numeric_limits, but also that std::numeric_limits hasn't been defined. The simplest explanation for that is that the header that defines std::numeric_limits hasn't been included. In such case, the solution is to include the header that defines std::numeric_limits.
the sol.hpp file includes the following imports:
#include <stddef.h>
#include <limits.h>
This confirms the problem. Neither of those headers define std::numeric_limits.
https://sol2.readthedocs.io/en/latest/errors.html gives some hints about the why the compiler might not recognize these includes:
Those hints may apply to some other cases, but not this one. std::numeric_limits has been part of the C++ standard since the beginning, so language version has no effect on its existence.
Conclusion: According to the quoted error message, sol.hpp uses std::numeric_limits which is defined in the header <limits>, but according to you, it doesn't include that header. If this is the case, then this is a bug in the sol.hpp file. Correct solution would be to fix the sol.hpp file by including <limits> in that file before using std::numeric_limits.
I am using clang tool to parse standard header file located in /usr/lib/gcc/x86_64-linux-gnu/4.7/string. But I get the following error.
In file included from ~/PrototypeWork/user/header.hpp:3:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/string:41:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/char_traits.h:41:
In file included from /usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../include/c++/4.7/bits/postypes.h:41:
/usr/include/c++/4.7/tr1/cwchar:42:14: error: no member named 'wcstof' in namespace 'std'
using std::wcstof;
~~~~~^
/usr/include/c++/4.7/tr1/cwchar:45:14: error: no member named 'vfwscanf' in namespace 'std'
using std::vfwscanf;
~~~~~^
The problem seemed to be that clang is reading string header as a C header instead of c++ header and so it could not parse "using" keyword.
So I went ahead an added the -TP command line options that says to treat all source files as C++ but that did not help.
I get the following warning after using -TP command line option
warning: argument unused during compilation: '-T P'
Can anyone help me with this issue?
Clang command line options: http://clang.llvm.org/docs/UsersManual.html#id5
Code
My main function has these:
int main() {
std::vector<std::string> cmdLine = boost::assign::list_of
("-TP")
("-I/usr/include")
("-I/usr/include/c++/4.7/tr1/");
clang::tooling::FixedCompilationDatabase db(".",cmdLine);
// Provide clang with the header file that needs to be parsed
// Run the clang tool .
}
Sorry if this is a "Thank you, Captain Obvious" answer, but: is it possible that the code being parsed is simply failing to #include <cwchar>? clang is a bit more stringent by default than gcc, so you'll see an error like this if you've failed to include the header that declares the function.
I am trying to use the GNU C library regex functionality in my C++ project, particularly I'm trying to use the regex_t regcomp, regexec, regfree functions. Upon compilation I get errors stating that these symbols are undefined:
me> g++ -I/me/myheaders/ -c RootGenerator.cpp -o RootGenerator.o -std=gnu++0x -Wall
RootGenerator.cpp: In function ‘std::string findFirstFileInCurrentDirectory(std::string)’:
RootGenerator.cpp:1072: error: ‘regex_t’ was not declared in this scope
RootGenerator.cpp:1072: error: expected ‘;’ before ‘re’
RootGenerator.cpp:1073: error: ‘re’ was not declared in this scope
RootGenerator.cpp:1073: error: ‘REG_EXTENDED’ was not declared in this scope
RootGenerator.cpp:1073: error: ‘REG_NOSUB’ was not declared in this scope
RootGenerator.cpp:1073: error: ‘regcomp’ was not declared in this scope
RootGenerator.cpp:1074: error: expected ‘;’ before ‘int’
RootGenerator.cpp:1084: error: ‘status’ was not declared in this scope
RootGenerator.cpp:1084: error: ‘regexec’ was not declared in this scope
RootGenerator.cpp:1092: error: ‘REG_NOMATCH’ was not declared in this scope
RootGenerator.cpp:1108: error: ‘regfree’ was not declared in this scope
I realize that the regex header is a TR1 implementation and is therefore experimental for my version of GCC. I added the -std=gnu++0x compiler option according to the compiler warning recieved when first trying to compile but this doesn't seem to fix the issue. Is this an issue of the system not recognizing and adding paths to "experimental" headers? Are there additional include paths or compiler options that I need to specify?
As an additional note, I noticed in Eclipse/CDT that under the "includes" tab in the Project Explorer view, it shows a list of the system header paths. It lists many header files under the /user/include/c++/4.4.4 path tab, but It doesn't list the regex header. I think this is also reaffirming that there is a setting issue.
Found the problem:
#include <regex>
should be
#include <regex.h>
The regex.h header is the GNU C library implementation of regex, containing the functions I was trying to use in my source. The regex header is the TR1 (and incomplete) regex implemntation. So #Oli, I wasn't referencing the relevant header after all!
I'm looking for an implementation of Hybrid Tree(not important), and find an "old" one here.
The author said they have tried this code on the SUN Sparc platform (running Solaris 2.6) and with gcc-2.8.1 compiler. And my environment is gcc version 4.4.3 (Ubuntu 10.10).
The problem is:
I run "make" with the makefile he provides, but it gives me lots of error message as follows:
g++ -c Node.C
g++ -c DataNode.C
In file included from DataNode.h:18,
from DataNode.C:17:
Query.h:9:20: error: vector.h: No such file or directory
Query.h:10:19: error: stack.h: No such file or directory
Query.h:13:22: error: function.h: No such file or directory
Query.h:14:22: error: iostream.h: No such file or directory
DataNode.C:283:8: warning: extra tokens at end of #endif directive
In file included from DataNode.h:18,
from DataNode.C:17:
Query.h:29: warning: ‘typedef’ was ignored in this declaration
Query.h:44: warning: ‘typedef’ was ignored in this declaration
Query.h:86: error: expected initializer before ‘<’ token
Query.h:118: error: ISO C++ forbids declaration of ‘PQ’ with no type
Query.h:118: error: expected ‘;’ before ‘*’ token
Query.h:122: error: ISO C++ forbids declaration of ‘PQ’ with no type
Query.h:122: error: expected ‘;’ before ‘*’ token
Query.h:126: error: ISO C++ forbids declaration of ‘PQ’ with no type
Query.h:126: error: expected ‘;’ before ‘*’ token
Query.h:135: error: expected initializer before ‘<’ token
DataNode.C: In member function ‘void DataNode::DisconnectBranch(int)’:
DataNode.C:80: error: ‘memmove’ was not declared in this scope
make: *** [DataNode.o] Error 1
I know I need to modify the souce code so as to agree with the morden compiler, such as change vector.h to vector. But I find it's just endless.
So my question is: is there any convienent method to run this program, no matter automatically converting this code to "modern-style" or using a standalone "old-style" compiler ?
Any suggestions?
===Update:===
Thank you all, I installed gcc2.8.1 in a different dir using --prefix=/usr/local/gcc-2.8.1 and modify the "makefile" to use this old-version gcc(/usr/local/gcc-2.8.1/bin/gcc). But when I run "make", it still gives me errors of not finding the headers:
/usr/local/gcc-2.8.1/bin/gcc -c DataNode.C
In file included from DataNode.h:18,
from DataNode.C:17:
Query.h:9: vector.h: No such file or directory
Query.h:10: stack.h: No such file or directory
Query.h:11: deque: No such file or directory
Query.h:12: algorithm: No such file or directory
Query.h:13: function.h: No such file or directory
Query.h:14: iostream.h: No such file or directory
make: *** [DataNode.o] Error 1
Then I tried to find these heads in /usr/local/gcc-2.8.1 using find /usr/local/gcc-2.8.1 -name "*vector*", but got nothing.
So where are these heads for the old-version gcc?
You can make a vertor.h yourself which includes vector. This way you can fix the incompatibilities noninvasively.
Edit:
You may also need to add a
using namespace std;
in the header file(s). This is
generally a bad idea but this is one situation where i'd do it anyway.
Once you get it working i would reccomend rewriting it to use the new style header files and namespaces.
Debian Lenny (oldstable) has gcc 3.4. This might have a better backward compatibility. Try to make compatibility headers for the rest of the issues and include them via an extra -I directory, e.g. a vector.h header file that includes vector.
Do yourself the favor and try not to touch the old code. It is easy to break legacy code in unforeseen ways.
You could try running the program on QEMU which supports Solaris 2.6. The only problem might be hunting for the install disc/image. Also, there are people that sells old Solaris boxes on eBay for cheap, you might be able to grab one.
GCC provides download for very old versions, you might be able to get better chance if you try older version of the compiler.
gcc has -fpermissive option: try it and see whether at least some errors disappear. Also: try making a single header file that will include all requisite headers with using directives. For example, make stdinc.h containing:
#include <vector>
#include <iostream>
#include <stack>
...
using std::vector;
using std::fstream;
...
Replace all mentions of legacy C++ header files with a single include of stdinc.h. Old C++ didn't have namespaces, so even if you replace individual directives with just using namespace std;, clashes are unlikely.
If the only thing is
#include <vector.h>
to
#include <vector>
using namespace std;
Why not try sed?
grep for all includes to see if there are other includes than the c++ headers. If not your lucky.
Another thing that is more tricky is that there is old code that relies on accessing data through iterators in a non-standard way. I saw that in a Doom map editor for linux. Then you may need to do manual stuff.
I have the following very simple application that compiles and runs fine:
EDIT: changed the example to be simpilar to end confusion of the real issue
int main() {
return 0;
}
As soon as I add #include <string> (and not even reference std::string), it fails to compile and I get the following error:
/usr/include/c++/4.1.2/bits/allocator.h:82 error: expected template-name before '<' token
Along with about 456 other, similar errors.
Any ideas? Thanks!
UPDATE:
Line 82 of /usr/include/c++/4.1.2/bits/allocator.h references the template __glibcxx_base_allocator at the location of the error. That template is defined in bits/c++allocator.h. When I search the system for that file, I get 3 hits, but none of them are in /usr/include/c++/4.1.2/bits/ as one would expect.
I have version 3.1.6, 4.1.1, and 4.3.2, but not 4.1.2 as the rest of the includes I am using. I am not sure which one is being used (if any, however, I don't get any error for an unknown file), but it seems the problem may stem from this.
The problem appears to be the installed development packages are not correct or incomplete (not to be confused with corrupt). Forcing g++ to use different include versions corrects that:
g++ -nostdic++ hello.cc -o hello -I/usr/include/c++/3.4.6
All the alternative directories (4.1.1, 4.1.2 and 4.3.2) are incomplete causing inappropriate files to be included causing the unusually errors. For example:
/usr/include/c++/4.1.2/bits/allocator.h requires __glibcxx_base_allocator located in bits/c++allocator.h which is being included from either /usr/include/c++/4.1.1 or /usr/include/c++/4.3.2 and appear to be incompatible. Forcing the compiler to use the only complete set of includes rectifies this.
Almost certainly g++ is detecting .cc as a C source file, not C++ and passes it through to gcc instead of compiling as C++. You can easily test by renaming your file to hello.C. There's also a language parameter to g++ you can use.
EDIT: This seems to work fine in g++ 4.2 with a .cc extension so that might not be it. Do you have any other headers included you aren't showing us? They could be interfering with <string>.
EDIT2: Alternatively your headers might not be set up right. Does this work:
#include <string>
int main()
{
return 0;
}
Errors like this have been heard of to occur when the C++ standard library headers are corrupted/not fully installed – maybe there is even a message referring to a missing include among your 456 other errors.
In any case, make sure that libstdc++-devel, resp. the package containing the C++ standard library header files of your distribution, is properly installed.
Check your include path. The paths can be specified as environment variables or specified on the command line. You could be using an include file from a different compiler or different version of the same compiler.
Also, try using <cstdio> rather than <stdio.h>.
Another suggestion: change <> to "".
This could be error caused at preprocess stage. Just preprocess your cpp file by passing flag -E to gcc and Look at the place the compiler complains.