Including Files - Shared Source And Duplicate Names - include

I have a situation where I am using two libraries which have duplicate header file names. For example timer.h exists in both libraries. I think the normal solution to this would be to explicitly specify the directory in the include like #include <dir1/timer.h> or #include <dir2/timer.h> so that the compiler has a clue as to which I am specifying. However, my problem is that one of the libraries I am using is not in a sub directory of my project. It exists somewhere else at a higher level. That is...
Root
Library1
Projects
ProjectFolder
Library2
This was done so that multiple projects could reference Library1. It seemed like a good idea at the time. However, now that I have the name conflict of Library2 it creates issues. One other important detail is that I often use two different workstations. The absolute location of Library1 on these workstations is not the same, nor is the relative location (with respect to the project folder) the same between the two. What I have been doing to this point is adding both absolute locations to the search path of the preprocessor.
Anyway, I'd appreciate any guidance you might offer.

You are on the right track with "dir1/timer.h" and "dir2/timer.h". But rather than think of it as dir think of it as "project1/timer.h". Now in your makefile you will need to have the location of project1 added to your include search path if it's not in a common location.
You shouldn't have relative paths in either your code (no ../file.h). They should be relative to the base directory of their project (e.g. #include <sys/socket.h> or #include <linux/sched.h>). Then it's up to your makefile to find them (those two examples are in the standard search path so they will work). For your case you can -I<path to project directory> and then #include "other_project/library.h".

I'd prefer including a copy of a specific version of the external library with my project and updating to a newer version as needed (but not actually changing the external library from the project). If you just refer to the current (changing) version that everybody uses, then your project may change behavior without even having its code changed. A release of your project would also have to refer to whatever version of the library you were using at that point in time to be complete.
If you did it that way, the relative paths are always the same (say, "../ExternalLib") if you want to use that approach. Or you can do as dave suggests.

Related

CLion Indexing in Makefile project

So, I understand that CLion currently only fully supports CMake projects. I don't care if I can't compile or run anything with CLion, as I don't currently do that with Eclipse anyway. I am just looking for editor support, with nice click-to-follow, autocomplete, etc.
What I am wondering is whether or not indexing can still work for non-CMake projects. I can create my project just fine, and indexing completes just fine, but after that is done it can't find my include files. It creates a default CMakeLists.txt file, in which the appropriate sources and include_directories have been added. It doesn't seem to make a difference though, as after indexing completes I still can't click-to-follow #include lines, and any references to things in other files don't work correctly.
Is there something else I can do to make indexing work so I can use CLion as an editor, or is this a pipe dream until Makefile support is someday added?
After some research, I found out your best chances are:
Once it's created, edit CMakeLists.txt (for example, see How to
find libraries). One example:
set(Library "../Library")
include_directories(${Library})
set(SOURCES main.cpp)
add_executable(project_name ${SOURCES})
Note ../ goes to the up folder and in the main.cpp you can use #include "header_to_add.h" (header_to_add.h must be in ../Library folder.
Edit the source code of you .cpp, .h or whatever to add the full path of the library you want to #include taking into account the scope starts in the directory where the file is.
For example: #include "../Library/header_to_add.h" (note the "../" goes one level up from the current folder".
(Maybe not possible or hard) Modify the makefile to prepare CMake to get the necessary inputs (for example, see this).
I recommend the first one mainly because it maintains the structure outside the source files.
Edit: Also it's possible to prepare CMake to use makefile (Source).

Xcode header inclusion conflict [duplicate]

I have a project that was compiling ok within g++(I can't see the version right now) and now on xCode it is not.
I think that I got the problem now... I have a String.h file in my project and it seems tha the xCode compiler(that is gcc) is trying to add my own string file from the < cstring >... I am not sure of it, but take a look at this picture
http://www.jode.com.br/Joe/xCode1.png
from what it looks like, it is including my own instead of the system file, I was wondering... shouldn't #include < file > be a system include? because of the < > ? and shouldn't the system include a file within its own path and not the original path of my application?
As I said, I am not sure if this is what happening because I am just migrating to osx these past 2 days...
I was going to change my class and file name to not conflict, so it would work, if this is really the problem, but I was wondering, there should be another way to do this, because now my project isn't that big so I can do this in some time, but what if the project was bigger? it would be dificult to change all includes and class names...
Any help is appreciated
Thanks,
Jonathan
i had the same problem and it was hard to solve. took my hours to fix/find out.
the problem is the headermap of xcode. and the solution - besides avoiding those kind of reserved names, which is a good idea in general, but not always possible with third-party libs - is to add
USE_HEADERMAP = NO
to your user defined settings.
kudos to these guys:
http://meidell.dk/archives/2010/05/08/xcode-header-map-files/
http://www.cocoabuilder.com/archive/xcode/262586-header-file-problem-sorry-to-bug-this-list.html
Naming your headers with the same name as standard headers like string.h and including them simply with #include <String.h> is asking for trouble (the difference in casing makes no difference on some platforms).
As you said, however, it would be difficult to try to figure out what those are in advance when naming your headers. Thus, the easiest way to do this is to set to set your include path one directory level outside of a sub-directory in which your headers reside, ex:
#include <Jonathan/String.h>
Now you don't have to worry about whether the String.h file name conflicts with something in one the libraries you are using unless they happen to also be including <Jonathan/String.h> which is unlikely. All decent third-party libraries do this as well. We don't include <function.hpp> in boost, for instance, but instead include <boost/function.hpp>. Same with GL/GL.h instead of simply GL.h. This practice avoids conflicts for the most part and you don't have to work around problems by renaming String.h to something like Text.h.
Yes, if you use
#include "file"
the local directory is looked first and
#include <file>
only the system include folders are looked.
Notice the word first only in the first case. This means that every time is included your local version should never be reached (unless you have included your source path within the INCLUDE directive).
Said that, my dummy suggestion is to rename your local file with an unambiguous name...
On OSX the filesystem is case insensitive - so String.h you can wind up with conflicts like that. String.h == string.h
it worked by changing the name from String.h to Text.h
but that makes no sense, since the std library is including it's own string.h and not mine.
I mean, makes no sense for a developer to create his files thinking of what names he can't use, for an instance, lets say I change my String.h to Text.h(I already did, I need to work and this is not letting me) ad somehow I had to include another templated library that has a include called Text.h, would I have to change my text.h again or not use this new library? there should be an alternative.
Or shouldn't it?
thanks for the help so far,
Jonathan
Two things you're running into:
As noted above, the filesystem on Mac OS is case-insensitive unless you specifically set up your filesystem to be case-sensitive.
gcc does not distinguish all that much between local and system header include paths. When you specify a directory to be added to the path via -I, that directory will be used to locate both local and system includes. Only when you use -iquote or -I- does a directory get skipped for locating system includes. Further, the builtin "system include" directories on the compiler's search path are always searched for local includes.
Note that the current directory is used for local but not system includes. In this case, I believe it's picking up String.h because the project settings explicitly add the top-level project directory to the include path.
The workaround I would suggest, rather than renaming your includes, is to put your utilities into a directory whose name is unique for your project, and specify that directory in your include directive. For example:
#include "Josk/String.h"
and make sure Josk/ itself isn't in your include search path. This way you aren't stuck with an awkward rename, though you may have to shuffle some files around in your project. You may also need to edit your project settings to make sure the parent directory of that utility directory is in your include path.
Another possibility to try is, if you see the top-level project directory added to your project's include path, remove it. This ought to keep items in your top-level project directory from being searched for system includes.
Finally, you may also be able to avoid this problem in this specific case by changing the case sensitivity of your file system. This can break some Mac applications, though, so research the issue before you embark on this – or pick a volume that nothing else is using.
This question already has some very good answers, yet none of them summarizes in all detail how the compiler will search for header files in general; or more precisely, how Xcode will make the compiler search for them.
When you include a user header, those are header files between quotes ("..."), the following search order applies:
The directory of the file performing the include.
All header search paths in the order provided.
First match inside a header map file, if headers maps are enabled.
Note that the full include path is used. So if your include is in the file foo/bar/file.c and you do a #include "subdir/header.h", then the first lookup will be foo/bar/subdir/header.h.
If that file doesn't exist, the compiler iterates the user header search paths. Those are provided by the build setting User Header Search Path (within config files or on command line it's named USER_HEADER_SEARCH_PATHS). Multiple such path can exist and again, the full include path is attached to each of them until there's a match.
If provides no match either and the build setting Use Header Maps (USE_HEADERMAP) is enabled, Xcode generates a map file of all your header files in the project and searches this map file for an entry that matches the name of the included file. In that case the path is irrelevant, as it would also match just the name of the file.
For system headers, those between spiky braces (<...>), only the search paths from the build setting System Header Search Paths (SYSTEM_HEADER_SEARCH_PATHS) are searched.
However if the build setting Always Search User Paths (ALWAYS_SEARCH_USER_PATHS) is enabled, the user search paths are also searched for system header includes. This allows you to override a system header with your own user header of the same name. Note however, that this is deprecated by Xcode and shouldn't be done anymore.
If your file system is case-insensitive, default on macOS, then case will play no role during all searches.
If you want maximum control over which file is being included, disable header maps and always include with a path relative to the file performing the include (you may use ".." as well). This avoids any ambiguity.

What is "Source Tree" in the Xcode preferences and what can I do with it?

I've been recently researching how I can manage source files in a project or multiple projects. I've read that Xcode has a built-in support for using svn, and will support git as well, both of which I found to be very useful.
The one thing I couldn't understand clearly is about Source Trees described in Xcode Project Management Guide. Here is my theory, but as I couldn't really verify this from anywhere (as far as I could tell), I would really like if someone could say what I'm missing, if any.
A Source Tree in Xcode preferences is more like a root of a source tree, which is a folder in my local file system.
I can use any files in any of my Xcode projects, even if the files are not in the project folders, if I can specify the files' location related to one of my source trees.
Now someone has the same project folder that is synchronized with mine. She has all files in the project folder, but the files referenced by a relative location to the source tree may exist out of the project folder.
But she has a source tree, with the same Setting Name to mine, (but absolutely in a different folder in her local file system), and if she has the file in the same relative location, then her Xcode can access the file without a problem.
So is this correct, and we use source trees because it enables us collaborating with files outside the project folder?
And even if the files outside the project folder is referenced by a relative path to the project folder itself (not to a source tree), if these files are all managed by SVN so they exist in the same relative location to the project folder in everyone's environments, then I wouldn't need source trees, right?
I never think I am an expert of Xcode, but it seems your question hasn't been answered for a while, so maybe it's worth commenting what I could say:
What you described is pretty much about it. Think is as an environmental variable of an operating system. Typically in a build system made by Autotools, for example, files are referenced by relative paths, such as $PROJECT_HOME/src/common/error.cpp. It doesn't matter where $PROJECT_HOME is in each user's local file system, as long as files are accessible by their relative paths to the user's $PROJECT_HOME directory.
And yes, you don't need to use source tree if the entire folder hierarchy used for a project is referenced by relative paths to the project home and somehow it is certain that everyone has the same files in the same location (for example, because a version control repository contains every files in a chunk as you said).
However, I think it's the best to keep all files in the project home folder, unless they are used across multiple projects, and therefore your version control repository only contains a single root directory (the project home) for your project. If there are files that are best to be shared by multiple projects, then I would have a separate repository for those files. In this case all of your coworkers must use the same protocol, say, having a source tree with the same setting name and put all project homes retrieved from your version control server directly under the source tree (so files outside a project home can be referenced in relation to the source tree for all programmers).
The most of my answer is kind of rephrasing what you already described, but that's how I use the source trees feature in Xcode myself. Maybe others can tell you more about it.

XCode can't find OpenSSL headers in /usr/include

I'm trying to use standard system header files in my C++ XCode project:
#include <openssl/bio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
The build fails and it complains:
"Openssl/bio.h: No such file or directory"
I added /usr/include to the "Header Search Paths" in Project settings, but that doesn't fix it.
I can fix it by adding the whole path like:
#include </usr/include/openssl/bio.h>
-- but the project is full of similar includes and I don't want to change all of them this way. Also, I feel I shouldn't have to do this.
Another way to fix it would be as another thread mentioned, which is to add /usr/include to User Header Search Paths. But if I do that, then I'd have to change all the angle brackets <> to quotes "", which again seems like a hack. I mean, these are standard system header files so I feel it should be something simple, not requiring these kinds of hacks.
Any ideas?
Thanks!
Xcode uses the currently selected SDK as a base path, which it prefixes on to system includes. So if your SDK is /Developer/SDKs/MacOSX10.6.sdk then it will look under /Developer/SDKs/MacOSX10.6.sdk/usr/include by default for system includes.
There are various possible workarounds - I would probably just put a symbolic link in /Developer/SDKs/MacOSX10.6.sdk/usr/include pointing at /usr/include/openssl but you can probably think of others now that you know the underlying problem.
It might depend on the fact that HFS(+) is case insensitive. The error message talks about "Openssl/bio.h" with capital "O", but you're specifying "openssl/bio.h" in the include and the path with /usr/include works.
I suspect that there's some "Openssl" (capital "O") directory in your include path, that gets used when looking for "openssl/bio.h". This wouldn't happen if HFS(+) were case sensitive from the very beginning (I know it's possible to have is case sensitive, but it's actually a PITA to use...)
I've been able to avoid having to specify paths on includes by simply making sure to select Create groups for any added folders for the Folders option in the Add Files to Project dialog which pops up when you're adding the files.
With the other option, Create folder reference for any added folders, I have to manually point it to the file via the full path (and the folder icons show up blue instead of the normal beige). Interestingly, even in this case, AutoComplete sees the file, but Xcode complains it can't find it.

Code snippet paths in GCC

Background: Keil C51 on a PC, currently moving to GCC (CrossPack-AVR) on an iMac.
Since I write firmware for micro's I have a lot of 'driver' source files etc. that I need to include with my programs, e.g. a LCD driver, i.e. reusing code. These code snippets (.c and .h files) live sub folders in a /snippets/ folder, i.e. /snippets/lcd/. My /snippets/ used to be in a folder that also had a /projects/ folder for, well, projects or applications. I had considered putting them in a library but I use various architectures so it would not always work.
The Question: How can one set that up in GCC without having to specify absolute paths to the snippets in, for example, the various #include paths etc. so that the source file, of the included snippet, gets re-compiled along with the project that uses/includes it? Thus, if I improve on a snippet, it benefits all projects that is compiled/re-compiled subsequently?
I looked around on google but must be using the wrong search term.
Thanks!
I think make files will do the trick.

Resources