I'm trying to get a Cocoa development environment working in Emacs, and I'm 80% of the way there. The one feature I miss is Xcode's "Open Quickly", which basically performs a fuzzy match of the string you type against the filenames referenced in the Xcode workspace and the symbols defined in those files.
My problem is that our project is huge: if I generate a TAGS file using etags for the .h and .m files in our project's sub-directories, the result is over a gig in size and Emacs complains "TAGS file is large. Really open?", and if I say yes, then Emacs hangs and becomes essentially unusable. Of course, this is before I've even considered indexing tags for system libraries. I've also tried projectile, but unfortunately it's similarly unusable on a project of my size (on the order of a full minute to find a match).
It occurs to me that all the indexing information I really want is in the Xcode projects themselves, so if I had an Emacs package that could parse them and traverse their dependencies, that might be a start, but I'm not aware of any such package.
Any suggestions/solutions in this respect?
I've never found a single function quite as convenient as Xcode's "Open Quickly", but these days I use
helm-projectile-git-grep when I want to match on strings I know to be in the filenames, and
helm-git-grep for quick searches through the contents of the files themselves.
I've found that this gets me really close to what I wanted in my original question.
Related
Background: I am working with Angular (but my problem is not particular to any language or framework). In Angular, each component requires four separate files. So, we often find ourselves with 40+ files open. But, most of these files can be tiny, less than 20 lines each.
Many IDEs allow you to open your files in multiple windows. Each window can have a different panel, and each panel can have different tabs. This is great, but honestly, still isn't enough.
What I want: In addition to windows, panels, and tabs, I'd like to add another level of organization.
I speculate this has probably existed for decades, but I just don't know what it's called. At the very least, I speculate this has existed at least since Angular was a thing.
For example, here is a screenshot of VSCode with four files open across four panels. (Code taken from Angular dynamic component tutorial):
And here is a quick mockup showing what I'm looking for. Four files are open, but the three shortest ones are "concatenated" into one editor. Arrow-key down from the bottom of one file will bring you to the first line of the next file.
Notably, these files are not actually concatenated on-disk.
TLDR: What text editor can allow me to edit multiple files as if they were concatenated, as in the mockup above?
If the files stay as separate windows/tabs, the file editor would have to shrink each tab to a minimal height, and then tile them vertically. If any editor can do it, I suspect it would be emacs or vim. You might also be able to do it by opening separate editor windows and using a tiling window manager.
We can achieve a similar effect with some text editing magic. It would be something like:
Add a header to each file consisting of a unique separator (e.g. # === magic separator === filename my_file.js ===)
Use cat to combine all the files into one file
Edit this one file
When done, use the separator to break them up and put the text back into the original files
You could easily write some scripts for combining and splitting so you can do it quickly. You can also set up a background script that automatically runs the splitter as you edit the combined file. However, the combined file would essentially be a new file, so you could not view changes on it with git, and VS Code's CodeLens/Inline blame wouldn't work.
One option would be to develop your codebase with the combined files checked in to VCS, and then only have the splitter script as part of your "build" step. So you would make your changes, run ./build.sh which splits the files into some temp directory, and then run your application from there.
Lastly, and I hate to be snide, but the fact is that this problem is best solved by avoiding poorly designed frameworks that do not consider developer ergonomics. Many other languages give the developer much freedom and many tools to organize their code as they wish, rather than imposing constraints like requiring many small components to be in separate files. Java for example also had a similar problem (dunno if more recent versions fixed it) - you can only have one class per file, which creates a huge mess if you like having many small files. C# does not have this limitation and as a result C# codebases can be much tidier than Java codebases.
The CMake doc says about the command file GLOB:
We do not recommend using GLOB to collect a list of source files from your source tree. If no CMakeLists.txt file changes when a source is added or removed then the generated build system cannot know when to ask CMake to regenerate.
Several discussion threads in the web second that globbing source files is evil.
However, to make the build system know that a source has been added or removed, it's sufficient to say
touch CMakeLists.txt
Right?
Then that's less effort than editing CMakeLists.txt to insert or delete a source file name. Nor is it more difficult to remember. So I don't see any good reason to advise against file GLOB.
What's wrong with this argument?
The problem is when you're not alone working on a project.
Let's say project has developer A and B.
A adds a new source file x.c. He doesn't changes CMakeLists.txt and commits after he's finished implementing x.c.
Now B does a git pull, and since there have been no modifications to the CMakeLists.txt, CMake isn't run again and B causes linker errors when compiling, because x.c has not been added to its source files list.
2020 Edit: CMake 3.12 introduces the CONFIGURE_DEPENDS argument to file(GLOB which makes globbing scan for new files: https://cmake.org/cmake/help/v3.12/command/file.html#filesystem
This is however not portable (as Visual Studio or Xcode solutions don't support the feature) so please only use that as a first approximation, else other people can have trouble building your CMake files under their IDE of choice!
It's not inherently evil - it has advantanges and disadvantages, covered relatively well in this answer here on StackOverflow. But if you use it carelessly, you could end up ignoring dependency changes and requiring clean rebuilds of large parts of your codebase.
I'm personally in favor of using it - in smaller projects, or on certain subdirectories in larger ones - to avoid having to enter every file manually into the build files. Edit: My preference has changed and I currently tend to avoid it.
On top of the reasons other people here posted, imho the worst issue with glob is that it can yield DIFFERENT file lists on different platforms. As I see it, that's a bug. In OSX glob ignores case sensitivity and in a ubuntu box it doesn't.
Globbing breaks all code inspection in things like CLion that otherwise understand limited subsets of CMakeLists.txt and do not and never will support globbing as it is unsafe.
Write script to dump the globbed list and paste it in, its very simple, and then CLion can actually find the referenced files and infer them as useful. Maybe even put such script into the tree so that the other devs can either run it without being a moron OR set git hooks to make it happen.
In no case should some random file dropped into some directory ever get automatically linked that's how trojans happen.
Also CLion without context jumping to known definitions and what not, is like hiking barefoot /// why bother.
I am developing a Node.js project in IntelliJ.
The only way to rename files seems to be Shift+F6 which attempts to find all usages which takes too long (~30s - 1min).
Is there a way to simply rename the file without searching for usages?
This only happens when code is stored in Modules (which is necessary to be able to compact empty middle packages).
Best way I have found is to map ALT+SHIFT+F6 to Reveal in Finder. Then just press enter and type in new name.
It's good because its very similar to SHIFT+F6 rename refactor.
No.
IntelliJ must find the usages to rename them, otherwise you're just renaming the file, not refactoring. If you only want to rename the file, use the mv command from a terminal. You can also tell IntelliJ not to look in strings and text, which speeds things up somewhat, but is probably a bad idea in a javascript project (where almost everything is string or text).
I use rename a lot, and on my codebase, which is pretty big, it only takes a couple of seconds. Maybe intellij needs more memory to operate in, so you could try increasing that.
If You are doing it many times, You can create a custom scope for the refactoring:
There You can narrow the scope to few files/folders/modules etc. And for very narrow scope it will work as normal rename.
I know there are a lot of questions on this topic, and I've looked through a fair number of them. However I am still having problems.
I started writing a test program for a prototype PCB, and now that it's grown to nearly 1000 lines I'm trying to break it up into libraries that I can use for particular functions.
I thought this would be very simple. Make .c and .h files for each library that I need. I.e. I would have OLED.h and OLED.c for functions that control an OLED display. Copy the appropriate functions/definitions into each file. Then copy these files into the solution in Atmel Studio. I put them into the src folder under the project name.
However, this doesn't work! I get an exceedingly long list of errors. All of the things that are defined in the .h file are apparently undefined as far as the compiler is concerned. I also get many error messages of the type "unknown type name int16_t/uint16_t/uint8_t/etc..." That part is really baffling to me. Why should it matter that functions are in an external library, now the compiler doesn't understand what those data types mean?
So, this is probably a stupid problem to have. I don't want Atmel Studio to control my libraries by wrapping them up in some "library project" or somethig, I want to put them in a folder of my choosing and add them when I need them. I've searched for answers to this problem and I find long tutorials about changing the compiler settings for the project, the linker settings, etc... I tried this tutorial and still no dice: http://www.engblaze.com/tutorial-using-avr-studio-5-with-arduino-projects/#setup
I also can't find a way to add something by right clicking the project and clicking "Add." It wants me to find .a files. The "Add Library" dialog box in Atmel Studio is awful, it seems.
Surely it can't be that convoluted to just add a library to an existing project and have it function normally?! I've used PICs in the past and coming to Atmel I've found horrible documentation and a weird super-slick super-fly whizz bang interface that can't leave well enough alone and obfuscates simple function. What can I do to add these libraries?
UPDATE: Seemed to answer my own question. Turns out I needed to include all of the libraries to recognize data types and whatnot into the .c file. I somehow assumed this only had to be done in the main file but obviously I was mistaken. Adding asf.h seems to work well as it includes all of the MCU specific port definitions/names and all of that. All good for now!
Adding library files to a solution should be simple. Go to the Solution Explorer, right-click on your solution, and go to "Add->Existing Item". If you want to add a pre-existing library and keep it in a separate folder from your solution, click the arrow next to "Add" and choose "Add as link". That saves many headaches due to having a duplicate copy of your library in your solution folder, and files not staying up-to-date.
You are right in saying that you need to include the necessary header files in the .c files where they are used.
The compiler compiles each C file separately, and then links them together at the end, so you got the error unknown typename int_* because the compiler had not seen the relevant header in the context of compiling that C file.
You also seem to be in some confusion as to the difference between definition and declaration.
A function is:
Declared in the header file. This means there is a function prototype, e.g. int some_func(char some_var); which tells the compiler that the function exists, but does not tell it what it is. This is necessary because the compiler only looks at one C file at a time, so needs to be told that other functions exist.
Defined in the C file.This is the actual function body, i.e. int some_func(char some_var) { do_stuff(some_var); }. After compilation of each individual C file in isolation, the linker is called to put all the pieces together and give you your final binary, which you flash to the device.
A function can be (and must be) defined only once, but may be declared many times - even in the same file, so long as the declarations are not conflicting.
I'm producing a hex file to run on an ARM processor which I want to keep below 32K. It's currently a lot larger than that and I wondered if someone might have some advice on what's the best approach to slim it down?
Here's what I've done so far
So I've run 'size' on it to determine how big the hex file is.
Then 'size' again to see how big each of the object files are that link to create the hex files. It seems the majority of the size comes from external libraries.
Then I used 'readelf' to see which functions take up the most memory.
I searched through the code to see if I could eliminate calls to those functions.
Here's where I get stuck, there's some functions which I don't call directly (e.g. _vfprintf) and I can't find what calls it so I can remove the call (as I think I don't need it).
So what are the next steps?
Response to answers:
As I can see there are functions being called which take up a lot of memory. I cannot however find what is calling it.
I want to omit those functions (if possible) but I can't find what's calling them! Could be called from any number of library functions I guess.
The linker is working as desired, I think, it only includes the relevant library files. How do you know if only the relevant functions are being included? Can you set a flag or something for that?
I'm using GCC
General list:
Make sure that you have the compiler and linker debug options disabled
Compile and link with all size options turned on (-Os in gcc)
Run strip on the executable
Generate a map file and check your function sizes. You can either get your linker to generate your map file (-M when using ld), or you can use objdump on the final executable (note that this will only work on an unstripped executable!) This won't actually fix the problem, but it will let you know of the worst offenders.
Use nm to investigate the symbols that are called from each of your object files. This should help in finding who's calling functions that you don't want called.
In the original question was a sub-question about including only relevant functions. gcc will include all functions within every object file that is used. To put that another way, if you have an object file that contains 10 functions, all 10 functions are included in your executable even if one 1 is actually called.
The standard libraries (eg. libc) will split functions into many separate object files, which are then archived. The executable is then linked against the archive.
By splitting into many object files the linker is able to include only the functions that are actually called. (this assumes that you're statically linking)
There is no reason why you can't do the same trick. Of course, you could argue that if the functions aren't called the you can probably remove them yourself.
If you're statically linking against other libraries you can run the tools listed above over them too to make sure that they're following similar rules.
Another optimization that might save you work is -ffunction-sections, -Wl,--gc-sections, assuming you're using GCC. A good toolchain will not need to be told that, though.
Explanation: GNU ld links sections, and GCC emits one section per translation unit unless you tell it otherwise. But in C++, the nodes in the dependecy graph are objects and functions.
On deeply embedded projects I always try to avoid using any standard library functions. Even simple functions like "strtol()" blow up the binary size. If possible just simply avoid those calls.
In most deeply embedded projects you don't need a versatile "printf()" or dynamic memory allocation (many controllers have 32kb or less RAM).
Instead of just using "printf()" I use a very simple custom "printf()", this function can only print numbers in hexadecimal or decimal format not more. Most data structures are preallocated at compile time.
Andrew EdgeCombe has a great list, but if you really want to scrape every last byte, sstrip is a good tool that is missing from the list and and can shave off a few more kB.
For example, when run on strip itself, it can shave off ~2kB.
From an old README (see the comments at the top of this indirect source file):
sstrip is a small utility that removes the contents at the end of an
ELF file that are not part of the program's memory image.
Most ELF executables are built with both a program header table and a
section header table. However, only the former is required in order
for the OS to load, link and execute a program. sstrip attempts to
extract the ELF header, the program header table, and its contents,
leaving everything else in the bit bucket. It can only remove parts of
the file that occur at the end, after the parts to be saved. However,
this almost always includes the section header table, and occasionally
a few random sections that are not used when running a program.
Note that due to some of the information that it removes, a sstrip'd executable is rumoured to have issues with some tools. This is discussed more in the comments of the source.
Also... for an entertaining/crazy read on how to make the smallest possible executable, this article is worth a read.
Just to double-check and document for future reference, but do you use Thumb instructions? They're 16 bit versions of the normal instructions. Sometimes you might need 2 16 bit instructions, so it won't save 50% in code space.
A decent linker should take just the functions needed. However, you might need compiler & linke settings to package functions for individual linking.
Ok so in the end I just reduced the project to it's simplest form, then slowly added files one by one until the function that I wanted to remove appeared in the 'readelf' file. Then when I had the file I commented everything out and slowly add things back in until the function popped up again. So in the end I found out what called it and removed all those calls...Now it works as desired...sweet!
Must be a better way to do it though.
To answer this specific need:
•I want to omit those functions (if possible) but I can't find what's
calling them!! Could be called from any number of library functions I
guess.
If you want to analyze your code base to see who calls what, by whom a given function is being called and things like that, there is a great tool out there called "Understand C" provided by SciTools.
https://scitools.com/
I have used it very often in the past to perform static code analysis. It can really help to determine library dependency tree. It allows to easily browse up and down the calling tree among other things.
They provide a limited time evaluation, then you must purchase a license.
You could look at something like executable compression.