What option you use to generat preprocessor intermediate files of qemu code, i tried stuff like --enable-debug but it didn't work, any ideas?.
Thanks.
Use --extra-cflags=-save-temps.
You have to ask the compiler to save the preprocessor output by using command-line switches, and since it is the GCC in your case, then the command-line option is save-temps, for more command-line options
please refer to GCC command-line options.
To pass that command-line option to the GCC use --extra-cflags=,
You can use --extra-cflags= to pass any command-line options to the compiler.
Related
Several static analysis tools designed for C/C++ exist, but they are not particularly useful for testing CUDA sources.
Since clang version 6 is able to compile CUDA, I wanted to check what are my options with using clang-tidy, which does not seem to have option for switching architectures.
Is there a way to make it work? For example compile time switch for turning on CUDA parser, extension in form of custom check, or is it maybe planned feature?
One of the problem with the clang-based tools is that they are not parsing the files in exactly the same way as clang does.
The first problem is that unlike C/C++ compilation, CUDA compilation compiles the source multiple times. By default clang creates multiple compilation jobs when you give it a CUDA file and that trips many tools that expect only one compilation. In order to work that around you need to pass --cuda-host-only option to clang-tidy.
You may also need to pass --cuda-path=/path/to/your/CUDA/install/root so clang can find CUDA headers.
Another problem you may run into would be related to include paths. Clang-derived tools do not have the same default include paths that clang itself uses and that occasionally causes weird problems. At the very least clang-tidy needs to find __clang_cuda_runtime_wrapper.h which is installed along with clang. If you run clang-tidy your-file.c -- -v it will print clang's arguments and include search paths it uses. Compare that to what clang -x c /dev/null -fsyntax-only -vprints. You may need to give clang-tidy extra include paths to match those used by clang itself. Note that you should not explicitly add the path to the CUDA includes here. It will be added in the right place automatically by --cuda-path=....
Once you have it all in place, clang-tidy should work on CUDA files.
Something like this:
clang-tidy your-file.cu -- --cuda-host-only --cuda-path=... -isystem /clang/includes -isystem /extra/system/includes
I switch between so many projects and IDEs a lot. They run each project with default options of IDE. For example
g++ test.cpp
I know make file can solve the problem. But it is not IDE friendly way. I am thinking if there is any way to impose option
-std=c++11
In the code rather than in calling g++.
The same problem with linker. I want to tell the linker in the code that I want to link to armadillo library
-larmadillo
Maybe setting a prepossessing command could solve the problem. Is there any solution for it?
Have you tried CMake? With this you can create compiler and IDE independent makefiles and then generate the makefiles/project files for the environment of your choise. You can freely script it so you can set certin swithces for gcc and other for vc++ or clang.
You can also use it if you want to create different build configurations.
I was looking at the output from my build in Eclipse. I'm cross compiling for a ColdFire processor. The compilation line looks like this:
m68k-elf-g++ -O2 -falign-functions=4 -IC:\nburn\include -IC:\nburn\MOD52...
followed by more include file, obvious "compiler" flags and finally the one source file I changed. The next line invokes the same tool again:
m68k-elf-g++ src\main.o src\TouchPanelMediator.o src\Startup.o....
followed by more .o files some .ld files and some .a files. This appears to be linking all the various types of object files together.
In the Gnu family is g++ some uber application that can determine based on arguments whether it needs to compile or link? Does it have both capabilities built-in or is it just dispatching compiling to gcc and linking to ld and my log just doesn't show that?
g++ and gcc are drivers. Usually, they run the preprocessor (cpp), compiler proper (cc1plus for C++ and cc1 for C) and the linker (gold or GNU ld) and all other things necessary. The difference between gcc and g++ is that the latter includes one additional library to link against (libstdc++).
Depending on what type of file they are invoked on, they may omit some steps or do things differently. For .o files, it doesn't need to run the compiler proper or the preprocessor, for example.
If you pass -### to them, you can see it print the tools it invokes in each step of its execution.
Taken from this little GCC guide:
Based on the file extension that you gave your program, it selects the appropriate commands it needs to run to turn the source you gave it into the output file you specified.
With a nice little flowchart of what GCC exactly does, depending on the file extensions:
input extensions runs if output
It dispatches linking to ld.
Also see here:
How to get GCC linker command?
My definition of powerful is ability to customize.
I'm familiar with gcc I wanted to try MSVC. So, I was searching for gcc equivalent options in msvc. I'm unable to find many of them.
controlling kind of output
Stop after the preprocessing stage; do not run the compiler proper.
gcc: -E
msvc: ???
Stop after the stage of compilation proper; do not assemble.
gcc: -S
msvc: ???
Compile or assemble the source files, but do not link.
gcc: -c
msvc:/c
Useful for debugging
Print (on standard error output) the commands executed to run the stages of compilation.
gcc: -v
msvc: ???
Store the usual “temporary” intermediate files permanently;
gcc: -save-temps
msvc: ???
Is there some kind of gcc <--> msvc compiler option mapping guide?
gcc Option Summary lists more options in each section than Compiler Options Listed by Category. There are hell lot of important and interesting things missing in msvc. Am I missing something or msvc is really less powerful than gcc.
MSVC is an IDE, gcc is just a compiler. CL (the MSVC compiler) can do most of the steps that you are describing from gcc's point of view. CL /? gives help.
E.g.
Pre-process to stdout:
CL /E
Compile without linking:
CL /c
Generate assembly (unlike gcc, though, this doesn't prevent compiling):
CL /Fa
CL is really just a compiler, if you want to see what commands the IDE generates for compiling and linking the easiest thing to look at the the command line section of the property pages for an item in the IDE. CL doesn't call a separate preprocessor or assembler, though, so there are no separate commands to see.
For -save-temps, the IDE performs separate compiling and linking so object files are preserved anyway. To preserve pre-processor output and assembler output you can enable the /P and /Fa through the IDE.
gcc and CL are different but I wouldn't say that the MSVC lacks "a hell lot" of things, certainly not the outputs that you are looking for.
For the equivalent of -E, cl.exe has /P (it doesn't "stop after preprocessing stage" but it outputs the preprocessor output to a file, which is largely the same thing).
For -S, it's a little murkier, since the "compilation" and "assembling" steps happen in multiple places depending on what other options you have specified (for example, if you have whole program optimization turned on, then machine code is not generated until the link stage).
For -v, Visual C++ is not the same as GCC. It executes all stages of compilation directly in cl.exe (and link.exe) so there are no "commands executed" to display. Similarly for -save-temps: because everything happens inside cl.exe and link.exe directly, the only "temporary" files are the .obj files that cl.exe produces and they're always saved anyway.
At the end of the day, though, GCC is an open source project. That means anybody with an itch to scratch can add whatever command-line options they like with relatively little resistance. For Visual C++, a commercial closed-source product, every option needs to have a business case, design meetings, test plans and so on. Every new feature starts with minus 100 points.
Both compilers have a plethora of options for modifying... everything. I suspect that any option not present in either is an option for something not worth doing in the first place. Most "normal" users don't find a use for most of those options anyway.
If you're looking purely at the number of available options as a measure of "power" or "flexibility" then you'll probably find gcc to be the winner, simply because gcc handles many platforms other than Windows and has specific options for many of those platforms that you obviously won't find in MSVC. gcc (well, the gcc toolchain) also compiles a whole lot of languages beyond C and C++; I recently used it for Objective-C, for example.
EDIT: I'm with Dean in questioning the validity of your question. Yes, MSVC (cl) has options for the equivalent of many of gcc's options, but no, the number of options doesn't really mean much.
In short: Unless you're doing something very special, you'll find MSVC easily "powerful enough" on the Windows platform that you will likely not be missing any gcc options.
I'm building the boost libraries with bjam for both the intel compiler and vs2008, and I can't tell what optimizations are being passed to the compiler from bjam. For one of the compiler's gcc, I can see some optimizations in one of the bjam files, but I can't find the optimization flags for the compilers I care about. So, my questions are -
Does anyone know where the default optimization flags are located?
If they're declared within bjam, does anyone know how I can override them?
If you are interested in looking at the entire set of options that are passed to invoke the compiler when building you can run bjam with the -n -a options and the rest of the building options to give you the complete set of commands invoked, and any response files generated (see Boost Jam Options). Also you can look at the Boost Build sources directly and see what the specified features are translated into (see Boost Build Tools Files). For example:
For GCC see gcc.jam
For MSVC see msvc.jam
You can likely figure out the same for other compilers by just looking through the sources as they are fairly self explanatory. And you can just search for "<optimization>" and "<inlining>" in the *.jam sources.
You can override them in the command line by specifying the feature=value option in the command line when building. The options match the <feature>value specifications you see in the toolset files. For example, to override the optimizations feature you would specify in the command line some like "optimization=speed". If you want more fine grained control you would have to delve into Boost Build specifications and likely have to create a variant of your own to define specific options and features to build with.