I am trying to generate listing file with Clang C compiler, but I do not found any command line option for that.
Does anyone know how to generate listing file (.lst) with clang C compiler ?
Compile your file and after that run:
objdump -d -Mintel <filename>
Related
I use gcc compiled the hello.c:
dele-MBP:temp ldl$ ls
a.out hello.c
now, when I cat a.out:
$ cat a.out
??????? H__PAGEZERO?__TEXT__text__TEXTP1P?__stubs__TEXT??__stub_helper__TEXT???__cstring__TEXT??__unwind_info__TEXT?H??__DATA__nl_symbol_ptr__DATA__la_symbol_ptr__DATH__LINKEDIT ?"? 0 0h ? 8
P?
/usr/lib/dyldס??;K????t22
?*(?P
8??/usr/lib/libSystem.B.dylib&`)h UH??H?? ?E??}?H?u?H?=5??1ɉE??H?? ]Ð?%?L?yAS?%i?h?????Hello
P44?4
there shows the messy code.
I want to know what type of the a.out? is it assembly language? if is why there have so many ??? or %%%?
There are several intermediate file formats, depending on the compiler system you use. Most systems use the following steps, here shown with GCC as example:
Preprocessed C source (gcc -E test.c -o test.i), but this is before compilation, strictly speaking
Assembly source (gcc -S test.c -o test.s)
Object file containing machine code, not executable because calls to external functions are not resolved (gcc -c test.c -o test.o)
Executable file containing machine code (gcc test.c -o test)
Only the first two steps generate text files that you could read by cat or in a text editor. This is BTW a valuable source for insight. However, you can use objdump to see most informations contained in the other formats. Please read its documentation.
Each step does also all steps before it. So (gcc test.c -o test) generates assembly source and object file in temporary files that are removed automatically. You can watch that process by giving GCC the option -v.
Use gcc --help to see some entry points for further investigations.
There is at lot more to say about this process but it would fill a book.
I want to get the preprocessor output when compiling my c-code through mex of MATLAB using MinGW64 Compiler (C) so using gcc (right?).
From this post I got that you can do this with pure gcc passing the option -E to gcc.
However I installed gcc through MATLAB app and therefore cannot access it through command line (would also appreciate a command how to do that, without reinstalling MinGW64 and setting it up manually for use with MATLAB).
I tried to do the following assuming that compiler flags are the right way to pass the argument:
mex -c grampc_run.c -I../../include -I../include COMPFLAGS='$COMPFLAGS -E'
This just results in the creation of the object file.
COMPFLAGS is used by the MSCV compiler. The GCC compiler loos at CFLAGS and CXXFLAGS (for C and C++ compilation, respectively). See here. Thus, you should use the following syntax:
mex -c grampc_run.c -I../../include -I../include CFLAGS='$CFLAGS -E'
You might also want to add the -v option to mex. GCC puts the preprocessor output to the standard output, which mex might not show you. With -v it does show you all the output.
A weird behaviour when I shell:
bush#ubuntu:~/CPPWorkspace/Ex12$ gcc users/dubi/justPrnit.C
Returns an error:
gcc: error trying to exec 'cc1plus': execvp: No such file or directory
But when I change justPrnit.C to justPrnit.c (with little 'c') it compiled successfully.
What's that?
error trying to exec 'cc1plus'
Because .C is assumed to be a C++ source file (cc1plus is the C++ parser backend of GCC - by the way, it seems that your local installation of GCC lacks g++ - are you using the default [incomplete] setup?).
To solve this, use the -x switch to force the language:
gcc -x c users/dubi/justPrnit.C
GCC recognises .C as C++, rather than C
I need to compile a program in MS DOS. I have Borland Editor, I can compile it using Alt+F9 but the things is what it do at the backend. I want to compile it in MS DOS. I m trying this:
c:\tc\bin>tcc -o hello.exe hello.c
where hello.c is is my file, hello.exe the file I want to produce. Its not working, what shouldI do? and also please tell me also how do I compile .cpp file manually from MS DOS.
If I remember correctly, Borland/Turbo C compiler's command line options didn't look like gcc options. You should try tcc /? for a command line help.
Turbo C++ Version 3.00 Copyright (c) 1992 Borland International
Syntax is: TCC [ options ] file[s] * = default; -x- = turn switch x off
-1 80186/286 Instructions -2 80286 Protected Mode Inst.
-Ax Disable extensions -B Compile via assembly
-C Allow nested comments -Dxxx Define macro
-Exxx Alternate Assembler name -G Generate for speed
-Ixxx Include files directory -K Default char is unsigned
-Lxxx Libraries directory -M Generate link map
-N Check stack overflow -O Optimize jumps
-P Force C++ compile -Qxxx Memory usage control
-S Produce assembly output -Txxx Set assembler option
-Uxxx Undefine macro -Vx Virtual table control
-X Suppress autodep. output -Yx Overlay control
-Z Suppress register reloads -a Generate word alignment
-b * Treat enums as integers -c Compile only
-d Merge duplicate strings -exxx Executable file name
-fxx Floating point options -gN Stop after N warnings
-iN Max. identifier length -jN Stop after N errors
-k Standard stack frame -lx Set linker option
-mx Set Memory Model -nxxx Output file directory
-oxxx Object file name -p Pascal calls
-r * Register variables -u * Underscores on externs
-v Source level debugging -wxxx Warning control
-y Produce line number info -zxxx Set segment names
C:\TC\BIN>
So, I think you should type:
tcc hello.c for C programs and tcc -P hello.cpp for C++ programs.
I belive this things must work
c:\tc\bin\tcc -c File.c \\ To generate objective file
c:\tc\bin\tcc -o File.obj \\ To generate exe from obj and please use .obj and not .o
c:\tc\bin\ tcc -run File.c \\ to generate exe file without .obj file
c:\tc\bin\File.exe \\ to run the exe file
I dont know why the
tcc -o good.exe File.obj \\not working, the error is good.exe file not found
I think we cant give a name to .exe file in tcc command line prompt.but its possible in gcc. I dont know about TCC much. If i find it i will let you know it !
Just take a look at these http://bellard.org/tcc/tcc-doc.html#SEC3. This is what I found on google . and googling makes you more powerful so keep on googling the things when you dont know .
Thanks
Further to Prof Falken's answer
tcc file.c <-- will compile in C
tcc file.cpp <-- will compile in cpp
tcc file.ext where .ext is anything other than cpp, will compile in C Unless --P is used then cpp is used to compile it, in which case .cpp is used, even if the extension is .c
I am running TCC in a VM and can't copy/paste from there here. But your test should find the same result as mine, if not, then perhaps I erred, but you can test for yourself given this code that works in C and not CPP, and code that works in CPP and not C. You can then experiment with changing the extension, and using -P or not.
The following code works in C only
conly.c
(A C++ expert told me re the following example, works in C and not C++, because C allows void* -> T* conversions. C++ does not)
#include <stdio.h>
#include <stdlib.h>
void main() {int *x=malloc(4);}
The following code works in C++ only
cpponly.cpp
#include <stdio.h>
void main() {
int a=9;
int& b=a;
printf("b=%d",b);
}
I would like to know how to generate assembler code from a C program using Unix.
I tried the gcc: gcc -c file.c
I also used firstly cpp and then try as but I'm getting errors.
I'm trying to build an assembler program from 3 different programs
prog1.c prog2.c prog.h
Is it correct to do gcc -S prog1.c prog2.c prog.h?
Seems that is not correct. I don't know if I have to generate the assembler from each of them and then link them
Thanks
According the manual:
`-S'
Stop after the stage of compilation proper; do not assemble. The
output is in the form of an assembler code file for each
non-assembler input file specified.
By default, the assembler file name for a source file is made by
replacing the suffix `.c', `.i', etc., with `.s'.
Input files that don't require compilation are ignored.
so try gcc -S file.c.
From man gcc:
-S Stop after the stage of compilation proper; do not
assemble. The output is an assembler code file for
each non-assembler input file specified.
By default, GCC makes the assembler file name for a
source file by replacing the suffix `.c', `.i',
etc., with `.s'. Use -o to select another name.
GCC ignores any input files that don't require com-
pilation.
If you're using gcc (as it seems) it's gcc -S.
Don't forget to specify the include paths with -I if needed.
gcc -I ../my_includes -S my_file.c
and you'll get my_file.s with the Assembler instructions.
objdump -d also works very nicely, and will give you the assembly listing for the whole binary (exe or shared lib).
This can be a lot clearer than using the compiler generated asm since calls to functions within the same source file can show up not yet resolved to their final locations.
Build your code with -g and you can also add --line and/or --source to the objdump flags.