Assuming I'm currently in /home/testUser/gcovTest/test1/ directory where I have a file test.c which I compile with gcc -fprofile-arcs -ftest-coverage test.c which generates relevant .gcda and .gcno files.
After successful compilation, I execute the generated binary ./a.out and run the following command to generate the .gcov report.
gcov -p test.c
What I expected
The resultant test.c.gcov file should have contained the full path of test.c i.e. home/testUser/gcovTest/test1/test.c in the source: tag but actually it contains just test.c
Question
How I can get gcov to preserve the complete path of test.c in test.c.gcov file?
I have even tried the follwing but it still prints test.c in source of test.c.gcov
gcov -p home/testUser/gcovTest/test1/test.c
The -p switch for gcov preserves the path of the input file in the file name of the output. That is,
gcov -p /foo/bar/baz.c
generates the file #foo#bar#baz.c.gcov instead of simply baz.c.gcov - but the contents of the file are identical.
The name of the source file, as shown in the .gcov report, is generated by gcc. If you wish the full path to be included in the report, simply specify the full path on your compilation command line:
$ gcc -fprofile-arcs -ftest-coverage /foo/bar/test.c
$ ./a.out
$ gcov test.c
File '/foo/bar/test.c'
Lines executed: ...
Creating 'test.c.gcov'
$ head -n 1 test.c.gcov
-: 0: Source:/foo/bar/test.c
Related
I have this command here:
gcc -MD -fno-builtin -nostdinc -fno-stack-protector -Os -g -m32 -I. -c -o boot1lib.o
boot1lib.c
It runs fine if I run this in the folder where boot1lib.o and boot1lib.c located. But when I tried to run it from the upper folder i.e. ./boot/boot1/boot1lib.c
It will shows:
./boot/boot1/boot1lib.c:1:10: fatal error: boot1lib.h: No such file or directory #include <boot1lib.h>
How do I modify the parameters to fix this issue? I am trying to build a makefile in the root folder so I don't have to copy and paste the command every time I tried to compile.
With GCC, #include <file> looks for files only in configured system directories, including those added with switches. #include "file" looks in the directory of the source file it is in.
I use GCC compiler to compile and run C program on CMD.
When I compile C program using command gcc hello.c it creates an executable file file with name a.exe but when I use IDE it uses the name same as .c file as hello.exe.
Is it possible to create .exe file name same as .c file on CMD?
Just tell GCC the output name you want.
gcc hello.c -o hello
You have to specify the name of the executable
gcc -c hello.c // compiling
gcc -o hello hello.o // linking
^------------------------- name of the executable
you can do the compiling and the linking in one command
gcc -o hello hello.c
^------------------------- name of the executable
You need to understand the syntax of output. Following is the description of the command:
$ gcc [options] [source files] [object files] -o output file
In your case you should execute the commands as following:
$ gcc myfile.c -o myfile
$ ./myfile
For more descriptions and more optimized ways refer to the following url:
http://www.rapidtables.com/code/linux/gcc/gcc-o.htm
I've watched tons of videos about how to use sublime text 3 I do what they say but it doesn't work. When i type "subl test.c" in terminal it opens up a a file called test.c in sublime text 3 when i use the command gcc -c test.c everything is fine too, but when I try to run the code using ./test it says bash: ./test: No such file or directory
Bash says that there is no such file or directory because you haven't created a file called 'test'. You should specify an output filename, i.e. you should type gcc test.c -o your_out_filename. Then you may run your program using ./your_out_filename. Without -o flag gcc will create a a.out by default, so your out_filename will be a.out.
You have to use the following command to create a file called test:
gcc test.c -o test
If you don't use the -o option (gcc test.c) your created file will be a.out.
The option -c of gcc only compiles your file and doesn't link it to a program which you can run. The result of the -c option is only an object file called test.o.
Therefore the easiest way is the one I have mentionend above (-o option).
You have to run:
gcc -o output test.c
output is the file you have to do ./output in terminal for it to execute
Suppose there are 2 c program named abc.c and xyz.c . Now we want to work with the 2 executables at a time. So we change the name of the ./a.out using
gcc -g abc.c -o abc
gcc -g xyz.c -o xyz
Even gcc -o abc abc.c works.
What does the -g and -o in the above commands specify or describe?
What is the significance of -g and -o in the command for renaming ./a.out file.
Thanks in advance.
-g means to leave debugging information in the output file, it's unrelated to renaming.
-o means to put the result in the specified file instead of the default filename (abc.o for object files, a.out for linked executable files).
From https://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html:
-g
Produce debugging information in the operating system's native format (stabs, COFF, XCOFF, or DWARF). GDB can work with this debugging information.
-o file
Place output in file file. This applies to whatever sort of output is being produced, whether it be an executable file, an object file, an assembler file or preprocessed C code.
-g starts becoming useful once you use debuggers such as gdb and lldb. When you attach to a running program and advancing one line at a time printing/altering the state as it changes.
if we specify -g option while compiling, debugging symbols will be available in the output file which will be useful when you try to debug using GDB.
If we won't specify -o option, the output will be placed in default a.out file. So if we run
gcc a.c - output will be in a.out
gcc b.c - output is a.out which is replacing old a.out file
If you want the output not to be a.out file, you can give -o option while compiling
gcc abc.c -o a
-o and -g options are not related.
I was reading about ELF files on the net and am stuck in understanding a standard command to generate an ELF file.
Till now I have been running my code using > gcc test.c -o test.o .Thats it!!
One article says:
gcc -c test.c // will generate ELF file test.o
Now -o option is to tell the compiler to create an executable ( which is not ELF)
Another article says:
gcc -c test.c -o test.o // will generate ELF test.o -> here's where I am confused.
-o should always generate Executable.
The option -c tells GCC to generate an object file. This object file is only the compiled code from the source file test.c, not a complete program. To generate a complete program you need to link the object file. Or not use the -c option.
The -o option tells GCC what to name the output file, no matter what kind of output file it is.
So, to generate an executable file from a single source file, the simplest command is
$ gcc test.c
The above command will create an executable named a.out in the current directory. To name the output file something else you use the -o option:
$ gcc test.c -o myprogram
The above commands names the executable program myprogram.
To use the intermediate step with object files you use the -c option, and then use a separate step to link the program, like
$ gcc -c test.c
$ gcc test.o -o myprogram
The above two commands is the same as the single command gcc test.c -o myprogram.