gcov not generating gcda file

Question

Note: this could be considered as a duplicate of Gcov is not generating *.gcda file, however :

1. This question has no answer
2. I don't think the OP has the same system than me, so I don't think it'll be ok for me to just go and edit his question. Moreover, the question is 5yo.
3. I produce here a "minimal" and reproducible example.

So, I was trying to reproduce an error that I had with gcov...and I run on another instead. Here are some files:

main.c:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "modeAlpha.c"
//~ #include "modeBeta.c"
//~ #include "modeGamma.c"

int main(){
    char MyText[256];
    printf("Hello! This is a gcov test. Enter some word here: ");
    scanf("%s", MyText);
    printf("This is your text: %s\n",MyText);
    mode_write_Alpha(MyText);
    //~ mode_write_Beta(MyText);
    mode_wait_Alpha();
    //~ mode_free_Beta(MyText);
    //~ mode_end_Beta();
}

modeAlpha.c:

#ifdef modeAlpha
#include "modeAlpha.h"
#include "AlphaFunctions.c"
#endif

modeAlpha.h:

#ifdef mode_write
#undef mode_write
#endif
#define mode_write mode_write_Alpha

#ifdef mode_wait
#undef mode_wait
#endif
#define mode_wait mode_wait_Alpha

#ifdef mode_free
#undef mode_free
#endif
#define mode_free mode_free_Alpha

#ifdef mode_end
#undef mode_end
#endif
#define mode_end mode_end_Alpha

#include "modes.h"

AlphaFunctions.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "modes.h" 

void mode_write(char* string){
    printf("Alpha Writing what you said:  %s\n", string);
}

void mode_wait(){
    printf("Alpha Waiting to process\n");
}

void mode_free(char* string){
    printf("Alpha Free memory\n");
    free(string);
}

void mode_end(){
    printf("This is the end of Alpha\n");
}

modes.h:

void mode_write(char* test);
void mode_wait(void);
void mode_free(char* test);
void mode_end(void);

And the Makefile:

GCOVOPT= -std=c99 --coverage -fprofile-arcs -ftest-coverage -fprofile-generate
LDLIBS= -lpthread -lgcov
LDFLAGS= -Wall -pedantic -g -g3 -ggdb $(GCOVOPT)
CFLAGS= -c -Wall -pedantic -g -g3 -ggdb

OBJS=MyProg.o modeAlpha.o 
SRCS=main.c modeAlpha.c 

MODEALPHA=modeAlpha
MODEBETA=modeBeta
MODEGAMMA=modeGamma

MyProg: $(OBJS)
    gcc $(OBJS) $(LDFLAGS) $(LDLIBS) -o MyProg
    
MyProg.o: main.c
    gcc -c $< -o $@ $(LDFLAGS) $(LDLIBS) -D$(MODEALPHA)
    
modeAlpha.o: modeAlpha.c
    gcc -c $< -o $@ $(CFLAGS) $(LDLIBS) 

Now I know those files may feel weirds and the code is far from perfect, but remember I was trying to reproduce another error. Still, this is working well, generating .gcno file after compiling and then .gcda file after execution of the prog.

The problem appears when I add a "modeBeta". I will simply have a modeBeta.c, BetaFunctions.c and modeBeta.h, all exactly the same as the ones I gave here except that all occurences of the word "Alpha" are replaced with "Beta". You can see some commented lines in the main, related to this modeBeta thing; I uncomment them. And finally changed the makefile like this:

Makefile:

LDLIBS= -lpthread -lgcov
LDFLAGS= -Wall -pedantic -g -g3 -ggdb $(GCOVOPT)
CFLAGS= -c -Wall -pedantic -g -g3 -ggdb

OBJS=MyProg.o modeAlpha.o modeBeta.o
SRCS=main.c modeAlpha.c modeBeta.c

MODEALPHA=modeAlpha
MODEBETA=modeBeta
MODEGAMMA=modeGamma

MyProg: $(OBJS)
    gcc $(OBJS) $(LDFLAGS) $(LDLIBS) -o MyProg
    
MyProg.o: main.c
    gcc -c $< -o $@ $(LDFLAGS) $(LDLIBS) -D$(MODEALPHA) -D$(MODEBETA)
    
modeAlpha.o: modeAlpha.c
    gcc -c $< -o $@ $(CFLAGS) $(LDLIBS) 
    
modeBeta.o: modeBeta.c
    gcc -c $< -o $@ $(CFLAGS) $(LDLIBS) 

I still got the .gcno file, but no more .gcda after executing the prog. Note that if I don't call for any mode_XXX_Beta function in the main (like, if I don't uncomment the commented lines in main.c), then the gcda file is produced just as it should.

Any idea of what's going on here??

OS: i'm running on Win10 64bits with MinGW (winLib repo) and gcc 10.1.0.

Answer 1

I found out the problem: mode_free_Beta was freeing a not-allocated memory, which resulted in the end of the prog without any message error. So I thought it was running well, but didn't paid attention to the fact that I never reach mode_end_Beta.

Program ending unnaturally = no gcda file.

In this case, it can be corrected just with

char* MyText;
MyText=(char*) malloc(256);

If it happens to you, just make sure that your prog is running well until the end ;)