Thanks for the help! I’ll definitely start using -Wall. I don’t know why I don’t do it by default…

Wow that’s cool. I had no idea GCC did stuff like this.

Awesome, thank you so much!

How do you use fanalyzer? I’m passing it as a build option in GCC, assuming that it’ll alert me of any issues on either compile or runtime.

I tried -fsanitize=undefined and -fsanitize=unreachable with no luck. Are there other appropriate sanitizers I’m missing?

Only a file that doesn’t change between runs. I posted a copy of the full source code in a different post here in this thread. It’s been minimised down to 105 lines. Still can’t figure out where the bug is.

I’ll try your suggestion though, thank you!

Thanks for the suggestion! I managed to squish the program down into 105 lines. This is my MRE.

#include<stdlib.h>
#include<confuse.h>

struct entry
	{
	int Day;
	long int Date;
	float C;
	float F;
	float P;
	float L;
	};

int DiaryNum;
struct entry  *Diary;
char DiaryPath[] = "/home/lofenyy/.config/Calorimeter/Diary";

cfg_opt_t entry_opts[] = 
	{
	CFG_INT("Date", 0, CFGF_NONE),
	CFG_INT("Day", 0, CFGF_NONE),
	CFG_FLOAT("C", 0, CFGF_NONE),
	CFG_FLOAT("F", 0, CFGF_NONE),
	CFG_FLOAT("P", 0, CFGF_NONE),
	CFG_FLOAT("L", 0, CFGF_NONE),
	CFG_END()
	};

cfg_opt_t entry_base_opts[] =
	{
	CFG_SEC("Entry", entry_opts, CFGF_MULTI),
	CFG_END()
	};

int lodEntry()
	{
	//Initialization
	cfg_t *cfg;
	cfg_t *cfg_entry;
	cfg = cfg_init(entry_base_opts, CFGF_NONE);
	
	//Open our file and check for errors
	if(cfg_parse(cfg, DiaryPath) == CFG_PARSE_ERROR)
		printf("Err!\n");
	
	//Allocate enough memory for our internal diary
	DiaryNum = cfg_size(cfg, "Entry");
	Diary = malloc(DiaryNum * sizeof(struct entry));	
	
	//For every entry in our external diary
	for(int C = 0;C < cfg_size(cfg, "Entry");C++)
		{
		//Copy our entries to our internal diary
		cfg_entry = cfg_getnsec(cfg, "Entry", C);
		Diary[C].Date	= cfg_getint(cfg_entry, "Date");
		Diary[C].Day	= cfg_getint(cfg_entry, "Day");
		Diary[C].C	= cfg_getfloat(cfg_entry, "C");
		Diary[C].F	= cfg_getfloat(cfg_entry, "F");
		Diary[C].P	= cfg_getfloat(cfg_entry, "P");
		Diary[C].L	= cfg_getfloat(cfg_entry, "L");
		}
	
	cfg_free(cfg);
	}

double getEntryCalories(int C)
	{
	//4 calories per carb and protein. 9 per lipid. 
	return 4*(Diary[C].C+Diary[C].P)+9*(Diary[C].L);
	}

int prnStats()
	{
	float C,F,P,L,Calories = 0;
	int day0 = Diary[0].Day;
	int day1 = Diary[DiaryNum -1].Day;
	int days = (day1 - day0) +1;
	
	//For every diary entry
	for(int i = 0;i < DiaryNum;i++)
		{
		//Count up our nutrients
		C = C + Diary[i].C;
		F = F + Diary[i].F;
		P = P + Diary[i].P;
		L = L + Diary[i].L;
		Calories = Calories + getEntryCalories(i);
		}
	
	//Print them out
	printf("Average Calories: %2.2f\n", (float)(Calories/days));
	printf("Average Carbs: %2.2f\n", (float)(C/days));
	printf("Average Fibre: %2.2f\n", (float)(F/days));
	printf("Average Proteins: %2.2f\n", (float)(P/days));
	printf("Average Lipids: %2.2f\n", (float)(L/days));
	}

int main(int argc, char  *argv[])
	{
	// Load our internal food diary from our external food diary
	// print out our statistics
	lodEntry();
	prnStats();
	}

This is the contents of Diary

Entry
{
	Date = 1679542784
	Day = 0
	C = 6.000000
	F = 5.000000
	P = 4.000000
	L = 3.000000
}

Entry
{
	Date = 1679546112
	Day = 0
	C = 60.000000
	F = 50.000000
	P = 20.000000
	L = 1.000000
}

Entry
{
	Date = 1679547008
	Day = 0
	C = 4.000000
	F = 4.000000
	P = 4.000000
	L = 4.000000
}

Entry
{
	Date = 1679547136
	Day = 1
	C = 4.000000
	F = 4.000000
	P = 4.000000
	L = 4.000000
}

Entry
{
	Date = 1679547136
	Day = 5
	C = 60.000000
	F = 50.000000
	P = 20.000000
	L = 1.000000
}

Is this likely the case if the program runs only in a single thread?