Let's start with an example, I think this will show the problem that I am dealing with immediately. This is a simple test program, far from realistic, but it illustrates the problem very well.
1 #include <stdio.h>
2 #include <stdlib.h>
3
4 struct first {
5 int i_value;
6 };
7
8 struct second {
9 float f_value;
10 };
11
12 #define DEFINE_FUNCTION(type, struct_name, field_name) \
13 void my_ ## type ## _function(struct struct_name *object, type value) \
14 { \
15 /* Deliberately read an uninitialized value to make valgrind */ \
16 /* report the issue */ \
17 if (object->field_name == -1) \
18 return; \
19 object->field_name = value; \
20 }
21
22 DEFINE_FUNCTION(int, first, i_value);
23 DEFINE_FUNCTION(float, second, f_value);
24
25 void
26 my_test_function(struct first *object, int value)
27 {
28 /* Deliberately read an uninitialized value to make valgrind */
29 /* report the issue */
30 if (object->i_value == -1)
31 return;
32 object->i_value = value;
33 }
34
35 int
36 main(void)
37 {
38 struct first frst;
39 struct second scnd;
40
41 my_test_function(&frst, -5);
42 my_int_function(&frst, -2);
43 my_float_function(&scnd, 3.0);
44
45 return 0;
46 }
If you compile this code and use
valgrind --show-origins=yes ./compiled-program
you will see the exit
==25304== Memcheck, a memory error detector
==25304== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==25304== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==25304== Command: ./macro-valgrind
==25304==
==25304== Conditional jump or move depends on uninitialised value(s)
==25304== at 0x40056F: my_test_function (macro-valgrind.c:30)
==25304== by 0x400597: main (macro-valgrind.c:41)
==25304== Uninitialised value was created by a stack allocation
==25304== at 0x40057F: main (macro-valgrind.c:37)
==25304==
==25304== Conditional jump or move depends on uninitialised value(s)
==25304== at 0x40053A: my_float_function (macro-valgrind.c:23)
==25304== by 0x4005BC: main (macro-valgrind.c:43)
==25304== Uninitialised value was created by a stack allocation
==25304== at 0x40057F: main (macro-valgrind.c:37)
==25304==
==25304== Conditional jump or move depends on uninitialised value(s)
==25304== at 0x400547: my_float_function (macro-valgrind.c:23)
==25304== by 0x4005BC: main (macro-valgrind.c:43)
==25304== Uninitialised value was created by a stack allocation
==25304== at 0x40057F: main (macro-valgrind.c:37)
==25304==
==25304==
==25304== HEAP SUMMARY:
==25304== in use at exit: 0 bytes in 0 blocks
==25304== total heap usage: 0 allocs, 0 frees, 0 bytes allocated
==25304==
==25304== All heap blocks were freed -- no leaks are possible
==25304==
==25304== For counts of detected and suppressed errors, rerun with: -v
==25304== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)
As you can see in valgrind's output above, the first uninitialized read message is described from a function my_test_function(), and it displays the exact line where the problem occurred. Thus, it is quite easy to fix the code. It is impossible to understand other reports. The best thing you can do with them is to know what function was, but that's all.
I understand that the generated code is confusing valgrind and why my actual question is: