#pragma pack(1) breaks Function Return Value Sequences

[alexsconway]

Describe the bug
I'm using Ceedling with Unity and FFF to unit test some embedded code.
To make some things work I need to specify #pragma pack(1) for some structures.
I was trying to mock a sequence of return values for a function and the results were not as expected.
Some hours later I have trimmed it down to a minimal reproduction case:

To Reproduce
make sure you have Ceedling and FFF set up etc... This was on Windows 10 with MinGW
Unzip the TestFFFseq.zip, start a command prompt in the TestFFFseq folder and run
ceedling test:all

the result will be

FAILED TEST SUMMARY

[test_FFFseq.c]
Test: test_One
At line (28): "Expected 1 Was 0"

OVERALL TEST SUMMARY

TESTED: 1
PASSED: 0
FAILED: 1
IGNORED: 0

Expected behavior

OVERALL TEST SUMMARY

TESTED: 1
PASSED: 1
FAILED: 0
IGNORED: 0

Compiler, toolset, platform (please complete the following information):

• Windows 10 Home
• MinGW, Ceedling 0.31.1, latest FFF (Feb 2022)

If one comments out the #pragma pack(1) on line 3 of test_FFFseq.c then the test passes.

I tried but couldn't reproduce without Ceedling generating the fake.

This can be avoided by using #pragma pack(push, 1) and #pragma pack(pop) where one needs it in one's code

TestFFFseq.zip

[samthode]

Thanks for posting this. Just spent 5 hours debugging a non sense issue. Turns out it was b/c pragma pack