[M] Change in flashrom[master]: tests: Add prefix to io_mock functions not to clash with macros

[Felix Singer (Code Review)]

Attention is currently required from: Thomas Heijligen, Anastasia Klimchuk.

Felix Singer has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/68433 )

Change subject: tests: Add prefix to io_mock functions not to clash with macros
......................................................................

Patch Set 5:

(3 comments)

Commit Message:

https://review.coreboot.org/c/flashrom/+/68433/comment/2d813b15_5fee52ea 
PS5, Line 10: because the latter are allowed
            : to be macros. Adding a prefix to flashrom mock functions avoids
            : them being accidentally expanded. Standard I/O functions are
            : expanded and flashrom mocks stays as they are
I don't understand this yet. I have some questions:

* Why is it a problem that standard IO functions are macros?
* How does the prefix prevent that the flashrom mocks are expanded? I don't understand the relation between that function pointer and the standard I/O functions.
* Shouldn't undefining _FORTIFY_SOURCE solve that problem? In my understanding standard I/O functions are not expanded when _FORTIFY_SOURCE is undefined.

https://review.coreboot.org/c/flashrom/+/68433/comment/2731a9ce_9ca9658f 
PS5, Line 13: stays
typo: stay (without s)

File tests/io_mock.h:

https://review.coreboot.org/c/flashrom/+/68433/comment/4584ff5e_6e5b08c6 
PS5, Line 73: 	/* Port I/O */
            : 	void (*outb)(void *state, unsigned char value, unsigned short port);
            : 	unsigned char (*inb)(void *state, unsigned short port);
            : 
            : 	void (*outw)(void *state, unsigned short value, unsigned short port);
            : 	unsigned short (*inw)(void *state, unsigned short port);
            : 
            : 	void (*outl)(void *state, unsigned int value, unsigned short port);
            : 	unsigned int (*inl)(void *state, unsigned short port);
            : 
            : 	/* USB I/O */
            : 	int (*libusb_init)(void *state, libusb_context **ctx);
            : 	int (*libusb_control_transfer)(void *state,
            : 					libusb_device_handle *devh,
            : 					uint8_t bmRequestType,
            : 					uint8_t bRequest,
            : 					uint16_t wValue,
            : 					uint16_t wIndex,
            : 					unsigned char *data,
            : 					uint16_t wLength,
            : 					unsigned int timeout);
            : 	ssize_t (*libusb_get_device_list)(void *state, libusb_context *, libusb_device ***list);
            : 	void (*libusb_free_device_list)(void *state, libusb_device **list, int unref_devices);
            : 	int (*libusb_get_device_descriptor)(void *state, libusb_device *, struct libusb_device_descriptor *);
            : 	int (*libusb_get_config_descriptor)(void *state,
            : 						libusb_device *,
            : 						uint8_t config_index,
            : 						struct libusb_config_descriptor **);
            : 	void (*libusb_free_config_descriptor)(void *state, struct libusb_config_descriptor *);
I am wondering, should these functions be renamed as well?