[cfe-dev] How to refer to linker script symbols?

Anton Blanchard anton at samba.org
Mon Nov 3 16:07:37 PST 2014


The Linux kernel makes extensive use of linker script symbols indicating
the start and end of section. An example:

extern const char *__start___trace_bprintk_fmt[];
extern const char *__stop___trace_bprintk_fmt[];

int foo(void)
	return __stop___trace_bprintk_fmt != __start___trace_bprintk_fmt;

Clang assumes these two symbols can't alias, emits a warning and optimises
the comparison away:

foo.c:6:36: warning: array comparison always evaluates to true


	li 3, 1

In this particular case the section is empty, so the two symbols do
point to the same address. Any thoughts on the best way to solve this? 


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