https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101551
--- Comment #2 from Thomas Schwinge <tschwinge at gcc dot gnu.org> ---
I've noticed that with an offloading-enabled build of GCC we're losing "note:
in expansion of macro '[...]'" diagnostics. (Effectively
'-ftrack-macro-expansion=0'?)
For example, 'libgomp.oacc-c-c++-common/vred2d-128.c' with '-fopenacc
-Wuninitialized' for a (default) GCC build without
'--enable-offload-targets=[...]':
[...]
[...]/libgomp.oacc-c-c++-common/vred2d-128.c: In function ‘test1’:
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:34:8: warning: ‘t1’ is used
uninitialized [-Wuninitialized]
34 | "acc loop vector reduction(+:t1) reduction(-:t2)")
| ^ ~
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:11:14: note: ‘t1’ was declared
here
11 | long i, j, t1, t2, t3; \
| ^~
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:33:1: note: in expansion of
macro ‘gentest’
33 | gentest (test1, "acc parallel loop gang vector_length (128)
firstprivate (t1, t2)",
| ^~~~~~~
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:34:8: warning: ‘t2’ is used
uninitialized [-Wuninitialized]
[...]
... vs. a GCC build with '--enable-offload-targets=[...]':
[...]
[...]/libgomp.oacc-c-c++-common/vred2d-128.c: In function ‘test1’:
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:34:8: warning: ‘t1’ is used
uninitialized [-Wuninitialized]
34 | "acc loop vector reduction(+:t1) reduction(-:t2)")
| ^ ~
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:11:14: note: ‘t1’ was declared
here
11 | long i, j, t1, t2, t3; \
| ^~
[...]/libgomp.oacc-c-c++-common/vred2d-128.c:34:8: warning: ‘t2’ is used
uninitialized [-Wuninitialized]
[...]
Note that an explicit '-foffload=disable' does not cure this.
