| Message ID | 20190327184531.30986-10-julien.grall@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | xen/arm: Add support to build with clang | expand |
On Wed, 27 Mar 2019, Julien Grall wrote: > Clang 8.0 throws an error in the get_top_bit function: > > guest_walk.c:328:15: error: variable 'topbit' is used uninitialized > whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] > else if ( is_64bit_domain(d) ) > ^~~~~~~~~~~~~~~~~~ > > This is happening because clang thinks that is_32bit_domain(d) is not > the exact inverse of is_64bit_domain(d). So it expects a else case to > handle the case where the latter call is false. > > In other part of the code, dealing with difference between 32-bit and > 64-bit domain, we usually use if ( is_XXbit_domain ) ... else ... > > So use the same pattern here. > > Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> > --- > xen/arch/arm/guest_walk.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/xen/arch/arm/guest_walk.c b/xen/arch/arm/guest_walk.c > index 7db7a7321b..1bee198777 100644 > --- a/xen/arch/arm/guest_walk.c > +++ b/xen/arch/arm/guest_walk.c > @@ -325,7 +325,7 @@ static unsigned int get_top_bit(struct domain *d, vaddr_t gva, register_t tcr) > */ > if ( is_32bit_domain(d) ) > topbit = 31; > - else if ( is_64bit_domain(d) ) > + else > { > if ( ((gva & BIT_ULL(55)) && (tcr & TCR_EL1_TBI1)) || > (!(gva & BIT_ULL(55)) && (tcr & TCR_EL1_TBI0)) ) > -- > 2.11.0 >
diff --git a/xen/arch/arm/guest_walk.c b/xen/arch/arm/guest_walk.c index 7db7a7321b..1bee198777 100644 --- a/xen/arch/arm/guest_walk.c +++ b/xen/arch/arm/guest_walk.c @@ -325,7 +325,7 @@ static unsigned int get_top_bit(struct domain *d, vaddr_t gva, register_t tcr) */ if ( is_32bit_domain(d) ) topbit = 31; - else if ( is_64bit_domain(d) ) + else { if ( ((gva & BIT_ULL(55)) && (tcr & TCR_EL1_TBI1)) || (!(gva & BIT_ULL(55)) && (tcr & TCR_EL1_TBI0)) )
Clang 8.0 throws an error in the get_top_bit function: guest_walk.c:328:15: error: variable 'topbit' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] else if ( is_64bit_domain(d) ) ^~~~~~~~~~~~~~~~~~ This is happening because clang thinks that is_32bit_domain(d) is not the exact inverse of is_64bit_domain(d). So it expects a else case to handle the case where the latter call is false. In other part of the code, dealing with difference between 32-bit and 64-bit domain, we usually use if ( is_XXbit_domain ) ... else ... So use the same pattern here. Signed-off-by: Julien Grall <julien.grall@arm.com> --- xen/arch/arm/guest_walk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)