Re: [PATCH 1/2] Fix new -Wparentheses warnings encountered during bootstrap

[Patrick Palka <patrick at parcs dot ath dot cx>]

On Thu, 31 Mar 2016, Bernd Schmidt wrote:

> On 03/31/2016 10:53 PM, Patrick Palka wrote:
> > This patch fixes the new -Wparentheses warnings (implemented by the
> > subsequent patch) that are encountered during bootstrap:
> > 
> > /home/patrick/code/gcc/gcc/omp-low.c: In function âvoid
> > scan_sharing_clauses(tree, omp_context*, bool)â:
> > /home/patrick/code/gcc/gcc/omp-low.c:2381:6: error: suggest explicit braces
> > to avoid ambiguous âelseâ [-Werror=parentheses]
> >     if (scan_array_reductions)
> >        ^
> > /home/patrick/code/gcc/gcc/gimplify.c: In function âgimple*
> > gimplify_omp_ordered(tree, gimple_seq)â:
> > /home/patrick/code/gcc/gcc/gimplify.c:9880:6: error: suggest explicit braces
> > to avoid ambiguous âelseâ [-Werror=parentheses]
> >     if (gimplify_omp_ctxp)
> >        ^
> > In file included from /home/patrick/code/gcc/gcc/cp/optimize.c:25:0:
> > /home/patrick/code/gcc/gcc/cp/optimize.c: In function âvoid
> > populate_clone_array(tree, tree_node**)â:
> > /home/patrick/code/gcc/gcc/cp/cp-tree.h:2529:6: error: suggest explicit
> > braces to avoid ambiguous âelseâ [-Werror=parentheses]
> >     if (TREE_CODE (FN) == FUNCTION_DECL   \
> >        ^
> > /home/patrick/code/gcc/gcc/cp/optimize.c:222:3: note: in expansion of macro
> > âFOR_EACH_CLONEâ
> >     FOR_EACH_CLONE (clone, fn)
> >     ^~~~~~~~~~~~~~
> > /home/patrick/code/gcc/gcc/fortran/openmp.c: In function âgfc_omp_udr*
> > gfc_find_omp_udr(gfc_namespace*, const char*, gfc_typespec*)â:
> > /home/patrick/code/gcc/gcc/fortran/openmp.c:177:10: error: suggest explicit
> > braces to avoid ambiguous âelseâ [-Werror=parentheses]
> >         if (st != NULL)
> >            ^
> > 
> > In each case I think the warning is harmless since the indentation of
> > the code in question corresponds to how the "else" is actually parsed
> > so I fixed each case simply by enclosing the entire body of the outer
> > "if" in braces.
> > 
> > The FOR_EACH_CLONE change resolves the cp/optimize.c warning.  It
> > adjusts the layout of the macro from
> > 
> >    if (p)
> >      for (...)
> > 
> > to
> > 
> >    if (!p)
> >      ;
> >    else for (...)
> > 
> > so that an "else" encountered in the body of the for-statement can no
> > longer possibly bind to the outer "if (p)" conditional.
> > 
> > Is this OK to commit after bootstrap + regtesting?
> 
> I think this is OK, now or in stage1 depending on whether the warning
> improvements go in now or later.
> 
> I see a patch for the C++ side fixing the warning, do you also intend to do C?
> 
> 
> Bernd
> 
> 

I hope someone else could do it since I'm not very familiar with the C
parser :)  I think Marek said he would take care of it.