| Message ID | 20210507075329.GG1179226@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | libcpp: Fix up pragma preprocessing [PR100450] | expand |
On Fri, May 07, 2021 at 09:53:29AM +0200, Jakub Jelinek wrote: > Hi! > > Since the r0-85991-ga25a8f3be322fe0f838947b679f73d6efc2a412c > https://gcc.gnu.org/legacy-ml/gcc-patches/2008-02/msg01329.html > changes, so that we handle macros inside of pragmas that should expand > macros, during preprocessing we print those pragmas token by token, > with CPP_PRAGMA printed as > fputs ("#pragma ", print.outf); > if (space) > fprintf (print.outf, "%s %s", space, name); > else > fprintf (print.outf, "%s", name); > where name is some identifier (so e.g. print > #pragma omp parallel > or > #pragma omp for > etc.). Because it ends in an identifier, we need to handle it like > an identifier (i.e. CPP_NAME) for the decision whether a space needs > to be emitted in between that #pragma whatever or #pragma whatever whatever > and following token, otherwise the attached testcase is preprocessed as > #pragma omp forreduction(+:red) > rather than > #pragma omp for reduction(+:red) > The cpp_avoid_paste function is only called for this purpose. Nice explanation, it helped me to understand this. > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk > and release branches (in particular 8 which freezes later today)? OK. I don't think we'd ever want to actually concatenate in this context. > 2021-05-07 Jakub Jelinek <jakub@redhat.com> > > PR c/100450 > * lex.c (cpp_avoid_paste): Handle token1 CPP_PRAGMA like CPP_NAME. > > * c-c++-common/gomp/pr100450.c: New test. > > --- libcpp/lex.c.jj 2021-05-04 21:02:13.633917100 +0200 > +++ libcpp/lex.c 2021-05-06 20:32:07.695035739 +0200 > @@ -3709,6 +3709,7 @@ cpp_avoid_paste (cpp_reader *pfile, cons > case CPP_DEREF: return c == '*'; > case CPP_DOT: return c == '.' || c == '%' || b == CPP_NUMBER; > case CPP_HASH: return c == '#' || c == '%'; /* Digraph form. */ > + case CPP_PRAGMA: > case CPP_NAME: return ((b == CPP_NUMBER > && name_p (pfile, &token2->val.str)) > || b == CPP_NAME > --- gcc/testsuite/c-c++-common/gomp/pr100450.c.jj 2021-05-06 20:33:45.302961055 +0200 > +++ gcc/testsuite/c-c++-common/gomp/pr100450.c 2021-05-06 20:33:39.882020738 +0200 > @@ -0,0 +1,20 @@ > +/* PR c/100450 */ > +/* { dg-do compile } */ > +/* { dg-options "-fopenmp -save-temps -Wunknown-pragmas" } */ > + > +#define TEST(T) { \ > + {T} \ > +} > +#define CLAUSES reduction(+:red) > +#define PARALLEL_FOR(X) TEST({ \ > +_Pragma("omp for CLAUSES") \ > +X \ > +}) > + > +void foo() > +{ > + int red = 0; > + int A[3] = {}; > + #pragma omp parallel shared(red) > + PARALLEL_FOR( for(int i=0; i < 3; i++) red += A[i]; ) > +} > > Jakub > Marek
--- libcpp/lex.c.jj 2021-05-04 21:02:13.633917100 +0200 +++ libcpp/lex.c 2021-05-06 20:32:07.695035739 +0200 @@ -3709,6 +3709,7 @@ cpp_avoid_paste (cpp_reader *pfile, cons case CPP_DEREF: return c == '*'; case CPP_DOT: return c == '.' || c == '%' || b == CPP_NUMBER; case CPP_HASH: return c == '#' || c == '%'; /* Digraph form. */ + case CPP_PRAGMA: case CPP_NAME: return ((b == CPP_NUMBER && name_p (pfile, &token2->val.str)) || b == CPP_NAME --- gcc/testsuite/c-c++-common/gomp/pr100450.c.jj 2021-05-06 20:33:45.302961055 +0200 +++ gcc/testsuite/c-c++-common/gomp/pr100450.c 2021-05-06 20:33:39.882020738 +0200 @@ -0,0 +1,20 @@ +/* PR c/100450 */ +/* { dg-do compile } */ +/* { dg-options "-fopenmp -save-temps -Wunknown-pragmas" } */ + +#define TEST(T) { \ + {T} \ +} +#define CLAUSES reduction(+:red) +#define PARALLEL_FOR(X) TEST({ \ +_Pragma("omp for CLAUSES") \ +X \ +}) + +void foo() +{ + int red = 0; + int A[3] = {}; + #pragma omp parallel shared(red) + PARALLEL_FOR( for(int i=0; i < 3; i++) red += A[i]; ) +}
Hi! Since the r0-85991-ga25a8f3be322fe0f838947b679f73d6efc2a412c https://gcc.gnu.org/legacy-ml/gcc-patches/2008-02/msg01329.html changes, so that we handle macros inside of pragmas that should expand macros, during preprocessing we print those pragmas token by token, with CPP_PRAGMA printed as fputs ("#pragma ", print.outf); if (space) fprintf (print.outf, "%s %s", space, name); else fprintf (print.outf, "%s", name); where name is some identifier (so e.g. print #pragma omp parallel or #pragma omp for etc.). Because it ends in an identifier, we need to handle it like an identifier (i.e. CPP_NAME) for the decision whether a space needs to be emitted in between that #pragma whatever or #pragma whatever whatever and following token, otherwise the attached testcase is preprocessed as #pragma omp forreduction(+:red) rather than #pragma omp for reduction(+:red) The cpp_avoid_paste function is only called for this purpose. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk and release branches (in particular 8 which freezes later today)? 2021-05-07 Jakub Jelinek <jakub@redhat.com> PR c/100450 * lex.c (cpp_avoid_paste): Handle token1 CPP_PRAGMA like CPP_NAME. * c-c++-common/gomp/pr100450.c: New test. Jakub