On Thu, Jan 31, 2019 at 12:09 AM David Malcolm <dmalc...@redhat.com> wrote:
>
> PR c/89122 reports that we emit a bogus fix-it hint for the case where
> the code uses FLT_MAX, but has included <limits.h> rather than <float.h>:
>
> x.c:3:11: error: 'FLT_MAX' undeclared here (not in a function); did you
> mean 'INT_MAX'?
> 3 | float f = FLT_MAX;
> | ^~~~~~~
> | INT_MAX
>
> This patch adds some knowledge of <float.h> (and <cfloat>) to
> known-headers.cc, fixing the issue:
>
> x.c:3:11: error: 'FLT_MAX' undeclared here (not in a function)
> 3 | float f = FLT_MAX;
> | ^~~~~~~
> x.c:2:1: note: 'FLT_MAX' is defined in header '<float.h>'; did you forget
> to '#include <float.h>'?
> 1 | #include <limits.h>
> +++ |+#include <float.h>
> 2 |
>
> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
>
> Is this OK for trunk in stage 4? (presumably very low risk)
What does it not say for
int i = FLT_MAX;
? Hopefully it doesn't suggest to include float.h but suggests
to include limits.h and INT_MAX?
> gcc/c-family/ChangeLog:
> PR c/89122
> * known-headers.cc (get_stdlib_header_for_name): Add
> {FLT|DBL|LDBL}_{MAX|MIN} to "hints" array.
>
> gcc/testsuite/ChangeLog:
> PR c/89122
> * g++.dg/spellcheck-stdlib.C (test_FLT_MAX): New test.
> * gcc.dg/spellcheck-stdlib.c (test_FLT_MAX): New test.
> ---
> gcc/c-family/known-headers.cc | 8 ++++++++
> gcc/testsuite/g++.dg/spellcheck-stdlib.C | 5 +++++
> gcc/testsuite/gcc.dg/spellcheck-stdlib.c | 5 +++++
> 3 files changed, 18 insertions(+)
>
> diff --git a/gcc/c-family/known-headers.cc b/gcc/c-family/known-headers.cc
> index e3dcf73..c222f30 100644
> --- a/gcc/c-family/known-headers.cc
> +++ b/gcc/c-family/known-headers.cc
> @@ -84,6 +84,14 @@ get_stdlib_header_for_name (const char *name, enum stdlib
> lib)
> {"ULONG_MAX", {"<limits.h>", "<climits>"} },
> {"USHRT_MAX", {"<limits.h>", "<climits>"} },
>
> + /* <float.h> and <cfloat>. */
> + {"DBL_MAX", {"<float.h>", "<cfloat>"} },
> + {"DBL_MIN", {"<float.h>", "<cfloat>"} },
> + {"FLT_MAX", {"<float.h>", "<cfloat>"} },
> + {"FLT_MIN", {"<float.h>", "<cfloat>"} },
> + {"LDBL_MAX", {"<float.h>", "<cfloat>"} },
> + {"LDBL_MIN", {"<float.h>", "<cfloat>"} },
> +
> /* <stdarg.h> and <cstdarg>. */
> {"va_list", {"<stdarg.h>", "<cstdarg>"} },
>
> diff --git a/gcc/testsuite/g++.dg/spellcheck-stdlib.C
> b/gcc/testsuite/g++.dg/spellcheck-stdlib.C
> index 11a4e3e..31e91fe 100644
> --- a/gcc/testsuite/g++.dg/spellcheck-stdlib.C
> +++ b/gcc/testsuite/g++.dg/spellcheck-stdlib.C
> @@ -77,6 +77,11 @@ int test_INT_MAX (void)
> // { dg-message "'INT_MAX' is defined in header '<climits>'; did you
> forget to '#include <climits>'?" "" { target *-*-* } INT_MAX_line }
> }
>
> +/* Missing <cfloat>. */
> +float test_FLT_MAX = FLT_MAX; // { dg-line FLT_MAX_line }
> +// { dg-error "'FLT_MAX' was not declared" "" { target *-*-* } FLT_MAX_line }
> +// { dg-message "'FLT_MAX' is defined in header '<cfloat>'; did you forget
> to '#include <cfloat>'?" "" { target *-*-* } FLT_MAX_line }
> +
> /* Missing <cstring>. */
>
> void test_cstring (char *dest, char *src)
> diff --git a/gcc/testsuite/gcc.dg/spellcheck-stdlib.c
> b/gcc/testsuite/gcc.dg/spellcheck-stdlib.c
> index 7474c9a..1ae3b5e 100644
> --- a/gcc/testsuite/gcc.dg/spellcheck-stdlib.c
> +++ b/gcc/testsuite/gcc.dg/spellcheck-stdlib.c
> @@ -62,3 +62,8 @@ int test_INT_MAX (void)
> /* { dg-bogus "__INT_MAX__" "" { target *-*-* } INT_MAX_line } */
> /* { dg-message "'INT_MAX' is defined in header '<limits.h>'; did you
> forget to '#include <limits.h>'?" "" { target *-*-* } INT_MAX_line } */
> }
> +
> +/* Missing <float.h>. */
> +float test_FLT_MAX = FLT_MAX; /* { dg-line FLT_MAX_line } */
> +/* { dg-error "'FLT_MAX' undeclared" "" { target *-*-* } FLT_MAX_line } */
> +/* { dg-message "'FLT_MAX' is defined in header '<float.h>'; did you forget
> to '#include <float.h>'?" "" { target *-*-* } FLT_MAX_line } */
> --
> 1.8.5.3
>
