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[PATCH] Fix bogus fix-it for FLT_MAX (PR c/89122)
- From: David Malcolm <dmalcolm at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: David Malcolm <dmalcolm at redhat dot com>
- Date: Wed, 30 Jan 2019 18:58:53 -0500
- Subject: [PATCH] Fix bogus fix-it for FLT_MAX (PR c/89122)
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)
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