[PATCH] Fix GDBHISTSIZE test failure on i686

Patrick Palka
2015-06-23T14:31:07Z

The test

test_histsize_history_setting "99999999999999999999999999999999999" "unlimited"

was failing on i686 because the condition in init_history() for
determining whether to map a large GDBHISTSIZE value to infinity was

long var = strtol (tmpenv);
if (var > INT_MAX)
history_size = unlimited;

but this condition is never true on i686 because INT_MAX == LONG_MAX.
So in order to properly map large out-of-range values of GDBHISTSIZE to
infinity on targets where LONG_MAX > INT_MAX as well as on i686, we have
to instead change the above condition to

if (var > INT_MAX
|| (var == INT_MAX && errno == ERANGE))
history_size = unlimited;

[ I did not test this patch on i686 because I don't have access to
such a machine. But the patch seems straightforward enough... ]

gdb/ChangeLog:

* top.c (init_history): Look at the errno set by strtol to
properly map large GDBHISTSIZE values to infinity.
---
gdb/top.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/gdb/top.c b/gdb/top.c
index 5114c2e..afb14be 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -1734,10 +1734,12 @@ init_history (void)
if (tmpenv)
{
long var;
+ int saved_errno;
char *endptr;

tmpenv = skip_spaces (tmpenv);
var = strtol (tmpenv, &endptr, 10);
+ saved_errno = errno;
endptr = skip_spaces (endptr);

/* If GDBHISTSIZE is non-numeric then ignore it. If GDBHISTSIZE is the
@@ -1749,7 +1751,12 @@ init_history (void)
;
else if (*tmpenv == '\0'
|| var < 0
- || var > INT_MAX)
+ || var > INT_MAX
+ /* On targets where INT_MAX == LONG_MAX, we have to look at
+ the errno set by strtol to distinguish between a value that
+ is exactly INT_MAX and an overflowing value that was clamped
+ to INT_MAX. */
+ || (var == INT_MAX && saved_errno == ERANGE))
history_size_setshow_var = -1;
else
history_size_setshow_var = var;
--
2.4.4.410.g43ed522.dirty