On Tue, Jun 11, 2024 at 12:22 PM Nathan Bossart <nathandboss...@gmail.com>
wrote:
> I personally find that much easier to read. Since the existing
open-coded
> overflow check is apparently insufficient, I think there's a reasonably
> strong case for centralizing this sort of thing so that we don't
continue
> to make the same mistakes.
Sounds good, the attached patch has these changes.
> tm2timestamp() in src/interfaces/ecpg/pgtypeslib/timestamp.c has the
same
> comment. The code there looks very similar to the code for
tm2timestamp()
> in the other timestamp.c...
The attached patch has updated this file too. For some reason I was
under the impression that I should leave the ecpg/ files alone, though
I can't remember why.
Thanks,
Joe Koshakow
From adcf89561cec31499754a7c04da50c408a12724a Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <kosh...@gmail.com>
Date: Sat, 8 Jun 2024 22:16:46 -0400
Subject: [PATCH] Remove dependence on integer wrapping
This commit updates various parts of the code to no longer rely on
integer wrapping for correctness. Not all compilers support -fwrapv, so
it's best not to rely on it.
---
src/backend/utils/adt/cash.c | 7 +-
src/backend/utils/adt/numeric.c | 5 +-
src/backend/utils/adt/numutils.c | 34 ++++---
src/backend/utils/adt/timestamp.c | 28 +-----
src/include/common/int.h | 105 +++++++++++++++++++++
src/interfaces/ecpg/pgtypeslib/timestamp.c | 11 +--
src/test/regress/expected/timestamp.out | 13 +++
src/test/regress/expected/timestamptz.out | 13 +++
src/test/regress/sql/timestamp.sql | 4 +
src/test/regress/sql/timestamptz.sql | 4 +
10 files changed, 169 insertions(+), 55 deletions(-)
diff --git a/src/backend/utils/adt/cash.c b/src/backend/utils/adt/cash.c
index 32fbad2f57..f6f095a57b 100644
--- a/src/backend/utils/adt/cash.c
+++ b/src/backend/utils/adt/cash.c
@@ -352,8 +352,11 @@ cash_out(PG_FUNCTION_ARGS)
if (value < 0)
{
- /* make the amount positive for digit-reconstruction loop */
- value = -value;
+ /*
+ * make the amount positive for digit-reconstruction loop, we can
+ * leave INT64_MIN unchanged
+ */
+ pg_neg_s64_overflow(value, &value);
/* set up formatting data */
signsymbol = (*lconvert->negative_sign != '\0') ? lconvert->negative_sign : "-";
sign_posn = lconvert->n_sign_posn;
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 5510a203b0..4ea2d9b0b4 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -8110,15 +8110,14 @@ int64_to_numericvar(int64 val, NumericVar *var)
/* int64 can require at most 19 decimal digits; add one for safety */
alloc_var(var, 20 / DEC_DIGITS);
+ uval = pg_abs_s64(val);
if (val < 0)
{
var->sign = NUMERIC_NEG;
- uval = -val;
}
else
{
var->sign = NUMERIC_POS;
- uval = val;
}
var->dscale = 0;
if (val == 0)
@@ -11222,7 +11221,7 @@ power_var_int(const NumericVar *base, int exp, int exp_dscale,
* Now we can proceed with the multiplications.
*/
neg = (exp < 0);
- mask = abs(exp);
+ mask = pg_abs_s32(exp);
init_var(&base_prod);
set_var_from_var(base, &base_prod);
diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c
index adc1e8a4cb..a3d7d6bf01 100644
--- a/src/backend/utils/adt/numutils.c
+++ b/src/backend/utils/adt/numutils.c
@@ -18,6 +18,7 @@
#include <limits.h>
#include <ctype.h>
+#include "common/int.h"
#include "port/pg_bitutils.h"
#include "utils/builtins.h"
@@ -131,6 +132,7 @@ pg_strtoint16_safe(const char *s, Node *escontext)
uint16 tmp = 0;
bool neg = false;
unsigned char digit;
+ int16 result;
/*
* The majority of cases are likely to be base-10 digits without any
@@ -190,10 +192,9 @@ pg_strtoint16_safe(const char *s, Node *escontext)
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (unlikely(tmp > (uint16) (-(PG_INT16_MIN + 1)) + 1))
+ if (pg_neg_u16_overflow(tmp, &result))
goto out_of_range;
- return -((int16) tmp);
+ return result;
}
if (unlikely(tmp > PG_INT16_MAX))
@@ -333,10 +334,9 @@ slow:
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (tmp > (uint16) (-(PG_INT16_MIN + 1)) + 1)
+ if (pg_neg_u16_overflow(tmp, &result))
goto out_of_range;
- return -((int16) tmp);
+ return result;
}
if (tmp > PG_INT16_MAX)
@@ -393,6 +393,7 @@ pg_strtoint32_safe(const char *s, Node *escontext)
uint32 tmp = 0;
bool neg = false;
unsigned char digit;
+ int32 result;
/*
* The majority of cases are likely to be base-10 digits without any
@@ -452,10 +453,9 @@ pg_strtoint32_safe(const char *s, Node *escontext)
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (unlikely(tmp > (uint32) (-(PG_INT32_MIN + 1)) + 1))
+ if (pg_neg_u32_overflow(tmp, &result))
goto out_of_range;
- return -((int32) tmp);
+ return result;
}
if (unlikely(tmp > PG_INT32_MAX))
@@ -595,10 +595,9 @@ slow:
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (tmp > (uint32) (-(PG_INT32_MIN + 1)) + 1)
+ if (pg_neg_u32_overflow(tmp, &result))
goto out_of_range;
- return -((int32) tmp);
+ return result;
}
if (tmp > PG_INT32_MAX)
@@ -655,6 +654,7 @@ pg_strtoint64_safe(const char *s, Node *escontext)
uint64 tmp = 0;
bool neg = false;
unsigned char digit;
+ int64 result;
/*
* The majority of cases are likely to be base-10 digits without any
@@ -714,10 +714,9 @@ pg_strtoint64_safe(const char *s, Node *escontext)
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (unlikely(tmp > (uint64) (-(PG_INT64_MIN + 1)) + 1))
+ if (pg_neg_u64_overflow(tmp, &result))
goto out_of_range;
- return -((int64) tmp);
+ return result;
}
if (unlikely(tmp > PG_INT64_MAX))
@@ -857,10 +856,9 @@ slow:
if (neg)
{
- /* check the negative equivalent will fit without overflowing */
- if (tmp > (uint64) (-(PG_INT64_MIN + 1)) + 1)
+ if (pg_neg_u64_overflow(tmp, &result))
goto out_of_range;
- return -((int64) tmp);
+ return result;
}
if (tmp > PG_INT64_MAX)
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index e4715605a2..c419c46540 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -617,19 +617,8 @@ make_timestamp_internal(int year, int month, int day,
time = (((hour * MINS_PER_HOUR + min) * SECS_PER_MINUTE)
* USECS_PER_SEC) + (int64) rint(sec * USECS_PER_SEC);
- result = date * USECS_PER_DAY + time;
- /* check for major overflow */
- if ((result - time) / USECS_PER_DAY != date)
- ereport(ERROR,
- (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
- errmsg("timestamp out of range: %d-%02d-%02d %d:%02d:%02g",
- year, month, day,
- hour, min, sec)));
-
- /* check for just-barely overflow (okay except time-of-day wraps) */
- /* caution: we want to allow 1999-12-31 24:00:00 */
- if ((result < 0 && date > 0) ||
- (result > 0 && date < -1))
+ if (pg_mul_s64_overflow(date, USECS_PER_DAY, &result) ||
+ pg_add_s64_overflow(result, time, &result))
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range: %d-%02d-%02d %d:%02d:%02g",
@@ -2009,17 +1998,8 @@ tm2timestamp(struct pg_tm *tm, fsec_t fsec, int *tzp, Timestamp *result)
date = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - POSTGRES_EPOCH_JDATE;
time = time2t(tm->tm_hour, tm->tm_min, tm->tm_sec, fsec);
- *result = date * USECS_PER_DAY + time;
- /* check for major overflow */
- if ((*result - time) / USECS_PER_DAY != date)
- {
- *result = 0; /* keep compiler quiet */
- return -1;
- }
- /* check for just-barely overflow (okay except time-of-day wraps) */
- /* caution: we want to allow 1999-12-31 24:00:00 */
- if ((*result < 0 && date > 0) ||
- (*result > 0 && date < -1))
+ if (pg_mul_s64_overflow(date, USECS_PER_DAY, result) ||
+ pg_add_s64_overflow(*result, time, result))
{
*result = 0; /* keep compiler quiet */
return -1;
diff --git a/src/include/common/int.h b/src/include/common/int.h
index 7fc046e78a..3065d586d4 100644
--- a/src/include/common/int.h
+++ b/src/include/common/int.h
@@ -154,6 +154,23 @@ pg_mul_s32_overflow(int32 a, int32 b, int32 *result)
#endif
}
+static inline uint32
+pg_abs_s32(int32 a)
+{
+ if (unlikely(a == PG_INT32_MIN))
+ {
+ return ((uint32) PG_INT32_MAX) + 1;
+ }
+ else if (a < 0)
+ {
+ return (uint32) -a;
+ }
+ else
+ {
+ return (uint32) a;
+ }
+}
+
/*
* INT64
*/
@@ -258,6 +275,37 @@ pg_mul_s64_overflow(int64 a, int64 b, int64 *result)
#endif
}
+static inline bool
+pg_neg_s64_overflow(int64 a, int64 *result)
+{
+ if (unlikely(a == PG_INT64_MIN))
+ {
+ return true;
+ }
+ else
+ {
+ *result = -a;
+ return false;
+ }
+}
+
+static inline uint64
+pg_abs_s64(int64 a)
+{
+ if (unlikely(a == PG_INT64_MIN))
+ {
+ return ((uint64) PG_INT64_MAX) + 1;
+ }
+ else if (a < 0)
+ {
+ return (uint64) -a;
+ }
+ else
+ {
+ return (uint64) a;
+ }
+}
+
/*------------------------------------------------------------------------
* Overflow routines for unsigned integers
*------------------------------------------------------------------------
@@ -318,6 +366,25 @@ pg_mul_u16_overflow(uint16 a, uint16 b, uint16 *result)
#endif
}
+static inline bool
+pg_neg_u16_overflow(uint16 a, int16 *result)
+{
+ if (unlikely(a > ((uint16) PG_INT16_MAX) + 1))
+ {
+ return true;
+ }
+ else if (unlikely(a == ((uint16) PG_INT16_MAX) + 1))
+ {
+ *result = PG_INT16_MIN;
+ return false;
+ }
+ else
+ {
+ *result = -((int16) a);
+ return false;
+ }
+}
+
/*
* INT32
*/
@@ -373,6 +440,25 @@ pg_mul_u32_overflow(uint32 a, uint32 b, uint32 *result)
#endif
}
+static inline bool
+pg_neg_u32_overflow(uint32 a, int32 *result)
+{
+ if (unlikely(a > ((uint32) PG_INT32_MAX) + 1))
+ {
+ return true;
+ }
+ else if (unlikely(a == ((uint32) PG_INT32_MAX) + 1))
+ {
+ *result = PG_INT32_MIN;
+ return false;
+ }
+ else
+ {
+ *result = -((int32) a);
+ return false;
+ }
+}
+
/*
* UINT64
*/
@@ -438,6 +524,25 @@ pg_mul_u64_overflow(uint64 a, uint64 b, uint64 *result)
#endif
}
+static inline bool
+pg_neg_u64_overflow(uint64 a, int64 *result)
+{
+ if (unlikely(a > ((uint64) PG_INT64_MAX) + 1))
+ {
+ return true;
+ }
+ else if (unlikely(a == ((uint64) PG_INT64_MAX) + 1))
+ {
+ *result = PG_INT64_MIN;
+ return false;
+ }
+ else
+ {
+ *result = -((int64) a);
+ return false;
+ }
+}
+
/*------------------------------------------------------------------------
*
* Comparison routines for integer types.
diff --git a/src/interfaces/ecpg/pgtypeslib/timestamp.c b/src/interfaces/ecpg/pgtypeslib/timestamp.c
index f1b143fbd2..93d4cc323d 100644
--- a/src/interfaces/ecpg/pgtypeslib/timestamp.c
+++ b/src/interfaces/ecpg/pgtypeslib/timestamp.c
@@ -11,6 +11,7 @@
#error -ffast-math is known to break this code
#endif
+#include "common/int.h"
#include "dt.h"
#include "pgtypes_date.h"
#include "pgtypes_timestamp.h"
@@ -48,14 +49,8 @@ tm2timestamp(struct tm *tm, fsec_t fsec, int *tzp, timestamp * result)
dDate = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) - date2j(2000, 1, 1);
time = time2t(tm->tm_hour, tm->tm_min, tm->tm_sec, fsec);
- *result = (dDate * USECS_PER_DAY) + time;
- /* check for major overflow */
- if ((*result - time) / USECS_PER_DAY != dDate)
- return -1;
- /* check for just-barely overflow (okay except time-of-day wraps) */
- /* caution: we want to allow 1999-12-31 24:00:00 */
- if ((*result < 0 && dDate > 0) ||
- (*result > 0 && dDate < -1))
+ if (pg_mul_s64_overflow(dDate, USECS_PER_DAY, result) ||
+ pg_add_s64_overflow(*result, time, result))
return -1;
if (tzp != NULL)
*result = dt2local(*result, -(*tzp));
diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index cf337da517..e287260051 100644
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -2201,3 +2201,16 @@ select age(timestamp '-infinity', timestamp 'infinity');
select age(timestamp '-infinity', timestamp '-infinity');
ERROR: interval out of range
+-- test timestamp near POSTGRES_EPOCH_JDATE
+select timestamp '1999-12-31 24:00:00';
+ timestamp
+--------------------------
+ Sat Jan 01 00:00:00 2000
+(1 row)
+
+select make_timestamp(1999, 12, 31, 24, 0, 0);
+ make_timestamp
+--------------------------
+ Sat Jan 01 00:00:00 2000
+(1 row)
+
diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index bfb3825ff6..d01d174983 100644
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -3286,3 +3286,16 @@ SELECT age(timestamptz '-infinity', timestamptz 'infinity');
SELECT age(timestamptz '-infinity', timestamptz '-infinity');
ERROR: interval out of range
+-- test timestamp near POSTGRES_EPOCH_JDATE
+select timestamptz '1999-12-31 24:00:00';
+ timestamptz
+------------------------------
+ Sat Jan 01 00:00:00 2000 PST
+(1 row)
+
+select make_timestamptz(1999, 12, 31, 24, 0, 0);
+ make_timestamptz
+------------------------------
+ Sat Jan 01 00:00:00 2000 PST
+(1 row)
+
diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index 820ef7752a..748469576d 100644
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -424,3 +424,7 @@ select age(timestamp 'infinity', timestamp 'infinity');
select age(timestamp 'infinity', timestamp '-infinity');
select age(timestamp '-infinity', timestamp 'infinity');
select age(timestamp '-infinity', timestamp '-infinity');
+
+-- test timestamp near POSTGRES_EPOCH_JDATE
+select timestamp '1999-12-31 24:00:00';
+select make_timestamp(1999, 12, 31, 24, 0, 0);
diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index ccfd90d646..c71d5489b4 100644
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -668,3 +668,7 @@ SELECT age(timestamptz 'infinity', timestamptz 'infinity');
SELECT age(timestamptz 'infinity', timestamptz '-infinity');
SELECT age(timestamptz '-infinity', timestamptz 'infinity');
SELECT age(timestamptz '-infinity', timestamptz '-infinity');
+
+-- test timestamp near POSTGRES_EPOCH_JDATE
+select timestamptz '1999-12-31 24:00:00';
+select make_timestamptz(1999, 12, 31, 24, 0, 0);
--
2.34.1
