Re: Potential issue in ecpg-informix decimal converting functions
Daniel Gustafsson писал(а) 2024-03-06 18:03: On 27 Feb 2024, at 06:08, Michael Paquier wrote: On Mon, Feb 26, 2024 at 12:28:51AM +0100, Daniel Gustafsson wrote: Yeah, I think this is for HEAD only, especially given the lack of complaints against backbranches. Daniel, are you planning to look at that? I haven't done any detailed lookup, but would be happy to do so it that helps. I had a look at this today and opted for trimming back the patch a bit. Reading the informix docs the functions we are mimicking for compatibility here does not have an underflow returnvalue, so adding one doesn't seem right (or helpful). The attached fixes the return of overflow and leaves it at that, which makes it possible to backpatch since it's fixing the code to match the documented behavior. -- Daniel Gustafsson I agree with the proposed changes in favor of backward compatibility. Also, is it a big deal that the PGTYPESnumeric_to_long() function doesn't exactly match the documentation, compared to PGTYPESnumeric_to_int()? It handles underflow case separately and sets errno to PGTYPES_NUM_UNDERFLOW additionally.
Re: Potential issue in ecpg-informix decimal converting functions
Michael Paquier писал(а) 2024-02-28 02:14: On Tue, Feb 27, 2024 at 09:24:25AM +0100, Daniel Gustafsson wrote: I have it on my TODO for the upcoming CF. Okay, thanks. -- Michael Greetings! Sorry, I had been waiting for a few days for my cool-off period to end. The patch now is registered to CF in the 'Refactoring' topic. -- Aidar
Re: Potential issue in ecpg-informix decimal converting functions
Daniel Gustafsson писал(а) 2024-02-23 13:44:
On 22 Feb 2024, at 17:54, a.ima...@postgrespro.ru wrote:
PGTYPESnumeric_to_int() and PGTYPESnumeric_to_long()
functions return only 0 or -1. So ECPG_INFORMIX_NUM_OVERFLOW can never
be returned.
Indeed, this looks like an oversight.
I think dectoint(), dectolong() and PGTYPESnumeric_to_int() functions
should be a little bit different like in proposing patch.
What do you think?
-Convert a variable to type decimal to an integer.
+Convert a variable of type decimal to an integer.
While related, this should be committed and backpatched regardless.
+ int errnum = 0;
Stylistic nit, we typically don't initialize a variable which cannot be
accessed before being set.
Overall the patch looks sane, please register it for the next
commitfest to
make it's not missed.
--
Daniel Gustafsson
Thank you for feedback,
-Convert a variable to type decimal to an integer.
+Convert a variable of type decimal to an integer.
I removed this from the patch and proposed to
pgsql-d...@lists.postgresql.org
+ int errnum = 0;
fixed
Thank's for advice, the patch will be registered for the next
commitfest.
--
Aidar Imamovdiff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml
index 73351a9136..aa86afa1d9 100644
--- a/doc/src/sgml/ecpg.sgml
+++ b/doc/src/sgml/ecpg.sgml
@@ -8892,8 +8892,9 @@ int dectoint(decimal *np, int *ip);
On success, 0 is returned and a negative value if the conversion
-failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW
-is returned.
+failed. If overflow or underflow occurred, the function returns
+ECPG_INFORMIX_NUM_OVERFLOW or
+ECPG_INFORMIX_NUM_UNDERFLOW respectively.
Note that the ECPG implementation differs from the Informix
@@ -8918,8 +8919,9 @@ int dectolong(decimal *np, long *lngp);
On success, 0 is returned and a negative value if the conversion
-failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW
-is returned.
+failed. If overflow or underflow occurred, the function returns
+ECPG_INFORMIX_NUM_OVERFLOW or
+ECPG_INFORMIX_NUM_UNDERFLOW respectively.
Note that the ECPG implementation differs from the Informix
diff --git a/src/interfaces/ecpg/compatlib/informix.c b/src/interfaces/ecpg/compatlib/informix.c
index 80d40aa3e0..5f9d71d0f3 100644
--- a/src/interfaces/ecpg/compatlib/informix.c
+++ b/src/interfaces/ecpg/compatlib/informix.c
@@ -434,6 +434,7 @@ int
dectoint(decimal *np, int *ip)
{
int ret;
+ int errnum;
numeric*nres = PGTYPESnumeric_new();
if (nres == NULL)
@@ -445,11 +446,18 @@ dectoint(decimal *np, int *ip)
return ECPG_INFORMIX_OUT_OF_MEMORY;
}
+ errno = 0;
ret = PGTYPESnumeric_to_int(nres, ip);
+ errnum = errno;
PGTYPESnumeric_free(nres);
- if (ret == PGTYPES_NUM_OVERFLOW)
- ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ if (ret)
+ {
+ if (errnum == PGTYPES_NUM_UNDERFLOW)
+ ret = ECPG_INFORMIX_NUM_UNDERFLOW;
+ else if (errnum == PGTYPES_NUM_OVERFLOW)
+ ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ }
return ret;
}
@@ -458,6 +466,7 @@ int
dectolong(decimal *np, long *lngp)
{
int ret;
+ int errnum;
numeric*nres = PGTYPESnumeric_new();
if (nres == NULL)
@@ -469,11 +478,18 @@ dectolong(decimal *np, long *lngp)
return ECPG_INFORMIX_OUT_OF_MEMORY;
}
+ errno = 0;
ret = PGTYPESnumeric_to_long(nres, lngp);
+ errnum = errno;
PGTYPESnumeric_free(nres);
- if (ret == PGTYPES_NUM_OVERFLOW)
- ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ if (ret)
+ {
+ if (errnum == PGTYPES_NUM_UNDERFLOW)
+ ret = ECPG_INFORMIX_NUM_UNDERFLOW;
+ else if (errnum == PGTYPES_NUM_OVERFLOW)
+ ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ }
return ret;
}
diff --git a/src/interfaces/ecpg/pgtypeslib/numeric.c b/src/interfaces/ecpg/pgtypeslib/numeric.c
index 35e7b92da4..52b49e1ce9 100644
--- a/src/interfaces/ecpg/pgtypeslib/numeric.c
+++ b/src/interfaces/ecpg/pgtypeslib/numeric.c
@@ -1502,7 +1502,12 @@ PGTYPESnumeric_to_int(numeric *nv, int *ip)
/* silence compilers that might complain about useless tests */
#if SIZEOF_LONG > SIZEOF_INT
- if (l < INT_MIN || l > INT_MAX)
+ if (l < INT_MIN)
+ {
+ errno = PGTYPES_NUM_UNDERFLOW;
+ return -1;
+ }
+ else if(l > INT_MAX)
{
errno = PGTYPES_NUM_OVERFLOW;
return -1;
diff --git a/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout b/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
index 1f8675b3f3..71a5afa4a7 100644
--- a/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
+++ b/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
@@ -3,8 +3,8 @@
(no errno set) - dec[0,3]: r: -1, *
(no errno set) - dec[0,4]: r: -1, *
dec[0,5]: r: 0, 0.00
-(errno == PGTYPES_NUM_OVERFLOW) - dec[0,6]: 0 (r: -1)
-(errno == PGTYPES_NUM_OVERFLOW) - dec[0,8]:
Potential issue in ecpg-informix decimal converting functions
Hi, everyone!
I found a potential bug in dectoint() and dectolong() functions from
informix.c. "Informix Compatibility Mode" doc chapter says that
ECPG_INFORMIX_NUM_OVERFLOW is returned if an overflow occurred. But
check this line in dectoint() or dectolong() (it is present in both):
if (ret == PGTYPES_NUM_OVERFLOW) - condition is always
false because PGTYPESnumeric_to_int() and PGTYPESnumeric_to_long()
functions return only 0 or -1. So ECPG_INFORMIX_NUM_OVERFLOW can never
be returned.
I think dectoint(), dectolong() and PGTYPESnumeric_to_int() functions
should be a little bit different like in proposing patch.
What do you think?
The flaw was catched with the help of Svace static analyzer.
https://svace.pages.ispras.ru/svace-website/en/
Thank you!diff --git a/doc/src/sgml/ecpg.sgml b/doc/src/sgml/ecpg.sgml
index 73351a9136..8390a61cf4 100644
--- a/doc/src/sgml/ecpg.sgml
+++ b/doc/src/sgml/ecpg.sgml
@@ -8882,7 +8882,7 @@ int dectodbl(decimal *np, double *dblp);
dectoint
-Convert a variable to type decimal to an integer.
+Convert a variable of type decimal to an integer.
int dectoint(decimal *np, int *ip);
@@ -8892,8 +8892,9 @@ int dectoint(decimal *np, int *ip);
On success, 0 is returned and a negative value if the conversion
-failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW
-is returned.
+failed. If overflow or underflow occurred, the function returns
+ECPG_INFORMIX_NUM_OVERFLOW or
+ECPG_INFORMIX_NUM_UNDERFLOW respectively.
Note that the ECPG implementation differs from the Informix
@@ -8908,7 +8909,7 @@ int dectoint(decimal *np, int *ip);
dectolong
-Convert a variable to type decimal to a long integer.
+Convert a variable of type decimal to a long integer.
int dectolong(decimal *np, long *lngp);
@@ -8918,8 +8919,9 @@ int dectolong(decimal *np, long *lngp);
On success, 0 is returned and a negative value if the conversion
-failed. If an overflow occurred, ECPG_INFORMIX_NUM_OVERFLOW
-is returned.
+failed. If overflow or underflow occurred, the function returns
+ECPG_INFORMIX_NUM_OVERFLOW or
+ECPG_INFORMIX_NUM_UNDERFLOW respectively.
Note that the ECPG implementation differs from the Informix
diff --git a/src/interfaces/ecpg/compatlib/informix.c b/src/interfaces/ecpg/compatlib/informix.c
index 80d40aa3e0..73e84bc6e3 100644
--- a/src/interfaces/ecpg/compatlib/informix.c
+++ b/src/interfaces/ecpg/compatlib/informix.c
@@ -435,6 +435,7 @@ dectoint(decimal *np, int *ip)
{
int ret;
numeric*nres = PGTYPESnumeric_new();
+ int errnum = 0;
if (nres == NULL)
return ECPG_INFORMIX_OUT_OF_MEMORY;
@@ -445,11 +446,18 @@ dectoint(decimal *np, int *ip)
return ECPG_INFORMIX_OUT_OF_MEMORY;
}
+ errno = 0;
ret = PGTYPESnumeric_to_int(nres, ip);
+ errnum = errno;
PGTYPESnumeric_free(nres);
- if (ret == PGTYPES_NUM_OVERFLOW)
- ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ if (ret)
+ {
+ if (errnum == PGTYPES_NUM_UNDERFLOW)
+ ret = ECPG_INFORMIX_NUM_UNDERFLOW;
+ else if (errnum == PGTYPES_NUM_OVERFLOW)
+ ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ }
return ret;
}
@@ -459,6 +467,7 @@ dectolong(decimal *np, long *lngp)
{
int ret;
numeric*nres = PGTYPESnumeric_new();
+ int errnum = 0;
if (nres == NULL)
return ECPG_INFORMIX_OUT_OF_MEMORY;
@@ -469,11 +478,18 @@ dectolong(decimal *np, long *lngp)
return ECPG_INFORMIX_OUT_OF_MEMORY;
}
+ errno = 0;
ret = PGTYPESnumeric_to_long(nres, lngp);
+ errnum = errno;
PGTYPESnumeric_free(nres);
- if (ret == PGTYPES_NUM_OVERFLOW)
- ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ if (ret)
+ {
+ if (errnum == PGTYPES_NUM_UNDERFLOW)
+ ret = ECPG_INFORMIX_NUM_UNDERFLOW;
+ else if (errnum == PGTYPES_NUM_OVERFLOW)
+ ret = ECPG_INFORMIX_NUM_OVERFLOW;
+ }
return ret;
}
diff --git a/src/interfaces/ecpg/pgtypeslib/numeric.c b/src/interfaces/ecpg/pgtypeslib/numeric.c
index 35e7b92da4..52b49e1ce9 100644
--- a/src/interfaces/ecpg/pgtypeslib/numeric.c
+++ b/src/interfaces/ecpg/pgtypeslib/numeric.c
@@ -1502,7 +1502,12 @@ PGTYPESnumeric_to_int(numeric *nv, int *ip)
/* silence compilers that might complain about useless tests */
#if SIZEOF_LONG > SIZEOF_INT
- if (l < INT_MIN || l > INT_MAX)
+ if (l < INT_MIN)
+ {
+ errno = PGTYPES_NUM_UNDERFLOW;
+ return -1;
+ }
+ else if(l > INT_MAX)
{
errno = PGTYPES_NUM_OVERFLOW;
return -1;
diff --git a/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout b/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
index 1f8675b3f3..71a5afa4a7 100644
--- a/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
+++ b/src/interfaces/ecpg/test/expected/compat_informix-dec_test.stdout
@@ -3,8 +3,8 @@
(no errno set) - dec[0,3]: r: -1, *
(no errno set) - dec[0,4]: r: -1, *
dec[0,5]: r: 0, 0.00
-
