Thread

1. Avoid use scoped block variable

   Ranier Vilela <ranier.vf@gmail.com> — 2025-12-09T16:06:35Z

   Hi.
   
   I noticed a possible violation of C rules.
   Some functions rely on local block variables,
   but this are a mistake.
   Once that block exits, the memory of the variable is released.
   
   Fix by moving the declaration variables.
   
   best regards,
   Ranier Vilela
   

2. Re: Avoid use scoped block variable

   Andres Freund <andres@anarazel.de> — 2025-12-09T16:19:06Z

   Hi,
   
   On 2025-12-09 13:06:35 -0300, Ranier Vilela wrote:
   > I noticed a possible violation of C rules.
   > Some functions rely on local block variables,
   > but this are a mistake.
   > Once that block exits, the memory of the variable is released.
   
   CStringGetTextDatum() copies its input to a fresh allocation. So there's no
   longer-lived references to the local memory, unless I miss something?
   
   Greetings,
   
   Andres Freund
   
   
   
   

3. Re: Avoid use scoped block variable

   Tomas Vondra <tomas@vondra.me> — 2025-12-09T16:20:48Z

   On 12/9/25 17:06, Ranier Vilela wrote:
   > Hi.
   > 
   > I noticed a possible violation of C rules.
   > Some functions rely on local block variables, 
   > but this are a mistake.
   > Once that block exits, the memory of the variable is released.
   > 
   > Fix by moving the declaration variables.
   > 
   
   When you say "possible violation", did you check the issue is real?
   
   All these places call CStringGetTextDatum, which calls cstring_to_text,
   which allocates a new varlena copy of the string. So why is this an
   issue, exactly?
   
   
   regards
   
   -- 
   Tomas Vondra
   
   
   
   
   

4. Re: Avoid use scoped block variable

   Ranier Vilela <ranier.vf@gmail.com> — 2025-12-09T16:24:14Z

   Em ter., 9 de dez. de 2025 às 13:19, Andres Freund <andres@anarazel.de>
   escreveu:
   
   > Hi,
   >
   > On 2025-12-09 13:06:35 -0300, Ranier Vilela wrote:
   > > I noticed a possible violation of C rules.
   > > Some functions rely on local block variables,
   > > but this are a mistake.
   > > Once that block exits, the memory of the variable is released.
   >
   > CStringGetTextDatum() copies its input to a fresh allocation. So there's no
   > longer-lived references to the local memory, unless I miss something?
   >
   Yeah. My bad.
   cstring_to_text use palloc.
   
   Sorry for the noise.
   
   best regards,
   Ranier Vilela