Re: [Tarantool-patches] [PATCH v1 01/21] sql: refactor CHAR() function

[Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Hi! Thank you for the review! My answer and diff below. Also, I fixed the
argument types passed to the U8_* macros as they were throwing an error for
some targents in CI. I believe this was due to the old ICU.

On Sat, Oct 30, 2021 at 01:42:42AM +0200, Vladislav Shpilevoy wrote:
> Hi! Thanks for the fixes!
> 
> See 3 comments below.
> 
> > diff --git a/src/box/sql/func.c b/src/box/sql/func.c
> > index afe34f7f0..dee28b852 100644
> > --- a/src/box/sql/func.c
> > +++ b/src/box/sql/func.c
> > @@ -717,6 +717,57 @@ func_substr_characters(struct sql_context *ctx, int argc, struct Mem *argv)
> >  		ctx->is_aborted = true;
> >  }
> >  
> > +/**
> > + * Implementation of the CHAR() function.
> > + *
> > + * This function takes zero or more arguments, each of which is an integer. It
> > + * constructs a string where each character of the string is the unicode
> > + * character for the corresponding integer argument.
> > + *
> > + * If an argument is negative or greater than 0x10ffff, the symbol "�" is used.
> > + * Symbol '\0' used instead of NULL argument.
> > + */
> > +static void
> > +func_char(struct sql_context *ctx, int argc, struct Mem *argv)
> > +{
> > +	if (argc == 0)
> > +		return mem_set_str_static(ctx->pOut, "", 0);
> > +	struct region *region = &fiber()->gc;
> > +	size_t svp = region_used(region);
> > +	UChar32 *buf = region_alloc(region, argc * sizeof(*buf));
> 
> 1. Would be better to use region_alloc_array(). Otherwise you
> risk to get misaligned data.
> 
Thanks, fixed.

> > +	if (buf == NULL) {
> > +		ctx->is_aborted = true;
> 
> 2. Need to use diag_set() here.
> 
Fixed.

> > +		return;
> > +	}
> > +	int len = 0;
> > +	for (int i = 0; i < argc; ++i) {
> > +		if (mem_is_null(&argv[i]))
> > +			buf[i] = 0;
> > +		else if (!mem_is_uint(&argv[i]) || argv[i].u.u > 0x10ffff)
> > +			buf[i] = 0xfffd;
> > +		else
> > +			buf[i] = argv[i].u.u;
> > +		len += U8_LENGTH(buf[i]);
> > +	}
> > +
> > +	char *str = sqlDbMallocRawNN(sql_get(), len);
> > +	if (str == NULL) {
> > +		ctx->is_aborted = true;
> 
> 3. region leaks here, doesn't it?
True, fixed.


Diff:

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 71c46924e..0cd8f8f69 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -745,9 +745,11 @@ func_char(struct sql_context *ctx, int argc, struct Mem *argv)
 		return mem_set_str_static(ctx->pOut, "", 0);
 	struct region *region = &fiber()->gc;
 	size_t svp = region_used(region);
-	UChar32 *buf = region_alloc(region, argc * sizeof(*buf));
+	uint32_t size;
+	UChar32 *buf = region_alloc_array(region, typeof(*buf), argc, &size);
 	if (buf == NULL) {
 		ctx->is_aborted = true;
+		diag_set(OutOfMemory, size, "region_alloc_array", "buf");
 		return;
 	}
 	int len = 0;
@@ -763,13 +765,14 @@ func_char(struct sql_context *ctx, int argc, struct Mem *argv)
 
 	char *str = sqlDbMallocRawNN(sql_get(), len);
 	if (str == NULL) {
+		region_truncate(region, svp);
 		ctx->is_aborted = true;
 		return;
 	}
 	int pos = 0;
 	for (int i = 0; i < argc; ++i) {
-		bool is_error = false;
-		U8_APPEND(str, pos, len, buf[i], is_error);
+		UBool is_error = false;
+		U8_APPEND((uint8_t *)str, pos, len, buf[i], is_error);
 		assert(!is_error);
 		(void)is_error;
 	}