From 79765fabe6c4a925a26c635c439991daca532111 Mon Sep 17 00:00:00 2001 From: Antonin Houska Date: Wed, 11 Mar 2026 14:53:19 +0100 Subject: [PATCH 2/5] Add va_header field to the varattrib_4b union. Since VARSIZE_ANY() may call VARSIZE_4B(), it's possible that the compiler (when invoked with -Warray-bounds) complains if the argument of VARSIZE_ANY() is actually smaller than what VARSIZE_4B() expects. With the new field, VARSIZE_4B() can check the size w/o dereferencing varattrib_4b pointer. The problem does not exist in the tree at the moment since the current users of VARSIZE_ANY() pass a pointer to a dynamically allocated memory, so the compiler has no idea about the memory available. However, in an upcoming patch, it makes sense to pass a pointer to a local variable of "varlena" type. In such a case, the compiler warning might appear because sizeof(varlena) is lower than sizeof(varattrib_4b). --- src/include/varatt.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/include/varatt.h b/src/include/varatt.h index 000bdf33b92..c54d5160c22 100644 --- a/src/include/varatt.h +++ b/src/include/varatt.h @@ -137,6 +137,10 @@ typedef union * compression method; see va_extinfo */ char va_data[FLEXIBLE_ARRAY_MEMBER]; /* Compressed data */ } va_compressed; + uint32 va_header; /* Without this, compiler might raise warning + * (-Warray-bounds) if the argument of + * VARSIZE_ANY() is smaller than + * varattrib_4b */ } varattrib_4b; typedef struct @@ -207,7 +211,7 @@ typedef struct /* VARSIZE_4B() should only be used on known-aligned data */ #define VARSIZE_4B(PTR) \ - (((const varattrib_4b *) (PTR))->va_4byte.va_header & 0x3FFFFFFF) + (*((const uint32 *) (PTR)) & 0x3FFFFFFF) #define VARSIZE_1B(PTR) \ (((const varattrib_1b *) (PTR))->va_header & 0x7F) #define VARTAG_1B_E(PTR) \ @@ -240,7 +244,7 @@ typedef struct /* VARSIZE_4B() should only be used on known-aligned data */ #define VARSIZE_4B(PTR) \ - ((((const varattrib_4b *) (PTR))->va_4byte.va_header >> 2) & 0x3FFFFFFF) + ((*((const uint32 *) (PTR)) >> 2) & 0x3FFFFFFF) #define VARSIZE_1B(PTR) \ ((((const varattrib_1b *) (PTR))->va_header >> 1) & 0x7F) #define VARTAG_1B_E(PTR) \ -- 2.47.3