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From: "qinzhao at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107952] tree-object-size: inconsistent size
 for flexible arrays nested in structs
Date: Mon, 23 Jan 2023 19:44:13 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107952

--- Comment #7 from qinzhao at gcc dot gnu.org ---
(In reply to Richard Biener from comment #1)
> GCC considered this as a flex-array.=20

do you mean for the following example:

typedef struct {
  char pad;
  char data[];
} F2;

typedef struct {
  unsigned pad;
  F2 flex;
} S2;

although C standard disallow the above, GCC extension treats S2.flex.data a=
s a
flex-array?=20

How about:

typedef struct {
  char pad;
  char data[];
} F2;

typedef struct {
  F2 flex;
  unsigned pad;
} S2;

do we have any documentation on this Gcc extension?=