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Tue, 29 Apr 2025 13:34:36 -0700 (PDT) Received: from ezingerman-mba ([2620:10d:c090:500::6:8cbd]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-309ef09985asm12929219a91.28.2025.04.29.13.34.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Apr 2025 13:34:35 -0700 (PDT) From: Eduard Zingerman To: Andrii Nakryiko Cc: Alan Maguire , Arnaldo Carvalho de Melo , Alexei Starovoitov , Andrii Nakryiko , Ihor Solodrai , bpf , dwarves@vger.kernel.org, Kumar Kartikeya Dwivedi Subject: Re: pahole and gcc-14 issues In-Reply-To: (Andrii Nakryiko's message of "Tue, 29 Apr 2025 12:50:14 -0700") References: <076e52f6-248a-4a41-a199-3c705cb3d3c5@oracle.com> <4aa02e25-7231-40f4-a0ba-e10db3833d81@oracle.com> Date: Tue, 29 Apr 2025 13:34:34 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: dwarves@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Andrii Nakryiko writes: [...] >> Is that different from what happens already? > > yes, it's different, we don't follow pointers. that identical_structs > recurse only for embedded/nested structs, not structs-by-pointer. > idential_arrays also doesn't follow any references > > so it could lead to loop only if BTF is broken and we have one struct > embedding another, while that other embeds its parent, which isn't > legal in BTF and C (so whatever) Missed that, thank you for explaining. [...] > And yes, "visited" marks are the solution, but I was thinking that if > we implement a pre-processing deduplication step as we discussed > offline, we won't need to do any of this, so didn't want to pursue > this further. >From logical pov the pre-processing step would do the same thing, right? Follow pointer/array/qualifier chains and merge structs that can be trivially merged. [...] > [0] https://gist.github.com/anakryiko/fd1c84dcad91141d27d8bd33453521d1 Thanks, I actually cleaned up and applied what you posted in email :)