[ELF] Initialize Symbol fields in the constructor instead of via memset#198129
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MaskRay merged 1 commit intoMay 16, 2026
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`initSectionsAndLocalSyms` and `makeDefined` memset the storage to zero and then placement-new a Symbol-derived object into it. Placement new begins a new object's lifetime. The standard does not seem to guarantee the memset bytes carry into members the constructor leaves uninitialized. lld built by GCC 16 can make Valgrind report reads of Symbol::flags (via getSymSectionIndex during finalizeSections) as uses of uninitialized values (ClangBuiltLinux/linux#2162). This patch reinstates the per-field initialization that commit 7787427 ("[ELF] Avoid redundant assignment to Symbol fields. NFC") had replaced with a bulk memset.
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Thanks for the fix! Should this be applied to |
pedroMVicente
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May 19, 2026
…et (llvm#198129) `initSectionsAndLocalSyms` and `makeDefined` memset the storage to zero and then placement-new a Symbol-derived object into it. Placement new begins a new object's lifetime. The standard does not seem to guarantee the memset bytes carry into members the constructor leaves uninitialized. lld built by GCC 16 can make Valgrind report reads of Symbol::flags (via getSymSectionIndex during finalizeSections) as uses of uninitialized values (ClangBuiltLinux/linux#2162). This patch reinstates the per-field initialization that commit 7787427 ("[ELF] Avoid redundant assignment to Symbol fields. NFC") had replaced with a bulk memset.
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/cherry-pick 905a88b |
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Error: Command failed due to missing milestone. |
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/cherry-pick 905a88b |
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/pull-request #198665 |
c-rhodes
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May 26, 2026
…et (llvm#198129) `initSectionsAndLocalSyms` and `makeDefined` memset the storage to zero and then placement-new a Symbol-derived object into it. Placement new begins a new object's lifetime. The standard does not seem to guarantee the memset bytes carry into members the constructor leaves uninitialized. lld built by GCC 16 can make Valgrind report reads of Symbol::flags (via getSymSectionIndex during finalizeSections) as uses of uninitialized values (ClangBuiltLinux/linux#2162). This patch reinstates the per-field initialization that commit 7787427 ("[ELF] Avoid redundant assignment to Symbol fields. NFC") had replaced with a bulk memset. (cherry picked from commit 905a88b)
daunabomba
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Jun 2, 2026
…et (llvm#198129) `initSectionsAndLocalSyms` and `makeDefined` memset the storage to zero and then placement-new a Symbol-derived object into it. Placement new begins a new object's lifetime. The standard does not seem to guarantee the memset bytes carry into members the constructor leaves uninitialized. lld built by GCC 16 can make Valgrind report reads of Symbol::flags (via getSymSectionIndex during finalizeSections) as uses of uninitialized values (ClangBuiltLinux/linux#2162). This patch reinstates the per-field initialization that commit 7787427 ("[ELF] Avoid redundant assignment to Symbol fields. NFC") had replaced with a bulk memset. (cherry picked from commit 905a88b)
nga888
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Jun 9, 2026
On the "main" branch, Symbol no longer has the `used` member which was moved in PR llvm#190117 (commit 6a87416). Therefore, when the cherry pick from PR llvm#198129 (commit 905a88b) was merged to the "release/22.x" branch, the initialization of `used` was lost.
dyung
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Jun 10, 2026
On the "main" branch, Symbol no longer has the `used` member which was moved in PR llvm#190117 (commit 6a87416). Therefore, when the cherry pick from PR llvm#198129 (commit 905a88b) was merged to the "release/22.x" branch, the initialization of `used` was lost.
daunabomba
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Jun 17, 2026
On the "main" branch, Symbol no longer has the `used` member which was moved in PR llvm#190117 (commit 6a87416). Therefore, when the cherry pick from PR llvm#198129 (commit 905a88b) was merged to the "release/22.x" branch, the initialization of `used` was lost.
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initSectionsAndLocalSymsandmakeDefinedmemset the storage to zeroand then placement-new a Symbol-derived object into it. Placement new
begins a new object's lifetime. The standard does not seem to guarantee
the memset bytes carry into members the constructor leaves
uninitialized.
lld built by GCC 16 can make Valgrind report reads of Symbol::flags
(via getSymSectionIndex during finalizeSections) as uses of
uninitialized values (ClangBuiltLinux/linux#2162).
This patch reinstates the per-field initialization that commit
7787427 ("[ELF] Avoid redundant assignment to Symbol fields. NFC")
had replaced with a bulk memset.