[PATCH] D94329: [lld-macho] Fix TLV data initialization

[Nico Weber via Phabricator via llvm-commits]

thakis accepted this revision.
thakis added a comment.
This revision is now accepted and ready to land.

Very nice!



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Comment at: lld/MachO/InputSection.cpp:50
+        // References from thread-local variable sections are treated as offsets
+        // relative to the start of the first thread-local data section, instead
+        // of as absolute addresses.
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fwiw I think of it as a single thread-local data memory area – it's kind of more like a segment than a section I suppose, and it implicitly consists of __DATA,__thread_data and __DATA,__thread_bss (and, per dyld code, everything in between -- which is why we don't want anything in between, since that'd uselessly waste memory)


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Comment at: lld/MachO/InputSection.h:78
+  return sectionType(flags) == llvm::MachO::S_THREAD_LOCAL_ZEROFILL ||
+         sectionType(flags) == llvm::MachO::S_THREAD_LOCAL_REGULAR;
 }
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very nit: swap order of ZEROFILL and REGULAR since REGULAR comes first in the TLV area in memory :)


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Comment at: lld/MachO/Writer.cpp:566
+    // to minimize the amount of memory used. Additionally, since zerofill
+    // sections must be at the end of their segments, and since TLV data
+    // sections can be zerofills, we end up putting all TLV data sections at the
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Are there zerofill sections in segments other than `__DATA`? `__DATA_CONST` I guess, but that can't be TLV. (I'm wondering about the plural "segments" here.)


Repository:
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https://reviews.llvm.org/D94329