[PATCH] D36749: [LLD][ELF][AArch64] Complete implementation of -fix-cortex-a53-843419

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added a comment.

I have an impression that this patch can be simplified.

Does it make sense to separate Patch and PatchSection? Naively, I was thinking that patching can be done this way.

1. Fix the output layout
2. Scan all input sections in address-increasing order while creating and adding patch sections

In step 2, we create a synthetic patch section for each problematic instruction and add it after the current input section. When you add a synthetic patch section, you already know the distance from the problematic instruction and the synthetic patch section, so you don't need to create Relocation but can just fix instruction operands.



================
Comment at: ELF/SectionPatcher.cpp:65
+// Patch consists of:
+// Instruction 4.) load/store register (unsigned immediate)
+// Branch to next instruction after instruction 4.
----------------
What is "Instruction 4"?


================
Comment at: ELF/SyntheticSections.h:760
+  size_t Size = 0;
+  size_t AlignToSize;
+};
----------------
By convention, AlignToSize -> Alignment, if it means an (required) alignment.


https://reviews.llvm.org/D36749