[llvm] [Bolt] Fix issue 110407 (Support CREL) (PR #119150)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-bolt

Author: 2:5030/1559 (0xfk0)

<details>
<summary>Changes</summary>

This commit fixes issue #<!-- -->110407 in Bolt subproject: BOLT programs not support CREL-type relocations.

---
Full diff: https://github.com/llvm/llvm-project/pull/119150.diff


1 Files Affected:

- (modified) bolt/lib/Rewrite/RewriteInstance.cpp (+10-2) 


``````````diff
diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
index 76e1f0156f828d..f1ef97888a26ce 100644
--- a/bolt/lib/Rewrite/RewriteInstance.cpp
+++ b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -1938,8 +1938,11 @@ Error RewriteInstance::readSpecialSections() {
                   "Use -update-debug-sections to keep it.\n";
   }
 
-  HasTextRelocations = (bool)BC->getUniqueSectionByName(
-      ".rela" + std::string(BC->getMainCodeSectionName()));
+  const char *code_sec = BC->getMainCodeSectionName();
+  HasTextRelocations = !!BC->getUniqueSectionByName(std::string{".rela"} + code_sec);
+  if (!HasTextRelocations)
+    HasTextRelocations = !!BC->getUniqueSectionByName(std::string{".crel"} + code_sec);
+
   HasSymbolTable = (bool)BC->getUniqueSectionByName(".symtab");
   EHFrameSection = BC->getUniqueSectionByName(".eh_frame");
 
@@ -2127,6 +2130,11 @@ int64_t getRelocationAddend(const ELFObjectFile<ELFT> *Obj,
     llvm_unreachable("unexpected relocation section type");
   case ELF::SHT_REL:
     break;
+  case ELF::SHT_CREL: {
+    auto ERela = Obj->getCrel(Rel);
+    Addend = ERela.r_addend;
+    break; 
+  }
   case ELF::SHT_RELA: {
     const Elf_Rela *RelA = Obj->getRela(Rel);
     Addend = RelA->r_addend;

``````````

</details>


https://github.com/llvm/llvm-project/pull/119150