Revert "[llvm-objcopy] Add --compress-sections"

This reverts commit 9e3b64b9f95aadf57568576712902a272fe66503.

Reason: Broke the UBSan buildbot. See the comments in the pull request
(https://github.com/llvm/llvm-project/pull/85036) for more information.

1 files changed, 8 insertions, 26 deletions

diff --git a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
index f343d14..205bc1e 100644
--- a/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
+++ b/llvm/lib/ObjCopy/ELF/ELFObjcopy.cpp
@@ -215,41 +215,23 @@ static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
 }
 
 Error Object::compressOrDecompressSections(const CommonConfig &Config) {
-  // Build a list of sections we are going to replace.
-  // We can't call `addSection` while iterating over sections,
+  // Build a list of the debug sections we are going to replace.
+  // We can't call `AddSection` while iterating over sections,
   // because it would mutate the sections array.
   SmallVector<std::pair<SectionBase *, std::function<SectionBase *()>>, 0>
       ToReplace;
   for (SectionBase &Sec : sections()) {
-    std::optional<DebugCompressionType> CType;
-    for (auto &[Matcher, T] : Config.compressSections)
-      if (Matcher.matches(Sec.Name))
-        CType = T;
-    // Handle --compress-debug-sections and --decompress-debug-sections, which
-    // apply to non-ALLOC debug sections.
-    if (!(Sec.Flags & SHF_ALLOC) && StringRef(Sec.Name).starts_with(".debug")) {
-      if (Config.CompressionType != DebugCompressionType::None)
-        CType = Config.CompressionType;
-      else if (Config.DecompressDebugSections)
-        CType = DebugCompressionType::None;
-    }
-    if (!CType)
+    if ((Sec.Flags & SHF_ALLOC) || !StringRef(Sec.Name).starts_with(".debug"))
       continue;
-
-    if (Sec.ParentSegment)
-      return createStringError(
-          errc::invalid_argument,
-          "section '" + Sec.Name +
-              "' within a segment cannot be (de)compressed");
-
     if (auto *CS = dyn_cast<CompressedSection>(&Sec)) {
-      if (*CType == DebugCompressionType::None)
+      if (Config.DecompressDebugSections) {
         ToReplace.emplace_back(
             &Sec, [=] { return &addSection<DecompressedSection>(*CS); });
-    } else if (*CType != DebugCompressionType::None) {
-      ToReplace.emplace_back(&Sec, [=, S = &Sec] {
+      }
+    } else if (Config.CompressionType != DebugCompressionType::None) {
+      ToReplace.emplace_back(&Sec, [&, S = &Sec] {
         return &addSection<CompressedSection>(
-            CompressedSection(*S, *CType, Is64Bits));
+            CompressedSection(*S, Config.CompressionType, Is64Bits));
       });
     }
   }