[llvm-objcopy] - Remove an excessive zlib::isAvailable() check and dead code.

There are 2 places where llvm-objcopy creates CompressedSection:

For --compress-debug-sections. It might create the compressed section from
regular here:
https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-objcopy/ELF/ELFObjcopy.cpp#L486

All initially compressed sections are created as CompressedSection during reading the sections
from an object:
https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-objcopy/ELF/Object.cpp#L1118
Those have DebugCompressionType::None type and a different constructor.

Case 1 has the following code in its constructor:

if (!zlib::isAvailable()) {
  CompressionType = DebugCompressionType::None;
  return;
}
(https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-objcopy/ELF/Object.cpp#L267)

We can never reach that code with because would report an error much earlier:
https://github.com/llvm-mirror/llvm/blob/master/tools/llvm-objcopy/CopyConfig.cpp#L480

So the code I am removing is dead. Landing this will address the issue mentioned in https://bugs.llvm.org/show_bug.cgi?id=40886.

Differential revision: https://reviews.llvm.org/D59019

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@355503 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/tools/llvm-objcopy/ELF/Object.cpp b/tools/llvm-objcopy/ELF/Object.cpp
index c90e7c646129d14d199102dc1ffec0c6ef442dc9..6bc179661987b451d4d12d7f5942205259340f41 100644 (file)
--- a/tools/llvm-objcopy/ELF/Object.cpp
+++ b/tools/llvm-objcopy/ELF/Object.cpp
@@ -263,12 +263,6 @@ CompressedSection::CompressedSection(const SectionBase &Sec,
                                      DebugCompressionType CompressionType)
     : SectionBase(Sec), CompressionType(CompressionType),
       DecompressedSize(Sec.OriginalData.size()), DecompressedAlign(Sec.Align) {
-
-  if (!zlib::isAvailable()) {
-    CompressionType = DebugCompressionType::None;
-    return;
-  }
-
   if (Error E = zlib::compress(
           StringRef(reinterpret_cast<const char *>(OriginalData.data()),
                     OriginalData.size()),