[llvm-objcopy] Dwarf .debug section compression support (zlib, zlib-gnu).

  Second Attempt. Alignment issues resolved. zlib::isAvailable() detected.

  Usage:

  llvm-objcopy --compress-debug-sections=zlib foo.o
  llvm-objcopy --compress-debug-sections=zlib-gnu foo.o

  In both cases the debug section contents is compressed with zlib. In the GNU
  style case the header is the "ZLIB" magic string followed by the uint64 big-
  endian decompressed size. In the non-GNU mode the header is the
  Elf(32|64)_Chdr.

  Decompression support is coming soon.

  Differential Revision: https://reviews.llvm.org/D49678

llvm-svn: 341607

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-objcopy/compress-debug-sections-default.test b/llvm/test/tools/llvm-objcopy/compress-debug-sections-default.test
new file mode 100644
index 00000000000..8ed887da3b0
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/compress-debug-sections-default.test
@@ -0,0 +1,13 @@
+# REQUIRES: zlib
+
+# RUN: yaml2obj %p/Inputs/compress-debug-sections.yaml -o %t.o
+# RUN: llvm-objcopy --compress-debug-sections %t.o %t-compressed.o
+# RUN: llvm-readobj -s %t-compressed.o | FileCheck %s
+
+# CHECK: Name: .debug_foo
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_COMPRESSED
+# CHECK-NEXT: ]
+# CHECK-NOT: Name: .debug_foo
+