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

  Third Attempt:
    - Alignment issues resolved.
    - zlib::isAvailable() detected.
    - ArrayRef misuse fixed.

  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: 341635

6 files changed, 146 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-objcopy/Inputs/compress-debug-sections.yaml b/llvm/test/tools/llvm-objcopy/Inputs/compress-debug-sections.yaml
new file mode 100644
index 00000000000..bb1e9e6c338
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/Inputs/compress-debug-sections.yaml
@@ -0,0 +1,21 @@
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .debug_foo
+    Type:            SHT_PROGBITS
+    Content:         0000000000000000
+  - Name:            .notdebug_foo
+    Type:            SHT_PROGBITS
+    Content:         0000000000000000
+  - Name:            .rela.debug_foo
+    Type:            SHT_RELA
+    Info:            .debug_foo
+    Relocations:
+      - Offset:          0x1
+        Symbol:          .debug_foo
+        Type:            R_X86_64_32
+...
diff --git a/llvm/test/tools/llvm-objcopy/compress-debug-sections-default-gnu.test b/llvm/test/tools/llvm-objcopy/compress-debug-sections-default-gnu.test
new file mode 100644
index 00000000000..9db3d3b7f9c
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/compress-debug-sections-default-gnu.test
@@ -0,0 +1,9 @@
+# REQUIRES: zlib
+
+# RUN: yaml2obj %p/Inputs/compress-debug-sections.yaml -o %t.o
+# RUN: llvm-objcopy --compress-debug-sections --compress-debug-sections=zlib-gnu %t.o %t-compressed.o
+# RUN: llvm-objdump -s %t-compressed.o | FileCheck %s
+
+# CHECK: .zdebug_foo:
+# CHECK: ZLIB
+
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
+
diff --git a/llvm/test/tools/llvm-objcopy/compress-debug-sections-invalid-format.test b/llvm/test/tools/llvm-objcopy/compress-debug-sections-invalid-format.test
new file mode 100644
index 00000000000..854dfe26560
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/compress-debug-sections-invalid-format.test
@@ -0,0 +1,5 @@
+# RUN: yaml2obj %p/Inputs/compress-debug-sections.yaml -o %t.o
+# RUN: not llvm-objcopy --compress-debug-sections=zlib-fake %t.o 2>&1 | FileCheck %s
+
+# CHECK: Invalid or unsupported --compress-debug-sections format: zlib-fake.
+
diff --git a/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib-gnu.test b/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib-gnu.test
new file mode 100644
index 00000000000..eb697522de2
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib-gnu.test
@@ -0,0 +1,49 @@
+# REQUIRES: zlib
+
+# RUN: yaml2obj %p/Inputs/compress-debug-sections.yaml -o %t.o
+# RUN: llvm-objcopy --compress-debug-sections=zlib-gnu %t.o %t-compressed.o
+
+# RUN: llvm-objdump -s %t.o -section=.debug_foo | FileCheck %s
+# RUN: llvm-objdump -s %t-compressed.o | FileCheck %s --check-prefix=CHECK-COMPRESSED
+# RUN: llvm-readobj -relocations -s %t-compressed.o | FileCheck %s --check-prefix=CHECK-FLAGS
+
+# CHECK: .debug_foo:
+
+# CHECK-COMPRESSED: .zdebug_foo:
+# CHECK-COMPRESSED: ZLIB
+# CHECK-COMPRESSED: .notdebug_foo:
+
+# CHECK-FLAGS-NOT: Name: .debug_foo
+# CHECK-FLAGS: Index: 1
+# CHECK-FLAGS-NEXT: Name: .zdebug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_PROGBITS
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size: 23
+
+# CHECK-FLAGS: Name: .notdebug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_PROGBITS
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size: 8
+
+# CHECK-FLAGS: Name: .rela.debug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_RELA
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size:
+# CHECK-FLAGS-NEXT: Link:
+# CHECK-FLAGS-NEXT: Info: 1
+
+# CHECK-FLAGS: Relocations [
+# CHECK-FLAGS-NEXT:   .rela.debug_foo {
+# CHECK-FLAGS-NEXT:     0x1 R_X86_64_32 - 0x0
+# CHECK-FLAGS-NEXT:   }
+# CHECK-FLAGS-NEXT: ]
+
diff --git a/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib.test b/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib.test
new file mode 100644
index 00000000000..843dbf267d7
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/compress-debug-sections-zlib.test
@@ -0,0 +1,49 @@
+# REQUIRES: zlib
+
+# RUN: yaml2obj %p/Inputs/compress-debug-sections.yaml -o %t.o
+# RUN: llvm-objcopy --compress-debug-sections=zlib %t.o %t-compressed.o
+
+# RUN: llvm-objdump -s %t.o -section=.debug_foo | FileCheck %s
+# RUN: llvm-objdump -s %t-compressed.o | FileCheck %s --check-prefix=CHECK-COMPRESSED
+# RUN: llvm-readobj -relocations -s %t-compressed.o | FileCheck %s --check-prefix=CHECK-FLAGS
+
+# CHECK: .debug_foo:
+
+# CHECK-COMPRESSED: .debug_foo:
+# CHECK-COMPRESSED: .notdebug_foo:
+
+# CHECK-FLAGS: Index: 1
+# CHECK-FLAGS-NEXT: Name: .debug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_PROGBITS
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: SHF_COMPRESSED
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size: 35
+# CHECK-FLAGS-NOT: Name: .debug_foo
+
+# CHECK-FLAGS: Name: .notdebug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_PROGBITS
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size: 8
+
+# CHECK-FLAGS: Name: .rela.debug_foo
+# CHECK-FLAGS-NEXT: Type: SHT_RELA
+# CHECK-FLAGS-NEXT: Flags [
+# CHECK-FLAGS-NEXT: ]
+# CHECK-FLAGS-NEXT: Address:
+# CHECK-FLAGS-NEXT: Offset:
+# CHECK-FLAGS-NEXT: Size:
+# CHECK-FLAGS-NEXT: Link:
+# CHECK-FLAGS-NEXT: Info: 1
+
+# CHECK-FLAGS: Relocations [
+# CHECK-FLAGS-NEXT:   .rela.debug_foo {
+# CHECK-FLAGS-NEXT:     0x1 R_X86_64_32 - 0x0
+# CHECK-FLAGS-NEXT:   }
+# CHECK-FLAGS-NEXT: ]
+