[llvm-objcopy] Add support for removing sections

This change adds support for removing sections using the -R field (as
GNU objcopy does as well). This change should let us add many helpful
tests and is a proper stepping stone for adding more general kinds of
stripping.

Differential Revision: https://reviews.llvm.org/D38260

llvm-svn: 315346

1 files changed, 32 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-objcopy/reloc-error-remove-symtab.test b/llvm/test/tools/llvm-objcopy/reloc-error-remove-symtab.test
new file mode 100644
index 00000000000..539e6ea1ce1
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/reloc-error-remove-symtab.test
@@ -0,0 +1,32 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-objcopy -R .symtab %t %t2 2>&1 >/dev/null | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Address:         0x1000
+    AddressAlign:    0x0000000000000010
+    Content:         "0000000000000000"
+  - Name:            .rel.text
+    Type:            SHT_REL
+    Link:            .symtab
+    Info:            .text
+    Relocations:
+      - Offset: 0x1000
+        Symbol: foo
+        Type:   R_X86_64_PC32
+
+Symbols:
+  Global:
+    - Name:     foo
+      Type:     STT_FUNC
+      Size:     4
+
+# CHECK: Symbol table .symtab cannot be removed because it is referenced by the relocation section .rel.text.