[llvm-strip] Add support for -remove-section

This diff adds support for -remove-section to llvm-strip.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D46567

llvm-svn: 332081

llvm/test/tools/llvm-objcopy/strip-all-and-remove.test

@@ -0,0 +1,49 @@
+# RUN: yaml2obj %s > %t
+# RUN: cp %t %t1
+
+# RUN: llvm-strip -remove-section=.text.bar %t
+# RUN: llvm-readobj -file-headers -sections -symbols %t | FileCheck %s
+
+# RUN: llvm-objcopy -strip-all -remove-section=.text.bar %t1 %t1
+# RUN: cmp %t %t1
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .debug_foo
+    Type:            SHT_PROGBITS
+    Content:         "00000000"
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000010
+    Content:         "00000000"
+  - Name:            .text.bar
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000010
+    Content:         "00000000"
+Symbols:
+  Global:
+    - Name: debugfoo
+      Section: .debug_foo
+    - Name: foo
+      Section: .text
+    - Name: bar
+      Section: .text.bar
+
+# CHECK: SectionHeaderCount: 3
+
+# CHECK:     Name: .text
+# CHECK:     Name: .shstrtab
+# CHECK-NOT: Name: .text.bar
+# CHECK-NOT: Name: .debug_foo
+# CHECK-NOT: Name: .symtab
+
+# Check that *only* foo is copied and no debugfoo or textbar
+# CHECK:      Symbols [
+# CHECK-NEXT: ]

llvm/test/tools/llvm-objcopy/strip-debug-and-remove.test

@@ -0,0 +1,68 @@
+# RUN: yaml2obj %s > %t
+# RUN: cp %t %t1
+
+# RUN: llvm-strip -strip-debug -remove-section=.text.bar %t
+# RUN: llvm-readobj -file-headers -sections -symbols %t | FileCheck %s
+
+# RUN: llvm-objcopy -strip-debug -remove-section=.text.bar %t1 %t1
+# RUN: cmp %t %t1
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .debug_foo
+    Type:            SHT_PROGBITS
+    Content:         "00000000"
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000010
+    Content:         "00000000"
+  - Name:            .text.bar
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000010
+    Content:         "00000000"
+Symbols:
+  Global:
+    - Name: debugfoo
+      Section: .debug_foo
+    - Name: foo
+      Section: .text
+    - Name: bar
+      Section: .text.bar
+
+# CHECK: SectionHeaderCount: 5
+
+# CHECK:     Name: .text
+# CHECK:     Name: .symtab
+# CHECK:     Name: .strtab
+# CHECK:     Name: .shstrtab
+# CHECK-NOT: Name: .text.bar
+# CHECK-NOT: Name: .debug_foo
+
+# Check that *only* foo is copied and no debugfoo or textbar
+# CHECK:      Symbols [
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name:
+# CHECK-NEXT:     Value:
+# CHECK-NEXT:     Size:
+# CHECK-NEXT:     Binding:
+# CHECK-NEXT:     Type:
+# CHECK-NEXT:     Other:
+# CHECK-NEXT:     Section: Undefined
+# CHECK-NEXT:   }
+# CHECK-NEXT:   Symbol {
+# CHECK-NEXT:     Name: foo
+# CHECK-NEXT:     Value:
+# CHECK-NEXT:     Size:
+# CHECK-NEXT:     Binding: Global
+# CHECK-NEXT:     Type:
+# CHECK-NEXT:     Other:
+# CHECK-NEXT:     Section: .text
+# CHECK-NEXT:   }
+# CHECK-NEXT: ]

llvm/tools/llvm-objcopy/StripOpts.td

@@ -10,3 +10,9 @@ def help : Flag<["-", "--"], "help">;
 def strip_debug : Flag<["-", "--"], "strip-debug">,
                   HelpText<"Remove debugging symbols only">;
 
+defm remove_section : Eq<"remove-section">,
+                      MetaVarName<"section">,
+                      HelpText<"Remove <section>">;
+
+def R : JoinedOrSeparate<["-"], "R">,
+        Alias<remove_section>;

llvm/tools/llvm-objcopy/llvm-objcopy.cpp

@@ -528,6 +528,10 @@ CopyConfig ParseStripOptions(ArrayRef<const char *> ArgsArr) {
   Config.StripDebug = InputArgs.hasArg(STRIP_strip_debug);
   if (!Config.StripDebug)
     Config.StripAll = true;
+
+  for (auto Arg : InputArgs.filtered(STRIP_remove_section))
+    Config.ToRemove.push_back(Arg->getValue());
+
   return Config;
 }