[PATCH] D39769: [llvm-objcopy] Add --strip-all option to llvm-objcopy

[Jake Ehrlich via Phabricator via llvm-commits]

jakehehrlich updated this revision to Diff 122524.
jakehehrlich retitled this revision from "[llvm-objcopy] Add --strip-all option to remove all non-allocated sections but keep section header table" to "[llvm-objcopy] Add --strip-all option to llvm-objcopy".
jakehehrlich edited the summary of this revision.
jakehehrlich added a comment.

Ok I think this should just follow what GNU objcopy does for mass consistency but I'm also going to add --only-keep-allocated to do what I intended this to do in the first place

1. I couldn't add dynamic relocations because yaml2obj will only give a relocation section a link for a non-dynamic symbol table and llvm-objcopy throws an error if you give it a dynamic relocation section without a dynamic symbol table. I added every other section requested though.
2. Changed how StripAll is handled so that it dosn't keep allocated sections that are removed by a previous flag.


Repository:
  rL LLVM

https://reviews.llvm.org/D39769

Files:
  test/tools/llvm-objcopy/strip-all.test
  tools/llvm-objcopy/llvm-objcopy.cpp


Index: tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- tools/llvm-objcopy/llvm-objcopy.cpp
+++ tools/llvm-objcopy/llvm-objcopy.cpp
@@ -81,6 +81,8 @@
                                       cl::desc("Remove a specific section"));
 static cl::alias ToRemoveA("R", cl::desc("Alias for remove-section"),
                            cl::aliasopt(ToRemove));
+static cl::opt<bool> StripAll("strip-all",
+                              cl::desc("Removes symbol, relocation, and debug information"));
 static cl::opt<bool> StripSections("strip-sections",
                                    cl::desc("Remove all section headers"));
 static cl::opt<bool>
@@ -170,6 +172,24 @@
       return OnlyKeepDWOPred(*Obj, Sec) || RemovePred(Sec);
     };
 
+  if (StripAll)
+    RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
+      if (RemovePred(Sec))
+        return true;
+      if ((Sec.Flags & SHF_ALLOC) != 0)
+        return false;
+      if (&Sec == Obj->getSectionHeaderStrTab())
+        return false;
+      switch(Sec.Type) {
+      case SHT_SYMTAB:
+      case SHT_REL:
+      case SHT_RELA:
+      case SHT_STRTAB:
+        return true;
+      }
+      return Sec.Name.startswith(".debug");
+    };
+
   if (StripSections) {
     RemovePred = [RemovePred](const SectionBase &Sec) {
       return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
Index: test/tools/llvm-objcopy/strip-all.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/strip-all.test
@@ -0,0 +1,54 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy --strip-all %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .dynstr
+    Type:            SHT_STRTAB
+    Flags:           [ SHF_ALLOC ]
+  - Name:            .symtab.dyn
+    Type:            SHT_SYMTAB
+    Flags:           [ SHF_ALLOC ]
+    Type:            SHT_NOBITS
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    Size:            4
+  - Name:            .debug_info
+    Type:            SHT_PROGBITS
+    Flags:           [ ]
+    AddressAlign:    0x1
+    Size:            4
+  - Name:            .debug_loc
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC ]
+    AddressAlign:    0x1
+    Size:            4
+  - Name:            .comment
+    Type:            SHT_PROGBITS
+  - Name:            .random_section_name
+    Type:            SHT_PROGBITS
+  - Name:            .debug_not_a_real_debug_section
+    Type:            SHT_PROGBITS
+  - Name:            .rel.text
+    Type:            SHT_REL
+    Info:            .text
+  - Name:            .rela.text
+    Type:            SHT_RELA
+    Info:            .text
+
+# CHECK: SectionHeaderCount: 8
+
+# CHECK:      Name: .dynstr
+# CHECK:      Name: .symtab.dyn
+# CHECK:      Name: .text
+# CHECK:      Name: .debug_loc
+# CHECK:      Name: .comment
+# CHECK:      Name: .random_section_name
+# CHECK:      Name: .shstrtab


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