[llvm-objcopy] Add --prefix-symbols option

Differential Revision: https://reviews.llvm.org/D50381

llvm-svn: 339362

llvm/test/tools/llvm-objcopy/prefix-symbols.test

@@ -0,0 +1,71 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy --prefix-symbols prefix %t %t2
+# RUN: llvm-readobj -symbols %t2 | FileCheck %s --check-prefix=COMMON --check-prefix=BASIC
+# RUN: llvm-objcopy --redefine-sym bar=baz --prefix-symbols prefix %t %t3
+# RUN: llvm-readobj -symbols %t3 | FileCheck %s --check-prefix=COMMON --check-prefix=REDEF
+
+!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
+    Size:            64
+Symbols:
+  Local:
+    - Name:     foo
+      Type:     STT_SECTION
+      Section:  .text
+    - Name:     bar
+      Type:     STT_FILE
+      Section:  .text
+  Global:
+    - Name:     foobar
+      Type:     STT_FUNC
+      Section:  .text
+
+# COMMON: Symbols [
+# COMMON-NEXT:  Symbol {
+# COMMON-NEXT:    Name:
+# COMMON-NEXT:    Value: 0x0
+# COMMON-NEXT:    Size: 0
+# COMMON-NEXT:    Binding: Local
+# COMMON-NEXT:    Type: None
+# COMMON-NEXT:    Other: 0
+# COMMON-NEXT:    Section: Undefined
+# COMMON-NEXT:  }
+# COMMON-NEXT:  Symbol {
+# COMMON-NEXT:    Name: foo
+# COMMON-NEXT:    Value: 0x0
+# COMMON-NEXT:    Size: 0
+# COMMON-NEXT:    Binding: Local
+# COMMON-NEXT:    Type: Section
+# COMMON-NEXT:    Other: 0
+# COMMON-NEXT:    Section: .text
+# COMMON-NEXT:  }
+# COMMON-NEXT:  Symbol {
+# BASIC-NEXT:    Name: prefixbar
+# REDEF-NEXT:    Name: prefixbaz
+# COMMON-NEXT:    Value: 0x0
+# COMMON-NEXT:    Size: 0
+# COMMON-NEXT:    Binding: Local
+# COMMON-NEXT:    Type: File
+# COMMON-NEXT:    Other: 0
+# COMMON-NEXT:    Section: .text
+# COMMON-NEXT:  }
+# COMMON-NEXT:  Symbol {
+# COMMON-NEXT:    Name: prefixfoobar
+# COMMON-NEXT:    Value: 0x0
+# COMMON-NEXT:    Size: 0
+# COMMON-NEXT:    Binding: Global
+# COMMON-NEXT:    Type: Function
+# COMMON-NEXT:    Other: 0
+# COMMON-NEXT:    Section: .text
+# COMMON-NEXT:  }
+# COMMON-NEXT:]

llvm/tools/llvm-objcopy/ObjcopyOpts.td

@@ -105,3 +105,6 @@ def keep_file_symbols : Flag<["-", "--"], "keep-file-symbols">,
 defm dump_section : Eq<"dump-section">,
                    MetaVarName<"section=file">,
                    HelpText<"Dump contents of section named <section> into file <file>">;
+defm prefix_symbols : Eq<"prefix-symbols">,
+                       MetaVarName<"prefix">,
+                       HelpText<"Add <prefix> to the start of every symbol name">;

llvm/tools/llvm-objcopy/Object.h

@@ -387,7 +387,7 @@ struct Symbol {
   SectionBase *DefinedIn = nullptr;
   SymbolShndxType ShndxType;
   uint32_t Index;
-  StringRef Name;
+  std::string Name;
   uint32_t NameIndex;
   uint64_t Size;
   uint8_t Type;

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

@@ -133,6 +133,7 @@ struct CopyConfig {
 
   StringRef SplitDWO;
   StringRef AddGnuDebugLink;
+  StringRef SymbolsPrefix;
   std::vector<StringRef> ToRemove;
   std::vector<StringRef> Keep;
   std::vector<StringRef> OnlyKeep;
@@ -388,6 +389,9 @@ static void HandleArgs(const CopyConfig &Config, Object &Obj,
       const auto I = Config.SymbolsToRename.find(Sym.Name);
       if (I != Config.SymbolsToRename.end())
         Sym.Name = I->getValue();
+
+      if (!Config.SymbolsPrefix.empty() && Sym.Type != STT_SECTION)
+        Sym.Name = (Config.SymbolsPrefix + Sym.Name).str();
     });
 
     // The purpose of this loop is to mark symbols referenced by sections
@@ -723,6 +727,7 @@ static CopyConfig ParseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
 
   Config.SplitDWO = InputArgs.getLastArgValue(OBJCOPY_split_dwo);
   Config.AddGnuDebugLink = InputArgs.getLastArgValue(OBJCOPY_add_gnu_debuglink);
+  Config.SymbolsPrefix = InputArgs.getLastArgValue(OBJCOPY_prefix_symbols);
 
   for (auto Arg : InputArgs.filtered(OBJCOPY_redefine_symbol)) {
     if (!StringRef(Arg->getValue()).contains('='))