[llvm-objcopy] Add basic support for --rename-section

Summary:
Add basic support for --rename-section=old=new to llvm-objcopy.

A full replacement for GNU objcopy requires also modifying flags (i.e. --rename-section=old=new,flag1,flag2); I'd like to keep that in a separate change to keep this simple.

Reviewers: jakehehrlich, alexshap

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49576

llvm-svn: 337604

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index 12e9ca17e19..3a25e3f690b 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -133,6 +133,7 @@ struct CopyConfig {
   std::vector<StringRef> SymbolsToWeaken;
   std::vector<StringRef> SymbolsToRemove;
   std::vector<StringRef> SymbolsToKeep;
+  StringMap<StringRef> SectionsToRename;
   StringMap<StringRef> SymbolsToRename;
   bool StripAll = false;
   bool StripAllGNU = false;
@@ -430,6 +431,14 @@ static void HandleArgs(const CopyConfig &Config, Object &Obj,
 
   Obj.removeSections(RemovePred);
 
+  if (!Config.SectionsToRename.empty()) {
+    for (auto &Sec : Obj.sections()) {
+      const auto Iter = Config.SectionsToRename.find(Sec.Name);
+      if (Iter != Config.SectionsToRename.end())
+        Sec.Name = Iter->second;
+    }
+  }
+
   if (!Config.AddSection.empty()) {
     for (const auto &Flag : Config.AddSection) {
       auto SecPair = Flag.split("=");
@@ -587,6 +596,14 @@ static CopyConfig ParseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
       error("Multiple redefinition of symbol " + Old2New.first);
   }
 
+  for (auto Arg : InputArgs.filtered(OBJCOPY_rename_section)) {
+    if (!StringRef(Arg->getValue()).contains('='))
+      error("Bad format for --rename-section");
+    auto Old2New = StringRef(Arg->getValue()).split('=');
+    if (!Config.SectionsToRename.insert(Old2New).second)
+      error("Already have a section rename for " + Old2New.first);
+  }
+
   for (auto Arg : InputArgs.filtered(OBJCOPY_remove_section))
     Config.ToRemove.push_back(Arg->getValue());
   for (auto Arg : InputArgs.filtered(OBJCOPY_keep))