commit 7f19dd1ebff0456feaf18437bb231856b6e49b5c
author Seiya Nuta <nuta@seiya.me> Mon Oct 28 15:40:37 2019 +0900
committer Seiya Nuta <nuta@seiya.me> Mon Oct 28 16:00:20 2019 +0900
tree cd2df1153e4fec073471b5347977b359ba8bddec
parent f4d7caf6df819d18b4d5b460d21f7f8fe1e1b705

[llvm-objcopy][MachO] Implement --only-section

Reviewers: alexshap, rupprecht, jdoerfert, jhenderson

Reviewed By: alexshap, rupprecht, jhenderson

Subscribers: mgorny, jakehehrlich, abrachet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65541

llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp

diff --git a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
index 6d586e7..73983a1 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
@@ -18,6 +18,19 @@
 namespace macho {
 
 using namespace object;
+using SectionPred = std::function<bool(const Section &Sec)>;
+
+static void removeSections(const CopyConfig &Config, Object &Obj) {
+  SectionPred RemovePred = [](const Section &) { return false; };
+
+  if (!Config.OnlySection.empty()) {
+    RemovePred = [&Config, RemovePred](const Section &Sec) {
+      return !Config.OnlySection.matches(Sec.CanonicalName);
+    };
+  }
+
+  return Obj.removeSections(RemovePred);
+}
 
 static Error handleArgs(const CopyConfig &Config, Object &Obj) {
   if (Config.AllowBrokenLinks || !Config.BuildIdLinkDir.empty() ||
@@ -25,11 +38,10 @@
       !Config.SplitDWO.empty() || !Config.SymbolsPrefix.empty() ||
       !Config.AllocSectionsPrefix.empty() || !Config.AddSection.empty() ||
       !Config.DumpSection.empty() || !Config.KeepSection.empty() ||
-      Config.NewSymbolVisibility || !Config.OnlySection.empty() ||
-      !Config.SymbolsToGlobalize.empty() || !Config.SymbolsToKeep.empty() ||
-      !Config.SymbolsToLocalize.empty() || !Config.SymbolsToWeaken.empty() ||
-      !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() ||
-      !Config.SymbolsToRename.empty() ||
+      Config.NewSymbolVisibility || !Config.SymbolsToGlobalize.empty() ||
+      !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
+      !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
+      !Config.SectionsToRename.empty() || !Config.SymbolsToRename.empty() ||
       !Config.UnneededSymbolsToRemove.empty() ||
       !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() ||
       !Config.ToRemove.empty() || Config.ExtractDWO || Config.KeepFileSymbols ||
@@ -43,6 +55,7 @@
                              "option not supported by llvm-objcopy for MachO");
   }
 
+  removeSections(Config, Obj);
   return Error::success();
 }
 

llvm/tools/llvm-objcopy/MachO/MachOReader.cpp

diff --git a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
index b48a0d8..ed2b3eb 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOReader.cpp
@@ -35,6 +35,7 @@
           .str();
   S.Segname =
       StringRef(Sec.segname, strnlen(Sec.segname, sizeof(Sec.sectname))).str();
+  S.CanonicalName = (Twine(S.Segname) + "," + S.Sectname).str();
   S.Addr = Sec.addr;
   S.Size = Sec.size;
   S.Offset = Sec.offset;

llvm/tools/llvm-objcopy/MachO/Object.cpp

diff --git a/llvm/tools/llvm-objcopy/MachO/Object.cpp b/llvm/tools/llvm-objcopy/MachO/Object.cpp
index 264f39c..ba3e2ef 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/Object.cpp
@@ -10,6 +10,13 @@
   return Symbols[Index].get();
 }
 
+void Object::removeSections(function_ref<bool(const Section &)> ToRemove) {
+  for (LoadCommand &LC : LoadCommands)
+    LC.Sections.erase(std::remove_if(std::begin(LC.Sections),
+                                     std::end(LC.Sections), ToRemove),
+                      std::end(LC.Sections));
+}
+
 } // end namespace macho
 } // end namespace objcopy
 } // end namespace llvm

llvm/tools/llvm-objcopy/MachO/Object.h

diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 1cebf82..36b0f7e 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -38,6 +38,8 @@
 struct Section {
   std::string Sectname;
   std::string Segname;
+  // CanonicalName is a string formatted as “<Segname>,<Sectname>".
+  std::string CanonicalName;
   uint64_t Addr;
   uint64_t Size;
   uint32_t Offset;
@@ -250,6 +252,8 @@
   Optional<size_t> DataInCodeCommandIndex;
   /// The index LC_FUNCTION_STARTS load comamnd if present.
   Optional<size_t> FunctionStartsCommandIndex;
+
+  void removeSections(function_ref<bool(const Section &)> ToRemove);
 };
 
 } // end namespace macho