commit 41695f8e7397dfa1bc1691a7f3198dbf65adb3f1
author Paul Semel <semelpaul@gmail.com> Wed May 02 20:19:22 2018 +0000
committer Paul Semel <semelpaul@gmail.com> Wed May 02 20:19:22 2018 +0000
tree 37c59efca37732a5129f792ba0f597730e9579a1
parent b374bca7eb48b5a4d37d416fd805cbd133c4bba2

[llvm-objcopy] Add --discard-all (-x) option

llvm-svn: 331400

llvm/tools/llvm-objcopy/Object.cpp

diff --git a/llvm/tools/llvm-objcopy/Object.cpp b/llvm/tools/llvm-objcopy/Object.cpp
index 07b6036..93487dc 100644
--- a/llvm/tools/llvm-objcopy/Object.cpp
+++ b/llvm/tools/llvm-objcopy/Object.cpp
@@ -194,12 +194,7 @@
           " cannot be removed because it is referenced by the symbol table " +
           this->Name);
   }
-  auto Iter =
-      std::remove_if(std::begin(Symbols), std::end(Symbols),
-                     [=](const SymPtr &Sym) { return Sym->DefinedIn == Sec; });
-  Size -= (std::end(Symbols) - Iter) * this->EntrySize;
-  Symbols.erase(Iter, std::end(Symbols));
-  assignIndices();
+  removeSymbols([Sec](const Symbol &Sym) { return Sym.DefinedIn == Sec; });
 }
 
 void SymbolTableSection::updateSymbols(function_ref<void(Symbol &)> Callable) {
@@ -211,6 +206,15 @@
   assignIndices();
 }
 
+void SymbolTableSection::removeSymbols(function_ref<bool(Symbol &)> ToRemove) {
+  Symbols.erase(
+      std::remove_if(std::begin(Symbols), std::end(Symbols),
+                     [ToRemove](const SymPtr &Sym) { return ToRemove(*Sym); }),
+      std::end(Symbols));
+  Size = Symbols.size() * EntrySize;
+  assignIndices();
+}
+
 void SymbolTableSection::initialize(SectionTableRef SecTable) {
   Size = 0;
   setStrTab(SecTable.getSectionOfType<StringTableSection>(

llvm/tools/llvm-objcopy/Object.h

diff --git a/llvm/tools/llvm-objcopy/Object.h b/llvm/tools/llvm-objcopy/Object.h
index 2598b24..845d681 100644
--- a/llvm/tools/llvm-objcopy/Object.h
+++ b/llvm/tools/llvm-objcopy/Object.h
@@ -366,6 +366,7 @@
   const SectionBase *getStrTab() const { return SymbolNames; }
   const Symbol *getSymbolByIndex(uint32_t Index) const;
   void updateSymbols(function_ref<void(Symbol &)> Callable);
+  void removeSymbols(function_ref<bool(Symbol &)> ToRemove);
 
   void removeSectionReferences(const SectionBase *Sec) override;
   void initialize(SectionTableRef SecTable) override;

llvm/tools/llvm-objcopy/Opts.td

diff --git a/llvm/tools/llvm-objcopy/Opts.td b/llvm/tools/llvm-objcopy/Opts.td
index 9698cef..487a312 100644
--- a/llvm/tools/llvm-objcopy/Opts.td
+++ b/llvm/tools/llvm-objcopy/Opts.td
@@ -74,3 +74,7 @@
         Alias<weaken_symbol>;
 def weaken : Flag<["-", "--"], "weaken">,
                   HelpText<"Mark all global symbols as weak">;
+def discard_all : Flag<["-", "--"], "discard-all">,
+                      HelpText<"Remove all local symbols except file and section symbols">;
+def x : Flag<["-"], "x">,
+        Alias<discard_all>;

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

diff --git a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
index 8bf7ac7..900a11d 100644
--- a/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ b/llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -131,6 +131,7 @@
   bool ExtractDWO;
   bool LocalizeHidden;
   bool Weaken;
+  bool DiscardAll;
 };
 
 using SectionPred = std::function<bool(const SectionBase &Sec)>;
@@ -343,6 +344,14 @@
       if (I != Config.SymbolsToRename.end())
         Sym.Name = I->getValue();
     });
+
+    Obj.SymbolTable->removeSymbols([&](const Symbol &Sym) {
+      if (Config.DiscardAll && Sym.Binding == STB_LOCAL &&
+          Sym.getShndx() != SHN_UNDEF && Sym.Type != STT_FILE &&
+          Sym.Type != STT_SECTION)
+        return true;
+      return false;
+    });
   }
 }
 
@@ -429,6 +438,7 @@
   Config.ExtractDWO = InputArgs.hasArg(OBJCOPY_extract_dwo);
   Config.LocalizeHidden = InputArgs.hasArg(OBJCOPY_localize_hidden);
   Config.Weaken = InputArgs.hasArg(OBJCOPY_weaken);
+  Config.DiscardAll = InputArgs.hasArg(OBJCOPY_discard_all);
   for (auto Arg : InputArgs.filtered(OBJCOPY_localize_symbol))
     Config.SymbolsToLocalize.push_back(Arg->getValue());
   for (auto Arg : InputArgs.filtered(OBJCOPY_globalize_symbol))