[llvm-objcopy] Allow the visibility of symbols created by --binary and

--add-symbol to be specified with --new-symbol-visibility

llvm-svn: 370458

11 files changed, 111 insertions, 23 deletions

diff --git a/llvm/docs/CommandGuide/llvm-objcopy.rst b/llvm/docs/CommandGuide/llvm-objcopy.rst
index 044293c7e8a..065811c782b 100644
--- a/llvm/docs/CommandGuide/llvm-objcopy.rst
+++ b/llvm/docs/CommandGuide/llvm-objcopy.rst
@@ -318,6 +318,18 @@ them.
  represents a single symbol, with leading and trailing whitespace ignored, as is
  anything following a '#'. Can be specified multiple times to read names from
  multiple files.
+ 
+.. option:: --new-symbol-visibility <visibility>
+
+ Specify the visibility of the symbols automatically created when using binary
+ input or :option:`--add-symbol`. Valid options are:
+
+ - `default`
+ - `hidden`
+ - `internal`
+ - `protected`
+
+ The default is `default`.
 
 .. option:: --output-target <format>, -O
 
diff --git a/llvm/test/tools/llvm-objcopy/ELF/add-symbol-new-symbol-visibility.test b/llvm/test/tools/llvm-objcopy/ELF/add-symbol-new-symbol-visibility.test
new file mode 100644
index 00000000000..9ef5849f991
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/ELF/add-symbol-new-symbol-visibility.test
@@ -0,0 +1,20 @@
+## Ensure that the visibility of symbols added with --add-symbol can be
+## specified with the --new-symbol-visibility switch.
+
+# RUN: yaml2obj %s -o %t.obj
+# RUN: llvm-objcopy --new-symbol-visibility protected --add-symbol symbol_protected=.text:42 \
+# RUN:              --add-symbol symbol_hidden=.text:42,hidden %t.obj %t
+# RUN: llvm-readelf -s %t | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64
+Sections:
+  - Name: .text
+    Type: SHT_PROGBITS
+
+# CHECK: PROTECTED {{.*}} symbol_protected
+# CHECK: HIDDEN {{.*}} symbol_hidden
diff --git a/llvm/test/tools/llvm-objcopy/ELF/new-symbol-visibility.test b/llvm/test/tools/llvm-objcopy/ELF/new-symbol-visibility.test
new file mode 100644
index 00000000000..143a18c0a7e
--- /dev/null
+++ b/llvm/test/tools/llvm-objcopy/ELF/new-symbol-visibility.test
@@ -0,0 +1,22 @@
+## Ensure that the visibility of the start, end and size symbols created when
+## using binary input can be specified with the --new-symbol-visibility switch.
+
+# RUN: llvm-objcopy -I binary -B i386:x86-64 %s %t.unspecified
+# RUN: llvm-readelf -s %t.unspecified | FileCheck %s --check-prefix=BINARY -DVISIBILITY=DEFAULT
+# RUN: llvm-objcopy --new-symbol-visibility default -I binary -B i386:x86-64 %s %t.default
+# RUN: llvm-readelf -s %t.default | FileCheck %s --check-prefix=BINARY -DVISIBILITY=DEFAULT
+# RUN: llvm-objcopy --new-symbol-visibility hidden -I binary -B i386:x86-64 %s %t.hidden
+# RUN: llvm-readelf -s %t.hidden | FileCheck %s --check-prefix=BINARY -DVISIBILITY=HIDDEN
+# RUN: llvm-objcopy --new-symbol-visibility protected -I binary -B i386:x86-64 %s %t.protected
+# RUN: llvm-readelf -s %t.protected | FileCheck %s --check-prefix=BINARY -DVISIBILITY=PROTECTED
+# RUN: llvm-objcopy --new-symbol-visibility internal -I binary -B i386:x86-64 %s %t.internal
+# RUN: llvm-readelf -s %t.internal | FileCheck %s --check-prefix=BINARY -DVISIBILITY=INTERNAL
+
+# BINARY:      [[VISIBILITY]] {{.*}} _binary{{.*}}_start
+# BINARY-NEXT: [[VISIBILITY]] {{.*}} _binary{{.*}}_end
+# BINARY-NEXT: [[VISIBILITY]] {{.*}} _binary{{.*}}_size
+
+# RUN: not llvm-objcopy --new-symbol-visibility fluff -I binary -B i386:x86-64 %s %t.error 2>&1 \
+# RUN:   | FileCheck %s --check-prefix=ERR
+
+# ERR: error: 'fluff' is not a valid symbol visibility
diff --git a/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp b/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
index 55bf69ce85b..28de0eb6efd 100644
--- a/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/COFF/COFFObjcopy.cpp
@@ -204,14 +204,14 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj) {
       Config.BuildIdLinkInput || Config.BuildIdLinkOutput ||
       !Config.SplitDWO.empty() || !Config.SymbolsPrefix.empty() ||
       !Config.AllocSectionsPrefix.empty() || !Config.DumpSection.empty() ||
-      !Config.KeepSection.empty() || !Config.SymbolsToGlobalize.empty() ||
-      !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
-      !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
-      !Config.SectionsToRename.empty() || !Config.SetSectionFlags.empty() ||
-      !Config.SymbolsToRename.empty() || Config.ExtractDWO ||
-      Config.KeepFileSymbols || Config.LocalizeHidden || Config.PreserveDates ||
-      Config.StripDWO || Config.StripNonAlloc || Config.StripSections ||
-      Config.Weaken || Config.DecompressDebugSections ||
+      !Config.KeepSection.empty() || Config.NewSymbolVisibility ||
+      !Config.SymbolsToGlobalize.empty() || !Config.SymbolsToKeep.empty() ||
+      !Config.SymbolsToLocalize.empty() || !Config.SymbolsToWeaken.empty() ||
+      !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() ||
+      !Config.SetSectionFlags.empty() || !Config.SymbolsToRename.empty() ||
+      Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
+      Config.PreserveDates || Config.StripDWO || Config.StripNonAlloc ||
+      Config.StripSections || Config.Weaken || Config.DecompressDebugSections ||
       Config.DiscardMode == DiscardType::Locals ||
       !Config.SymbolsToAdd.empty() || Config.EntryExpr) {
     return createStringError(llvm::errc::invalid_argument,
diff --git a/llvm/tools/llvm-objcopy/CopyConfig.cpp b/llvm/tools/llvm-objcopy/CopyConfig.cpp
index 2c1dab98c53..9591e5aeb77 100644
--- a/llvm/tools/llvm-objcopy/CopyConfig.cpp
+++ b/llvm/tools/llvm-objcopy/CopyConfig.cpp
@@ -177,7 +177,8 @@ parseSetSectionFlagValue(StringRef FlagValue) {
   return SFU;
 }
 
-static Expected<NewSymbolInfo> parseNewSymbolInfo(StringRef FlagValue) {
+static Expected<NewSymbolInfo> parseNewSymbolInfo(StringRef FlagValue,
+                                                  uint8_t DefaultVisibility) {
   // Parse value given with --add-symbol option and create the
   // new symbol if possible. The value format for --add-symbol is:
   //
@@ -222,6 +223,8 @@ static Expected<NewSymbolInfo> parseNewSymbolInfo(StringRef FlagValue) {
     return createStringError(errc::invalid_argument, "bad symbol value: '%s'",
                              Flags[0].str().c_str());
 
+  SI.Visibility = DefaultVisibility;
+
   using Functor = std::function<void(void)>;
   SmallVector<StringRef, 6> UnsupportedFlags;
   for (size_t I = 1, NumFlags = Flags.size(); I < NumFlags; ++I)
@@ -488,6 +491,21 @@ Expected<DriverConfig> parseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
     Config.BinaryArch = *MI;
   }
 
+  if (opt::Arg *A = InputArgs.getLastArg(OBJCOPY_new_symbol_visibility)) {
+    const uint8_t Invalid = 0xff;
+    Config.NewSymbolVisibility = StringSwitch<uint8_t>(A->getValue())
+                                     .Case("default", ELF::STV_DEFAULT)
+                                     .Case("hidden", ELF::STV_HIDDEN)
+                                     .Case("internal", ELF::STV_INTERNAL)
+                                     .Case("protected", ELF::STV_PROTECTED)
+                                     .Default(Invalid);
+
+    if (Config.NewSymbolVisibility == Invalid)
+      return createStringError(
+          errc::invalid_argument, "'%s' is not a valid symbol visibility",
+          InputArgs.getLastArgValue(OBJCOPY_new_symbol_visibility).str().c_str());
+  }
+
   Config.OutputFormat = StringSwitch<FileFormat>(OutputFormat)
                             .Case("binary", FileFormat::Binary)
                             .Case("ihex", FileFormat::IHex)
@@ -696,7 +714,9 @@ Expected<DriverConfig> parseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
                                      Arg->getValue(), UseRegex))
       return std::move(E);
   for (auto Arg : InputArgs.filtered(OBJCOPY_add_symbol)) {
-    Expected<NewSymbolInfo> NSI = parseNewSymbolInfo(Arg->getValue());
+    Expected<NewSymbolInfo> NSI = parseNewSymbolInfo(
+        Arg->getValue(),
+        Config.NewSymbolVisibility.getValueOr(ELF::STV_DEFAULT));
     if (!NSI)
       return NSI.takeError();
     Config.SymbolsToAdd.push_back(*NSI);
diff --git a/llvm/tools/llvm-objcopy/CopyConfig.h b/llvm/tools/llvm-objcopy/CopyConfig.h
index f7bb587d8e0..e7f293d7fc2 100644
--- a/llvm/tools/llvm-objcopy/CopyConfig.h
+++ b/llvm/tools/llvm-objcopy/CopyConfig.h
@@ -145,6 +145,7 @@ struct CopyConfig {
   StringRef SymbolsPrefix;
   StringRef AllocSectionsPrefix;
   DiscardType DiscardMode = DiscardType::None;
+  Optional<uint8_t> NewSymbolVisibility;
 
   // Repeated options
   std::vector<StringRef> AddSection;
diff --git a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
index bfc2ecaa2c8..07197769996 100644
--- a/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
@@ -755,7 +755,9 @@ Error executeObjcopyOnIHex(const CopyConfig &Config, MemoryBuffer &In,
 
 Error executeObjcopyOnRawBinary(const CopyConfig &Config, MemoryBuffer &In,
                                 Buffer &Out) {
-  BinaryReader Reader(Config.BinaryArch, &In);
+  uint8_t NewSymbolVisibility =
+      Config.NewSymbolVisibility.getValueOr(ELF::STV_DEFAULT);
+  BinaryReader Reader(Config.BinaryArch, &In, NewSymbolVisibility);
   std::unique_ptr<Object> Obj = Reader.create();
 
   // Prefer OutputArch (-O<format>) if set, otherwise fallback to BinaryArch
diff --git a/llvm/tools/llvm-objcopy/ELF/Object.cpp b/llvm/tools/llvm-objcopy/ELF/Object.cpp
index 79245aef026..54cddcdd2cd 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/Object.cpp
@@ -1161,11 +1161,12 @@ void BinaryELFBuilder::addData(SymbolTableSection *SymTab) {
   Twine Prefix = Twine("_binary_") + SanitizedFilename;
 
   SymTab->addSymbol(Prefix + "_start", STB_GLOBAL, STT_NOTYPE, &DataSection,
-                    /*Value=*/0, STV_DEFAULT, 0, 0);
+                    /*Value=*/0, NewSymbolVisibility, 0, 0);
   SymTab->addSymbol(Prefix + "_end", STB_GLOBAL, STT_NOTYPE, &DataSection,
-                    /*Value=*/DataSection.Size, STV_DEFAULT, 0, 0);
+                    /*Value=*/DataSection.Size, NewSymbolVisibility, 0, 0);
   SymTab->addSymbol(Prefix + "_size", STB_GLOBAL, STT_NOTYPE, nullptr,
-                    /*Value=*/DataSection.Size, STV_DEFAULT, SHN_ABS, 0);
+                    /*Value=*/DataSection.Size, NewSymbolVisibility, SHN_ABS,
+                    0);
 }
 
 std::unique_ptr<Object> BinaryELFBuilder::build() {
@@ -1610,7 +1611,7 @@ Writer::~Writer() {}
 Reader::~Reader() {}
 
 std::unique_ptr<Object> BinaryReader::create() const {
-  return BinaryELFBuilder(MInfo.EMachine, MemBuf).build();
+  return BinaryELFBuilder(MInfo.EMachine, MemBuf, NewSymbolVisibility).build();
 }
 
 Expected<std::vector<IHexRecord>> IHexReader::parse() const {
diff --git a/llvm/tools/llvm-objcopy/ELF/Object.h b/llvm/tools/llvm-objcopy/ELF/Object.h
index 42d254c1b2b..42844dae3b4 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.h
+++ b/llvm/tools/llvm-objcopy/ELF/Object.h
@@ -889,11 +889,13 @@ public:
 
 class BinaryELFBuilder : public BasicELFBuilder {
   MemoryBuffer *MemBuf;
+  uint8_t NewSymbolVisibility;
   void addData(SymbolTableSection *SymTab);
 
 public:
-  BinaryELFBuilder(uint16_t EM, MemoryBuffer *MB)
-      : BasicELFBuilder(EM), MemBuf(MB) {}
+  BinaryELFBuilder(uint16_t EM, MemoryBuffer *MB, uint8_t NewSymbolVisibility)
+      : BasicELFBuilder(EM), MemBuf(MB),
+        NewSymbolVisibility(NewSymbolVisibility) {}
 
   std::unique_ptr<Object> build();
 };
@@ -942,10 +944,12 @@ public:
 class BinaryReader : public Reader {
   const MachineInfo &MInfo;
   MemoryBuffer *MemBuf;
+  uint8_t NewSymbolVisibility;
 
 public:
-  BinaryReader(const MachineInfo &MI, MemoryBuffer *MB)
-      : MInfo(MI), MemBuf(MB) {}
+  BinaryReader(const MachineInfo &MI, MemoryBuffer *MB,
+               const uint8_t NewSymbolVisibility)
+      : MInfo(MI), MemBuf(MB), NewSymbolVisibility(NewSymbolVisibility) {}
   std::unique_ptr<Object> create() const override;
 };
 
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
index c59fa2bd795..a52931e469f 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
@@ -25,10 +25,11 @@ static Error handleArgs(const CopyConfig &Config, Object &Obj) {
       !Config.SplitDWO.empty() || !Config.SymbolsPrefix.empty() ||
       !Config.AllocSectionsPrefix.empty() || !Config.AddSection.empty() ||
       !Config.DumpSection.empty() || !Config.KeepSection.empty() ||
-      !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.OnlySection.empty() ||
+      !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.SetSectionFlags.empty() || !Config.ToRemove.empty() ||
       Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
diff --git a/llvm/tools/llvm-objcopy/ObjcopyOpts.td b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
index 94a4dc8bfb1..55e26fc881e 100644
--- a/llvm/tools/llvm-objcopy/ObjcopyOpts.td
+++ b/llvm/tools/llvm-objcopy/ObjcopyOpts.td
@@ -25,6 +25,11 @@ def O : JoinedOrSeparate<["-"], "O">,
         Alias<output_target>,
         HelpText<"Alias for --output-target">;
 
+defm new_symbol_visibility : Eq<"new-symbol-visibility", "Visibility of "
+                                "symbols generated for binary input or added"
+                                " with --add-symbol unless otherwise"
+                                " specified. The default value is 'default'.">;
+
 def compress_debug_sections : Flag<["--"], "compress-debug-sections">;
 def compress_debug_sections_eq
     : Joined<["--"], "compress-debug-sections=">,