1 files changed, 133 insertions, 0 deletions
diff --git a/llvm/tools/llvm-objcopy/ELF/ELFConfig.cpp b/llvm/tools/llvm-objcopy/ELF/ELFConfig.cpp
new file mode 100644
index 000000000000..40993760add7
--- /dev/null
+++ b/llvm/tools/llvm-objcopy/ELF/ELFConfig.cpp
@@ -0,0 +1,133 @@
+//===- ELFConfig.cpp ------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "CopyConfig.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/Error.h"
+
+namespace llvm {
+namespace objcopy {
+namespace elf {
+
+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:
+  //
+  // <name>=[<section>:]<value>[,<flags>]
+  //
+  // where:
+  // <name> - symbol name, can be empty string
+  // <section> - optional section name. If not given ABS symbol is created
+  // <value> - symbol value, can be decimal or hexadecimal number prefixed
+  //           with 0x.
+  // <flags> - optional flags affecting symbol type, binding or visibility:
+  //           The following are currently supported:
+  //
+  //           global, local, weak, default, hidden, file, section, object,
+  //           indirect-function.
+  //
+  //           The following flags are ignored and provided for GNU
+  //           compatibility only:
+  //
+  //           warning, debug, constructor, indirect, synthetic,
+  //           unique-object, before=<symbol>.
+  NewSymbolInfo SI;
+  StringRef Value;
+  std::tie(SI.SymbolName, Value) = FlagValue.split('=');
+  if (Value.empty())
+    return createStringError(
+        errc::invalid_argument,
+        "bad format for --add-symbol, missing '=' after '%s'",
+        SI.SymbolName.str().c_str());
+
+  if (Value.contains(':')) {
+    std::tie(SI.SectionName, Value) = Value.split(':');
+    if (SI.SectionName.empty() || Value.empty())
+      return createStringError(
+          errc::invalid_argument,
+          "bad format for --add-symbol, missing section name or symbol value");
+  }
+
+  SmallVector<StringRef, 6> Flags;
+  Value.split(Flags, ',');
+  if (Flags[0].getAsInteger(0, SI.Value))
+    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)
+    static_cast<Functor>(
+        StringSwitch<Functor>(Flags[I])
+            .CaseLower("global", [&SI] { SI.Bind = ELF::STB_GLOBAL; })
+            .CaseLower("local", [&SI] { SI.Bind = ELF::STB_LOCAL; })
+            .CaseLower("weak", [&SI] { SI.Bind = ELF::STB_WEAK; })
+            .CaseLower("default", [&SI] { SI.Visibility = ELF::STV_DEFAULT; })
+            .CaseLower("hidden", [&SI] { SI.Visibility = ELF::STV_HIDDEN; })
+            .CaseLower("protected",
+                       [&SI] { SI.Visibility = ELF::STV_PROTECTED; })
+            .CaseLower("file", [&SI] { SI.Type = ELF::STT_FILE; })
+            .CaseLower("section", [&SI] { SI.Type = ELF::STT_SECTION; })
+            .CaseLower("object", [&SI] { SI.Type = ELF::STT_OBJECT; })
+            .CaseLower("function", [&SI] { SI.Type = ELF::STT_FUNC; })
+            .CaseLower("indirect-function",
+                       [&SI] { SI.Type = ELF::STT_GNU_IFUNC; })
+            .CaseLower("debug", [] {})
+            .CaseLower("constructor", [] {})
+            .CaseLower("warning", [] {})
+            .CaseLower("indirect", [] {})
+            .CaseLower("synthetic", [] {})
+            .CaseLower("unique-object", [] {})
+            .StartsWithLower("before", [] {})
+            .Default([&] { UnsupportedFlags.push_back(Flags[I]); }))();
+  if (!UnsupportedFlags.empty())
+    return createStringError(errc::invalid_argument,
+                             "unsupported flag%s for --add-symbol: '%s'",
+                             UnsupportedFlags.size() > 1 ? "s" : "",
+                             join(UnsupportedFlags, "', '").c_str());
+  return SI;
+}
+
+Expected<ELFCopyConfig> parseConfig(const CopyConfig &Config) {
+  ELFCopyConfig ELFConfig;
+  if (Config.NewSymbolVisibility) {
+    const uint8_t Invalid = 0xff;
+    ELFConfig.NewSymbolVisibility =
+        StringSwitch<uint8_t>(*Config.NewSymbolVisibility)
+            .Case("default", ELF::STV_DEFAULT)
+            .Case("hidden", ELF::STV_HIDDEN)
+            .Case("internal", ELF::STV_INTERNAL)
+            .Case("protected", ELF::STV_PROTECTED)
+            .Default(Invalid);
+
+    if (ELFConfig.NewSymbolVisibility == Invalid)
+      return createStringError(errc::invalid_argument,
+                               "'%s' is not a valid symbol visibility",
+                               Config.NewSymbolVisibility->str().c_str());
+  }
+
+  for (StringRef Arg : Config.SymbolsToAdd) {
+    Expected<elf::NewSymbolInfo> NSI = parseNewSymbolInfo(
+        Arg,
+        ELFConfig.NewSymbolVisibility.getValueOr((uint8_t)ELF::STV_DEFAULT));
+    if (!NSI)
+      return NSI.takeError();
+    ELFConfig.SymbolsToAdd.push_back(*NSI);
+  }
+
+  return ELFConfig;
+}
+
+} // end namespace elf
+} // end namespace objcopy
+} // end namespace llvm