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Diffstat (limited to 'tools/llvm-objcopy/ELF/ELFConfig.cpp')
-rw-r--r-- | tools/llvm-objcopy/ELF/ELFConfig.cpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/tools/llvm-objcopy/ELF/ELFConfig.cpp b/tools/llvm-objcopy/ELF/ELFConfig.cpp new file mode 100644 index 000000000000..40993760add7 --- /dev/null +++ b/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 |