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authorDimitry Andric <dim@FreeBSD.org>2017-01-09 21:23:48 +0000
committerDimitry Andric <dim@FreeBSD.org>2017-01-09 21:23:48 +0000
commitb047fead11133644be3dbae34b85be39ce2819e9 (patch)
tree3e7f6a4c9e5ffd7af6044225e9be2962e4d8eabf /ELF/LinkerScript.cpp
parentc09ce7fd2d62d85dcdf370f4bef732380fca4f1b (diff)
downloadsrc-b047fead11133644be3dbae34b85be39ce2819e9.tar.gz
src-b047fead11133644be3dbae34b85be39ce2819e9.zip
Vendor import of lld trunk r291476:vendor/lld/lld-trunk-r291476
Notes
Notes: svn path=/vendor/lld/dist/; revision=311826 svn path=/vendor/lld/lld-trunk-r291476/; revision=311827; tag=vendor/lld/lld-trunk-r291476
Diffstat (limited to 'ELF/LinkerScript.cpp')
-rw-r--r--ELF/LinkerScript.cpp100
1 files changed, 59 insertions, 41 deletions
diff --git a/ELF/LinkerScript.cpp b/ELF/LinkerScript.cpp
index ccc1059949db..59ef36c87de5 100644
--- a/ELF/LinkerScript.cpp
+++ b/ELF/LinkerScript.cpp
@@ -56,29 +56,30 @@ using namespace lld::elf;
LinkerScriptBase *elf::ScriptBase;
ScriptConfiguration *elf::ScriptConfig;
-template <class ELFT> static void addRegular(SymbolAssignment *Cmd) {
+template <class ELFT> static SymbolBody *addRegular(SymbolAssignment *Cmd) {
uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
- Symbol *Sym = Symtab<ELFT>::X->addRegular(Cmd->Name, Visibility, STT_NOTYPE,
- 0, 0, STB_GLOBAL, nullptr, nullptr);
- Cmd->Sym = Sym->body();
+ Symbol *Sym = Symtab<ELFT>::X->addUndefined(
+ Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
+ /*Type*/ 0,
+ /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
- // If we have no SECTIONS then we don't have '.' and don't call
- // assignAddresses(). We calculate symbol value immediately in this case.
- if (!ScriptConfig->HasSections)
- cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Cmd->Expression(0);
+ replaceBody<DefinedRegular<ELFT>>(Sym, Cmd->Name, /*IsLocal=*/false,
+ Visibility, STT_NOTYPE, 0, 0, nullptr,
+ nullptr);
+ return Sym->body();
}
-template <class ELFT> static void addSynthetic(SymbolAssignment *Cmd) {
- // If we have SECTIONS block then output sections haven't been created yet.
+template <class ELFT> static SymbolBody *addSynthetic(SymbolAssignment *Cmd) {
+ uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
const OutputSectionBase *Sec =
ScriptConfig->HasSections ? nullptr : Cmd->Expression.Section();
- Symbol *Sym = Symtab<ELFT>::X->addSynthetic(
- Cmd->Name, Sec, 0, Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT);
- Cmd->Sym = Sym->body();
+ Symbol *Sym = Symtab<ELFT>::X->addUndefined(
+ Cmd->Name, /*IsLocal=*/false, STB_GLOBAL, Visibility,
+ /*Type*/ 0,
+ /*CanOmitFromDynSym*/ false, /*File*/ nullptr);
- // If we already know section then we can calculate symbol value immediately.
- if (Sec)
- cast<DefinedSynthetic>(Cmd->Sym)->Value = Cmd->Expression(0) - Sec->Addr;
+ replaceBody<DefinedSynthetic>(Sym, Cmd->Name, 0, Sec);
+ return Sym->body();
}
static bool isUnderSysroot(StringRef Path) {
@@ -90,21 +91,39 @@ static bool isUnderSysroot(StringRef Path) {
return false;
}
-template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
- if (Cmd->Expression.IsAbsolute())
- addRegular<ELFT>(Cmd);
- else
- addSynthetic<ELFT>(Cmd);
+template <class ELFT> static void assignSymbol(SymbolAssignment *Cmd) {
+ // If there are sections, then let the value be assigned later in
+ // `assignAddresses`.
+ if (ScriptConfig->HasSections)
+ return;
+
+ uint64_t Value = Cmd->Expression(0);
+ if (Cmd->Expression.IsAbsolute()) {
+ cast<DefinedRegular<ELFT>>(Cmd->Sym)->Value = Value;
+ } else {
+ const OutputSectionBase *Sec = Cmd->Expression.Section();
+ if (Sec)
+ cast<DefinedSynthetic>(Cmd->Sym)->Value = Value - Sec->Addr;
+ }
}
-// If a symbol was in PROVIDE(), we need to define it only when
-// it is an undefined symbol.
-template <class ELFT> static bool shouldDefine(SymbolAssignment *Cmd) {
+
+template <class ELFT> static void addSymbol(SymbolAssignment *Cmd) {
if (Cmd->Name == ".")
- return false;
- if (!Cmd->Provide)
- return true;
+ return;
+
+ // If a symbol was in PROVIDE(), we need to define it only when
+ // it is a referenced undefined symbol.
SymbolBody *B = Symtab<ELFT>::X->find(Cmd->Name);
- return B && B->isUndefined();
+ if (Cmd->Provide && (!B || B->isDefined()))
+ return;
+
+ // Otherwise, create a new symbol if one does not exist or an
+ // undefined one does exist.
+ if (Cmd->Expression.IsAbsolute())
+ Cmd->Sym = addRegular<ELFT>(Cmd);
+ else
+ Cmd->Sym = addSynthetic<ELFT>(Cmd);
+ assignSymbol<ELFT>(Cmd);
}
bool SymbolAssignment::classof(const BaseCommand *C) {
@@ -283,8 +302,7 @@ void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
// Handle symbol assignments outside of any output section.
if (auto *Cmd = dyn_cast<SymbolAssignment>(Base1.get())) {
- if (shouldDefine<ELFT>(Cmd))
- addSymbol<ELFT>(Cmd);
+ addSymbol<ELFT>(Cmd);
continue;
}
@@ -326,8 +344,7 @@ void LinkerScript<ELFT>::processCommands(OutputSectionFactory<ELFT> &Factory) {
// ".foo : { ...; bar = .; }". Handle them.
for (const std::unique_ptr<BaseCommand> &Base : Cmd->Commands)
if (auto *OutCmd = dyn_cast<SymbolAssignment>(Base.get()))
- if (shouldDefine<ELFT>(OutCmd))
- addSymbol<ELFT>(OutCmd);
+ addSymbol<ELFT>(OutCmd);
// Handle subalign (e.g. ".foo : SUBALIGN(32) { ... }"). If subalign
// is given, input sections are aligned to that value, whether the
@@ -1143,20 +1160,21 @@ void ScriptParser::readGroup() {
void ScriptParser::readInclude() {
StringRef Tok = unquote(next());
+
// https://sourceware.org/binutils/docs/ld/File-Commands.html:
// The file will be searched for in the current directory, and in any
// directory specified with the -L option.
- auto MBOrErr = MemoryBuffer::getFile(Tok);
- if (!MBOrErr)
- if (Optional<std::string> Path = findFromSearchPaths(Tok))
- MBOrErr = MemoryBuffer::getFile(*Path);
- if (!MBOrErr) {
- setError("cannot open " + Tok);
+ if (sys::fs::exists(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(Tok))
+ tokenize(*MB);
+ return;
+ }
+ if (Optional<std::string> Path = findFromSearchPaths(Tok)) {
+ if (Optional<MemoryBufferRef> MB = readFile(*Path))
+ tokenize(*MB);
return;
}
- MemoryBufferRef MBRef = (*MBOrErr)->getMemBufferRef();
- make<std::unique_ptr<MemoryBuffer>>(std::move(*MBOrErr)); // take MB ownership
- tokenize(MBRef);
+ setError("cannot open " + Tok);
}
void ScriptParser::readOutput() {