Remove DefinedSynthetic.
With this we have a single section hierarchy. It is a bit less code,
but the main advantage will be in a future patch being able to handle
foo = symbol_in_obj;
in a linker script. Currently that fails since we try to find the
output section of symbol_in_obj. With this we should be able to just
return an InputSection from the expression.
llvm-svn: 297313
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 45727ee..0e60c27 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -63,21 +63,10 @@
Cmd->Name, /*Type*/ 0, Visibility, /*CanOmitFromDynSym*/ false,
/*File*/ nullptr);
Sym->Binding = STB_GLOBAL;
+ OutputSection *Sec =
+ Cmd->Expression.IsAbsolute() ? nullptr : Cmd->Expression.Section();
replaceBody<DefinedRegular>(Sym, Cmd->Name, /*IsLocal=*/false, Visibility,
- STT_NOTYPE, 0, 0, nullptr, nullptr);
- return Sym->body();
-}
-
-template <class ELFT> static SymbolBody *addSynthetic(SymbolAssignment *Cmd) {
- Symbol *Sym;
- uint8_t Visibility = Cmd->Hidden ? STV_HIDDEN : STV_DEFAULT;
- const OutputSection *Sec =
- ScriptConfig->HasSections ? nullptr : Cmd->Expression.Section();
- std::tie(Sym, std::ignore) = Symtab<ELFT>::X->insert(
- Cmd->Name, /*Type*/ 0, Visibility, /*CanOmitFromDynSym*/ false,
- /*File*/ nullptr);
- Sym->Binding = STB_GLOBAL;
- replaceBody<DefinedSynthetic>(Sym, Cmd->Name, 0, Sec);
+ STT_NOTYPE, 0, 0, Sec, nullptr);
return Sym->body();
}
@@ -119,18 +108,14 @@
if (!Cmd->Sym)
return;
- if (auto *Body = dyn_cast<DefinedSynthetic>(Cmd->Sym)) {
- Body->Section = Cmd->Expression.Section();
- if (Body->Section) {
- uint64_t VA = 0;
- if (Body->Section->Flags & SHF_ALLOC)
- VA = Body->Section->Addr;
- Body->Value = Cmd->Expression(Dot) - VA;
- }
- return;
+ auto *Sym = cast<DefinedRegular>(Cmd->Sym);
+ Sym->Value = Cmd->Expression(Dot);
+ if (!Cmd->Expression.IsAbsolute()) {
+ Sym->Section = Cmd->Expression.Section();
+ if (auto *Sec = dyn_cast_or_null<OutputSection>(Sym->Section))
+ if (Sec->Flags & SHF_ALLOC)
+ Sym->Value -= Sec->Addr;
}
-
- cast<DefinedRegular>(Cmd->Sym)->Value = Cmd->Expression(Dot);
}
template <class ELFT>
@@ -144,12 +129,7 @@
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);
+ Cmd->Sym = addRegular<ELFT>(Cmd);
// If there are sections, then let the value be assigned later in
// `assignAddresses`.
@@ -321,6 +301,19 @@
template <class ELFT>
void LinkerScript<ELFT>::processCommands(OutputSectionFactory &Factory) {
+ // A symbol can be assigned before any section is mentioned in the linker
+ // script. In an DSO, the symbol values are addresses, so the only important
+ // section values are:
+ // * SHN_UNDEF
+ // * SHN_ABS
+ // * Any value meaning a regular section.
+ // To handle that, create a dummy aether section that fills the void before
+ // the linker scripts switches to another section. It has an index of one
+ // which will map to whatever the first actual section is.
+ Aether = make<OutputSection>("", 0, SHF_ALLOC);
+ Aether->SectionIndex = 1;
+ CurOutSec = Aether;
+
for (unsigned I = 0; I < Opt.Commands.size(); ++I) {
auto Iter = Opt.Commands.begin() + I;
const std::unique_ptr<BaseCommand> &Base1 = *Iter;
@@ -385,6 +378,7 @@
Factory.addInputSec<ELFT>(S, Cmd->Name);
}
}
+ CurOutSec = nullptr;
}
// Add sections that didn't match any sections command.
@@ -772,18 +766,6 @@
void LinkerScript<ELFT>::assignAddresses(std::vector<PhdrEntry> &Phdrs) {
// Assign addresses as instructed by linker script SECTIONS sub-commands.
Dot = 0;
-
- // A symbol can be assigned before any section is mentioned in the linker
- // script. In an DSO, the symbol values are addresses, so the only important
- // section values are:
- // * SHN_UNDEF
- // * SHN_ABS
- // * Any value meaning a regular section.
- // To handle that, create a dummy aether section that fills the void before
- // the linker scripts switches to another section. It has an index of one
- // which will map to whatever the first actual section is.
- auto *Aether = make<OutputSection>("", 0, SHF_ALLOC);
- Aether->SectionIndex = 1;
switchTo(Aether);
for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
@@ -924,8 +906,8 @@
}
template <class ELFT>
-const OutputSection *LinkerScript<ELFT>::getOutputSection(const Twine &Loc,
- StringRef Name) {
+OutputSection *LinkerScript<ELFT>::getOutputSection(const Twine &Loc,
+ StringRef Name) {
static OutputSection FakeSec("", 0, 0);
for (OutputSection *Sec : *OutputSections)
@@ -976,7 +958,7 @@
// specific section but isn't absolute at the same time, so we try
// to find suitable section for it as well.
template <class ELFT>
-const OutputSection *LinkerScript<ELFT>::getSymbolSection(StringRef S) {
+OutputSection *LinkerScript<ELFT>::getSymbolSection(StringRef S) {
if (SymbolBody *Sym = Symtab<ELFT>::X->find(S))
return Sym->getOutputSection<ELFT>();
return CurOutSec;
@@ -1634,7 +1616,7 @@
static Expr combine(StringRef Op, Expr L, Expr R) {
auto IsAbs = [=] { return L.IsAbsolute() && R.IsAbsolute(); };
auto GetOutSec = [=] {
- const OutputSection *S = L.Section();
+ OutputSection *S = L.Section();
return S ? S : R.Section();
};