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-rw-r--r--lld/ELF/LinkerScript.cpp96
-rw-r--r--lld/ELF/LinkerScript.h5
-rw-r--r--lld/ELF/Writer.cpp2
3 files changed, 69 insertions, 34 deletions
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 74b5aa0f1fc..f7bc2370ba4 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -475,10 +475,15 @@ void LinkerScript::addOrphanSections(OutputSectionFactory &Factory) {
return Cmd->Name == Name;
return false;
});
- if (I == Opt.Commands.end())
+ if (I == Opt.Commands.end()) {
Factory.addInputSec(S, Name);
- else
- Factory.addInputSec(S, Name, cast<OutputSectionCommand>(*I)->Sec);
+ } else {
+ auto *Cmd = cast<OutputSectionCommand>(*I);
+ Factory.addInputSec(S, Name, Cmd->Sec);
+ auto *ISD = make<InputSectionDescription>("");
+ ISD->Sections.push_back(S);
+ Cmd->Commands.push_back(ISD);
+ }
}
}
@@ -487,8 +492,6 @@ static bool isTbss(OutputSection *Sec) {
}
void LinkerScript::output(InputSection *S) {
- if (!AlreadyOutputIS.insert(S).second)
- return;
bool IsTbss = isTbss(CurOutSec);
uint64_t Pos = IsTbss ? Dot + ThreadBssOffset : Dot;
@@ -520,19 +523,9 @@ void LinkerScript::output(InputSection *S) {
Dot = Pos;
}
-void LinkerScript::flush() {
- assert(CurOutSec);
- if (!AlreadyOutputOS.insert(CurOutSec).second)
- return;
- for (InputSection *I : CurOutSec->Sections)
- output(I);
-}
-
void LinkerScript::switchTo(OutputSection *Sec) {
if (CurOutSec == Sec)
return;
- if (AlreadyOutputOS.count(Sec))
- return;
CurOutSec = Sec;
@@ -583,7 +576,7 @@ void LinkerScript::process(BaseCommand &Base) {
if (!Sec->Live)
continue;
- assert(CurOutSec == Sec->OutSec || AlreadyOutputOS.count(Sec->OutSec));
+ assert(CurOutSec == Sec->OutSec);
output(cast<InputSection>(Sec));
}
}
@@ -642,19 +635,8 @@ void LinkerScript::assignOffsets(OutputSectionCommand *Cmd) {
Dot = CurMemRegion->Offset;
switchTo(Sec);
- // flush() may add orphan sections, so the order of flush() and
- // symbol assignments is important. We want to call flush() first so
- // that symbols pointing the end of the current section points to
- // the location after orphan sections.
- auto Mid =
- std::find_if(Cmd->Commands.rbegin(), Cmd->Commands.rend(),
- [](BaseCommand *Cmd) { return !isa<SymbolAssignment>(Cmd); })
- .base();
- for (auto I = Cmd->Commands.begin(); I != Mid; ++I)
- process(**I);
- flush();
- for (auto I = Mid, E = Cmd->Commands.end(); I != E; ++I)
- process(**I);
+ for (BaseCommand *C : Cmd->Commands)
+ process(*C);
}
void LinkerScript::removeEmptyCommands() {
@@ -824,15 +806,24 @@ void LinkerScript::placeOrphanSections() {
++CmdIndex;
}
+ // If there is no command corresponding to this output section,
+ // create one and put a InputSectionDescription in it so that both
+ // representations agree on which input sections to use.
auto Pos = std::find_if(CmdIter, E, [&](BaseCommand *Base) {
auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
return Cmd && Cmd->Name == Name;
});
if (Pos == E) {
auto *Cmd = make<OutputSectionCommand>(Name);
- Cmd->Sec = Sec;
Opt.Commands.insert(CmdIter, Cmd);
++CmdIndex;
+
+ Cmd->Sec = Sec;
+ auto *ISD = make<InputSectionDescription>("");
+ for (InputSection *IS : Sec->Sections)
+ ISD->Sections.push_back(IS);
+ Cmd->Commands.push_back(ISD);
+
continue;
}
@@ -850,6 +841,51 @@ void LinkerScript::processNonSectionCommands() {
}
}
+// Do a last effort at synchronizing the linker script "AST" and the section
+// list. This is needed to account for last minute changes, like adding a
+// .ARM.exidx terminator and sorting SHF_LINK_ORDER sections.
+//
+// FIXME: We should instead create the "AST" earlier and the above changes would
+// be done directly in the "AST".
+//
+// This can only handle new sections being added and sections being reordered.
+void LinkerScript::synchronize() {
+ for (BaseCommand *Base : Opt.Commands) {
+ auto *Cmd = dyn_cast<OutputSectionCommand>(Base);
+ if (!Cmd)
+ continue;
+ ArrayRef<InputSection *> Sections = Cmd->Sec->Sections;
+ std::vector<InputSectionBase **> ScriptSections;
+ DenseSet<InputSectionBase *> ScriptSectionsSet;
+ for (BaseCommand *Base : Cmd->Commands) {
+ auto *ISD = dyn_cast<InputSectionDescription>(Base);
+ if (!ISD)
+ continue;
+ for (InputSectionBase *&IS : ISD->Sections) {
+ if (IS->Live) {
+ ScriptSections.push_back(&IS);
+ ScriptSectionsSet.insert(IS);
+ }
+ }
+ }
+ std::vector<InputSectionBase *> Missing;
+ for (InputSection *IS : Sections)
+ if (!ScriptSectionsSet.count(IS))
+ Missing.push_back(IS);
+ if (!Missing.empty()) {
+ auto ISD = make<InputSectionDescription>("");
+ ISD->Sections = Missing;
+ Cmd->Commands.push_back(ISD);
+ for (InputSectionBase *&IS : ISD->Sections)
+ if (IS->Live)
+ ScriptSections.push_back(&IS);
+ }
+ assert(ScriptSections.size() == Sections.size());
+ for (int I = 0, N = Sections.size(); I < N; ++I)
+ *ScriptSections[I] = Sections[I];
+ }
+}
+
void LinkerScript::assignAddresses(std::vector<PhdrEntry> &Phdrs) {
// Assign addresses as instructed by linker script SECTIONS sub-commands.
Dot = 0;
diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h
index 61942b2db35..dd96d335a66 100644
--- a/lld/ELF/LinkerScript.h
+++ b/lld/ELF/LinkerScript.h
@@ -228,7 +228,6 @@ protected:
MemoryRegion *findMemoryRegion(OutputSectionCommand *Cmd);
void switchTo(OutputSection *Sec);
- void flush();
void output(InputSection *Sec);
void process(BaseCommand &Base);
@@ -242,9 +241,6 @@ protected:
OutputSection *CurOutSec = nullptr;
MemoryRegion *CurMemRegion = nullptr;
- llvm::DenseSet<OutputSection *> AlreadyOutputOS;
- llvm::DenseSet<InputSectionBase *> AlreadyOutputIS;
-
public:
bool hasPhdrsCommands() { return !Opt.PhdrsCommands.empty(); }
uint64_t getDot() { return Dot; }
@@ -271,6 +267,7 @@ public:
void assignOffsets(OutputSectionCommand *Cmd);
void placeOrphanSections();
void processNonSectionCommands();
+ void synchronize();
void assignAddresses(std::vector<PhdrEntry> &Phdrs);
int getSectionIndex(StringRef Name);
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index f4d41ebfa78..e2ab48433a5 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -254,6 +254,7 @@ template <class ELFT> void Writer<ELFT>::run() {
fixSectionAlignments();
Script->fabricateDefaultCommands(Config->MaxPageSize);
}
+ Script->synchronize();
Script->assignAddresses(Phdrs);
// Remove empty PT_LOAD to avoid causing the dynamic linker to try to mmap a
@@ -1080,6 +1081,7 @@ static void removeUnusedSyntheticSections(std::vector<OutputSection *> &V) {
SS->OutSec->Sections.erase(std::find(SS->OutSec->Sections.begin(),
SS->OutSec->Sections.end(), SS));
+ SS->Live = false;
// If there are no other sections in the output section, remove it from the
// output.
if (SS->OutSec->Sections.empty())
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