[lld-macho][NFC] Refactor ObjCSelRefsSection => ObjCSelRefsHelper (#86456)
In a previous PR: https://github.com/llvm/llvm-project/pull/83878, the
intent was to make no functional changes, just refactor out the code for
reuse.
However, by creating `ObjCSelRefsSection` as a `SyntheticSection` - this
slightly changed the functionality of the application as the
`SyntheticSection` constructor registers the `SyntheticSection` as a
functional one - with an associated `SyntheticInputSection`.
With this change we remove this unintended consequence by making the
code not use a `SyntheticSection` as base, but just by having it be a
static helper.
GitOrigin-RevId: e1a003dbbd016f57b349c87981bf210f8ec3e1e0
diff --git a/MachO/Driver.cpp b/MachO/Driver.cpp
index 919a14b..14c111c 100644
--- a/MachO/Driver.cpp
+++ b/MachO/Driver.cpp
@@ -1394,6 +1394,7 @@
syntheticSections.clear();
thunkMap.clear();
unprocessedLCLinkerOptions.clear();
+ ObjCSelRefsHelper::cleanup();
firstTLVDataSection = nullptr;
tar = nullptr;
diff --git a/MachO/SyntheticSections.cpp b/MachO/SyntheticSections.cpp
index 1b36945..0afbbd4 100644
--- a/MachO/SyntheticSections.cpp
+++ b/MachO/SyntheticSections.cpp
@@ -806,10 +806,9 @@
dyldPrivate->used = true;
}
-ObjCSelRefsSection::ObjCSelRefsSection()
- : SyntheticSection(segment_names::data, section_names::objcSelrefs) {}
-
-void ObjCSelRefsSection::initialize() {
+llvm::DenseMap<llvm::CachedHashStringRef, ConcatInputSection *>
+ ObjCSelRefsHelper::methnameToSelref;
+void ObjCSelRefsHelper::initialize() {
// Do not fold selrefs without ICF.
if (config->icfLevel == ICFLevel::none)
return;
@@ -836,7 +835,9 @@
}
}
-ConcatInputSection *ObjCSelRefsSection::makeSelRef(StringRef methname) {
+void ObjCSelRefsHelper::cleanup() { methnameToSelref.clear(); }
+
+ConcatInputSection *ObjCSelRefsHelper::makeSelRef(StringRef methname) {
auto methnameOffset =
in.objcMethnameSection->getStringOffset(methname).outSecOff;
@@ -861,7 +862,7 @@
return objcSelref;
}
-ConcatInputSection *ObjCSelRefsSection::getSelRef(StringRef methname) {
+ConcatInputSection *ObjCSelRefsHelper::getSelRef(StringRef methname) {
auto it = methnameToSelref.find(CachedHashStringRef(methname));
if (it == methnameToSelref.end())
return nullptr;
@@ -890,8 +891,8 @@
void ObjCStubsSection::addEntry(Symbol *sym) {
StringRef methname = getMethname(sym);
// We create a selref entry for each unique methname.
- if (!in.objcSelRefs->getSelRef(methname))
- in.objcSelRefs->makeSelRef(methname);
+ if (!ObjCSelRefsHelper::getSelRef(methname))
+ ObjCSelRefsHelper::makeSelRef(methname);
auto stubSize = config->objcStubsMode == ObjCStubsMode::fast
? target->objcStubsFastSize
@@ -940,7 +941,7 @@
Defined *sym = symbols[i];
auto methname = getMethname(sym);
- InputSection *selRef = in.objcSelRefs->getSelRef(methname);
+ InputSection *selRef = ObjCSelRefsHelper::getSelRef(methname);
assert(selRef != nullptr && "no selref for methname");
auto selrefAddr = selRef->getVA(0);
target->writeObjCMsgSendStub(buf + stubOffset, sym, in.objcStubs->addr,
diff --git a/MachO/SyntheticSections.h b/MachO/SyntheticSections.h
index 6d85f0a..4586a4a 100644
--- a/MachO/SyntheticSections.h
+++ b/MachO/SyntheticSections.h
@@ -315,24 +315,16 @@
Defined *dyldPrivate = nullptr;
};
-class ObjCSelRefsSection final : public SyntheticSection {
+class ObjCSelRefsHelper {
public:
- ObjCSelRefsSection();
- void initialize();
+ static void initialize();
+ static void cleanup();
- // This SyntheticSection does not do directly write data to the output, it is
- // just a placeholder for easily creating SyntheticInputSection's which will
- // be inserted into inputSections and handeled by the default writing
- // mechanism.
- uint64_t getSize() const override { return 0; }
- bool isNeeded() const override { return false; }
- void writeTo(uint8_t *buf) const override {}
-
- ConcatInputSection *getSelRef(StringRef methname);
- ConcatInputSection *makeSelRef(StringRef methname);
+ static ConcatInputSection *getSelRef(StringRef methname);
+ static ConcatInputSection *makeSelRef(StringRef methname);
private:
- llvm::DenseMap<llvm::CachedHashStringRef, ConcatInputSection *>
+ static llvm::DenseMap<llvm::CachedHashStringRef, ConcatInputSection *>
methnameToSelref;
};
@@ -813,7 +805,6 @@
LazyPointerSection *lazyPointers = nullptr;
StubsSection *stubs = nullptr;
StubHelperSection *stubHelper = nullptr;
- ObjCSelRefsSection *objcSelRefs = nullptr;
ObjCStubsSection *objcStubs = nullptr;
UnwindInfoSection *unwindInfo = nullptr;
ObjCImageInfoSection *objCImageInfo = nullptr;
diff --git a/MachO/Writer.cpp b/MachO/Writer.cpp
index 8f33518..a18b526 100644
--- a/MachO/Writer.cpp
+++ b/MachO/Writer.cpp
@@ -720,7 +720,7 @@
void Writer::scanSymbols() {
TimeTraceScope timeScope("Scan symbols");
- in.objcSelRefs->initialize();
+ ObjCSelRefsHelper::initialize();
for (Symbol *sym : symtab->getSymbols()) {
if (auto *defined = dyn_cast<Defined>(sym)) {
if (!defined->isLive())
@@ -1359,7 +1359,6 @@
in.got = make<GotSection>();
in.tlvPointers = make<TlvPointerSection>();
in.stubs = make<StubsSection>();
- in.objcSelRefs = make<ObjCSelRefsSection>();
in.objcStubs = make<ObjCStubsSection>();
in.unwindInfo = makeUnwindInfoSection();
in.objCImageInfo = make<ObjCImageInfoSection>();
