[lld] ac0986f - [ELF] Change std::vector<InputSectionBase *> to SmallVector

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2022-01-17T10:25:07-08:00
New Revision: ac0986f88058b5d82559ca84c607c7a664827cbc

URL: https://github.com/llvm/llvm-project/commit/ac0986f88058b5d82559ca84c607c7a664827cbc
DIFF: https://github.com/llvm/llvm-project/commit/ac0986f88058b5d82559ca84c607c7a664827cbc.diff

LOG: [ELF] Change std::vector<InputSectionBase *> to SmallVector

There is no remaining std::vector<InputSectionBase> now. My x86-64 lld
executable is 2KiB small.

Added: 
    

Modified: 
    lld/ELF/LinkerScript.cpp
    lld/ELF/SyntheticSections.cpp
    lld/ELF/SyntheticSections.h
    lld/ELF/Writer.cpp

Removed: 
    


################################################################################
diff  --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 30bf9abc8fafd..3dd3df80e36f4 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -574,8 +574,9 @@ void LinkerScript::discardSynthetic(OutputSection &outCmd) {
   for (Partition &part : partitions) {
     if (!part.armExidx || !part.armExidx->isLive())
       continue;
-    std::vector<InputSectionBase *> secs(part.armExidx->exidxSections.begin(),
-                                         part.armExidx->exidxSections.end());
+    SmallVector<InputSectionBase *, 0> secs(
+        part.armExidx->exidxSections.begin(),
+        part.armExidx->exidxSections.end());
     for (SectionCommand *cmd : outCmd.commands)
       if (auto *isd = dyn_cast<InputSectionDescription>(cmd))
         for (InputSectionBase *s : computeInputSections(isd, secs))

diff  --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index 3e67735451423..c1eb53e9d44b0 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -171,7 +171,7 @@ MipsOptionsSection<ELFT> *MipsOptionsSection<ELFT>::create() {
   if (!ELFT::Is64Bits)
     return nullptr;
 
-  std::vector<InputSectionBase *> sections;
+  SmallVector<InputSectionBase *, 0> sections;
   for (InputSectionBase *sec : inputSections)
     if (sec->type == SHT_MIPS_OPTIONS)
       sections.push_back(sec);
@@ -228,7 +228,7 @@ MipsReginfoSection<ELFT> *MipsReginfoSection<ELFT>::create() {
   if (ELFT::Is64Bits)
     return nullptr;
 
-  std::vector<InputSectionBase *> sections;
+  SmallVector<InputSectionBase *, 0> sections;
   for (InputSectionBase *sec : inputSections)
     if (sec->type == SHT_MIPS_REGINFO)
       sections.push_back(sec);
@@ -550,9 +550,9 @@ void EhFrameSection::finalizeContents() {
 // Returns data for .eh_frame_hdr. .eh_frame_hdr is a binary search table
 // to get an FDE from an address to which FDE is applied. This function
 // returns a list of such pairs.
-std::vector<EhFrameSection::FdeData> EhFrameSection::getFdeData() const {
+SmallVector<EhFrameSection::FdeData, 0> EhFrameSection::getFdeData() const {
   uint8_t *buf = Out::bufferStart + getParent()->offset + outSecOff;
-  std::vector<FdeData> ret;
+  SmallVector<FdeData, 0> ret;
 
   uint64_t va = getPartition().ehFrameHdr->getVA();
   for (CieRecord *rec : cieRecords) {
@@ -3030,8 +3030,7 @@ void EhFrameHeader::writeTo(uint8_t *buf) {
 void EhFrameHeader::write() {
   uint8_t *buf = Out::bufferStart + getParent()->offset + outSecOff;
   using FdeData = EhFrameSection::FdeData;
-
-  std::vector<FdeData> fdes = getPartition().ehFrame->getFdeData();
+  SmallVector<FdeData, 0> fdes = getPartition().ehFrame->getFdeData();
 
   buf[0] = 1;
   buf[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4;

diff  --git a/lld/ELF/SyntheticSections.h b/lld/ELF/SyntheticSections.h
index 6f8453288a8eb..9f4073048ce57 100644
--- a/lld/ELF/SyntheticSections.h
+++ b/lld/ELF/SyntheticSections.h
@@ -86,7 +86,7 @@ class EhFrameSection final : public SyntheticSection {
     uint32_t fdeVARel;
   };
 
-  std::vector<FdeData> getFdeData() const;
+  SmallVector<FdeData, 0> getFdeData() const;
   ArrayRef<CieRecord *> getCieRecords() const { return cieRecords; }
   template <class ELFT>
   void iterateFDEWithLSDA(llvm::function_ref<void(InputSection &)> fn);

diff  --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index ba69189eeccd4..9eefe5c84a114 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -120,7 +120,7 @@ static void removeEmptyPTLoad(SmallVector<PhdrEntry *, 0> &phdrs) {
 }
 
 void elf::copySectionsIntoPartitions() {
-  std::vector<InputSectionBase *> newSections;
+  SmallVector<InputSectionBase *, 0> newSections;
   for (unsigned part = 2; part != partitions.size() + 1; ++part) {
     for (InputSectionBase *s : inputSections) {
       if (!(s->flags & SHF_ALLOC) || !s->isLive())