vendor/lld/lld-release_60-r321788

4 files changed, 37 insertions, 20 deletions

diff --git a/ELF/Driver.cpp b/ELF/Driver.cpp
index cc76fea2ad5e5..b159fe63eb181 100644
--- a/ELF/Driver.cpp
+++ b/ELF/Driver.cpp
@@ -1043,7 +1043,8 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &Args) {
     return;
 
   // Handle undefined symbols in DSOs.
-  Symtab->scanShlibUndefined<ELFT>();
+  if (!Config->Shared)
+    Symtab->scanShlibUndefined<ELFT>();
 
   // Handle the -exclude-libs option.
   if (Args.hasArg(OPT_exclude_libs))
diff --git a/ELF/Relocations.cpp b/ELF/Relocations.cpp
index 1aa0957b1d01e..37bc8bcbd571c 100644
--- a/ELF/Relocations.cpp
+++ b/ELF/Relocations.cpp
@@ -367,7 +367,7 @@ static bool isRelExpr(RelExpr Expr) {
 static bool isStaticLinkTimeConstant(RelExpr E, RelType Type, const Symbol &Sym,
                                      InputSectionBase &S, uint64_t RelOff) {
   // These expressions always compute a constant
-  if (isRelExprOneOf<R_SIZE, R_GOT_FROM_END, R_GOT_OFF, R_MIPS_GOT_LOCAL_PAGE,
+  if (isRelExprOneOf<R_GOT_FROM_END, R_GOT_OFF, R_MIPS_GOT_LOCAL_PAGE,
                      R_MIPS_GOT_OFF, R_MIPS_GOT_OFF32, R_MIPS_GOT_GP_PC,
                      R_MIPS_TLSGD, R_GOT_PAGE_PC, R_GOT_PC, R_GOTONLY_PC,
                      R_GOTONLY_PC_FROM_END, R_PLT_PC, R_TLSGD_PC, R_TLSGD,
@@ -384,6 +384,10 @@ static bool isStaticLinkTimeConstant(RelExpr E, RelType Type, const Symbol &Sym,
   if (!Config->Pic)
     return true;
 
+  // The size of a non preemptible symbol is a constant.
+  if (E == R_SIZE)
+    return true;
+
   // For the target and the relocation, we want to know if they are
   // absolute or relative.
   bool AbsVal = isAbsoluteValue(Sym);
@@ -592,6 +596,12 @@ static RelExpr adjustExpr(Symbol &Sym, RelExpr Expr, RelType Type,
   if (IsConstant)
     return Expr;
 
+  // We can create any dynamic relocation supported by the dynamic linker if a
+  // section is writable or we are passed -z notext.
+  bool CanWrite = (S.Flags & SHF_WRITE) || !Config->ZText;
+  if (CanWrite && Target->isPicRel(Type))
+    return Expr;
+
   // If the relocation is to a weak undef, and we are producing
   // executable, give up on it and produce a non preemptible 0.
   if (!Config->Shared && Sym.isUndefWeak()) {
@@ -600,12 +610,6 @@ static RelExpr adjustExpr(Symbol &Sym, RelExpr Expr, RelType Type,
     return Expr;
   }
 
-  // We can create any dynamic relocation supported by the dynamic linker if a
-  // section is writable or we are passed -z notext.
-  bool CanWrite = (S.Flags & SHF_WRITE) || !Config->ZText;
-  if (CanWrite && Target->isPicRel(Type))
-    return Expr;
-
   // If we got here we know that this relocation would require the dynamic
   // linker to write a value to read only memory or use an unsupported
   // relocation.
diff --git a/ELF/SyntheticSections.cpp b/ELF/SyntheticSections.cpp
index a5e291b79a4db..f878acf8cf3f6 100644
--- a/ELF/SyntheticSections.cpp
+++ b/ELF/SyntheticSections.cpp
@@ -1064,7 +1064,7 @@ template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
     addInt(DT_DEBUG, 0);
 
   this->Link = InX::DynStrTab->getParent()->SectionIndex;
-  if (InX::RelaDyn->getParent() && !InX::RelaDyn->empty()) {
+  if (!InX::RelaDyn->empty()) {
     addInSec(InX::RelaDyn->DynamicTag, InX::RelaDyn);
     addSize(InX::RelaDyn->SizeDynamicTag, InX::RelaDyn->getParent());
 
@@ -1081,7 +1081,13 @@ template <class ELFT> void DynamicSection<ELFT>::finalizeContents() {
         addInt(IsRela ? DT_RELACOUNT : DT_RELCOUNT, NumRelativeRels);
     }
   }
-  if (InX::RelaPlt->getParent() && !InX::RelaPlt->empty()) {
+  // .rel[a].plt section usually consists of two parts, containing plt and
+  // iplt relocations. It is possible to have only iplt relocations in the
+  // output. In that case RelaPlt is empty and have zero offset, the same offset
+  // as RelaIplt have. And we still want to emit proper dynamic tags for that
+  // case, so here we always use RelaPlt as marker for the begining of
+  // .rel[a].plt section.
+  if (InX::RelaPlt->getParent()->Live) {
     addInSec(DT_JMPREL, InX::RelaPlt);
     addSize(DT_PLTRELSZ, InX::RelaPlt->getParent());
     switch (Config->EMachine) {
diff --git a/ELF/Writer.cpp b/ELF/Writer.cpp
index 15f3821047560..24c3e1ee207c1 100644
--- a/ELF/Writer.cpp
+++ b/ELF/Writer.cpp
@@ -1767,30 +1767,36 @@ template <class ELFT> void Writer<ELFT>::fixSectionAlignments() {
 // virtual address (modulo the page size) so that the loader can load
 // executables without any address adjustment.
 static uint64_t getFileAlignment(uint64_t Off, OutputSection *Cmd) {
-  // If the section is not in a PT_LOAD, we just have to align it.
-  if (!Cmd->PtLoad)
-    return alignTo(Off, Cmd->Alignment);
-
-  OutputSection *First = Cmd->PtLoad->FirstSec;
+  OutputSection *First = Cmd->PtLoad ? Cmd->PtLoad->FirstSec : nullptr;
   // The first section in a PT_LOAD has to have congruent offset and address
   // module the page size.
   if (Cmd == First)
     return alignTo(Off, std::max<uint64_t>(Cmd->Alignment, Config->MaxPageSize),
                    Cmd->Addr);
 
+  // For SHT_NOBITS we don't want the alignment of the section to impact the
+  // offset of the sections that follow. Since nothing seems to care about the
+  // sh_offset of the SHT_NOBITS section itself, just ignore it.
+  if (Cmd->Type == SHT_NOBITS)
+    return Off;
+
+  // If the section is not in a PT_LOAD, we just have to align it.
+  if (!Cmd->PtLoad)
+    return alignTo(Off, Cmd->Alignment);
+
   // If two sections share the same PT_LOAD the file offset is calculated
   // using this formula: Off2 = Off1 + (VA2 - VA1).
   return First->Offset + Cmd->Addr - First->Addr;
 }
 
 static uint64_t setOffset(OutputSection *Cmd, uint64_t Off) {
-  if (Cmd->Type == SHT_NOBITS) {
-    Cmd->Offset = Off;
-    return Off;
-  }
-
   Off = getFileAlignment(Off, Cmd);
   Cmd->Offset = Off;
+
+  // For SHT_NOBITS we should not count the size.
+  if (Cmd->Type == SHT_NOBITS)
+    return Off;
+
   return Off + Cmd->Size;
 }