Vendor import of llvm-project branch release/10.xvendor/llvm-project/llvmorg-10.0.1-rc1-0-gf79cd71e145

llvmorg-10.0.1-rc1-0-gf79cd71e145.

6 files changed, 44 insertions, 17 deletions

diff --git a/lld/COFF/MarkLive.cpp b/lld/COFF/MarkLive.cpp
index 6d34cb864e3c..0afa615a1933 100644
--- a/lld/COFF/MarkLive.cpp
+++ b/lld/COFF/MarkLive.cpp
@@ -28,10 +28,12 @@ void markLive(ArrayRef<Chunk *> chunks) {
   // as we push, so sections never appear twice in the list.
   SmallVector<SectionChunk *, 256> worklist;
 
-  // COMDAT section chunks are dead by default. Add non-COMDAT chunks.
+  // COMDAT section chunks are dead by default. Add non-COMDAT chunks. Do not
+  // traverse DWARF sections. They are live, but they should not keep other
+  // sections alive.
   for (Chunk *c : chunks)
     if (auto *sc = dyn_cast<SectionChunk>(c))
-      if (sc->live)
+      if (sc->live && !sc->isDWARF())
         worklist.push_back(sc);
 
   auto enqueue = [&](SectionChunk *c) {
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 25330832339c..6de9698bb2c8 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -1906,8 +1906,17 @@ template <class ELFT> void LinkerDriver::link(opt::InputArgList &args) {
 
     // We do not want to emit debug sections if --strip-all
     // or -strip-debug are given.
-    return config->strip != StripPolicy::None &&
-           (s->name.startswith(".debug") || s->name.startswith(".zdebug"));
+    if (config->strip == StripPolicy::None)
+      return false;
+
+    if (isDebugSection(*s))
+      return true;
+    if (auto *isec = dyn_cast<InputSection>(s))
+      if (InputSectionBase *rel = isec->getRelocatedSection())
+        if (isDebugSection(*rel))
+          return true;
+
+    return false;
   });
 
   // Now that the number of partitions is fixed, save a pointer to the main
diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 147c51ab285e..d34abf641ed3 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -441,8 +441,7 @@ void InputSection::copyRelocations(uint8_t *buf, ArrayRef<RelTy> rels) {
       // See the comment in maybeReportUndefined for PPC64 .toc .
       auto *d = dyn_cast<Defined>(&sym);
       if (!d) {
-        if (!sec->name.startswith(".debug") &&
-            !sec->name.startswith(".zdebug") && sec->name != ".eh_frame" &&
+        if (!isDebugSection(*sec) && sec->name != ".eh_frame" &&
             sec->name != ".gcc_except_table" && sec->name != ".toc") {
           uint32_t secIdx = cast<Undefined>(sym).discardedSecIdx;
           Elf_Shdr_Impl<ELFT> sec =
diff --git a/lld/ELF/InputSection.h b/lld/ELF/InputSection.h
index 3c42af7db7b4..fe2c3c516a96 100644
--- a/lld/ELF/InputSection.h
+++ b/lld/ELF/InputSection.h
@@ -357,6 +357,10 @@ private:
   template <class ELFT> void copyShtGroup(uint8_t *buf);
 };
 
+inline bool isDebugSection(const InputSectionBase &sec) {
+  return sec.name.startswith(".debug") || sec.name.startswith(".zdebug");
+}
+
 // The list of all input sections.
 extern std::vector<InputSectionBase *> inputSections;
 
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index 6142cb0783ce..b609878be319 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -114,8 +114,7 @@ void OutputSection::commitSection(InputSection *isec) {
     flags = isec->flags;
   } else {
     // Otherwise, check if new type or flags are compatible with existing ones.
-    unsigned mask = SHF_TLS | SHF_LINK_ORDER;
-    if ((flags & mask) != (isec->flags & mask))
+    if ((flags ^ isec->flags) & SHF_TLS)
       error("incompatible section flags for " + name + "\n>>> " + toString(isec) +
             ": 0x" + utohexstr(isec->flags) + "\n>>> output section " + name +
             ": 0x" + utohexstr(flags));
@@ -367,8 +366,9 @@ void OutputSection::finalize() {
     // all InputSections in the OutputSection have the same dependency.
     if (auto *ex = dyn_cast<ARMExidxSyntheticSection>(first))
       link = ex->getLinkOrderDep()->getParent()->sectionIndex;
-    else if (auto *d = first->getLinkOrderDep())
-      link = d->getParent()->sectionIndex;
+    else if (first->flags & SHF_LINK_ORDER)
+      if (auto *d = first->getLinkOrderDep())
+        link = d->getParent()->sectionIndex;
   }
 
   if (type == SHT_GROUP) {
diff --git a/lld/ELF/Writer.cpp b/lld/ELF/Writer.cpp
index ac332de2a057..713c54dee509 100644
--- a/lld/ELF/Writer.cpp
+++ b/lld/ELF/Writer.cpp
@@ -1523,17 +1523,30 @@ template <class ELFT> void Writer<ELFT>::resolveShfLinkOrder() {
     // but sort must consider them all at once.
     std::vector<InputSection **> scriptSections;
     std::vector<InputSection *> sections;
+    bool started = false, stopped = false;
     for (BaseCommand *base : sec->sectionCommands) {
       if (auto *isd = dyn_cast<InputSectionDescription>(base)) {
         for (InputSection *&isec : isd->sections) {
-          scriptSections.push_back(&isec);
-          sections.push_back(isec);
-
-          InputSection *link = isec->getLinkOrderDep();
-          if (!link->getParent())
-            error(toString(isec) + ": sh_link points to discarded section " +
-                  toString(link));
+          if (!(isec->flags & SHF_LINK_ORDER)) {
+            if (started)
+              stopped = true;
+          } else if (stopped) {
+            error(toString(isec) + ": SHF_LINK_ORDER sections in " + sec->name +
+                  " are not contiguous");
+          } else {
+            started = true;
+
+            scriptSections.push_back(&isec);
+            sections.push_back(isec);
+
+            InputSection *link = isec->getLinkOrderDep();
+            if (!link->getParent())
+              error(toString(isec) + ": sh_link points to discarded section " +
+                    toString(link));
+          }
         }
+      } else if (started) {
+        stopped = true;
       }
     }