Vendor import of lld release_90 branch r369369:

https://llvm.org/svn/llvm-project/lld/branches/release_90@369369

COFF/Driver.cpp

@@ -184,8 +184,10 @@ void LinkerDriver::addBuffer(std::unique_ptr<MemoryBuffer> mb,
     if (wholeArchive) {
       std::unique_ptr<Archive> file =
           CHECK(Archive::create(mbref), filename + ": failed to parse archive");
+      Archive *archive = file.get();
+      make<std::unique_ptr<Archive>>(std::move(file)); // take ownership
 
-      for (MemoryBufferRef m : getArchiveMembers(file.get()))
+      for (MemoryBufferRef m : getArchiveMembers(archive))
         addArchiveBuffer(m, "<whole-archive>", filename, 0);
       return;
     }

COFF/Writer.cpp

@@ -762,6 +762,28 @@ void Writer::locateImportTables() {
   }
 }
 
+// Return whether a SectionChunk's suffix (the dollar and any trailing
+// suffix) should be removed and sorted into the main suffixless
+// PartialSection.
+static bool shouldStripSectionSuffix(SectionChunk *sc, StringRef name) {
+  // On MinGW, comdat groups are formed by putting the comdat group name
+  // after the '$' in the section name. For .eh_frame$<symbol>, that must
+  // still be sorted before the .eh_frame trailer from crtend.o, thus just
+  // strip the section name trailer. For other sections, such as
+  // .tls$$<symbol> (where non-comdat .tls symbols are otherwise stored in
+  // ".tls$"), they must be strictly sorted after .tls. And for the
+  // hypothetical case of comdat .CRT$XCU, we definitely need to keep the
+  // suffix for sorting. Thus, to play it safe, only strip the suffix for
+  // the standard sections.
+  if (!config->mingw)
+    return false;
+  if (!sc || !sc->isCOMDAT())
+    return false;
+  return name.startswith(".text$") || name.startswith(".data$") ||
+         name.startswith(".rdata$") || name.startswith(".pdata$") ||
+         name.startswith(".xdata$") || name.startswith(".eh_frame$");
+}
+
 // Create output section objects and add them to OutputSections.
 void Writer::createSections() {
   // First, create the builtin sections.
@@ -807,10 +829,7 @@ void Writer::createSections() {
       continue;
     }
     StringRef name = c->getSectionName();
-    // On MinGW, comdat groups are formed by putting the comdat group name
-    // after the '$' in the section name. Such a section name suffix shouldn't
-    // imply separate alphabetical sorting of those section chunks though.
-    if (config->mingw && sc && sc->isCOMDAT())
+    if (shouldStripSectionSuffix(sc, name))
       name = name.split('$').first;
     PartialSection *pSec = createPartialSection(name,
                                                 c->getOutputCharacteristics());
@@ -1076,6 +1095,13 @@ Optional<coff_symbol16> Writer::createSymbol(Defined *def) {
   }
   }
 
+  // Symbols that are runtime pseudo relocations don't point to the actual
+  // symbol data itself (as they are imported), but points to the IAT entry
+  // instead. Avoid emitting them to the symbol table, as they can confuse
+  // debuggers.
+  if (def->isRuntimePseudoReloc)
+    return None;
+
   StringRef name = def->getName();
   if (name.size() > COFF::NameSize) {
     sym.Name.Offset.Zeroes = 0;

ELF/SyntheticSections.cpp

@@ -3177,11 +3177,23 @@ static bool isDuplicateArmExidxSec(InputSection *prev, InputSection *cur) {
 
 // The .ARM.exidx table must be sorted in ascending order of the address of the
 // functions the table describes. Optionally duplicate adjacent table entries
-// can be removed. At the end of the function the ExecutableSections must be
+// can be removed. At the end of the function the executableSections must be
 // sorted in ascending order of address, Sentinel is set to the InputSection
 // with the highest address and any InputSections that have mergeable
 // .ARM.exidx table entries are removed from it.
 void ARMExidxSyntheticSection::finalizeContents() {
+  if (script->hasSectionsCommand) {
+    // The executableSections and exidxSections that we use to derive the
+    // final contents of this SyntheticSection are populated before the
+    // linker script assigns InputSections to OutputSections. The linker script
+    // SECTIONS command may have a /DISCARD/ entry that removes executable
+    // InputSections and their dependent .ARM.exidx section that we recorded
+    // earlier.
+    auto isDiscarded = [](const InputSection *isec) { return !isec->isLive(); };
+    llvm::erase_if(executableSections, isDiscarded);
+    llvm::erase_if(exidxSections, isDiscarded);
+  }
+
   // Sort the executable sections that may or may not have associated
   // .ARM.exidx sections by order of ascending address. This requires the
   // relative positions of InputSections to be known.

docs/ReleaseNotes.rst

@@ -28,6 +28,15 @@ ELF Improvements
   ``$ ld.lld --call-shared`` now prints
   ``unknown argument '--call-shared', did you mean '--call_shared'``.
 
+* lld now supports replacing ``JAL`` with ``JALX`` instructions in case
+  of MIPS - microMIPS cross-mode jumps.
+
+* lld now creates LA25 thunks for MIPS R6 code.
+
+* Put MIPS-specific .reginfo, .MIPS.options, and .MIPS.abiflags sections
+  into corresponding PT_MIPS_REGINFO, PT_MIPS_OPTIONS, and PT_MIPS_ABIFLAGS
+  segments.
+
 * ...
 
 COFF Improvements
@@ -53,6 +62,14 @@ COFF Improvements
 
 * Several speed and memory usage improvements.
 
+* Range extension thunks are now created for ARM64, if needed
+
+* lld-link now supports resource object files created by GNU windres and
+  MS cvtres, not only llvm-cvtres
+
+* The generated thunks for delayimports now share the majority of code
+  among thunks, significantly reducing the overhead of using delayimport
+
 * ...
 
 MinGW Improvements
@@ -62,6 +79,17 @@ MinGW Improvements
   terminators for the sections such as .eh_frame properly, fixing
   DWARF exception handling with libgcc and gcc's crtend.o.
 
+* lld now also handles DWARF unwind info generated by GCC, when linking
+  with libgcc
+
+* Many more GNU ld options are now supported, which e.g. allows the lld
+  MinGW frontend to be called by GCC
+
+* PDB output can be requested without manually specifying the PDB file
+  name, with the new option ``-pdb=`` with an empty value to the option.
+  (The old existing syntax ``-pdb <filename>`` was more cumbersome to use
+  with an empty parameter value.)
+
 MachO Improvements
 ------------------