[XCOFF] Add compiler version to an auxiliary symbol table entry (#80162)

C_FILE symbols. To match the behavior of the assembler and the legacy
compiler, this includes using the generic ".file" name for the C_FILE
symbol and generating the actual file name in an auxiliary entry.

Author: stephenpeckham

llvm/include/llvm/BinaryFormat/XCOFF.h

@@ -27,6 +27,7 @@ namespace XCOFF {
 
 constexpr size_t FileNamePadSize = 6;
 constexpr size_t NameSize = 8;
+constexpr size_t AuxFileEntNameSize = 14;
 constexpr size_t FileHeaderSize32 = 20;
 constexpr size_t FileHeaderSize64 = 24;
 constexpr size_t AuxFileHeaderSize32 = 72;

llvm/include/llvm/MC/MCAssembler.h

@@ -133,6 +133,8 @@ class MCAssembler {
 
   /// List of declared file names
   std::vector<std::pair<std::string, size_t>> FileNames;
+  // Optional compiler version.
+  std::string CompilerVersion;
 
   MCDwarfLineTableParams LTParams;
 
@@ -486,6 +488,12 @@ class MCAssembler {
     FileNames.emplace_back(std::string(FileName), Symbols.size());
   }
 
+  void setCompilerVersion(std::string CompilerVers) {
+    if (CompilerVersion.empty())
+      CompilerVersion = std::move(CompilerVers);
+  }
+  StringRef getCompilerVersion() { return CompilerVersion; }
+
   /// Write the necessary bundle padding to \p OS.
   /// Expects a fragment \p F containing instructions and its size \p FSize.
   void writeFragmentPadding(raw_ostream &OS, const MCEncodedFragment &F,

llvm/lib/MC/MCAsmStreamer.cpp

@@ -1590,17 +1590,22 @@ void MCAsmStreamer::emitFileDirective(StringRef Filename,
   assert(MAI->hasFourStringsDotFile());
   OS << "\t.file\t";
   PrintQuotedString(Filename, OS);
-  OS << ",";
-  if (!CompilerVersion.empty()) {
-    PrintQuotedString(CompilerVersion, OS);
-  }
-  if (!TimeStamp.empty()) {
-    OS << ",";
-    PrintQuotedString(TimeStamp, OS);
-  }
-  if (!Description.empty()) {
+  bool useTimeStamp = !TimeStamp.empty();
+  bool useCompilerVersion = !CompilerVersion.empty();
+  bool useDescription = !Description.empty();
+  if (useTimeStamp || useCompilerVersion || useDescription) {
     OS << ",";
-    PrintQuotedString(Description, OS);
+    if (useTimeStamp)
+      PrintQuotedString(TimeStamp, OS);
+    if (useCompilerVersion || useDescription) {
+      OS << ",";
+      if (useCompilerVersion)
+        PrintQuotedString(CompilerVersion, OS);
+      if (useDescription) {
+        OS << ",";
+        PrintQuotedString(Description, OS);
+      }
+    }
   }
   EmitEOL();
 }

llvm/lib/MC/MCObjectStreamer.cpp

@@ -902,7 +902,9 @@ void MCObjectStreamer::emitFileDirective(StringRef Filename,
                                          StringRef TimeStamp,
                                          StringRef Description) {
   getAssembler().addFileName(Filename);
-  // TODO: add additional info to integrated assembler.
+  getAssembler().setCompilerVersion(CompilerVerion.str());
+  // TODO: add TimeStamp and Description to .file symbol table entry
+  // with the integrated assembler.
 }
 
 void MCObjectStreamer::emitAddrsig() {

llvm/lib/MC/XCOFFObjectWriter.cpp

@@ -361,6 +361,8 @@ class XCOFFObjectWriter : public MCObjectWriter {
   bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
   bool nameShouldBeInStringTable(const StringRef &);
   void writeSymbolName(const StringRef &);
+  bool auxFileSymNameShouldBeInStringTable(const StringRef &);
+  void writeAuxFileSymName(const StringRef &);
 
   void writeSymbolEntryForCsectMemberLabel(const Symbol &SymbolRef,
                                            const XCOFFSection &CSectionRef,
@@ -391,7 +393,8 @@ class XCOFFObjectWriter : public MCObjectWriter {
                                            const MCAsmLayout &Layout,
                                            CInfoSymSectionEntry &CInfoSymEntry,
                                            uint64_t &CurrentAddressLocation);
-  void writeSymbolTable(const MCAsmLayout &Layout);
+  void writeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout);
+  void writeSymbolAuxFileEntry(StringRef &Name, uint8_t ftype);
   void writeSymbolAuxDwarfEntry(uint64_t LengthOfSectionPortion,
                                 uint64_t NumberOfRelocEnt = 0);
   void writeSymbolAuxCsectEntry(uint64_t SectionOrLength,
@@ -416,7 +419,7 @@ class XCOFFObjectWriter : public MCObjectWriter {
   // *) Assigns symbol table indices.
   // *) Builds up the section header table by adding any non-empty sections to
   //    `Sections`.
-  void assignAddressesAndIndices(const MCAsmLayout &);
+  void assignAddressesAndIndices(MCAssembler &Asm, const MCAsmLayout &);
   // Called after relocations are recorded.
   void finalizeSectionInfo();
   void finalizeRelocationInfo(SectionEntry *Sec, uint64_t RelCount);
@@ -640,12 +643,20 @@ void XCOFFObjectWriter::executePostLayoutBinding(MCAssembler &Asm,
   if (FileNames.empty())
     FileNames.emplace_back(".file", 0);
   for (const std::pair<std::string, size_t> &F : FileNames) {
-    if (nameShouldBeInStringTable(F.first))
+    if (auxFileSymNameShouldBeInStringTable(F.first))
       Strings.add(F.first);
   }
 
+  // Always add ".file" to the symbol table. The actual file name will be in
+  // the AUX_FILE auxiliary entry.
+  if (nameShouldBeInStringTable(".file"))
+    Strings.add(".file");
+  StringRef Vers = Asm.getCompilerVersion();
+  if (auxFileSymNameShouldBeInStringTable(Vers))
+    Strings.add(Vers);
+
   Strings.finalize();
-  assignAddressesAndIndices(Layout);
+  assignAddressesAndIndices(Asm, Layout);
 }
 
 void XCOFFObjectWriter::recordRelocation(MCAssembler &Asm,
@@ -818,7 +829,7 @@ uint64_t XCOFFObjectWriter::writeObject(MCAssembler &Asm,
   writeSectionHeaderTable();
   writeSections(Asm, Layout);
   writeRelocations();
-  writeSymbolTable(Layout);
+  writeSymbolTable(Asm, Layout);
   // Write the string table.
   Strings.write(W.OS);
 
@@ -878,6 +889,36 @@ void XCOFFObjectWriter::writeSymbolAuxCsectEntry(uint64_t SectionOrLength,
   }
 }
 
+bool XCOFFObjectWriter::auxFileSymNameShouldBeInStringTable(
+    const StringRef &SymbolName) {
+  return SymbolName.size() > XCOFF::AuxFileEntNameSize;
+}
+
+void XCOFFObjectWriter::writeAuxFileSymName(const StringRef &SymbolName) {
+  // Magic, Offset or SymbolName.
+  if (auxFileSymNameShouldBeInStringTable(SymbolName)) {
+    W.write<int32_t>(0);
+    W.write<uint32_t>(Strings.getOffset(SymbolName));
+    W.OS.write_zeros(XCOFF::FileNamePadSize);
+  } else {
+    char Name[XCOFF::AuxFileEntNameSize + 1];
+    std::strncpy(Name, SymbolName.data(), XCOFF::AuxFileEntNameSize);
+    ArrayRef<char> NameRef(Name, XCOFF::AuxFileEntNameSize);
+    W.write(NameRef);
+  }
+}
+
+void XCOFFObjectWriter::writeSymbolAuxFileEntry(StringRef &Name,
+                                                uint8_t ftype) {
+  writeAuxFileSymName(Name);
+  W.write<uint8_t>(ftype);
+  W.OS.write_zeros(2);
+  if (is64Bit())
+    W.write<uint8_t>(XCOFF::AUX_FILE);
+  else
+    W.OS.write_zeros(1);
+}
+
 void XCOFFObjectWriter::writeSymbolAuxDwarfEntry(
     uint64_t LengthOfSectionPortion, uint64_t NumberOfRelocEnt) {
   writeWord(LengthOfSectionPortion);
@@ -1109,8 +1150,11 @@ void XCOFFObjectWriter::writeRelocations() {
       writeRelocation(Reloc, *DwarfSection.DwarfSect);
 }
 
-void XCOFFObjectWriter::writeSymbolTable(const MCAsmLayout &Layout) {
+void XCOFFObjectWriter::writeSymbolTable(MCAssembler &Asm,
+                                         const MCAsmLayout &Layout) {
   // Write C_FILE symbols.
+  StringRef Vers = Asm.getCompilerVersion();
+
   for (const std::pair<std::string, size_t> &F : FileNames) {
     // The n_name of a C_FILE symbol is the source file's name when no auxiliary
     // entries are present.
@@ -1139,9 +1183,15 @@ void XCOFFObjectWriter::writeSymbolTable(const MCAsmLayout &Layout) {
     else
       CpuID = XCOFF::TCPU_COM;
 
-    writeSymbolEntry(FileName, /*Value=*/0, XCOFF::ReservedSectionNum::N_DEBUG,
+    int NumberOfFileAuxEntries = 1;
+    if (!Vers.empty())
+      ++NumberOfFileAuxEntries;
+    writeSymbolEntry(".file", /*Value=*/0, XCOFF::ReservedSectionNum::N_DEBUG,
                      /*SymbolType=*/(LangID << 8) | CpuID, XCOFF::C_FILE,
-                     /*NumberOfAuxEntries=*/0);
+                     NumberOfFileAuxEntries);
+    writeSymbolAuxFileEntry(FileName, XCOFF::XFT_FN);
+    if (!Vers.empty())
+      writeSymbolAuxFileEntry(Vers, XCOFF::XFT_CV);
   }
 
   if (CInfoSymSection.Entry)
@@ -1357,9 +1407,12 @@ void XCOFFObjectWriter::addCInfoSymEntry(StringRef Name, StringRef Metadata) {
       std::make_unique<CInfoSymInfo>(Name.str(), Metadata.str()));
 }
 
-void XCOFFObjectWriter::assignAddressesAndIndices(const MCAsmLayout &Layout) {
-  // The symbol table starts with all the C_FILE symbols.
-  uint32_t SymbolTableIndex = FileNames.size();
+void XCOFFObjectWriter::assignAddressesAndIndices(MCAssembler &Asm,
+                                                  const MCAsmLayout &Layout) {
+  // The symbol table starts with all the C_FILE symbols. Each C_FILE symbol
+  // requires 1 or 2 auxiliary entries.
+  uint32_t SymbolTableIndex =
+      (2 + (Asm.getCompilerVersion().empty() ? 0 : 1)) * FileNames.size();
 
   if (CInfoSymSection.Entry)
     SymbolTableIndex++;

llvm/test/CodeGen/PowerPC/aix-alias-alignment-2.ll

@@ -58,7 +58,7 @@ define void @foo3(%struct.B %a1) {
 ; ASM-NEXT:      .vbyte     4, 34
 
 ; SYM:      SYMBOL TABLE:
-; SYM-NEXT: 00000000      df *DEBUG*	00000000 <stdin>
+; SYM-NEXT: 00000000      df *DEBUG*	00000000 .file
 ; SYM-NEXT: 00000000 l       .text	0000008a 
 ; SYM-NEXT: 00000000 g     F .text (csect: ) 	00000000 .foo1
 ; SYM-NEXT: 00000030 g     F .text (csect: ) 	00000000 .foo2

llvm/test/CodeGen/PowerPC/aix-alias-alignment.ll

@@ -61,7 +61,7 @@ define void @foo(i32 %a1, i32 %a2, i32 %a3) {
 ; OBJ-NEXT:        c: 4e 80 00 20  	blr
 
 ; SYM:      SYMBOL TABLE:
-; SYM-NEXT: 00000000      df *DEBUG*	00000000 <stdin>
+; SYM-NEXT: 00000000      df *DEBUG*	00000000 .file
 ; SYM-NEXT: 00000000 l       .text	00000029 
 ; SYM-NEXT: 00000000 g     F .text (csect: ) 	00000000 .foo
 ; SYM-NEXT: 0000002c l       .data	00000008 .data

llvm/test/CodeGen/PowerPC/aix-available-externally-linkage-fun.ll

@@ -6,11 +6,11 @@
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff -mcpu=pwr4 \
 ; RUN:     -mattr=-altivec -filetype=obj -o %t.o < %s
-; RUN: llvm-readobj --symbols %t.o | FileCheck --check-prefix=OBJ %s
+; RUN: llvm-readobj --symbols %t.o | FileCheck -D#NFA=2 --check-prefix=OBJ %s
 
 ; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff -mcpu=pwr4 \
 ; RUN:     -mattr=-altivec -filetype=obj -o %t64.o < %s
-; RUN: llvm-readobj --symbols %t64.o | FileCheck --check-prefix=OBJ %s
+; RUN: llvm-readobj --symbols %t64.o | FileCheck -D#NFA=2 --check-prefix=OBJ %s
 
 define available_externally i32 @foo(i32 %a) {
 entry:
@@ -27,7 +27,7 @@ entry:
 ; OBJ-NEXT: StorageClass: C_EXT (0x2)
 ; OBJ-NEXT: NumberOfAuxEntries: 1
 ; OBJ-NEXT: CSECT Auxiliary Entry {
-; OBJ-NEXT:   Index: 2
+; OBJ-NEXT:   Index: [[#NFA+2]]
 ; OBJ-NEXT:   SectionLen: 0
 ; OBJ-NEXT:   ParameterHashIndex: 0x0
 ; OBJ-NEXT:   TypeChkSectNum: 0x0
@@ -42,7 +42,7 @@ entry:
 ; OBJ-NEXT: StorageClass: C_EXT (0x2)
 ; OBJ-NEXT: NumberOfAuxEntries: 1
 ; OBJ-NEXT: CSECT Auxiliary Entry {
-; OBJ-NEXT:   Index: 4
+; OBJ-NEXT:   Index: [[#NFA+4]]
 ; OBJ-NEXT:   SectionLen: 0
 ; OBJ-NEXT:   ParameterHashIndex: 0x0
 ; OBJ-NEXT:   TypeChkSectNum: 0x0

llvm/test/CodeGen/PowerPC/aix-extern-weak.ll

@@ -65,16 +65,15 @@ declare extern_weak void @foo_ext_weak(ptr)
 ; CHECKSYM:      Symbols [
 ; CHECKSYM-NEXT:   Symbol {
 ; CHECKSYM-NEXT:     Index: 0
-; CHECKSYM-NEXT:     Name: <stdin>
+; CHECKSYM-NEXT:     Name: .file
 ; CHECKSYM-NEXT:     Value (SymbolTableIndex): 0x0
 ; CHECKSYM-NEXT:     Section: N_DEBUG
 ; CHECKSYM-NEXT:     Source Language ID: TB_CPLUSPLUS (0x9)
 ; CHECKSYM32-NEXT:   CPU Version ID: TCPU_COM (0x3)
 ; CHECKSYM64-NEXT:   CPU Version ID: TCPU_PPC64 (0x2)
 ; CHECKSYM-NEXT:     StorageClass: C_FILE (0x67)
-; CHECKSYM-NEXT:     NumberOfAuxEntries: 0
-; CHECKSYM-NEXT:   }
-; CHECKSYM-NEXT:   Symbol {
+; CHECKSYM-NEXT:     NumberOfAuxEntries: 2
+; CHECKSYM:        Symbol {
 ; CHECKSYM-NEXT:     Index: [[#Index:]]
 ; CHECKSYM-NEXT:     Name: .foo_ext_weak
 ; CHECKSYM-NEXT:     Value (RelocatableAddress): 0x0

llvm/test/CodeGen/PowerPC/aix-extern.ll

@@ -88,16 +88,15 @@ declare i32 @bar_extern(ptr)
 ; CHECKSYM:       Symbols [
 ; CHECKSYM-NEXT:   Symbol {
 ; CHECKSYM-NEXT:     Index: 0
-; CHECKSYM-NEXT:     Name: <stdin>
+; CHECKSYM-NEXT:     Name: .file
 ; CHECKSYM-NEXT:     Value (SymbolTableIndex): 0x0
 ; CHECKSYM-NEXT:     Section: N_DEBUG
 ; CHECKSYM-NEXT:     Source Language ID: TB_CPLUSPLUS (0x9)
 ; CHECKSYM32-NEXT:   CPU Version ID: TCPU_COM (0x3)
 ; CHECKSYM64-NEXT:   CPU Version ID: TCPU_PPC64 (0x2)
 ; CHECKSYM-NEXT:     StorageClass: C_FILE (0x67)
-; CHECKSYM-NEXT:     NumberOfAuxEntries: 0
-; CHECKSYM-NEXT:   }
-; CHECKSYM-NEXT:   Symbol {
+; CHECKSYM-NEXT:     NumberOfAuxEntries: 2
+; CHECKSYM:        Symbol {
 ; CHECKSYM-NEXT:     Index: [[#Index:]]
 ; CHECKSYM-NEXT:     Name: .bar_extern
 ; CHECKSYM-NEXT:     Value (RelocatableAddress): 0x0