[XCOFF] handle string constants generation for AIX

This follows https://www.ibm.com/docs/en/aix/7.2?topic=constants-string

Reviewed By: hubert.reinterpretcast

Differential Revision: https://reviews.llvm.org/D101280

llvm/include/llvm/MC/MCAsmInfo.h

@@ -357,9 +357,15 @@ protected:
   LCOMM::LCOMMType LCOMMDirectiveAlignmentType = LCOMM::NoAlignment;
 
   /// True if the target only has basename for .file directive. False if the
-  /// target also needs the directory along with the basename. Default to true.
+  /// target also needs the directory along with the basename. Defaults to true.
   bool HasBasenameOnlyForFileDirective = true;
 
+  /// True if the target represents string constants as mostly raw characters in
+  /// paired double quotation with paired double quotation marks as the escape
+  /// mechanism to represent a double quotation mark within the string. Defaults
+  /// to false.
+  bool HasPairedDoubleQuoteStringConstants = false;
+
   // True if the target allows .align directives on functions. This is true for
   // most targets, so defaults to true.
   bool HasFunctionAlignment = true;
@@ -697,6 +703,9 @@ public:
   bool hasBasenameOnlyForFileDirective() const {
     return HasBasenameOnlyForFileDirective;
   }
+  bool hasPairedDoubleQuoteStringConstants() const {
+    return HasPairedDoubleQuoteStringConstants;
+  }
   bool hasFunctionAlignment() const { return HasFunctionAlignment; }
   bool hasDotTypeDotSizeDirective() const { return HasDotTypeDotSizeDirective; }
   bool hasSingleParameterDotFile() const { return HasSingleParameterDotFile; }

llvm/lib/MC/MCAsmInfoXCOFF.cpp

@@ -20,6 +20,11 @@ MCAsmInfoXCOFF::MCAsmInfoXCOFF() {
   IsLittleEndian = false;
   HasVisibilityOnlyWithLinkage = true;
   HasBasenameOnlyForFileDirective = false;
+
+  // For XCOFF, string constant consists of any number of characters enclosed in
+  // "" (double quotation marks).
+  HasPairedDoubleQuoteStringConstants = true;
+
   PrivateGlobalPrefix = "L..";
   PrivateLabelPrefix = "L..";
   SupportsQuotedNames = false;

llvm/lib/MC/MCAsmStreamer.cpp

@@ -60,6 +60,13 @@ class MCAsmStreamer final : public MCStreamer {
   unsigned UseDwarfDirectory : 1;
 
   void EmitRegisterName(int64_t Register);
+  void PrintQuotedString(StringRef Data, raw_ostream &OS) const;
+  void printDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                               StringRef Filename,
+                               Optional<MD5::MD5Result> Checksum,
+                               Optional<StringRef> Source,
+                               bool UseDwarfDirectory,
+                               raw_svector_ostream &OS) const;
   void emitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
   void emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
 
@@ -1039,33 +1046,53 @@ static void PrintByteList(StringRef Data, raw_ostream &OS,
   llvm_unreachable("Invalid AsmCharLiteralSyntax value!");
 }
 
-static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
+void MCAsmStreamer::PrintQuotedString(StringRef Data, raw_ostream &OS) const {
   OS << '"';
 
-  for (unsigned i = 0, e = Data.size(); i != e; ++i) {
-    unsigned char C = Data[i];
-    if (C == '"' || C == '\\') {
-      OS << '\\' << (char)C;
-      continue;
+  if (MAI->hasPairedDoubleQuoteStringConstants()) {
+    for (unsigned i = 0, e = Data.size(); i != e; ++i) {
+      unsigned char C = Data[i];
+      if (C == '"')
+        OS << "\"\"";
+      else
+        OS << (char)C;
     }
+  } else {
+    for (unsigned i = 0, e = Data.size(); i != e; ++i) {
+      unsigned char C = Data[i];
+      if (C == '"' || C == '\\') {
+        OS << '\\' << (char)C;
+        continue;
+      }
 
-    if (isPrint((unsigned char)C)) {
-      OS << (char)C;
-      continue;
-    }
+      if (isPrint((unsigned char)C)) {
+        OS << (char)C;
+        continue;
+      }
 
-    switch (C) {
-      case '\b': OS << "\\b"; break;
-      case '\f': OS << "\\f"; break;
-      case '\n': OS << "\\n"; break;
-      case '\r': OS << "\\r"; break;
-      case '\t': OS << "\\t"; break;
+      switch (C) {
+      case '\b':
+        OS << "\\b";
+        break;
+      case '\f':
+        OS << "\\f";
+        break;
+      case '\n':
+        OS << "\\n";
+        break;
+      case '\r':
+        OS << "\\r";
+        break;
+      case '\t':
+        OS << "\\t";
+        break;
       default:
         OS << '\\';
         OS << toOctal(C >> 6);
         OS << toOctal(C >> 3);
         OS << toOctal(C >> 0);
         break;
+      }
     }
   }
 
@@ -1390,12 +1417,10 @@ void MCAsmStreamer::emitFileDirective(StringRef Filename) {
   EmitEOL();
 }
 
-static void printDwarfFileDirective(unsigned FileNo, StringRef Directory,
-                                    StringRef Filename,
-                                    Optional<MD5::MD5Result> Checksum,
-                                    Optional<StringRef> Source,
-                                    bool UseDwarfDirectory,
-                                    raw_svector_ostream &OS) {
+void MCAsmStreamer::printDwarfFileDirective(
+    unsigned FileNo, StringRef Directory, StringRef Filename,
+    Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source,
+    bool UseDwarfDirectory, raw_svector_ostream &OS) const {
   SmallString<128> FullPathName;
 
   if (!UseDwarfDirectory && !Directory.empty()) {

llvm/test/CodeGen/PowerPC/aix-filename-special-character-double-quotation.ll

@@ -0,0 +1,8 @@
+; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff < %s \
+; RUN:   | FileCheck %s
+; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff < %s \
+; RUN:   | FileCheck %s
+
+; CHECK: .file "1""2.c"
+
+source_filename = "1\222.c"

llvm/test/CodeGen/PowerPC/aix-filename-special-character-single-quotation.ll

@@ -0,0 +1,8 @@
+; RUN: llc -verify-machineinstrs -mtriple powerpc-ibm-aix-xcoff < %s \
+; RUN:   | FileCheck %s
+; RUN: llc -verify-machineinstrs -mtriple powerpc64-ibm-aix-xcoff < %s \
+; RUN:   | FileCheck %s
+
+; CHECK: .file "1'2.c"
+
+source_filename = "1'2.c"