PPC: adding torque debug info for AIX on PPC

Due to ppc having a fixed 4 byte instruction length, changing
ByteChunk length from 8 to 4 bytes will fix any padding issues
while generating the "embed.S" file.

Change-Id: Ide799908effd88d5387e97627917b095fcc3051c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1524720
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60337}

src/snapshot/embedded-file-writer.cc

@@ -300,7 +300,9 @@ void PlatformDependentEmbeddedFileWriter::DeclareLabel(const char* name) {
   fprintf(fp_, "_%s:\n", name);
 }
 
-void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid, int line) {
+void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid,
+                                                     const char* filename,
+                                                     int line) {
   fprintf(fp_, ".loc %d %d\n", fileid, line);
 }
 
@@ -390,8 +392,10 @@ void PlatformDependentEmbeddedFileWriter::DeclareLabel(const char* name) {
   fprintf(fp_, "%s:\n", name);
 }
 
-void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid, int line) {
-  fprintf(fp_, ".loc %d %d\n", fileid, line);
+void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid,
+                                                     const char* filename,
+                                                     int line) {
+  fprintf(fp_, ".xline %d, \"%s\"\n", line, filename);
 }
 
 void PlatformDependentEmbeddedFileWriter::DeclareFunctionBegin(
@@ -416,7 +420,9 @@ void PlatformDependentEmbeddedFileWriter::FilePrologue() {}
 
 void PlatformDependentEmbeddedFileWriter::DeclareExternalFilename(
     int fileid, const char* filename) {
-  fprintf(fp_, ".file %d \"%s\"\n", fileid, filename);
+  // File name cannot be declared with an identifier on AIX.
+  // We use the SourceInfo method to emit debug info in
+  //.xline <line-number> <file-name> format.
 }
 
 void PlatformDependentEmbeddedFileWriter::FileEpilogue() {}
@@ -520,7 +526,9 @@ void PlatformDependentEmbeddedFileWriter::DeclareLabel(const char* name) {
           DirectiveAsString(kByte));
 }
 
-void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid, int line) {
+void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid,
+                                                     const char* filename,
+                                                     int line) {
   // TODO(mvstanton): output source information for MSVC.
   // Its syntax is #line <line> "<filename>"
 }
@@ -626,7 +634,9 @@ void PlatformDependentEmbeddedFileWriter::DeclareLabel(const char* name) {
   fprintf(fp_, "%s%s\n", SYMBOL_PREFIX, name);
 }
 
-void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid, int line) {
+void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid,
+                                                     const char* filename,
+                                                     int line) {
   // TODO(mvstanton): output source information for MSVC.
   // Its syntax is #line <line> "<filename>"
 }
@@ -759,7 +769,9 @@ void PlatformDependentEmbeddedFileWriter::DeclareLabel(const char* name) {
   fprintf(fp_, "%s%s:\n", SYMBOL_PREFIX, name);
 }
 
-void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid, int line) {
+void PlatformDependentEmbeddedFileWriter::SourceInfo(int fileid,
+                                                     const char* filename,
+                                                     int line) {
   fprintf(fp_, ".loc %d %d\n", fileid, line);
 }
 

src/snapshot/embedded-file-writer.h

@@ -59,7 +59,7 @@ class PlatformDependentEmbeddedFileWriter final {
 
   void DeclareLabel(const char* name);
 
-  void SourceInfo(int fileid, int line);
+  void SourceInfo(int fileid, const char* filename, int line);
   void DeclareFunctionBegin(const char* name);
   void DeclareFunctionEnd(const char* name);
 
@@ -268,6 +268,8 @@ class EmbeddedFileWriter : public EmbeddedFileWriterInterface {
       if (i == next_offset) {
         // Write source directive.
         w->SourceInfo(positions.source_position().ExternalFileId(),
+                      GetExternallyCompiledFilename(
+                          positions.source_position().ExternalFileId()),
                       positions.source_position().ExternalLine());
         positions.Advance();
         next_offset = static_cast<uint32_t>(
@@ -339,16 +341,13 @@ class EmbeddedFileWriter : public EmbeddedFileWriterInterface {
 #define V8_COMPILER_IS_MSVC
 #endif
 
-#if defined(V8_COMPILER_IS_MSVC) || defined(V8_OS_AIX)
+#if defined(V8_COMPILER_IS_MSVC)
   // Windows MASM doesn't have an .octa directive, use QWORDs instead.
   // Note: MASM *really* does not like large data streams. It takes over 5
   // minutes to assemble the ~350K lines of embedded.S produced when using
   // BYTE directives in a debug build. QWORD produces roughly 120KLOC and
   // reduces assembly time to ~40 seconds. Still terrible, but much better
   // than before. See also: https://crbug.com/v8/8475.
-
-  // GCC MASM on Aix doesn't have an .octa directive, use .llong instead.
-
   static constexpr DataDirective kByteChunkDirective = kQuad;
   static constexpr int kByteChunkSize = 8;
 
@@ -357,6 +356,19 @@ class EmbeddedFileWriter : public EmbeddedFileWriterInterface {
     const uint64_t* quad_ptr = reinterpret_cast<const uint64_t*>(data);
     return current_line_length + w->HexLiteral(*quad_ptr);
   }
+
+#elif defined(V8_OS_AIX)
+  // PPC uses a fixed 4 byte instruction set, using .long
+  // to prevent any unnecessary padding.
+  static constexpr DataDirective kByteChunkDirective = kLong;
+  static constexpr int kByteChunkSize = 4;
+
+  static int WriteByteChunk(PlatformDependentEmbeddedFileWriter* w,
+                            int current_line_length, const uint8_t* data) {
+    const uint32_t* long_ptr = reinterpret_cast<const uint32_t*>(data);
+    return current_line_length + w->HexLiteral(*long_ptr);
+  }
+
 #else  // defined(V8_COMPILER_IS_MSVC) || defined(V8_OS_AIX)
   static constexpr DataDirective kByteChunkDirective = kOcta;
   static constexpr int kByteChunkSize = 16;