[llvm-commits] [llvm] r120760 - in /llvm/trunk: include/llvm/MC/MCContext.h include/llvm/MC/MCDwarf.h lib/MC/MCAsmStreamer.cpp lib/MC/MCDwarf.cpp

[Devang Patel]

Author: dpatel
Date: Thu Dec  2 18:10:48 2010
New Revision: 120760

URL: http://llvm.org/viewvc/llvm-project?rev=120760&view=rev
Log:
It may not be an option to skip .debug_line if there are file reference in already emitted debug info. So, for now, emit dummy line table entry to make older linker and assemblers happy. This is not a new behavior, original AsmPrinter emitted similar line table entries.

Modified:
    llvm/trunk/include/llvm/MC/MCContext.h
    llvm/trunk/include/llvm/MC/MCDwarf.h
    llvm/trunk/lib/MC/MCAsmStreamer.cpp
    llvm/trunk/lib/MC/MCDwarf.cpp

Modified: llvm/trunk/include/llvm/MC/MCContext.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCContext.h?rev=120760&r1=120759&r2=120760&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCContext.h (original)
+++ llvm/trunk/include/llvm/MC/MCContext.h Thu Dec  2 18:10:48 2010
@@ -180,9 +180,6 @@
     bool hasDwarfFiles() const {
       return !MCDwarfFiles.empty();
     }
-    bool hasDwarfLines() const {
-      return !MCLineSectionOrder.empty();
-    }
 
     const std::vector<MCDwarfFile *> &getMCDwarfFiles() {
       return MCDwarfFiles;

Modified: llvm/trunk/include/llvm/MC/MCDwarf.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCDwarf.h?rev=120760&r1=120759&r2=120760&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCDwarf.h (original)
+++ llvm/trunk/include/llvm/MC/MCDwarf.h Thu Dec  2 18:10:48 2010
@@ -209,7 +209,8 @@
     // This emits the Dwarf file and the line tables.
     //
     static void Emit(MCStreamer *MCOS, const MCSection *DwarfLineSection,
-                     MCSectionData *DLS, int PointerSize);
+                     MCSectionData *DLS, int PointerSize,
+                     const MCSection *TextSection = NULL);
   };
 
   class MCDwarfLineAddr {

Modified: llvm/trunk/lib/MC/MCAsmStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAsmStreamer.cpp?rev=120760&r1=120759&r2=120760&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAsmStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCAsmStreamer.cpp Thu Dec  2 18:10:48 2010
@@ -885,9 +885,9 @@
 
 void MCAsmStreamer::Finish() {
   // Dump out the dwarf file & directory tables and line tables.
-  if (getContext().hasDwarfFiles() && getContext().hasDwarfLines() && TLOF) {
+  if (getContext().hasDwarfFiles() && TLOF) {
     MCDwarfFileTable::Emit(this, TLOF->getDwarfLineSection(), NULL,
-                           PointerSize);
+                           PointerSize, TLOF->getTextSection());
   }
 }
 

Modified: llvm/trunk/lib/MC/MCDwarf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCDwarf.cpp?rev=120760&r1=120759&r2=120760&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCDwarf.cpp (original)
+++ llvm/trunk/lib/MC/MCDwarf.cpp Thu Dec  2 18:10:48 2010
@@ -241,7 +241,8 @@
 void MCDwarfFileTable::Emit(MCStreamer *MCOS,
                             const MCSection *DwarfLineSection,
                             MCSectionData *DLS,
-                            int PointerSize) {
+                            int PointerSize,
+                            const MCSection *TextSection) {
   // Switch to the section where the table will be emitted into.
   MCOS->SwitchSection(DwarfLineSection);
 
@@ -339,6 +340,23 @@
     delete Line;
   }
 
+  if (TextSection && MCLineSectionOrder.begin() == MCLineSectionOrder.end()) {
+    // Emit dummy entry if line table is empty.
+
+    MCOS->SwitchSection(TextSection);
+    MCSymbol *SectionEnd = MCOS->getContext().CreateTempSymbol();
+    // Set the value of the symbol, as we are at the end of the section.
+    MCOS->EmitLabel(SectionEnd);
+
+    // Switch back the the dwarf line section.
+    MCOS->SwitchSection(DwarfLineSection);
+
+    // emit the sequence to set the address
+    EmitDwarfSetAddress(MCOS, SectionEnd, PointerSize);
+    // emit the sequence for the LineDelta (from 1) and a zero address delta.
+    MCDwarfLineAddr::Emit(MCOS, INT64_MAX, 0);
+  }
+
   // This is the end of the section, so set the value of the symbol at the end
   // of this section (that was used in a previous expression).
   MCOS->EmitLabel(LineEndSym);