[llvm-commits] [llvm] r103135 - /llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

[Dan Gohman]

Author: djg
Date: Wed May  5 18:41:32 2010
New Revision: 103135

URL: http://llvm.org/viewvc/llvm-project?rev=103135&view=rev
Log:
Emit debug info for MachineInstrs with unknown debug locations, instead
of just letting them inherit the debug locations of adjacent instructions.

Debug info should aim to be either accurate or absent.

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=103135&r1=103134&r2=103135&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Wed May  5 18:41:32 2010
@@ -2150,8 +2150,20 @@
 void DwarfDebug::beginScope(const MachineInstr *MI) {
   // Check location.
   DebugLoc DL = MI->getDebugLoc();
-  if (DL.isUnknown())
+  if (DL.isUnknown()) {
+    // This instruction has no debug location. If the preceding instruction
+    // did, emit debug location information to indicate that the debug
+    // location is now unknown.
+    MCSymbol *Label = NULL;
+    if (DL == PrevInstLoc)
+      Label = PrevLabel;
+    else {
+      Label = recordSourceLine(DL.getLine(), DL.getCol(), 0);
+      PrevInstLoc = DL;
+      PrevLabel = Label;
+    }
     return;
+  }
 
   MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
   
@@ -2564,23 +2576,28 @@
   StringRef Dir;
   StringRef Fn;
 
-  DIDescriptor Scope(S);
-  if (Scope.isCompileUnit()) {
-    DICompileUnit CU(S);
-    Dir = CU.getDirectory();
-    Fn = CU.getFilename();
-  } else if (Scope.isSubprogram()) {
-    DISubprogram SP(S);
-    Dir = SP.getDirectory();
-    Fn = SP.getFilename();
-  } else if (Scope.isLexicalBlock()) {
-    DILexicalBlock DB(S);
-    Dir = DB.getDirectory();
-    Fn = DB.getFilename();
-  } else
-    assert(0 && "Unexpected scope info");
+  unsigned Src = 1;
+  if (S) {
+    DIDescriptor Scope(S);
+
+    if (Scope.isCompileUnit()) {
+      DICompileUnit CU(S);
+      Dir = CU.getDirectory();
+      Fn = CU.getFilename();
+    } else if (Scope.isSubprogram()) {
+      DISubprogram SP(S);
+      Dir = SP.getDirectory();
+      Fn = SP.getFilename();
+    } else if (Scope.isLexicalBlock()) {
+      DILexicalBlock DB(S);
+      Dir = DB.getDirectory();
+      Fn = DB.getFilename();
+    } else
+      assert(0 && "Unexpected scope info");
+
+    Src = GetOrCreateSourceID(Dir, Fn);
+  }
 
-  unsigned Src = GetOrCreateSourceID(Dir, Fn);
   MCSymbol *Label = MMI->getContext().CreateTempSymbol();
   Lines.push_back(SrcLineInfo(Line, Col, Src, Label));
 
@@ -2967,8 +2984,6 @@
       MCSymbol *Label = LineInfo.getLabel();
       if (!Label->isDefined()) continue; // Not emitted, in dead code.
 
-      if (LineInfo.getLine() == 0) continue;
-
       if (Asm->isVerbose()) {
         std::pair<unsigned, unsigned> SrcID =
           getSourceDirectoryAndFileIds(LineInfo.getSourceID());