If the front end has emitted llvm.dbg.cu and other debug info anchors (clang does...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130759 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 31b7bf2ae9f1cc16bc6de9db40394158128e47ef..3bff71daf5dc65ddcf7d632e149339d3ef382097 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1113,44 +1113,66 @@ void DwarfDebug::beginModule(Module *M) {
   if (DisableDebugInfoPrinting)
     return;
 
-  DebugInfoFinder DbgFinder;
-  DbgFinder.processModule(*M);
-
   bool HasDebugInfo = false;
 
-  // Scan all the compile-units to see if there are any marked as the main unit.
-  // if not, we do not generate debug info.
-  for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
-       E = DbgFinder.compile_unit_end(); I != E; ++I) {
-    if (DICompileUnit(*I).isMain()) {
+  // If module has named metadata anchors then use them, otherwise scan the module
+  // using debug info finder to collect debug info.
+  NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
+  if (CU_Nodes) {
+    for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
       HasDebugInfo = true;
-      break;
+      constructCompileUnit(CU_Nodes->getOperand(i));
     }
-  }
+    if (!HasDebugInfo)
+      return;
 
-  if (!HasDebugInfo) return;
+    if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.gv"))
+      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
+        constructGlobalVariableDIE(NMD->getOperand(i));
+
+    if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.sp"))
+      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
+        constructSubprogramDIE(NMD->getOperand(i));
+    
+  } else {
 
+    DebugInfoFinder DbgFinder;
+    DbgFinder.processModule(*M);
+    
+    // Scan all the compile-units to see if there are any marked as the main unit.
+    // if not, we do not generate debug info.
+    for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
+           E = DbgFinder.compile_unit_end(); I != E; ++I) {
+      if (DICompileUnit(*I).isMain()) {
+        HasDebugInfo = true;
+        break;
+      }
+    }
+    
+    // Create all the compile unit DIEs.
+    for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
+           E = DbgFinder.compile_unit_end(); I != E; ++I)
+      constructCompileUnit(*I);
+    
+    // Create DIEs for each global variable.
+    for (DebugInfoFinder::iterator I = DbgFinder.global_variable_begin(),
+           E = DbgFinder.global_variable_end(); I != E; ++I)
+      constructGlobalVariableDIE(*I);
+    
+    // Create DIEs for each subprogram.
+    for (DebugInfoFinder::iterator I = DbgFinder.subprogram_begin(),
+           E = DbgFinder.subprogram_end(); I != E; ++I)
+      constructSubprogramDIE(*I);
+  }
+  
+  if (!HasDebugInfo) return;
+  
   // Tell MMI that we have debug info.
   MMI->setDebugInfoAvailability(true);
-
+  
   // Emit initial sections.
   EmitSectionLabels();
 
-  // Create all the compile unit DIEs.
-  for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
-         E = DbgFinder.compile_unit_end(); I != E; ++I)
-    constructCompileUnit(*I);
-
-  // Create DIEs for each global variable.
-  for (DebugInfoFinder::iterator I = DbgFinder.global_variable_begin(),
-         E = DbgFinder.global_variable_end(); I != E; ++I)
-    constructGlobalVariableDIE(*I);
-
-  // Create DIEs for each subprogram.
-  for (DebugInfoFinder::iterator I = DbgFinder.subprogram_begin(),
-         E = DbgFinder.subprogram_end(); I != E; ++I)
-    constructSubprogramDIE(*I);
-
   //getOrCreateTypeDIE
   if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.enum"))
     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {