Fix PR12942: Allow two CUs to be generated from the same source file.

Thanks Eric for the review.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169142 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 107 insertions, 24 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 0fb0f22c3d..718e0dceb0 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -32,9 +32,9 @@
 using namespace llvm;
 
 /// CompileUnit - Compile unit constructor.
-CompileUnit::CompileUnit(unsigned I, unsigned L, DIE *D, AsmPrinter *A,
+CompileUnit::CompileUnit(unsigned UID, unsigned L, DIE *D, AsmPrinter *A,
                          DwarfDebug *DW)
-  : ID(I), Language(L), CUDie(D), Asm(A), DD(DW), IndexTyDie(0) {
+  : UniqueID(UID), Language(L), CUDie(D), Asm(A), DD(DW), IndexTyDie(0) {
   DIEIntegerOne = new (DIEValueAllocator) DIEInteger(1);
 }
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
index fad9b6e066..bb69059045 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.h
@@ -32,9 +32,9 @@ class DbgVariable;
 /// CompileUnit - This dwarf writer support class manages information associated
 /// with a source file.
 class CompileUnit {
-  /// ID - File identifier for source.
+  /// UniqueID - a numeric ID unique among all CUs in the module
   ///
-  unsigned ID;
+  unsigned UniqueID;
 
   /// Language - The DW_AT_language of the compile unit
   ///
@@ -80,11 +80,11 @@ class CompileUnit {
   DenseMap<DIE *, const MDNode *> ContainingTypeMap;
 
 public:
-  CompileUnit(unsigned I, unsigned L, DIE *D, AsmPrinter *A, DwarfDebug *DW);
+  CompileUnit(unsigned UID, unsigned L, DIE *D, AsmPrinter *A, DwarfDebug *DW);
   ~CompileUnit();
 
   // Accessors.
-  unsigned getID()                  const { return ID; }
+  unsigned getUniqueID()            const { return UniqueID; }
   unsigned getLanguage()            const { return Language; }
   DIE* getCUDie()                   const { return CUDie.get(); }
   const StringMap<DIE*> &getGlobalTypes() const { return GlobalTypes; }
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 585332d97c..d008f0b296 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -156,7 +156,7 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   : Asm(A), MMI(Asm->MMI), FirstCU(0), FissionCU(0),
     AbbreviationsSet(InitAbbreviationsSetSize),
     SourceIdMap(DIEValueAllocator), StringPool(DIEValueAllocator),
-    PrevLabel(NULL) {
+    PrevLabel(NULL), GlobalCUIndexCount(0) {
   NextStringPoolNumber = 0;
 
   DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
@@ -615,11 +615,13 @@ CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
   DICompileUnit DIUnit(N);
   StringRef FN = DIUnit.getFilename();
   CompilationDir = DIUnit.getDirectory();
-  unsigned ID = getOrCreateSourceID(FN, CompilationDir);
+  // Call this to emit a .file directive if it wasn't emitted for the source
+  // file this CU comes from yet.
+  getOrCreateSourceID(FN, CompilationDir);
 
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
-  CompileUnit *NewCU = new CompileUnit(ID, DIUnit.getLanguage(), Die,
-                                       Asm, this);
+  CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++,
+                                       DIUnit.getLanguage(), Die, Asm, this);
   NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
   NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                  DIUnit.getLanguage());
@@ -1819,7 +1821,7 @@ void DwarfDebug::emitCompileUnits(const MCSection *Section) {
 
     // Emit the compile units header.
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("info_begin",
-                                                  TheCU->getID()));
+                                                  TheCU->getUniqueID()));
 
     // Emit size of content not including length itself
     unsigned ContentSize = Die->getSize() +
@@ -1838,7 +1840,8 @@ void DwarfDebug::emitCompileUnits(const MCSection *Section) {
     Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
 
     emitDIE(Die);
-    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("info_end", TheCU->getID()));
+    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("info_end",
+                                                  TheCU->getUniqueID()));
   }
 }
 
@@ -2031,22 +2034,25 @@ void DwarfDebug::emitDebugPubTypes() {
       Asm->getObjFileLowering().getDwarfPubTypesSection());
     Asm->OutStreamer.AddComment("Length of Public Types Info");
     Asm->EmitLabelDifference(
-      Asm->GetTempSymbol("pubtypes_end", TheCU->getID()),
-      Asm->GetTempSymbol("pubtypes_begin", TheCU->getID()), 4);
+      Asm->GetTempSymbol("pubtypes_end", TheCU->getUniqueID()),
+      Asm->GetTempSymbol("pubtypes_begin", TheCU->getUniqueID()), 4);
 
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_begin",
-                                                  TheCU->getID()));
+                                                  TheCU->getUniqueID()));
 
     if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DWARF Version");
     Asm->EmitInt16(dwarf::DWARF_VERSION);
 
     Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
-    Asm->EmitSectionOffset(Asm->GetTempSymbol("info_begin", TheCU->getID()),
+    Asm->EmitSectionOffset(Asm->GetTempSymbol("info_begin",
+                                              TheCU->getUniqueID()),
                            DwarfInfoSectionSym);
 
     Asm->OutStreamer.AddComment("Compilation Unit Length");
-    Asm->EmitLabelDifference(Asm->GetTempSymbol("info_end", TheCU->getID()),
-                             Asm->GetTempSymbol("info_begin", TheCU->getID()),
+    Asm->EmitLabelDifference(Asm->GetTempSymbol("info_end",
+                                                TheCU->getUniqueID()),
+                             Asm->GetTempSymbol("info_begin",
+                                                TheCU->getUniqueID()),
                              4);
 
     const StringMap<DIE*> &Globals = TheCU->getGlobalTypes();
@@ -2066,7 +2072,7 @@ void DwarfDebug::emitDebugPubTypes() {
     Asm->OutStreamer.AddComment("End Mark");
     Asm->EmitInt32(0);
     Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_end",
-                                                  TheCU->getID()));
+                                                  TheCU->getUniqueID()));
   }
 }
 
@@ -2317,11 +2323,10 @@ CompileUnit *DwarfDebug::constructFissionCU(const MDNode *N) {
   DICompileUnit DIUnit(N);
   StringRef FN = DIUnit.getFilename();
   CompilationDir = DIUnit.getDirectory();
-  unsigned ID = getOrCreateSourceID(FN, CompilationDir);
 
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
-  CompileUnit *NewCU = new CompileUnit(ID, DIUnit.getLanguage(), Die,
-                                       Asm, this);
+  CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++,
+                                       DIUnit.getLanguage(), Die, Asm, this);
   // FIXME: This should be the .dwo file.
   NewCU->addString(Die, dwarf::DW_AT_GNU_dwo_name, FN);
 
@@ -2350,7 +2355,7 @@ void DwarfDebug::emitFissionSkeletonCU(const MCSection *Section) {
 
   // Emit the compile units header.
   Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("skel_info_begin",
-                                                FissionCU->getID()));
+                                                FissionCU->getUniqueID()));
 
   // Emit size of content not including length itself
   unsigned ContentSize = Die->getSize() +
@@ -2369,7 +2374,8 @@ void DwarfDebug::emitFissionSkeletonCU(const MCSection *Section) {
   Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
 
   emitDIE(Die);
-  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("skel_info_end", FissionCU->getID()));
+  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("skel_info_end",
+                                                FissionCU->getUniqueID()));
 
 
 }
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 35bddee41b..d90a6d570f 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -316,6 +316,9 @@ class DwarfDebug {
   // have exposed. See accessor functions below for description.
   bool IsDarwinGDBCompat;
 
+  // Counter for assigning globally unique IDs for CUs.
+  unsigned GlobalCUIndexCount;
+
   // DWARF5 Experimental Options
   bool HasDwarfAccelTables;
   bool HasDwarfFission;
diff --git a/test/DebugInfo/two-cus-from-same-file.ll b/test/DebugInfo/two-cus-from-same-file.ll
new file mode 100644
index 0000000000..74817078e1
--- /dev/null
+++ b/test/DebugInfo/two-cus-from-same-file.ll
@@ -0,0 +1,74 @@
+; For http://llvm.org/bugs/show_bug.cgi?id=12942
+;   There are two CUs coming from /tmp/foo.c in this module. Make sure it doesn't
+;   blow llc up and produces something reasonable.
+;
+
+; RUN: llc %s -o %t -filetype=obj -O0
+; RUN: llvm-dwarfdump %t | FileCheck %s
+
+; ModuleID = 'test.bc'
+
+@str = private unnamed_addr constant [4 x i8] c"FOO\00"
+@str1 = private unnamed_addr constant [6 x i8] c"Main!\00"
+
+define void @foo() nounwind {
+entry:
+  %puts = tail call i32 @puts(i8* getelementptr inbounds ([4 x i8]* @str, i32 0, i32 0)), !dbg !23
+  ret void, !dbg !25
+}
+
+declare i32 @puts(i8* nocapture) nounwind
+
+define i32 @main(i32 %argc, i8** nocapture %argv) nounwind {
+entry:
+  tail call void @llvm.dbg.value(metadata !{i32 %argc}, i64 0, metadata !21), !dbg !26
+  tail call void @llvm.dbg.value(metadata !{i8** %argv}, i64 0, metadata !22), !dbg !27
+  %puts = tail call i32 @puts(i8* getelementptr inbounds ([6 x i8]* @str1, i32 0, i32 0)), !dbg !28
+  tail call void @foo() nounwind, !dbg !30
+  ret i32 0, !dbg !31
+}
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!llvm.dbg.cu = !{!0, !9}
+
+!0 = metadata !{i32 786449, i32 0, i32 12, metadata !"foo.c", metadata !"/tmp", metadata !"clang version 3.2 (trunk 156513)", i1 true, i1 true, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{metadata !2}
+!2 = metadata !{i32 0}
+!3 = metadata !{metadata !4}
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"foo", metadata !"foo", metadata !"", metadata !6, i32 5, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void ()* @foo, null, null, metadata !1, i32 5} ; [ DW_TAG_subprogram ]
+!6 = metadata !{i32 786473, metadata !"foo.c", metadata !"/tmp", null} ; [ DW_TAG_file_type ]
+!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!8 = metadata !{null}
+!9 = metadata !{i32 786449, i32 0, i32 12, metadata !"foo.c", metadata !"/tmp", metadata !"clang version 3.2 (trunk 156513)", i1 true, i1 true, metadata !"", i32 0, metadata !1, metadata !1, metadata !10, metadata !1} ; [ DW_TAG_compile_unit ]
+!10 = metadata !{metadata !11}
+!11 = metadata !{metadata !12}
+!12 = metadata !{i32 786478, i32 0, metadata !6, metadata !"main", metadata !"main", metadata !"", metadata !6, i32 11, metadata !13, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, i32 (i32, i8**)* @main, null, null, metadata !19, i32 11} ; [ DW_TAG_subprogram ]
+!13 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !14, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!14 = metadata !{metadata !15, metadata !15, metadata !16}
+!15 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!16 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 32, i64 32, i64 0, i32 0, metadata !17} ; [ DW_TAG_pointer_type ]
+!17 = metadata !{i32 786447, null, metadata !"", null, i32 0, i64 32, i64 32, i64 0, i32 0, metadata !18} ; [ DW_TAG_pointer_type ]
+!18 = metadata !{i32 786468, null, metadata !"char", null, i32 0, i64 8, i64 8, i64 0, i32 0, i32 6} ; [ DW_TAG_base_type ]
+!19 = metadata !{metadata !20}
+!20 = metadata !{metadata !21, metadata !22}
+!21 = metadata !{i32 786689, metadata !12, metadata !"argc", metadata !6, i32 16777227, metadata !15, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!22 = metadata !{i32 786689, metadata !12, metadata !"argv", metadata !6, i32 33554443, metadata !16, i32 0, i32 0} ; [ DW_TAG_arg_variable ]
+!23 = metadata !{i32 6, i32 3, metadata !24, null}
+!24 = metadata !{i32 786443, metadata !5, i32 5, i32 16, metadata !6, i32 0} ; [ DW_TAG_lexical_block ]
+!25 = metadata !{i32 7, i32 1, metadata !24, null}
+!26 = metadata !{i32 11, i32 14, metadata !12, null}
+!27 = metadata !{i32 11, i32 26, metadata !12, null}
+!28 = metadata !{i32 12, i32 3, metadata !29, null}
+!29 = metadata !{i32 786443, metadata !12, i32 11, i32 34, metadata !6, i32 0} ; [ DW_TAG_lexical_block ]
+!30 = metadata !{i32 13, i32 3, metadata !29, null}
+!31 = metadata !{i32 14, i32 3, metadata !29, null}
+
+; Expect two different compile units to be emitted with the same filename
+; attribute
+; CHECK: {{Compile Unit.*next CU at}}
+; CHECK: {{DW_AT_name.*foo\.c}}
+; CHECK: {{Compile Unit.*next CU at}}
+; CHECK: {{DW_AT_name.*foo\.c}}
+