The .dwo section shouldn't contain the unrelocated values (and

therefore not at all) of the pc or statement list. We also don't
need to emit the compilation dir so save so space and time
and don't bother.

Fix up the testcase accordingly and verify that we don't emit
the attributes or the items that they use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179114 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 34 insertions, 26 deletions

diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 75ebcff1961..762c475c8e5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -682,9 +682,12 @@ CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
   NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
                  DIUnit.getLanguage());
   NewCU->addString(Die, dwarf::DW_AT_name, FN);
+
   // 2.17.1 requires that we use DW_AT_low_pc for a single entry point
-  // into an entity. We're using 0 (or a NULL label) for this.
-  NewCU->addLabelAddress(Die, dwarf::DW_AT_low_pc, NULL);
+  // into an entity. We're using 0 (or a NULL label) for this. For
+  // split dwarf it's in the skeleton CU so omit it here.
+  if (!useSplitDwarf())
+    NewCU->addLabelAddress(Die, dwarf::DW_AT_low_pc, NULL);
 
   // Define start line table label for each Compile Unit.
   MCSymbol *LineTableStartSym = Asm->GetTempSymbol("line_table_start",
@@ -693,20 +696,25 @@ CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
                                                      NewCU->getUniqueID());
 
   // DW_AT_stmt_list is a offset of line number information for this
-  // compile unit in debug_line section.
+  // compile unit in debug_line section. For split dwarf this is
+  // left in the skeleton CU and so not included.
   // The line table entries are not always emitted in assembly, so it
   // is not okay to use line_table_start here.
-  if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
-    NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
-                    NewCU->getUniqueID() == 0 ?
-                    Asm->GetTempSymbol("section_line") : LineTableStartSym);
-  else if (NewCU->getUniqueID() == 0)
-    NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
-  else
-    NewCU->addDelta(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
-                    LineTableStartSym, DwarfLineSectionSym);
+  if (!useSplitDwarf()) {
+    if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
+      NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
+                      NewCU->getUniqueID() == 0 ?
+                      Asm->GetTempSymbol("section_line") : LineTableStartSym);
+    else if (NewCU->getUniqueID() == 0)
+      NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
+    else
+      NewCU->addDelta(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
+                      LineTableStartSym, DwarfLineSectionSym);
+  }
 
-  if (!CompilationDir.empty())
+  // If we're using split dwarf the compilation dir is going to be in the
+  // skeleton CU and so we don't need to duplicate it here.
+  if (!useSplitDwarf() && !CompilationDir.empty())
     NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
   if (DIUnit.isOptimized())
     NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
diff --git a/test/DebugInfo/X86/fission-cu.ll b/test/DebugInfo/X86/fission-cu.ll
index e139e3be77f..71381cec115 100644
--- a/test/DebugInfo/X86/fission-cu.ll
+++ b/test/DebugInfo/X86/fission-cu.ll
@@ -49,9 +49,9 @@
 ; CHECK: DW_AT_producer  DW_FORM_GNU_str_index
 ; CHECK: DW_AT_language  DW_FORM_data2
 ; CHECK: DW_AT_name      DW_FORM_GNU_str_index
-; CHECK: DW_AT_low_pc    DW_FORM_GNU_addr_index
-; CHECK: DW_AT_stmt_list DW_FORM_data4
-; CHECK: DW_AT_comp_dir  DW_FORM_GNU_str_index
+; CHECK-NOT: DW_AT_low_pc
+; CHECK-NOT: DW_AT_stmt_list
+; CHECK-NOT: DW_AT_comp_dir
 ; CHECK: DW_AT_GNU_dwo_id        DW_FORM_data8
 
 ; CHECK: [2] DW_TAG_base_type    DW_CHILDREN_no
@@ -73,32 +73,32 @@
 ; CHECK: DW_AT_producer [DW_FORM_GNU_str_index] ( indexed (00000000) string = "clang version 3.3 (trunk 169021) (llvm/trunk 169020)")
 ; CHECK: DW_AT_language [DW_FORM_data2]        (0x000c)
 ; CHECK: DW_AT_name [DW_FORM_GNU_str_index]    ( indexed (00000001) string = "baz.c")
-; CHECK: DW_AT_low_pc [DW_FORM_GNU_addr_index]     ( indexed (00000000) address = 0x0000000000000000)
+; CHECK-NOT: DW_AT_low_pc
+; CHECK-NOT: DW_AT_stmt_list
+; CHECK-NOT: DW_AT_comp_dir
 ; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8]  (0x0000000000000000)
 ; CHECK: DW_TAG_base_type
-; CHECK: DW_AT_name [DW_FORM_GNU_str_index]     ( indexed (00000004) string = "int")
+; CHECK: DW_AT_name [DW_FORM_GNU_str_index]     ( indexed (00000003) string = "int")
 ; CHECK: DW_TAG_variable
-; CHECK: DW_AT_name [DW_FORM_GNU_str_index]     ( indexed (00000003) string = "a")
-; CHECK: DW_AT_type [DW_FORM_ref4]       (cu + 0x001e => {0x0000001e})
+; CHECK: DW_AT_name [DW_FORM_GNU_str_index]     ( indexed (00000002) string = "a")
+; CHECK: DW_AT_type [DW_FORM_ref4]       (cu + 0x0018 => {0x00000018})
 ; CHECK: DW_AT_external [DW_FORM_flag_present]   (true)
 ; CHECK: DW_AT_decl_file [DW_FORM_data1] (0x01)
 ; CHECK: DW_AT_decl_line [DW_FORM_data1] (0x01)
-; CHECK: DW_AT_location [DW_FORM_block1] (<0x02> fb 01 )
+; CHECK: DW_AT_location [DW_FORM_block1] (<0x02> fb 00 )
 
 
 ; CHECK: .debug_str.dwo contents:
 ; CHECK: 0x00000000: "clang version 3.3 (trunk 169021) (llvm/trunk 169020)"
 ; CHECK: 0x00000035: "baz.c"
-; CHECK: 0x0000003b: "/usr/local/google/home/echristo/tmp"
-; CHECK: 0x0000005f: "a"
-; CHECK: 0x00000061: "int"
+; CHECK: 0x0000003b: "a"
+; CHECK: 0x0000003d: "int"
 
 ; CHECK: .debug_str_offsets.dwo contents:
 ; CHECK: 0x00000000: 00000000
 ; CHECK: 0x00000004: 00000035
 ; CHECK: 0x00000008: 0000003b
-; CHECK: 0x0000000c: 0000005f
-; CHECK: 0x00000010: 00000061
+; CHECK: 0x0000000c: 0000003d
 
 ; Object file checks
 ; For x86-64-linux we should have this set of relocations for the debug info section