[llvm] r203082 - DebugInfo: Tag units as having been indexed in GNU pubnames by using a DW_AT_GNU_pubnames of DW_FORM_flag(_present) rather than sec_offsets to the pubnames/types sections

[David Blaikie]

Author: dblaikie
Date: Wed Mar  5 23:47:39 2014
New Revision: 203082

URL: http://llvm.org/viewvc/llvm-project?rev=203082&view=rev
Log:
DebugInfo: Tag units as having been indexed in GNU pubnames by using a DW_AT_GNU_pubnames of DW_FORM_flag(_present) rather than sec_offsets to the pubnames/types sections

This is consistent with GDB ToT and reduces the number of relocations in
(type and compile) units, substantially reducing relocations and debug
size in fission + type units builds.

Modified:
    llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
    llvm/trunk/test/DebugInfo/X86/gnu-public-names-empty.ll
    llvm/trunk/test/DebugInfo/X86/gnu-public-names.ll

Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=203082&r1=203081&r2=203082&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Wed Mar  5 23:47:39 2014
@@ -733,13 +733,7 @@ void DwarfDebug::addGnuPubAttributes(Dwa
   if (!GenerateGnuPubSections)
     return;
 
-  addSectionLabel(Asm, U, D, dwarf::DW_AT_GNU_pubnames,
-                  Asm->GetTempSymbol("gnu_pubnames", U->getUniqueID()),
-                  DwarfGnuPubNamesSectionSym);
-
-  addSectionLabel(Asm, U, D, dwarf::DW_AT_GNU_pubtypes,
-                  Asm->GetTempSymbol("gnu_pubtypes", U->getUniqueID()),
-                  DwarfGnuPubTypesSectionSym);
+  U->addFlag(D, dwarf::DW_AT_GNU_pubnames);
 }
 
 // Create new DwarfCompileUnit for the given metadata node with tag

Modified: llvm/trunk/test/DebugInfo/X86/gnu-public-names-empty.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/gnu-public-names-empty.ll?rev=203082&r1=203081&r2=203082&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/gnu-public-names-empty.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/gnu-public-names-empty.ll Wed Mar  5 23:47:39 2014
@@ -6,8 +6,8 @@
 
 ; Check that the attributes in the compile unit both point to a correct
 ; location, even when nothing is exported.
-; CHECK: DW_AT_GNU_pubnames [DW_FORM_sec_offset]   (0x00000000)
-; CHECK: DW_AT_GNU_pubtypes [DW_FORM_sec_offset]   (0x00000000)
+; CHECK: DW_AT_GNU_pubnames [DW_FORM_flag_present]   (true)
+; CHECK-NOT: DW_AT_GNU_pubtypes [
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!3, !4}

Modified: llvm/trunk/test/DebugInfo/X86/gnu-public-names.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/gnu-public-names.ll?rev=203082&r1=203081&r2=203082&view=diff
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/gnu-public-names.ll (original)
+++ llvm/trunk/test/DebugInfo/X86/gnu-public-names.ll Wed Mar  5 23:47:39 2014
@@ -47,8 +47,8 @@
 
 ; CHECK: .debug_info contents:
 ; CHECK: Compile Unit: length = [[UNIT_SIZE:[0-9a-f]+]]
-; CHECK: DW_AT_GNU_pubnames [DW_FORM_sec_offset]   (0x00000000)
-; CHECK: DW_AT_GNU_pubtypes [DW_FORM_sec_offset]   (0x00000000)
+; CHECK: DW_AT_GNU_pubnames [DW_FORM_flag_present]   (true)
+; CHECK-NOT: DW_AT_GNU_pubtypes [
 
 ; CHECK: [[C:[0-9a-f]+]]: DW_TAG_structure_type
 ; CHECK-NEXT: DW_AT_name {{.*}} "C"
@@ -127,8 +127,8 @@
 
 ; DWARF3: .debug_info contents:
 ; DWARF3: Compile Unit: length = [[UNIT_SIZE:[0-9a-f]+]]
-; DWARF3: DW_AT_GNU_pubnames [DW_FORM_data4]   (0x00000000)
-; DWARF3: DW_AT_GNU_pubtypes [DW_FORM_data4]   (0x00000000)
+; DWARF3: DW_AT_GNU_pubnames [DW_FORM_flag]   (0x01)
+; DWARF3-NOT: DW_AT_GNU_pubtypes [
 
 ; DWARF3: [[C:[0-9a-f]+]]: DW_TAG_structure_type
 ; DWARF3-NEXT: DW_AT_name {{.*}} "C"