DebugInfo: Omit DW_AT_addr_base from skeletal type units.

Type units have no addresses, so there's no need for DW_AT_addr_base.
This removes another relocation from every skeletal type unit and brings
LLVM's skeletal type units in line with GCC's (containing only
GNU_dwo_name (strp), comp_dir (strp), and GNU_pubnames (flag_present)).

Cary's got some ideas about using str_index in the .o file to reduce
those last two relocations (well, replace two relocations with one
relocation (pointing to the string index) and two indicies)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204506 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
David Blaikie 2014-03-21 20:27:21 +00:00
parent 1eb67a4f84
commit 4d221b3e89
3 changed files with 9 additions and 11 deletions

View File

@ -2637,13 +2637,6 @@ void DwarfDebug::initSkeletonUnit(const DwarfUnit *U, DIE *Die,
NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name, NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
U->getCUNode().getSplitDebugFilename()); U->getCUNode().getSplitDebugFilename());
// Relocate to the beginning of the addr_base section, else 0 for the
// beginning of the one for this compile unit.
if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
NewU->addSectionLabel(Die, dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym);
else
NewU->addSectionOffset(Die, dwarf::DW_AT_GNU_addr_base, 0);
if (!CompilationDir.empty()) if (!CompilationDir.empty())
NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir); NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
@ -2668,6 +2661,13 @@ DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
initSkeletonUnit(CU, Die, NewCU); initSkeletonUnit(CU, Die, NewCU);
// Relocate to the beginning of the addr_base section, else 0 for the
// beginning of the one for this compile unit.
if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
NewCU->addSectionLabel(Die, dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym);
else
NewCU->addSectionOffset(Die, dwarf::DW_AT_GNU_addr_base, 0);
return NewCU; return NewCU;
} }

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@ -26,7 +26,6 @@
; CHECK: [1] DW_TAG_compile_unit DW_CHILDREN_no ; CHECK: [1] DW_TAG_compile_unit DW_CHILDREN_no
; CHECK: DW_AT_stmt_list DW_FORM_sec_offset ; CHECK: DW_AT_stmt_list DW_FORM_sec_offset
; CHECK: DW_AT_GNU_dwo_name DW_FORM_strp ; CHECK: DW_AT_GNU_dwo_name DW_FORM_strp
; CHECK: DW_AT_GNU_addr_base DW_FORM_sec_offset
; CHECK: DW_AT_comp_dir DW_FORM_strp ; CHECK: DW_AT_comp_dir DW_FORM_strp
; CHECK: DW_AT_GNU_dwo_id DW_FORM_data8 ; CHECK: DW_AT_GNU_dwo_id DW_FORM_data8
@ -59,8 +58,8 @@
; CHECK: DW_TAG_compile_unit ; CHECK: DW_TAG_compile_unit
; CHECK: DW_AT_stmt_list [DW_FORM_sec_offset] (0x00000000) ; CHECK: DW_AT_stmt_list [DW_FORM_sec_offset] (0x00000000)
; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000000] = "baz.dwo") ; CHECK: DW_AT_GNU_dwo_name [DW_FORM_strp] ( .debug_str[0x00000000] = "baz.dwo")
; CHECK: DW_AT_GNU_addr_base [DW_FORM_sec_offset] (0x00000000)
; CHECK: DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x00000008] = "/usr/local/google/home/echristo/tmp") ; CHECK: DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x00000008] = "/usr/local/google/home/echristo/tmp")
; CHECK: DW_AT_GNU_addr_base [DW_FORM_sec_offset] (0x00000000)
; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x1f1f859683d49324) ; CHECK: DW_AT_GNU_dwo_id [DW_FORM_data8] (0x1f1f859683d49324)
; Check that the rest of the compile units have information. ; Check that the rest of the compile units have information.
@ -106,8 +105,8 @@
; OBJ-NEXT: R_X86_64_32 .debug_abbrev ; OBJ-NEXT: R_X86_64_32 .debug_abbrev
; OBJ-NEXT: R_X86_64_32 .debug_line ; OBJ-NEXT: R_X86_64_32 .debug_line
; OBJ-NEXT: R_X86_64_32 .debug_str ; OBJ-NEXT: R_X86_64_32 .debug_str
; OBJ-NEXT: R_X86_64_32 .debug_addr
; OBJ-NEXT: R_X86_64_32 .debug_str ; OBJ-NEXT: R_X86_64_32 .debug_str
; OBJ-NEXT: R_X86_64_32 .debug_addr
; OBJ-NEXT: } ; OBJ-NEXT: }
; HDR-NOT: .debug_aranges ; HDR-NOT: .debug_aranges

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@ -77,7 +77,6 @@
; FISSION-LABEL: type_signature = 0x1d02f3be30cc5688 ; FISSION-LABEL: type_signature = 0x1d02f3be30cc5688
; FISSION: DW_TAG_type_unit ; FISSION: DW_TAG_type_unit
; FISSION-NEXT: DW_AT_GNU_dwo_name{{.*}}"bar.dwo" ; FISSION-NEXT: DW_AT_GNU_dwo_name{{.*}}"bar.dwo"
; FISSION-NEXT: DW_AT_GNU_addr_base
; FISSION-NEXT: DW_AT_comp_dir{{.*}}"/tmp/dbginfo" ; FISSION-NEXT: DW_AT_comp_dir{{.*}}"/tmp/dbginfo"
; FISSION-NOT: type_signature ; FISSION-NOT: type_signature
; FISSION-LABEL: type_signature = 0xb04af47397402e77 ; FISSION-LABEL: type_signature = 0xb04af47397402e77