[llvm] r274986 - [COFF, Dwarf] Don't emit DW_AT_location for dllimported entities
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Sat Jul 9 13:47:48 PDT 2016
Author: majnemer
Date: Sat Jul 9 15:47:48 2016
New Revision: 274986
URL: http://llvm.org/viewvc/llvm-project?rev=274986&view=rev
Log:
[COFF, Dwarf] Don't emit DW_AT_location for dllimported entities
There exists no relocation which can describe the address of a
dllimported variable: do not try to describe their location.
Added:
llvm/trunk/test/DebugInfo/X86/dllimport.ll
Modified:
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp?rev=274986&r1=274985&r2=274986&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp Sat Jul 9 15:47:48 2016
@@ -148,62 +148,69 @@ DIE *DwarfCompileUnit::getOrCreateGlobal
// Add location.
bool addToAccelTable = false;
if (auto *Global = dyn_cast_or_null<GlobalVariable>(GV->getVariable())) {
- addToAccelTable = true;
- DIELoc *Loc = new (DIEValueAllocator) DIELoc;
- const MCSymbol *Sym = Asm->getSymbol(Global);
- if (Global->isThreadLocal()) {
- if (Asm->TM.Options.EmulatedTLS) {
- // TODO: add debug info for emulated thread local mode.
- } else {
- // FIXME: Make this work with -gsplit-dwarf.
- unsigned PointerSize = Asm->getDataLayout().getPointerSize();
- assert((PointerSize == 4 || PointerSize == 8) &&
- "Add support for other sizes if necessary");
- // Based on GCC's support for TLS:
- if (!DD->useSplitDwarf()) {
- // 1) Start with a constNu of the appropriate pointer size
- addUInt(*Loc, dwarf::DW_FORM_data1, PointerSize == 4
- ? dwarf::DW_OP_const4u
- : dwarf::DW_OP_const8u);
- // 2) containing the (relocated) offset of the TLS variable
- // within the module's TLS block.
- addExpr(*Loc, dwarf::DW_FORM_udata,
- Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
+ // We cannot describe the location of dllimport'd variables: the computation
+ // of their address requires loads from the IAT.
+ if (!Global->hasDLLImportStorageClass()) {
+ addToAccelTable = true;
+ DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+ const MCSymbol *Sym = Asm->getSymbol(Global);
+ if (Global->isThreadLocal()) {
+ if (Asm->TM.Options.EmulatedTLS) {
+ // TODO: add debug info for emulated thread local mode.
} else {
- addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
- addUInt(*Loc, dwarf::DW_FORM_udata,
- DD->getAddressPool().getIndex(Sym, /* TLS */ true));
+ // FIXME: Make this work with -gsplit-dwarf.
+ unsigned PointerSize = Asm->getDataLayout().getPointerSize();
+ assert((PointerSize == 4 || PointerSize == 8) &&
+ "Add support for other sizes if necessary");
+ // Based on GCC's support for TLS:
+ if (!DD->useSplitDwarf()) {
+ // 1) Start with a constNu of the appropriate pointer size
+ addUInt(*Loc, dwarf::DW_FORM_data1, PointerSize == 4
+ ? dwarf::DW_OP_const4u
+ : dwarf::DW_OP_const8u);
+ // 2) containing the (relocated) offset of the TLS variable
+ // within the module's TLS block.
+ addExpr(*Loc, dwarf::DW_FORM_udata,
+ Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
+ } else {
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
+ addUInt(*Loc, dwarf::DW_FORM_udata,
+ DD->getAddressPool().getIndex(Sym, /* TLS */ true));
+ }
+ // 3) followed by an OP to make the debugger do a TLS lookup.
+ addUInt(*Loc, dwarf::DW_FORM_data1,
+ DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
+ : dwarf::DW_OP_form_tls_address);
}
- // 3) followed by an OP to make the debugger do a TLS lookup.
- addUInt(*Loc, dwarf::DW_FORM_data1,
- DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
- : dwarf::DW_OP_form_tls_address);
+ } else {
+ DD->addArangeLabel(SymbolCU(this, Sym));
+ addOpAddress(*Loc, Sym);
}
- } else {
- DD->addArangeLabel(SymbolCU(this, Sym));
- addOpAddress(*Loc, Sym);
- }
- addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
- if (DD->useAllLinkageNames())
- addLinkageName(*VariableDIE, GV->getLinkageName());
+ addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
+ if (DD->useAllLinkageNames())
+ addLinkageName(*VariableDIE, GV->getLinkageName());
+ }
} else if (const ConstantInt *CI =
dyn_cast_or_null<ConstantInt>(GV->getVariable())) {
addConstantValue(*VariableDIE, CI, GTy);
} else if (const ConstantExpr *CE = getMergedGlobalExpr(GV->getVariable())) {
- addToAccelTable = true;
- // GV is a merged global.
- DIELoc *Loc = new (DIEValueAllocator) DIELoc;
auto *Ptr = cast<GlobalValue>(CE->getOperand(0));
- MCSymbol *Sym = Asm->getSymbol(Ptr);
- DD->addArangeLabel(SymbolCU(this, Sym));
- addOpAddress(*Loc, Sym);
- addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
- SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
- addUInt(*Loc, dwarf::DW_FORM_udata,
- Asm->getDataLayout().getIndexedOffsetInType(Ptr->getValueType(), Idx));
- addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
- addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
+ if (!Ptr->hasDLLImportStorageClass()) {
+ addToAccelTable = true;
+ // GV is a merged global.
+ DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+ MCSymbol *Sym = Asm->getSymbol(Ptr);
+ DD->addArangeLabel(SymbolCU(this, Sym));
+ addOpAddress(*Loc, Sym);
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
+ SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
+ addUInt(*Loc, dwarf::DW_FORM_udata,
+ Asm->getDataLayout().getIndexedOffsetInType(Ptr->getValueType(),
+ Idx));
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
+ addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
+ }
}
if (addToAccelTable) {
Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp?rev=274986&r1=274985&r2=274986&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp (original)
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp Sat Jul 9 15:47:48 2016
@@ -1053,14 +1053,18 @@ void DwarfUnit::constructTemplateValuePa
if (ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(Val))
addConstantValue(ParamDIE, CI, resolve(VP->getType()));
else if (GlobalValue *GV = mdconst::dyn_extract<GlobalValue>(Val)) {
- // For declaration non-type template parameters (such as global values and
- // functions)
- DIELoc *Loc = new (DIEValueAllocator) DIELoc;
- addOpAddress(*Loc, Asm->getSymbol(GV));
- // Emit DW_OP_stack_value to use the address as the immediate value of the
- // parameter, rather than a pointer to it.
- addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
- addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
+ // We cannot describe the location of dllimport'd entities: the
+ // computation of their address requires loads from the IAT.
+ if (!GV->hasDLLImportStorageClass()) {
+ // For declaration non-type template parameters (such as global values
+ // and functions)
+ DIELoc *Loc = new (DIEValueAllocator) DIELoc;
+ addOpAddress(*Loc, Asm->getSymbol(GV));
+ // Emit DW_OP_stack_value to use the address as the immediate value of
+ // the parameter, rather than a pointer to it.
+ addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
+ addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
+ }
} else if (VP->getTag() == dwarf::DW_TAG_GNU_template_template_param) {
assert(isa<MDString>(Val));
addString(ParamDIE, dwarf::DW_AT_GNU_template_name,
Added: llvm/trunk/test/DebugInfo/X86/dllimport.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/X86/dllimport.ll?rev=274986&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/X86/dllimport.ll (added)
+++ llvm/trunk/test/DebugInfo/X86/dllimport.ll Sat Jul 9 15:47:48 2016
@@ -0,0 +1,27 @@
+; RUN: llc -mtriple=i686-pc-windows-msvc -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; CHECK-NOT: DW_AT_location
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i686-pc-windows-msvc"
+
+@"\01?id@?$numpunct at D@@0HA" = available_externally dllimport global i32 0, align 4
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!13, !14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.9.0 (trunk 272628) (llvm/trunk 272566)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3)
+!1 = !DIFile(filename: "/usr/local/google/home/majnemer/Downloads/<stdin>", directory: "/usr/local/google/home/majnemer/llvm/src")
+!2 = !{}
+!3 = !{!4}
+!4 = distinct !DIGlobalVariable(name: "id", linkageName: "\01?id@?$numpunct at D@@0HA", scope: !0, file: !5, line: 4, type: !6, isLocal: false, isDefinition: true, variable: i32* @"\01?id@?$numpunct at D@@0HA", declaration: !7)
+!5 = !DIFile(filename: "/usr/local/google/home/majnemer/Downloads/t.ii", directory: "/usr/local/google/home/majnemer/llvm/src")
+!6 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!7 = !DIDerivedType(tag: DW_TAG_member, name: "id", scope: !8, file: !5, line: 2, baseType: !6, flags: DIFlagStaticMember)
+!8 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "numpunct<char>", file: !5, line: 2, size: 8, align: 8, elements: !9, templateParams: !10)
+!9 = !{!7}
+!10 = !{!11}
+!11 = !DITemplateTypeParameter(type: !12)
+!12 = !DIBasicType(name: "char", size: 8, align: 8, encoding: DW_ATE_signed_char)
+!13 = !{i32 2, !"Dwarf Version", i32 3}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
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