//
// The LLVM Compiler Infrastructure
//
-// This file was developed by James M. Laskey and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
+#include "llvm/Constants.h"
+#include "llvm/GlobalVariable.h"
+#include "llvm/Function.h"
+#include "llvm/Module.h"
+#include "llvm/Type.h"
#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Dwarf.h"
+#include <cctype>
+#include <cstring>
using namespace llvm;
TargetAsmInfo::TargetAsmInfo() :
- TextSection(".text"),
- DataSection(".data"),
- BSSSection(".bss"),
- AddressSize(4),
+ TextSection("\t.text"),
+ TextSection_(0),
+ DataSection("\t.data"),
+ DataSection_(0),
+ BSSSection("\t.bss"),
+ BSSSection_(0),
+ ReadOnlySection(0),
+ ReadOnlySection_(0),
+ TLSDataSection("\t.section .tdata,\"awT\",@progbits"),
+ TLSDataSection_(0),
+ TLSBSSSection("\t.section .tbss,\"awT\",@nobits"),
+ TLSBSSSection_(0),
+ ZeroFillDirective(0),
+ NonexecutableStackDirective(0),
NeedsSet(false),
MaxInstLength(4),
+ PCSymbol("$"),
SeparatorChar(';'),
CommentString("#"),
GlobalPrefix(""),
PrivateGlobalPrefix("."),
+ JumpTableSpecialLabelPrefix(0),
GlobalVarAddrPrefix(""),
GlobalVarAddrSuffix(""),
FunctionAddrPrefix(""),
FunctionAddrSuffix(""),
+ PersonalityPrefix(""),
+ PersonalitySuffix(""),
+ NeedsIndirectEncoding(false),
InlineAsmStart("#APP"),
InlineAsmEnd("#NO_APP"),
AssemblerDialect(0),
+ StringConstantPrefix(".str"),
ZeroDirective("\t.zero\t"),
ZeroDirectiveSuffix(0),
AsciiDirective("\t.ascii\t"),
Data64bitsDirective("\t.quad\t"),
AlignDirective("\t.align\t"),
AlignmentIsInBytes(true),
+ TextAlignFillValue(0),
SwitchToSectionDirective("\t.section\t"),
TextSectionStartSuffix(""),
DataSectionStartSuffix(""),
SectionEndDirectiveSuffix(0),
- ConstantPoolSection("\t.section .rodata\n"),
- JumpTableDataSection("\t.section .rodata\n"),
+ ConstantPoolSection("\t.section .rodata"),
+ JumpTableDataSection("\t.section .rodata"),
JumpTableDirective(0),
CStringSection(0),
+ CStringSection_(0),
StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
FourByteConstantSection(0),
+ FourByteConstantSection_(0),
EightByteConstantSection(0),
+ EightByteConstantSection_(0),
SixteenByteConstantSection(0),
+ SixteenByteConstantSection_(0),
+ GlobalDirective("\t.globl\t"),
SetDirective(0),
LCOMMDirective(0),
COMMDirective("\t.comm\t"),
HasDotTypeDotSizeDirective(true),
UsedDirective(0),
WeakRefDirective(0),
+ WeakDefDirective(0),
HiddenDirective("\t.hidden\t"),
+ ProtectedDirective("\t.protected\t"),
+ AbsoluteDebugSectionOffsets(false),
+ AbsoluteEHSectionOffsets(false),
HasLEB128(false),
- HasDotLoc(false),
- HasDotFile(false),
+ HasDotLocAndDotFile(false),
+ SupportsDebugInformation(false),
+ SupportsExceptionHandling(false),
DwarfRequiresFrameSection(true),
+ GlobalEHDirective(0),
+ SupportsWeakOmittedEHFrame(true),
+ DwarfSectionOffsetDirective(0),
DwarfAbbrevSection(".debug_abbrev"),
DwarfInfoSection(".debug_info"),
DwarfLineSection(".debug_line"),
DwarfARangesSection(".debug_aranges"),
DwarfRangesSection(".debug_ranges"),
DwarfMacInfoSection(".debug_macinfo"),
+ DwarfEHFrameSection(".eh_frame"),
+ DwarfExceptionSection(".gcc_except_table"),
AsmTransCBE(0) {
+ TextSection_ = getUnnamedSection(TextSection);
+ DataSection_ = getUnnamedSection(DataSection);
}
TargetAsmInfo::~TargetAsmInfo() {
/// Measure the specified inline asm to determine an approximation of its
/// length.
+/// Comments (which run till the next SeparatorChar or newline) do not
+/// count as an instruction.
+/// Any other non-whitespace text is considered an instruction, with
+/// multiple instructions separated by SeparatorChar or newlines.
+/// Variable-length instructions are not handled here; this function
+/// may be overloaded in the target code to do that.
unsigned TargetAsmInfo::getInlineAsmLength(const char *Str) const {
// Count the number of instructions in the asm.
- unsigned NumInsts = 0;
+ bool atInsnStart = true;
+ unsigned Length = 0;
for (; *Str; ++Str) {
if (*Str == '\n' || *Str == SeparatorChar)
- ++NumInsts;
+ atInsnStart = true;
+ if (atInsnStart && !isspace(*Str)) {
+ Length += MaxInstLength;
+ atInsnStart = false;
+ }
+ if (atInsnStart && strncmp(Str, CommentString, strlen(CommentString))==0)
+ atInsnStart = false;
}
- // Multiply by the worst-case length for each instruction.
- return NumInsts * MaxInstLength;
+ return Length;
+}
+
+unsigned TargetAsmInfo::PreferredEHDataFormat(DwarfEncoding::Target Reason,
+ bool Global) const {
+ return dwarf::DW_EH_PE_absptr;
+}
+
+static bool isSuitableForBSS(const GlobalVariable *GV) {
+ if (!GV->hasInitializer())
+ return true;
+
+ // Leave constant zeros in readonly constant sections, so they can be shared
+ Constant *C = GV->getInitializer();
+ return (C->isNullValue() && !GV->isConstant() && !NoZerosInBSS);
+}
+
+SectionKind::Kind
+TargetAsmInfo::SectionKindForGlobal(const GlobalValue *GV) const {
+ // Early exit - functions should be always in text sections.
+ if (isa<Function>(GV))
+ return SectionKind::Text;
+
+ const GlobalVariable* GVar = dyn_cast<GlobalVariable>(GV);
+ bool isThreadLocal = GVar->isThreadLocal();
+ assert(GVar && "Invalid global value for section selection");
+
+ if (isSuitableForBSS(GVar)) {
+ // Variable can be easily put to BSS section.
+ return (isThreadLocal ? SectionKind::ThreadBSS : SectionKind::BSS);
+ } else if (GVar->isConstant() && !isThreadLocal) {
+ // Now we know, that varible has initializer and it is constant. We need to
+ // check its initializer to decide, which section to output it into. Also
+ // note, there is no thread-local r/o section.
+ Constant *C = GVar->getInitializer();
+ if (C->ContainsRelocations())
+ return SectionKind::ROData;
+ else {
+ const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
+ // Check, if initializer is a null-terminated string
+ if (CVA && CVA->isCString())
+ return SectionKind::RODataMergeStr;
+ else
+ return SectionKind::RODataMergeConst;
+ }
+ }
+
+ // Variable is not constant or thread-local - emit to generic data section.
+ return (isThreadLocal ? SectionKind::ThreadData : SectionKind::Data);
+}
+
+unsigned
+TargetAsmInfo::SectionFlagsForGlobal(const GlobalValue *GV,
+ const char* Name) const {
+ unsigned Flags = SectionFlags::None;
+
+ // Decode flags from global itself.
+ if (GV) {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV);
+ switch (Kind) {
+ case SectionKind::Text:
+ Flags |= SectionFlags::Code;
+ break;
+ case SectionKind::ThreadData:
+ case SectionKind::ThreadBSS:
+ Flags |= SectionFlags::TLS;
+ // FALLS THROUGH
+ case SectionKind::Data:
+ case SectionKind::BSS:
+ Flags |= SectionFlags::Writeable;
+ break;
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeStr:
+ case SectionKind::RODataMergeConst:
+ // No additional flags here
+ break;
+ default:
+ assert(0 && "Unexpected section kind!");
+ }
+
+ if (GV->isWeakForLinker())
+ Flags |= SectionFlags::Linkonce;
+ }
+
+ // Add flags from sections, if any.
+ if (Name && *Name) {
+ Flags |= SectionFlags::Named;
+
+ // Some lame default implementation based on some magic section names.
+ if (strncmp(Name, ".gnu.linkonce.b.", 16) == 0 ||
+ strncmp(Name, ".llvm.linkonce.b.", 17) == 0)
+ Flags |= SectionFlags::BSS;
+ else if (strcmp(Name, ".tdata") == 0 ||
+ strncmp(Name, ".tdata.", 7) == 0 ||
+ strncmp(Name, ".gnu.linkonce.td.", 17) == 0 ||
+ strncmp(Name, ".llvm.linkonce.td.", 18) == 0)
+ Flags |= SectionFlags::TLS;
+ else if (strcmp(Name, ".tbss") == 0 ||
+ strncmp(Name, ".tbss.", 6) == 0 ||
+ strncmp(Name, ".gnu.linkonce.tb.", 17) == 0 ||
+ strncmp(Name, ".llvm.linkonce.tb.", 18) == 0)
+ Flags |= SectionFlags::BSS | SectionFlags::TLS;
+ }
+
+ return Flags;
+}
+
+std::string
+TargetAsmInfo::SectionForGlobal(const GlobalValue *GV) const {
+ const Section* S;
+ // Select section name
+ if (GV->hasSection()) {
+ // Honour section already set, if any
+ unsigned Flags = SectionFlagsForGlobal(GV,
+ GV->getSection().c_str());
+ S = getNamedSection(GV->getSection().c_str(), Flags);
+ } else {
+ // Use default section depending on the 'type' of global
+ S = SelectSectionForGlobal(GV);
+ }
+
+ if (!S->isNamed())
+ return S->Name;
+
+ // If section is named we need to switch into it via special '.section'
+ // directive and also append funky flags. Otherwise - section name is just
+ // some magic assembler directive.
+ return getSwitchToSectionDirective() + S->Name + PrintSectionFlags(S->Flags);
+}
+
+// Lame default implementation. Calculate the section name for global.
+const Section*
+TargetAsmInfo::SelectSectionForGlobal(const GlobalValue *GV) const {
+ SectionKind::Kind Kind = SectionKindForGlobal(GV);
+
+ if (GV->isWeakForLinker()) {
+ std::string Name = UniqueSectionForGlobal(GV, Kind);
+ unsigned Flags = SectionFlagsForGlobal(GV, Name.c_str());
+ return getNamedSection(Name.c_str(), Flags);
+ } else {
+ if (Kind == SectionKind::Text)
+ return getTextSection_();
+ else if (Kind == SectionKind::BSS && getBSSSection_())
+ return getBSSSection_();
+ else if (getReadOnlySection_() &&
+ (Kind == SectionKind::ROData ||
+ Kind == SectionKind::RODataMergeConst ||
+ Kind == SectionKind::RODataMergeStr))
+ return getReadOnlySection_();
+ }
+
+ return getDataSection_();
+}
+
+std::string
+TargetAsmInfo::UniqueSectionForGlobal(const GlobalValue* GV,
+ SectionKind::Kind Kind) const {
+ switch (Kind) {
+ case SectionKind::Text:
+ return ".gnu.linkonce.t." + GV->getName();
+ case SectionKind::Data:
+ return ".gnu.linkonce.d." + GV->getName();
+ case SectionKind::BSS:
+ return ".gnu.linkonce.b." + GV->getName();
+ case SectionKind::ROData:
+ case SectionKind::RODataMergeConst:
+ case SectionKind::RODataMergeStr:
+ return ".gnu.linkonce.r." + GV->getName();
+ case SectionKind::ThreadData:
+ return ".gnu.linkonce.td." + GV->getName();
+ case SectionKind::ThreadBSS:
+ return ".gnu.linkonce.tb." + GV->getName();
+ default:
+ assert(0 && "Unknown section kind");
+ }
+}
+
+const Section*
+TargetAsmInfo::getNamedSection(const char *Name, unsigned Flags) const {
+ Section& S = Sections[Name];
+
+ // This is newly-created section, set it up properly.
+ if (S.Flags == SectionFlags::Invalid) {
+ S.Flags = Flags | SectionFlags::Named;
+ S.Name = Name;
+ }
+
+ return &S;
+}
+
+const Section*
+TargetAsmInfo::getUnnamedSection(const char *Directive, unsigned Flags) const {
+ Section& S = Sections[Directive];
+
+ // This is newly-created section, set it up properly.
+ if (S.Flags == SectionFlags::Invalid) {
+ S.Flags = Flags & ~SectionFlags::Named;
+ S.Name = Directive;
+ }
+
+ return &S;
}
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