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// SPDX-License-Identifier: GPL-3.0-or-later
#include "RISCVTargetObjectFile.h"
#include "rcc/CodeGen/GlobalObject.h"
#include "rcc/CodeGen/MachineConstantPool.h"
#include "rcc/CodeGen/MachineFunction.h"
#include "rcc/CodeGen/MachineJumpTableInfo.h"
#include "rcc/CodeGen/MachineMCContext.h"
#include "rcc/CodeGen/TargetConstant.h"
#include "rcc/MC/MCContext.h"
#include "rcc/MC/MCSymbol.h"
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <ranges>
#include <string>
namespace rcc::riscv {
namespace {
[[nodiscard]] bool initializerIsZero(const GlobalInitializer &Initializer, std::size_t Depth = 0) {
if (Depth > 1024)
return false;
switch (Initializer.kind()) {
case GlobalInitializer::Kind::Integer: {
const auto *Value = Initializer.getIf<APInt>();
return Value != nullptr &&
std::ranges::all_of(Value->words(), [](std::uint64_t Word) { return Word == 0; });
}
case GlobalInitializer::Kind::Floating: {
const auto *Value = Initializer.getIf<APFloat>();
return Value != nullptr &&
std::ranges::all_of(Value->words(), [](std::uint64_t Word) { return Word == 0; });
}
case GlobalInitializer::Kind::Bytes: {
const auto *Value = Initializer.getIf<std::vector<std::byte>>();
return Value != nullptr &&
std::ranges::all_of(*Value, [](std::byte Byte) { return Byte == std::byte{0}; });
}
case GlobalInitializer::Kind::ZeroFill:
case GlobalInitializer::Kind::UndefinedStorage:
return true;
case GlobalInitializer::Kind::Repeated: {
const auto *Value = Initializer.getIf<GlobalRepeatedInitializer>();
return Value != nullptr && Value->Value && initializerIsZero(*Value->Value, Depth + 1);
}
case GlobalInitializer::Kind::Aggregate: {
const auto *Value = Initializer.getIf<GlobalAggregateInitializer>();
return Value != nullptr && std::ranges::all_of(Value->Elements, [Depth](const auto &Element) {
return Element && initializerIsZero(*Element, Depth + 1);
});
}
case GlobalInitializer::Kind::AlignmentPadding: {
const auto *Value = Initializer.getIf<GlobalAlignmentPadding>();
return Value != nullptr && Value->Fill == 0;
}
case GlobalInitializer::Kind::Target: {
const auto *Value = Initializer.getIf<TargetConstant>();
if (Value == nullptr)
return false;
auto Emission = Value->emit();
return Emission && Emission->Fixups.empty() &&
std::ranges::all_of(Emission->Bytes,
[](std::byte Byte) { return Byte == std::byte{0}; });
}
case GlobalInitializer::Kind::Invalid:
case GlobalInitializer::Kind::SymbolAddress:
case GlobalInitializer::Kind::SymbolDifference:
return false;
}
return false;
}
[[nodiscard]] bool initializerHasRelocation(const GlobalInitializer &Initializer,
std::size_t Depth = 0) {
if (Depth > 1024)
return true;
switch (Initializer.kind()) {
case GlobalInitializer::Kind::SymbolAddress:
case GlobalInitializer::Kind::SymbolDifference:
return true;
case GlobalInitializer::Kind::Repeated: {
const auto *Value = Initializer.getIf<GlobalRepeatedInitializer>();
return Value == nullptr || !Value->Value || initializerHasRelocation(*Value->Value, Depth + 1);
}
case GlobalInitializer::Kind::Aggregate: {
const auto *Value = Initializer.getIf<GlobalAggregateInitializer>();
return Value == nullptr || std::ranges::any_of(Value->Elements, [Depth](const auto &Element) {
return !Element || initializerHasRelocation(*Element, Depth + 1);
});
}
case GlobalInitializer::Kind::Target: {
const auto *Value = Initializer.getIf<TargetConstant>();
if (Value == nullptr)
return true;
auto Emission = Value->emit();
return !Emission || !Emission->Fixups.empty();
}
case GlobalInitializer::Kind::Invalid:
return true;
case GlobalInitializer::Kind::Integer:
case GlobalInitializer::Kind::Floating:
case GlobalInitializer::Kind::Bytes:
case GlobalInitializer::Kind::ZeroFill:
case GlobalInitializer::Kind::AlignmentPadding:
case GlobalInitializer::Kind::UndefinedStorage:
return false;
}
return true;
}
[[nodiscard]] mc::MCSectionDesc textSectionDescription() {
return mc::MCSectionDesc{
.Name = ".text",
.Kind = mc::MCSectionKind::Text,
.Flags = {mc::MCSectionFlag::Alloc, mc::MCSectionFlag::Executable},
.Alignment = 4,
.EntrySize = 0,
.Group = {},
.UniqueID = std::nullopt,
};
}
[[nodiscard]] mc::MCSectionDesc readOnlySectionDescription() {
return mc::MCSectionDesc{
.Name = ".rodata",
.Kind = mc::MCSectionKind::ReadOnly,
.Flags = {mc::MCSectionFlag::Alloc},
.Alignment = 1,
.EntrySize = 0,
.Group = {},
.UniqueID = std::nullopt,
};
}
} // namespace
Expected<mc::MCSectionDesc> RISCVELFTargetObjectFile::textSection(const MachineFunction &) const {
return textSectionDescription();
}
Expected<mc::MCSectionDesc>
RISCVELFTargetObjectFile::globalSection(const GlobalObjectDesc &Object,
MachineMCContext &Context) const {
if (Object.AddressSpace != 0) {
return makeUnexpected(ErrorCode::Unsupported,
"RV64GC assembly does not support nonzero global address spaces");
}
if (Object.TargetFlags != 0 || !Object.TargetAttributes.empty()) {
return makeUnexpected(ErrorCode::Unsupported,
"RV64GC assembly does not recognize this global target state");
}
const bool IsTLS = Object.TLSModel != GlobalTLSModel::None;
const bool IsZero = Object.Initializer && initializerIsZero(*Object.Initializer);
const bool HasRelocation = Object.Initializer && initializerHasRelocation(*Object.Initializer);
mc::MCSectionDesc Result;
Result.Alignment = Object.Align.bytes();
if (IsTLS) {
Result.Name = IsZero ? ".tbss" : ".tdata";
Result.Kind = IsZero ? mc::MCSectionKind::TLSBSS : mc::MCSectionKind::TLSData;
Result.Flags = {mc::MCSectionFlag::Alloc, mc::MCSectionFlag::Writable, mc::MCSectionFlag::TLS};
} else if (Object.IsConstant && HasRelocation) {
Result.Name = ".data.rel.ro";
Result.Kind = mc::MCSectionKind::Data;
Result.Flags = {mc::MCSectionFlag::Alloc, mc::MCSectionFlag::Writable};
} else if (Object.IsConstant) {
Result = readOnlySectionDescription();
Result.Alignment = Object.Align.bytes();
} else if (IsZero) {
Result.Name = ".bss";
Result.Kind = mc::MCSectionKind::BSS;
Result.Flags = {mc::MCSectionFlag::Alloc, mc::MCSectionFlag::Writable};
} else {
Result.Name = ".data";
Result.Kind = mc::MCSectionKind::Data;
Result.Flags = {mc::MCSectionFlag::Alloc, mc::MCSectionFlag::Writable};
}
if (Object.Section)
Result.Name = *Object.Section;
if (Object.COMDAT) {
auto Group = Context.symbol(*Object.COMDAT);
if (!Group)
return std::unexpected(Group.error());
Result.Flags.set(mc::MCSectionFlag::Group);
Result.Group = std::move(*Group);
if (!Object.Section)
Result.Name += "." + Object.Symbol;
}
return Result;
}
Expected<mc::MCSectionDesc>
RISCVELFTargetObjectFile::constantPoolSection(const MachineFunction &Function,
const MachineConstantPoolEntry &Entry) const {
const MachineConstantPoolEntryDesc *Description = Entry.description();
if (Description == nullptr)
return makeUnexpected(ErrorCode::InvalidArgument, "constant-pool entry is not live");
if (Description->Placement.Section == ConstantPoolSectionKind::TextAdjacent)
return textSectionDescription();
mc::MCSectionDesc Result = readOnlySectionDescription();
if (Description->Placement.Section == ConstantPoolSectionKind::Data) {
Result.Name = ".data";
Result.Kind = mc::MCSectionKind::Data;
Result.Flags.set(mc::MCSectionFlag::Writable);
} else if (Description->Placement.Section == ConstantPoolSectionKind::Target) {
return makeUnexpected(ErrorCode::Unsupported,
"RV64GC constant pool has an unknown target section");
} else if (Description->Placement.Section == ConstantPoolSectionKind::MergeableReadOnly) {
Result.Name = ".rodata.cst" + std::to_string(Description->Size);
Result.Flags.set(mc::MCSectionFlag::Merge);
Result.EntrySize = Description->Size;
}
if (Description->Placement.UniqueSection) {
Result.Name += "." + std::to_string(Function.stableID().value()) + "." +
std::to_string(Entry.index().value());
Result.UniqueID = static_cast<std::uint64_t>(Entry.index().value()) + 1U;
}
Result.Alignment = Description->Align.bytes();
return Result;
}
Expected<mc::MCSectionDesc>
RISCVELFTargetObjectFile::jumpTableSection(const MachineFunction &Function,
const MachineJumpTableEntry &Entry) const {
const MachineJumpTableDesc *Description = Entry.description();
if (Description == nullptr)
return makeUnexpected(ErrorCode::InvalidArgument, "jump-table entry is not live");
mc::MCSectionDesc Result = Description->Placement.InTextSection ? textSectionDescription()
: readOnlySectionDescription();
if (Description->Placement.UniqueSection) {
Result.Name += "." + std::to_string(Function.stableID().value()) + ".jt." +
std::to_string(Entry.index().value());
Result.UniqueID = static_cast<std::uint64_t>(Entry.index().value()) + 1U;
}
Result.Alignment = Description->Align.bytes();
return Result;
}
} // namespace rcc::riscv
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