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llvm.zig
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llvm.zig
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const std = @import("std");
const builtin = @import("builtin");
const assert = std.debug.assert;
const Allocator = std.mem.Allocator;
const log = std.log.scoped(.codegen);
const math = std.math;
const native_endian = builtin.cpu.arch.endian();
const DW = std.dwarf;
const llvm = @import("llvm/bindings.zig");
const link = @import("../link.zig");
const Compilation = @import("../Compilation.zig");
const build_options = @import("build_options");
const Module = @import("../Module.zig");
const Package = @import("../Package.zig");
const TypedValue = @import("../TypedValue.zig");
const Air = @import("../Air.zig");
const Liveness = @import("../Liveness.zig");
const target_util = @import("../target.zig");
const Value = @import("../value.zig").Value;
const Type = @import("../type.zig").Type;
const LazySrcLoc = Module.LazySrcLoc;
const CType = @import("../type.zig").CType;
const x86_64_abi = @import("../arch/x86_64/abi.zig");
const wasm_c_abi = @import("../arch/wasm/abi.zig");
const aarch64_c_abi = @import("../arch/aarch64/abi.zig");
const Error = error{ OutOfMemory, CodegenFail };
pub fn targetTriple(allocator: Allocator, target: std.Target) ![:0]u8 {
var llvm_triple = std.ArrayList(u8).init(allocator);
defer llvm_triple.deinit();
const llvm_arch = switch (target.cpu.arch) {
.arm => "arm",
.armeb => "armeb",
.aarch64 => "aarch64",
.aarch64_be => "aarch64_be",
.aarch64_32 => "aarch64_32",
.arc => "arc",
.avr => "avr",
.bpfel => "bpfel",
.bpfeb => "bpfeb",
.csky => "csky",
.dxil => "dxil",
.hexagon => "hexagon",
.loongarch32 => "loongarch32",
.loongarch64 => "loongarch64",
.m68k => "m68k",
.mips => "mips",
.mipsel => "mipsel",
.mips64 => "mips64",
.mips64el => "mips64el",
.msp430 => "msp430",
.powerpc => "powerpc",
.powerpcle => "powerpcle",
.powerpc64 => "powerpc64",
.powerpc64le => "powerpc64le",
.r600 => "r600",
.amdgcn => "amdgcn",
.riscv32 => "riscv32",
.riscv64 => "riscv64",
.sparc => "sparc",
.sparc64 => "sparc64",
.sparcel => "sparcel",
.s390x => "s390x",
.tce => "tce",
.tcele => "tcele",
.thumb => "thumb",
.thumbeb => "thumbeb",
.i386 => "i386",
.x86_64 => "x86_64",
.xcore => "xcore",
.nvptx => "nvptx",
.nvptx64 => "nvptx64",
.le32 => "le32",
.le64 => "le64",
.amdil => "amdil",
.amdil64 => "amdil64",
.hsail => "hsail",
.hsail64 => "hsail64",
.spir => "spir",
.spir64 => "spir64",
.kalimba => "kalimba",
.shave => "shave",
.lanai => "lanai",
.wasm32 => "wasm32",
.wasm64 => "wasm64",
.renderscript32 => "renderscript32",
.renderscript64 => "renderscript64",
.ve => "ve",
.spu_2 => return error.@"LLVM backend does not support SPU Mark II",
.spirv32 => return error.@"LLVM backend does not support SPIR-V",
.spirv64 => return error.@"LLVM backend does not support SPIR-V",
};
try llvm_triple.appendSlice(llvm_arch);
try llvm_triple.appendSlice("-unknown-");
const llvm_os = switch (target.os.tag) {
.freestanding => "unknown",
.ananas => "ananas",
.cloudabi => "cloudabi",
.dragonfly => "dragonfly",
.freebsd => "freebsd",
.fuchsia => "fuchsia",
.kfreebsd => "kfreebsd",
.linux => "linux",
.lv2 => "lv2",
.netbsd => "netbsd",
.openbsd => "openbsd",
.solaris => "solaris",
.windows => "windows",
.zos => "zos",
.haiku => "haiku",
.minix => "minix",
.rtems => "rtems",
.nacl => "nacl",
.aix => "aix",
.cuda => "cuda",
.nvcl => "nvcl",
.amdhsa => "amdhsa",
.ps4 => "ps4",
.ps5 => "ps5",
.elfiamcu => "elfiamcu",
.mesa3d => "mesa3d",
.contiki => "contiki",
.amdpal => "amdpal",
.hermit => "hermit",
.hurd => "hurd",
.wasi => "wasi",
.emscripten => "emscripten",
.uefi => "windows",
.macos => "macosx",
.ios => "ios",
.tvos => "tvos",
.watchos => "watchos",
.driverkit => "driverkit",
.shadermodel => "shadermodel",
.opencl,
.glsl450,
.vulkan,
.plan9,
.other,
=> "unknown",
};
try llvm_triple.appendSlice(llvm_os);
if (target.os.tag.isDarwin()) {
const min_version = target.os.version_range.semver.min;
try llvm_triple.writer().print("{d}.{d}.{d}", .{
min_version.major,
min_version.minor,
min_version.patch,
});
}
try llvm_triple.append('-');
const llvm_abi = switch (target.abi) {
.none => "unknown",
.gnu => "gnu",
.gnuabin32 => "gnuabin32",
.gnuabi64 => "gnuabi64",
.gnueabi => "gnueabi",
.gnueabihf => "gnueabihf",
.gnux32 => "gnux32",
.gnuilp32 => "gnuilp32",
.code16 => "code16",
.eabi => "eabi",
.eabihf => "eabihf",
.android => "android",
.musl => "musl",
.musleabi => "musleabi",
.musleabihf => "musleabihf",
.muslx32 => "muslx32",
.msvc => "msvc",
.itanium => "itanium",
.cygnus => "cygnus",
.coreclr => "coreclr",
.simulator => "simulator",
.macabi => "macabi",
.pixel => "pixel",
.vertex => "vertex",
.geometry => "geometry",
.hull => "hull",
.domain => "domain",
.compute => "compute",
.library => "library",
.raygeneration => "raygeneration",
.intersection => "intersection",
.anyhit => "anyhit",
.closesthit => "closesthit",
.miss => "miss",
.callable => "callable",
.mesh => "mesh",
.amplification => "amplification",
};
try llvm_triple.appendSlice(llvm_abi);
return llvm_triple.toOwnedSliceSentinel(0);
}
pub fn targetOs(os_tag: std.Target.Os.Tag) llvm.OSType {
return switch (os_tag) {
.freestanding, .other, .opencl, .glsl450, .vulkan, .plan9 => .UnknownOS,
.windows, .uefi => .Win32,
.ananas => .Ananas,
.cloudabi => .CloudABI,
.dragonfly => .DragonFly,
.freebsd => .FreeBSD,
.fuchsia => .Fuchsia,
.ios => .IOS,
.kfreebsd => .KFreeBSD,
.linux => .Linux,
.lv2 => .Lv2,
.macos => .MacOSX,
.netbsd => .NetBSD,
.openbsd => .OpenBSD,
.solaris => .Solaris,
.zos => .ZOS,
.haiku => .Haiku,
.minix => .Minix,
.rtems => .RTEMS,
.nacl => .NaCl,
.aix => .AIX,
.cuda => .CUDA,
.nvcl => .NVCL,
.amdhsa => .AMDHSA,
.ps4 => .PS4,
.ps5 => .PS5,
.elfiamcu => .ELFIAMCU,
.tvos => .TvOS,
.watchos => .WatchOS,
.mesa3d => .Mesa3D,
.contiki => .Contiki,
.amdpal => .AMDPAL,
.hermit => .HermitCore,
.hurd => .Hurd,
.wasi => .WASI,
.emscripten => .Emscripten,
.driverkit => .DriverKit,
.shadermodel => .ShaderModel,
};
}
pub fn targetArch(arch_tag: std.Target.Cpu.Arch) llvm.ArchType {
return switch (arch_tag) {
.arm => .arm,
.armeb => .armeb,
.aarch64 => .aarch64,
.aarch64_be => .aarch64_be,
.aarch64_32 => .aarch64_32,
.arc => .arc,
.avr => .avr,
.bpfel => .bpfel,
.bpfeb => .bpfeb,
.csky => .csky,
.dxil => .dxil,
.hexagon => .hexagon,
.loongarch32 => .loongarch32,
.loongarch64 => .loongarch64,
.m68k => .m68k,
.mips => .mips,
.mipsel => .mipsel,
.mips64 => .mips64,
.mips64el => .mips64el,
.msp430 => .msp430,
.powerpc => .ppc,
.powerpcle => .ppcle,
.powerpc64 => .ppc64,
.powerpc64le => .ppc64le,
.r600 => .r600,
.amdgcn => .amdgcn,
.riscv32 => .riscv32,
.riscv64 => .riscv64,
.sparc => .sparc,
.sparc64 => .sparcv9, // In LLVM, sparc64 == sparcv9.
.sparcel => .sparcel,
.s390x => .systemz,
.tce => .tce,
.tcele => .tcele,
.thumb => .thumb,
.thumbeb => .thumbeb,
.i386 => .x86,
.x86_64 => .x86_64,
.xcore => .xcore,
.nvptx => .nvptx,
.nvptx64 => .nvptx64,
.le32 => .le32,
.le64 => .le64,
.amdil => .amdil,
.amdil64 => .amdil64,
.hsail => .hsail,
.hsail64 => .hsail64,
.spir => .spir,
.spir64 => .spir64,
.kalimba => .kalimba,
.shave => .shave,
.lanai => .lanai,
.wasm32 => .wasm32,
.wasm64 => .wasm64,
.renderscript32 => .renderscript32,
.renderscript64 => .renderscript64,
.ve => .ve,
.spu_2, .spirv32, .spirv64 => .UnknownArch,
};
}
pub fn supportsTailCall(target: std.Target) bool {
switch (target.cpu.arch) {
.wasm32, .wasm64 => return std.Target.wasm.featureSetHas(target.cpu.features, .tail_call),
// Although these ISAs support tail calls, LLVM does not support tail calls on them.
.mips, .mipsel, .mips64, .mips64el => return false,
.powerpc, .powerpcle, .powerpc64, .powerpc64le => return false,
else => return true,
}
}
/// TODO can this be done with simpler logic / different API binding?
fn deleteLlvmGlobal(llvm_global: *llvm.Value) void {
if (llvm_global.globalGetValueType().getTypeKind() == .Function) {
llvm_global.deleteFunction();
return;
}
return llvm_global.deleteGlobal();
}
pub const Object = struct {
gpa: Allocator,
module: *Module,
llvm_module: *llvm.Module,
di_builder: ?*llvm.DIBuilder,
/// One of these mappings:
/// - *Module.File => *DIFile
/// - *Module.Decl (Fn) => *DISubprogram
/// - *Module.Decl (Non-Fn) => *DIGlobalVariable
di_map: std.AutoHashMapUnmanaged(*const anyopaque, *llvm.DINode),
di_compile_unit: ?*llvm.DICompileUnit,
context: *llvm.Context,
target_machine: *llvm.TargetMachine,
target_data: *llvm.TargetData,
target: std.Target,
/// Ideally we would use `llvm_module.getNamedFunction` to go from *Decl to LLVM function,
/// but that has some downsides:
/// * we have to compute the fully qualified name every time we want to do the lookup
/// * for externally linked functions, the name is not fully qualified, but when
/// a Decl goes from exported to not exported and vice-versa, we would use the wrong
/// version of the name and incorrectly get function not found in the llvm module.
/// * it works for functions not all globals.
/// Therefore, this table keeps track of the mapping.
decl_map: std.AutoHashMapUnmanaged(Module.Decl.Index, *llvm.Value),
/// Serves the same purpose as `decl_map` but only used for the `is_named_enum_value` instruction.
named_enum_map: std.AutoHashMapUnmanaged(Module.Decl.Index, *llvm.Value),
/// Maps Zig types to LLVM types. The table memory itself is backed by the GPA of
/// the compiler, but the Type/Value memory here is backed by `type_map_arena`.
/// TODO we need to remove entries from this map in response to incremental compilation
/// but I think the frontend won't tell us about types that get deleted because
/// hasRuntimeBits() is false for types.
type_map: TypeMap,
/// The backing memory for `type_map`. Periodically garbage collected after flush().
/// The code for doing the periodical GC is not yet implemented.
type_map_arena: std.heap.ArenaAllocator,
di_type_map: DITypeMap,
/// The LLVM global table which holds the names corresponding to Zig errors.
/// Note that the values are not added until flushModule, when all errors in
/// the compilation are known.
error_name_table: ?*llvm.Value,
/// This map is usually very close to empty. It tracks only the cases when a
/// second extern Decl could not be emitted with the correct name due to a
/// name collision.
extern_collisions: std.AutoArrayHashMapUnmanaged(Module.Decl.Index, void),
pub const TypeMap = std.HashMapUnmanaged(
Type,
*llvm.Type,
Type.HashContext64,
std.hash_map.default_max_load_percentage,
);
/// This is an ArrayHashMap as opposed to a HashMap because in `flushModule` we
/// want to iterate over it while adding entries to it.
pub const DITypeMap = std.ArrayHashMapUnmanaged(
Type,
AnnotatedDITypePtr,
Type.HashContext32,
true,
);
pub fn create(gpa: Allocator, options: link.Options) !*Object {
const obj = try gpa.create(Object);
errdefer gpa.destroy(obj);
obj.* = try Object.init(gpa, options);
return obj;
}
pub fn init(gpa: Allocator, options: link.Options) !Object {
const context = llvm.Context.create();
errdefer context.dispose();
initializeLLVMTarget(options.target.cpu.arch);
const llvm_module = llvm.Module.createWithName(options.root_name.ptr, context);
errdefer llvm_module.dispose();
const llvm_target_triple = try targetTriple(gpa, options.target);
defer gpa.free(llvm_target_triple);
var error_message: [*:0]const u8 = undefined;
var target: *llvm.Target = undefined;
if (llvm.Target.getFromTriple(llvm_target_triple.ptr, &target, &error_message).toBool()) {
defer llvm.disposeMessage(error_message);
log.err("LLVM failed to parse '{s}': {s}", .{ llvm_target_triple, error_message });
return error.InvalidLlvmTriple;
}
llvm_module.setTarget(llvm_target_triple.ptr);
var opt_di_builder: ?*llvm.DIBuilder = null;
errdefer if (opt_di_builder) |di_builder| di_builder.dispose();
var di_compile_unit: ?*llvm.DICompileUnit = null;
if (!options.strip) {
switch (options.target.ofmt) {
.coff => llvm_module.addModuleCodeViewFlag(),
else => llvm_module.addModuleDebugInfoFlag(),
}
const di_builder = llvm_module.createDIBuilder(true);
opt_di_builder = di_builder;
// Don't use the version string here; LLVM misparses it when it
// includes the git revision.
const producer = try std.fmt.allocPrintZ(gpa, "zig {d}.{d}.{d}", .{
build_options.semver.major,
build_options.semver.minor,
build_options.semver.patch,
});
defer gpa.free(producer);
// For macOS stack traces, we want to avoid having to parse the compilation unit debug
// info. As long as each debug info file has a path independent of the compilation unit
// directory (DW_AT_comp_dir), then we never have to look at the compilation unit debug
// info. If we provide an absolute path to LLVM here for the compilation unit debug
// info, LLVM will emit DWARF info that depends on DW_AT_comp_dir. To avoid this, we
// pass "." for the compilation unit directory. This forces each debug file to have a
// directory rather than be relative to DW_AT_comp_dir. According to DWARF 5, debug
// files will no longer reference DW_AT_comp_dir, for the purpose of being able to
// support the common practice of stripping all but the line number sections from an
// executable.
const compile_unit_dir = d: {
if (options.target.isDarwin()) break :d ".";
const mod = options.module orelse break :d ".";
break :d mod.root_pkg.root_src_directory.path orelse ".";
};
const compile_unit_dir_z = try gpa.dupeZ(u8, compile_unit_dir);
defer gpa.free(compile_unit_dir_z);
di_compile_unit = di_builder.createCompileUnit(
DW.LANG.C99,
di_builder.createFile(options.root_name, compile_unit_dir_z),
producer,
options.optimize_mode != .Debug,
"", // flags
0, // runtime version
"", // split name
0, // dwo id
true, // emit debug info
);
}
const opt_level: llvm.CodeGenOptLevel = if (options.optimize_mode == .Debug)
.None
else
.Aggressive;
const reloc_mode: llvm.RelocMode = if (options.pic)
.PIC
else if (options.link_mode == .Dynamic)
llvm.RelocMode.DynamicNoPIC
else
.Static;
const code_model: llvm.CodeModel = switch (options.machine_code_model) {
.default => .Default,
.tiny => .Tiny,
.small => .Small,
.kernel => .Kernel,
.medium => .Medium,
.large => .Large,
};
// TODO handle float ABI better- it should depend on the ABI portion of std.Target
const float_abi: llvm.ABIType = .Default;
const target_machine = llvm.TargetMachine.create(
target,
llvm_target_triple.ptr,
if (options.target.cpu.model.llvm_name) |s| s.ptr else null,
options.llvm_cpu_features,
opt_level,
reloc_mode,
code_model,
options.function_sections,
float_abi,
if (target_util.llvmMachineAbi(options.target)) |s| s.ptr else null,
);
errdefer target_machine.dispose();
const target_data = target_machine.createTargetDataLayout();
errdefer target_data.dispose();
llvm_module.setModuleDataLayout(target_data);
if (options.pic) llvm_module.setModulePICLevel();
if (options.pie) llvm_module.setModulePIELevel();
if (code_model != .Default) llvm_module.setModuleCodeModel(code_model);
return Object{
.gpa = gpa,
.module = options.module.?,
.llvm_module = llvm_module,
.di_map = .{},
.di_builder = opt_di_builder,
.di_compile_unit = di_compile_unit,
.context = context,
.target_machine = target_machine,
.target_data = target_data,
.target = options.target,
.decl_map = .{},
.named_enum_map = .{},
.type_map = .{},
.type_map_arena = std.heap.ArenaAllocator.init(gpa),
.di_type_map = .{},
.error_name_table = null,
.extern_collisions = .{},
};
}
pub fn deinit(self: *Object, gpa: Allocator) void {
if (self.di_builder) |dib| {
dib.dispose();
self.di_map.deinit(gpa);
self.di_type_map.deinit(gpa);
}
self.target_data.dispose();
self.target_machine.dispose();
self.llvm_module.dispose();
self.context.dispose();
self.decl_map.deinit(gpa);
self.named_enum_map.deinit(gpa);
self.type_map.deinit(gpa);
self.type_map_arena.deinit();
self.extern_collisions.deinit(gpa);
self.* = undefined;
}
pub fn destroy(self: *Object, gpa: Allocator) void {
self.deinit(gpa);
gpa.destroy(self);
}
fn locPath(
arena: Allocator,
opt_loc: ?Compilation.EmitLoc,
cache_directory: Compilation.Directory,
) !?[*:0]u8 {
const loc = opt_loc orelse return null;
const directory = loc.directory orelse cache_directory;
const slice = try directory.joinZ(arena, &[_][]const u8{loc.basename});
return slice.ptr;
}
fn genErrorNameTable(self: *Object) !void {
// If self.error_name_table is null, there was no instruction that actually referenced the error table.
const error_name_table_ptr_global = self.error_name_table orelse return;
const mod = self.module;
const target = mod.getTarget();
const llvm_ptr_ty = self.context.intType(8).pointerType(0); // TODO: Address space
const llvm_usize_ty = self.context.intType(target.cpu.arch.ptrBitWidth());
const type_fields = [_]*llvm.Type{
llvm_ptr_ty,
llvm_usize_ty,
};
const llvm_slice_ty = self.context.structType(&type_fields, type_fields.len, .False);
const slice_ty = Type.initTag(.const_slice_u8_sentinel_0);
const slice_alignment = slice_ty.abiAlignment(target);
const error_name_list = mod.error_name_list.items;
const llvm_errors = try mod.gpa.alloc(*llvm.Value, error_name_list.len);
defer mod.gpa.free(llvm_errors);
llvm_errors[0] = llvm_slice_ty.getUndef();
for (llvm_errors[1..]) |*llvm_error, i| {
const name = error_name_list[1..][i];
const str_init = self.context.constString(name.ptr, @intCast(c_uint, name.len), .False);
const str_global = self.llvm_module.addGlobal(str_init.typeOf(), "");
str_global.setInitializer(str_init);
str_global.setLinkage(.Private);
str_global.setGlobalConstant(.True);
str_global.setUnnamedAddr(.True);
str_global.setAlignment(1);
const slice_fields = [_]*llvm.Value{
str_global.constBitCast(llvm_ptr_ty),
llvm_usize_ty.constInt(name.len, .False),
};
llvm_error.* = llvm_slice_ty.constNamedStruct(&slice_fields, slice_fields.len);
}
const error_name_table_init = llvm_slice_ty.constArray(llvm_errors.ptr, @intCast(c_uint, error_name_list.len));
const error_name_table_global = self.llvm_module.addGlobal(error_name_table_init.typeOf(), "");
error_name_table_global.setInitializer(error_name_table_init);
error_name_table_global.setLinkage(.Private);
error_name_table_global.setGlobalConstant(.True);
error_name_table_global.setUnnamedAddr(.True);
error_name_table_global.setAlignment(slice_alignment); // TODO: Dont hardcode
const error_name_table_ptr = error_name_table_global.constBitCast(llvm_slice_ty.pointerType(0)); // TODO: Address space
error_name_table_ptr_global.setInitializer(error_name_table_ptr);
}
fn genCmpLtErrorsLenFunction(object: *Object) !void {
// If there is no such function in the module, it means the source code does not need it.
const llvm_fn = object.llvm_module.getNamedFunction(lt_errors_fn_name) orelse return;
const mod = object.module;
const errors_len = mod.global_error_set.count();
// Delete previous implementation. We replace it with every flush() because the
// total number of errors may have changed.
while (llvm_fn.getFirstBasicBlock()) |bb| {
bb.deleteBasicBlock();
}
const builder = object.context.createBuilder();
const entry_block = object.context.appendBasicBlock(llvm_fn, "Entry");
builder.positionBuilderAtEnd(entry_block);
builder.clearCurrentDebugLocation();
// Example source of the following LLVM IR:
// fn __zig_lt_errors_len(index: u16) bool {
// return index < total_errors_len;
// }
const lhs = llvm_fn.getParam(0);
const rhs = lhs.typeOf().constInt(errors_len, .False);
const is_lt = builder.buildICmp(.ULT, lhs, rhs, "");
_ = builder.buildRet(is_lt);
}
fn genModuleLevelAssembly(object: *Object) !void {
const mod = object.module;
if (mod.global_assembly.count() == 0) return;
var buffer = std.ArrayList(u8).init(mod.gpa);
defer buffer.deinit();
var it = mod.global_assembly.iterator();
while (it.next()) |kv| {
try buffer.appendSlice(kv.value_ptr.*);
try buffer.append('\n');
}
object.llvm_module.setModuleInlineAsm2(buffer.items.ptr, buffer.items.len - 1);
}
fn resolveExportExternCollisions(object: *Object) !void {
const mod = object.module;
// This map has externs with incorrect symbol names.
for (object.extern_collisions.keys()) |decl_index| {
const entry = object.decl_map.getEntry(decl_index) orelse continue;
const llvm_global = entry.value_ptr.*;
// Same logic as below but for externs instead of exports.
const decl = mod.declPtr(decl_index);
const other_global = object.getLlvmGlobal(decl.name) orelse continue;
if (other_global == llvm_global) continue;
const new_global_ptr = other_global.constBitCast(llvm_global.typeOf());
llvm_global.replaceAllUsesWith(new_global_ptr);
deleteLlvmGlobal(llvm_global);
entry.value_ptr.* = new_global_ptr;
}
object.extern_collisions.clearRetainingCapacity();
const export_keys = mod.decl_exports.keys();
for (mod.decl_exports.values()) |export_list, i| {
const decl_index = export_keys[i];
const llvm_global = object.decl_map.get(decl_index) orelse continue;
for (export_list) |exp| {
// Detect if the LLVM global has already been created as an extern. In such
// case, we need to replace all uses of it with this exported global.
// TODO update std.builtin.ExportOptions to have the name be a
// null-terminated slice.
const exp_name_z = try mod.gpa.dupeZ(u8, exp.options.name);
defer mod.gpa.free(exp_name_z);
const other_global = object.getLlvmGlobal(exp_name_z.ptr) orelse continue;
if (other_global == llvm_global) continue;
// replaceAllUsesWith requires the type to be unchanged. So we bitcast
// the new global to the old type and use that as the thing to replace
// old uses.
const new_global_ptr = llvm_global.constBitCast(other_global.typeOf());
other_global.replaceAllUsesWith(new_global_ptr);
llvm_global.takeName(other_global);
deleteLlvmGlobal(other_global);
// Problem: now we need to replace in the decl_map that
// the extern decl index points to this new global. However we don't
// know the decl index.
// Even if we did, a future incremental update to the extern would then
// treat the LLVM global as an extern rather than an export, so it would
// need a way to check that.
// This is a TODO that needs to be solved when making
// the LLVM backend support incremental compilation.
}
}
}
pub fn flushModule(self: *Object, comp: *Compilation, prog_node: *std.Progress.Node) !void {
var sub_prog_node = prog_node.start("LLVM Emit Object", 0);
sub_prog_node.activate();
sub_prog_node.context.refresh();
defer sub_prog_node.end();
try self.resolveExportExternCollisions();
try self.genErrorNameTable();
try self.genCmpLtErrorsLenFunction();
try self.genModuleLevelAssembly();
if (self.di_builder) |dib| {
// When lowering debug info for pointers, we emitted the element types as
// forward decls. Now we must go flesh those out.
// Here we iterate over a hash map while modifying it but it is OK because
// we never add or remove entries during this loop.
var i: usize = 0;
while (i < self.di_type_map.count()) : (i += 1) {
const value_ptr = &self.di_type_map.values()[i];
const annotated = value_ptr.*;
if (!annotated.isFwdOnly()) continue;
const entry: Object.DITypeMap.Entry = .{
.key_ptr = &self.di_type_map.keys()[i],
.value_ptr = value_ptr,
};
_ = try self.lowerDebugTypeImpl(entry, .full, annotated.toDIType());
}
dib.finalize();
}
if (comp.verbose_llvm_ir) {
self.llvm_module.dump();
}
var arena_allocator = std.heap.ArenaAllocator.init(comp.gpa);
defer arena_allocator.deinit();
const arena = arena_allocator.allocator();
const mod = comp.bin_file.options.module.?;
const cache_dir = mod.zig_cache_artifact_directory;
if (std.debug.runtime_safety) {
var error_message: [*:0]const u8 = undefined;
// verifyModule always allocs the error_message even if there is no error
defer llvm.disposeMessage(error_message);
if (self.llvm_module.verify(.ReturnStatus, &error_message).toBool()) {
std.debug.print("\n{s}\n", .{error_message});
if (try locPath(arena, comp.emit_llvm_ir, cache_dir)) |emit_llvm_ir_path| {
_ = self.llvm_module.printModuleToFile(emit_llvm_ir_path, &error_message);
}
@panic("LLVM module verification failed");
}
}
var emit_bin_path: ?[*:0]const u8 = if (comp.bin_file.options.emit) |emit|
try emit.basenamePath(arena, try arena.dupeZ(u8, comp.bin_file.intermediary_basename.?))
else
null;
const emit_asm_path = try locPath(arena, comp.emit_asm, cache_dir);
var emit_llvm_ir_path = try locPath(arena, comp.emit_llvm_ir, cache_dir);
const emit_llvm_bc_path = try locPath(arena, comp.emit_llvm_bc, cache_dir);
const emit_asm_msg = emit_asm_path orelse "(none)";
const emit_bin_msg = emit_bin_path orelse "(none)";
const emit_llvm_ir_msg = emit_llvm_ir_path orelse "(none)";
const emit_llvm_bc_msg = emit_llvm_bc_path orelse "(none)";
log.debug("emit LLVM object asm={s} bin={s} ir={s} bc={s}", .{
emit_asm_msg, emit_bin_msg, emit_llvm_ir_msg, emit_llvm_bc_msg,
});
// Unfortunately, LLVM shits the bed when we ask for both binary and assembly.
// So we call the entire pipeline multiple times if this is requested.
var error_message: [*:0]const u8 = undefined;
if (emit_asm_path != null and emit_bin_path != null) {
if (self.target_machine.emitToFile(
self.llvm_module,
&error_message,
comp.bin_file.options.optimize_mode == .Debug,
comp.bin_file.options.optimize_mode == .ReleaseSmall,
comp.time_report,
comp.bin_file.options.tsan,
comp.bin_file.options.lto,
null,
emit_bin_path,
emit_llvm_ir_path,
null,
)) {
defer llvm.disposeMessage(error_message);
log.err("LLVM failed to emit bin={s} ir={s}: {s}", .{
emit_bin_msg, emit_llvm_ir_msg, error_message,
});
return error.FailedToEmit;
}
emit_bin_path = null;
emit_llvm_ir_path = null;
}
if (self.target_machine.emitToFile(
self.llvm_module,
&error_message,
comp.bin_file.options.optimize_mode == .Debug,
comp.bin_file.options.optimize_mode == .ReleaseSmall,
comp.time_report,
comp.bin_file.options.tsan,
comp.bin_file.options.lto,
emit_asm_path,
emit_bin_path,
emit_llvm_ir_path,
emit_llvm_bc_path,
)) {
defer llvm.disposeMessage(error_message);
log.err("LLVM failed to emit asm={s} bin={s} ir={s} bc={s}: {s}", .{
emit_asm_msg, emit_bin_msg, emit_llvm_ir_msg, emit_llvm_bc_msg,
error_message,
});
return error.FailedToEmit;
}
}
pub fn updateFunc(
o: *Object,
module: *Module,
func: *Module.Fn,
air: Air,
liveness: Liveness,
) !void {
const decl_index = func.owner_decl;
const decl = module.declPtr(decl_index);
const target = module.getTarget();
var dg: DeclGen = .{
.context = o.context,
.object = o,
.module = module,
.decl_index = decl_index,
.decl = decl,
.err_msg = null,
.gpa = module.gpa,
};
const llvm_func = try dg.resolveLlvmFunction(decl_index);
if (module.align_stack_fns.get(func)) |align_info| {
dg.addFnAttrInt(llvm_func, "alignstack", align_info.alignment);
dg.addFnAttr(llvm_func, "noinline");
} else {
DeclGen.removeFnAttr(llvm_func, "alignstack");
if (!func.is_noinline) DeclGen.removeFnAttr(llvm_func, "noinline");
}
if (func.is_cold) {
dg.addFnAttr(llvm_func, "cold");
} else {
DeclGen.removeFnAttr(llvm_func, "cold");
}
if (func.is_noinline) {
dg.addFnAttr(llvm_func, "noinline");
} else {
DeclGen.removeFnAttr(llvm_func, "noinline");
}
// TODO: disable this if safety is off for the function scope
const ssp_buf_size = module.comp.bin_file.options.stack_protector;
if (ssp_buf_size != 0) {
var buf: [12]u8 = undefined;
const arg = std.fmt.bufPrintZ(&buf, "{d}", .{ssp_buf_size}) catch unreachable;
dg.addFnAttr(llvm_func, "sspstrong");
dg.addFnAttrString(llvm_func, "stack-protector-buffer-size", arg);
}
// TODO: disable this if safety is off for the function scope
if (module.comp.bin_file.options.stack_check) {
dg.addFnAttrString(llvm_func, "probe-stack", "__zig_probe_stack");
} else if (target.os.tag == .uefi) {
dg.addFnAttrString(llvm_func, "no-stack-arg-probe", "");
}
if (decl.@"linksection") |section| {
llvm_func.setSection(section);
}
// Remove all the basic blocks of a function in order to start over, generating
// LLVM IR from an empty function body.
while (llvm_func.getFirstBasicBlock()) |bb| {
bb.deleteBasicBlock();
}
const builder = dg.context.createBuilder();
const entry_block = dg.context.appendBasicBlock(llvm_func, "Entry");
builder.positionBuilderAtEnd(entry_block);
// This gets the LLVM values from the function and stores them in `dg.args`.
const fn_info = decl.ty.fnInfo();
const sret = firstParamSRet(fn_info, target);
const ret_ptr = if (sret) llvm_func.getParam(0) else null;
const gpa = dg.gpa;
if (ccAbiPromoteInt(fn_info.cc, target, fn_info.return_type)) |s| switch (s) {
.signed => dg.addAttr(llvm_func, 0, "signext"),
.unsigned => dg.addAttr(llvm_func, 0, "zeroext"),
};
const err_return_tracing = fn_info.return_type.isError() and
module.comp.bin_file.options.error_return_tracing;
const err_ret_trace = if (err_return_tracing)
llvm_func.getParam(@boolToInt(ret_ptr != null))
else
null;
// This is the list of args we will use that correspond directly to the AIR arg
// instructions. Depending on the calling convention, this list is not necessarily
// a bijection with the actual LLVM parameters of the function.
var args = std.ArrayList(*llvm.Value).init(gpa);
defer args.deinit();
{
var llvm_arg_i = @as(c_uint, @boolToInt(ret_ptr != null)) + @boolToInt(err_return_tracing);
var it = iterateParamTypes(&dg, fn_info);
while (it.next()) |lowering| switch (lowering) {
.no_bits => continue,
.byval => {
assert(!it.byval_attr);
const param_index = it.zig_index - 1;
const param_ty = fn_info.param_types[param_index];
const param = llvm_func.getParam(llvm_arg_i);
try args.ensureUnusedCapacity(1);
if (isByRef(param_ty)) {
const alignment = param_ty.abiAlignment(target);
const param_llvm_ty = param.typeOf();
const arg_ptr = buildAllocaInner(builder, llvm_func, false, param_llvm_ty, alignment, target);
const store_inst = builder.buildStore(param, arg_ptr);
store_inst.setAlignment(alignment);
args.appendAssumeCapacity(arg_ptr);
} else {
args.appendAssumeCapacity(param);
dg.addByValParamAttrs(llvm_func, param_ty, param_index, fn_info, llvm_arg_i);
}
llvm_arg_i += 1;
},
.byref => {
const param_ty = fn_info.param_types[it.zig_index - 1];
const param_llvm_ty = try dg.lowerType(param_ty);
const param = llvm_func.getParam(llvm_arg_i);
const alignment = param_ty.abiAlignment(target);
dg.addByRefParamAttrs(llvm_func, llvm_arg_i, alignment, it.byval_attr, param_llvm_ty);
llvm_arg_i += 1;
try args.ensureUnusedCapacity(1);
if (isByRef(param_ty)) {
args.appendAssumeCapacity(param);
} else {
const load_inst = builder.buildLoad(param_llvm_ty, param, "");
load_inst.setAlignment(alignment);
args.appendAssumeCapacity(load_inst);
}
},
.abi_sized_int => {
assert(!it.byval_attr);
const param_ty = fn_info.param_types[it.zig_index - 1];
const param = llvm_func.getParam(llvm_arg_i);
llvm_arg_i += 1;
const param_llvm_ty = try dg.lowerType(param_ty);
const abi_size = @intCast(c_uint, param_ty.abiSize(target));
const int_llvm_ty = dg.context.intType(abi_size * 8);
const int_ptr_llvm_ty = int_llvm_ty.pointerType(0);
const alignment = @max(
param_ty.abiAlignment(target),