1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // See doc.rs for documentation.
14 use self::VariableAccess::*;
15 use self::VariableKind::*;
17 use self::utils::{DIB, span_start, create_DIArray, is_node_local_to_unit};
18 use self::namespace::mangled_name_of_instance;
19 use self::type_names::compute_debuginfo_type_name;
20 use self::metadata::{type_metadata, file_metadata, TypeMap};
21 use self::source_loc::InternalDebugLocation::{self, UnknownLocation};
24 use llvm::debuginfo::{DIFile, DIType, DIScope, DIBuilder, DISubprogram, DIArray, DIFlags};
25 use rustc::hir::CodegenFnAttrFlags;
26 use rustc::hir::def_id::{DefId, CrateNum};
27 use rustc::ty::subst::{Substs, UnpackedKind};
30 use common::CodegenCx;
32 use monomorphize::Instance;
33 use rustc::ty::{self, ParamEnv, Ty, InstanceDef};
35 use rustc::session::config::{self, DebugInfo};
36 use rustc::util::nodemap::{DefIdMap, FxHashMap, FxHashSet};
37 use rustc_data_structures::small_c_str::SmallCStr;
41 use std::cell::{Cell, RefCell};
42 use std::ffi::CString;
44 use syntax_pos::{self, Span, Pos};
46 use syntax::symbol::{Symbol, InternedString};
47 use rustc::ty::layout::{self, LayoutOf};
57 pub use self::create_scope_map::{create_mir_scopes, MirDebugScope};
58 pub use self::source_loc::start_emitting_source_locations;
59 pub use self::metadata::create_global_var_metadata;
60 pub use self::metadata::create_vtable_metadata;
61 pub use self::metadata::extend_scope_to_file;
62 pub use self::source_loc::set_source_location;
64 #[allow(non_upper_case_globals)]
65 const DW_TAG_auto_variable: c_uint = 0x100;
66 #[allow(non_upper_case_globals)]
67 const DW_TAG_arg_variable: c_uint = 0x101;
69 /// A context object for maintaining all state needed by the debuginfo module.
70 pub struct CrateDebugContext<'a, 'tcx> {
71 llcontext: &'a llvm::Context,
72 llmod: &'a llvm::Module,
73 builder: &'a mut DIBuilder<'a>,
74 created_files: RefCell<FxHashMap<(Symbol, Symbol), &'a DIFile>>,
75 created_enum_disr_types: RefCell<FxHashMap<(DefId, layout::Primitive), &'a DIType>>,
77 type_map: RefCell<TypeMap<'a, 'tcx>>,
78 namespace_map: RefCell<DefIdMap<&'a DIScope>>,
80 // This collection is used to assert that composite types (structs, enums,
81 // ...) have their members only set once:
82 composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
85 impl Drop for CrateDebugContext<'a, 'tcx> {
88 llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
93 impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
94 pub fn new(llmod: &'a llvm::Module) -> Self {
95 debug!("CrateDebugContext::new");
96 let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
97 // DIBuilder inherits context from the module, so we'd better use the same one
98 let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
103 created_files: Default::default(),
104 created_enum_disr_types: Default::default(),
105 type_map: Default::default(),
106 namespace_map: RefCell::new(DefIdMap()),
107 composite_types_completed: Default::default(),
112 pub enum FunctionDebugContext<'ll> {
113 RegularContext(FunctionDebugContextData<'ll>),
115 FunctionWithoutDebugInfo,
118 impl FunctionDebugContext<'ll> {
119 pub fn get_ref<'a>(&'a self, span: Span) -> &'a FunctionDebugContextData<'ll> {
121 FunctionDebugContext::RegularContext(ref data) => data,
122 FunctionDebugContext::DebugInfoDisabled => {
123 span_bug!(span, "{}", FunctionDebugContext::debuginfo_disabled_message());
125 FunctionDebugContext::FunctionWithoutDebugInfo => {
126 span_bug!(span, "{}", FunctionDebugContext::should_be_ignored_message());
131 fn debuginfo_disabled_message() -> &'static str {
132 "debuginfo: Error trying to access FunctionDebugContext although debug info is disabled!"
135 fn should_be_ignored_message() -> &'static str {
136 "debuginfo: Error trying to access FunctionDebugContext for function that should be \
137 ignored by debug info!"
141 pub struct FunctionDebugContextData<'ll> {
142 fn_metadata: &'ll DISubprogram,
143 source_locations_enabled: Cell<bool>,
144 pub defining_crate: CrateNum,
147 pub enum VariableAccess<'a, 'll> {
148 // The llptr given is an alloca containing the variable's value
149 DirectVariable { alloca: &'ll Value },
150 // The llptr given is an alloca containing the start of some pointer chain
151 // leading to the variable's content.
152 IndirectVariable { alloca: &'ll Value, address_operations: &'a [i64] }
155 pub enum VariableKind {
156 ArgumentVariable(usize /*index*/),
160 /// Create any deferred debug metadata nodes
161 pub fn finalize(cx: &CodegenCx) {
162 if cx.dbg_cx.is_none() {
168 if gdb::needs_gdb_debug_scripts_section(cx) {
169 // Add a .debug_gdb_scripts section to this compile-unit. This will
170 // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
171 // which activates the Rust pretty printers for binary this section is
173 gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
177 llvm::LLVMRustDIBuilderFinalize(DIB(cx));
178 // Debuginfo generation in LLVM by default uses a higher
179 // version of dwarf than macOS currently understands. We can
180 // instruct LLVM to emit an older version of dwarf, however,
181 // for macOS to understand. For more info see #11352
182 // This can be overridden using --llvm-opts -dwarf-version,N.
183 // Android has the same issue (#22398)
184 if cx.sess().target.target.options.is_like_osx ||
185 cx.sess().target.target.options.is_like_android {
186 llvm::LLVMRustAddModuleFlag(cx.llmod,
187 "Dwarf Version\0".as_ptr() as *const _,
191 // Indicate that we want CodeView debug information on MSVC
192 if cx.sess().target.target.options.is_like_msvc {
193 llvm::LLVMRustAddModuleFlag(cx.llmod,
194 "CodeView\0".as_ptr() as *const _,
198 // Prevent bitcode readers from deleting the debug info.
199 let ptr = "Debug Info Version\0".as_ptr();
200 llvm::LLVMRustAddModuleFlag(cx.llmod, ptr as *const _,
201 llvm::LLVMRustDebugMetadataVersion());
205 /// Creates the function-specific debug context.
207 /// Returns the FunctionDebugContext for the function which holds state needed
208 /// for debug info creation. The function may also return another variant of the
209 /// FunctionDebugContext enum which indicates why no debuginfo should be created
210 /// for the function.
211 pub fn create_function_debug_context(
212 cx: &CodegenCx<'ll, 'tcx>,
213 instance: Instance<'tcx>,
214 sig: ty::FnSig<'tcx>,
217 ) -> FunctionDebugContext<'ll> {
218 if cx.sess().opts.debuginfo == DebugInfo::None {
219 return FunctionDebugContext::DebugInfoDisabled;
222 if let InstanceDef::Item(def_id) = instance.def {
223 if cx.tcx.codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::NO_DEBUG) {
224 return FunctionDebugContext::FunctionWithoutDebugInfo;
230 // This can be the case for functions inlined from another crate
232 // FIXME(simulacrum): Probably can't happen; remove.
233 return FunctionDebugContext::FunctionWithoutDebugInfo;
236 let def_id = instance.def_id();
237 let containing_scope = get_containing_scope(cx, instance);
238 let loc = span_start(cx, span);
239 let file_metadata = file_metadata(cx, &loc.file.name, def_id.krate);
241 let function_type_metadata = unsafe {
242 let fn_signature = get_function_signature(cx, sig);
243 llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(cx), file_metadata, fn_signature)
246 // Find the enclosing function, in case this is a closure.
247 let def_key = cx.tcx.def_key(def_id);
248 let mut name = def_key.disambiguated_data.data.to_string();
250 let enclosing_fn_def_id = cx.tcx.closure_base_def_id(def_id);
252 // Get_template_parameters() will append a `<...>` clause to the function
253 // name if necessary.
254 let generics = cx.tcx.generics_of(enclosing_fn_def_id);
255 let substs = instance.substs.truncate_to(cx.tcx, generics);
256 let template_parameters = get_template_parameters(cx,
262 // Get the linkage_name, which is just the symbol name
263 let linkage_name = mangled_name_of_instance(cx, instance);
265 let scope_line = span_start(cx, span).line;
266 let is_local_to_unit = is_node_local_to_unit(cx, def_id);
268 let function_name = CString::new(name).unwrap();
269 let linkage_name = SmallCStr::new(&linkage_name.as_str());
271 let mut flags = DIFlags::FlagPrototyped;
273 let local_id = cx.tcx.hir.as_local_node_id(def_id);
274 if let Some((id, _, _)) = *cx.sess().entry_fn.borrow() {
275 if local_id == Some(id) {
276 flags |= DIFlags::FlagMainSubprogram;
280 if cx.layout_of(sig.output()).abi.is_uninhabited() {
281 flags |= DIFlags::FlagNoReturn;
284 let fn_metadata = unsafe {
285 llvm::LLVMRustDIBuilderCreateFunction(
288 function_name.as_ptr(),
289 linkage_name.as_ptr(),
292 function_type_metadata,
295 scope_line as c_uint,
297 cx.sess().opts.optimize != config::OptLevel::No,
303 // Initialize fn debug context (including scope map and namespace map)
304 let fn_debug_context = FunctionDebugContextData {
306 source_locations_enabled: Cell::new(false),
307 defining_crate: def_id.krate,
310 return FunctionDebugContext::RegularContext(fn_debug_context);
312 fn get_function_signature(
313 cx: &CodegenCx<'ll, 'tcx>,
314 sig: ty::FnSig<'tcx>,
316 if cx.sess().opts.debuginfo == DebugInfo::Limited {
317 return create_DIArray(DIB(cx), &[]);
320 let mut signature = Vec::with_capacity(sig.inputs().len() + 1);
322 // Return type -- llvm::DIBuilder wants this at index 0
323 signature.push(match sig.output().sty {
324 ty::Tuple(ref tys) if tys.is_empty() => None,
325 _ => Some(type_metadata(cx, sig.output(), syntax_pos::DUMMY_SP))
328 let inputs = if sig.abi == Abi::RustCall {
329 &sig.inputs()[..sig.inputs().len() - 1]
335 if cx.sess().target.target.options.is_like_msvc {
337 // There is a bug in MSDIA that leads to a crash when it encounters
338 // a fixed-size array of `u8` or something zero-sized in a
339 // function-type (see #40477).
340 // As a workaround, we replace those fixed-size arrays with a
341 // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
342 // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
343 // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
344 // This transformed type is wrong, but these function types are
345 // already inaccurate due to ABI adjustments (see #42800).
346 signature.extend(inputs.iter().map(|&t| {
347 let t = match t.sty {
349 if (ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() => {
350 cx.tcx.mk_imm_ptr(ct)
354 Some(type_metadata(cx, t, syntax_pos::DUMMY_SP))
357 signature.extend(inputs.iter().map(|t| {
358 Some(type_metadata(cx, t, syntax_pos::DUMMY_SP))
362 if sig.abi == Abi::RustCall && !sig.inputs().is_empty() {
363 if let ty::Tuple(args) = sig.inputs()[sig.inputs().len() - 1].sty {
365 args.iter().map(|argument_type| {
366 Some(type_metadata(cx, argument_type, syntax_pos::DUMMY_SP))
372 create_DIArray(DIB(cx), &signature[..])
375 fn get_template_parameters(
376 cx: &CodegenCx<'ll, 'tcx>,
377 generics: &ty::Generics,
378 substs: &Substs<'tcx>,
379 file_metadata: &'ll DIFile,
380 name_to_append_suffix_to: &mut String,
382 if substs.types().next().is_none() {
383 return create_DIArray(DIB(cx), &[]);
386 name_to_append_suffix_to.push('<');
387 for (i, actual_type) in substs.types().enumerate() {
389 name_to_append_suffix_to.push_str(",");
392 let actual_type = cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
393 // Add actual type name to <...> clause of function name
394 let actual_type_name = compute_debuginfo_type_name(cx,
397 name_to_append_suffix_to.push_str(&actual_type_name[..]);
399 name_to_append_suffix_to.push('>');
401 // Again, only create type information if full debuginfo is enabled
402 let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
403 let names = get_parameter_names(cx, generics);
404 substs.iter().zip(names).filter_map(|(kind, name)| {
405 if let UnpackedKind::Type(ty) = kind.unpack() {
406 let actual_type = cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
407 let actual_type_metadata =
408 type_metadata(cx, actual_type, syntax_pos::DUMMY_SP);
409 let name = SmallCStr::new(&name.as_str());
411 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
415 actual_type_metadata,
429 create_DIArray(DIB(cx), &template_params[..])
432 fn get_parameter_names(cx: &CodegenCx,
433 generics: &ty::Generics)
434 -> Vec<InternedString> {
435 let mut names = generics.parent.map_or(vec![], |def_id| {
436 get_parameter_names(cx, cx.tcx.generics_of(def_id))
438 names.extend(generics.params.iter().map(|param| param.name));
442 fn get_containing_scope(
443 cx: &CodegenCx<'ll, 'tcx>,
444 instance: Instance<'tcx>,
446 // First, let's see if this is a method within an inherent impl. Because
447 // if yes, we want to make the result subroutine DIE a child of the
448 // subroutine's self-type.
449 let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
450 // If the method does *not* belong to a trait, proceed
451 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
452 let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
454 ty::ParamEnv::reveal_all(),
455 &cx.tcx.type_of(impl_def_id),
458 // Only "class" methods are generally understood by LLVM,
459 // so avoid methods on other types (e.g. `<*mut T>::null`).
460 match impl_self_ty.sty {
461 ty::Adt(def, ..) if !def.is_box() => {
462 Some(type_metadata(cx, impl_self_ty, syntax_pos::DUMMY_SP))
467 // For trait method impls we still use the "parallel namespace"
473 self_type.unwrap_or_else(|| {
474 namespace::item_namespace(cx, DefId {
475 krate: instance.def_id().krate,
477 .def_key(instance.def_id())
479 .expect("get_containing_scope: missing parent?")
485 pub fn declare_local(
486 bx: &Builder<'a, 'll, 'tcx>,
487 dbg_context: &FunctionDebugContext<'ll>,
488 variable_name: ast::Name,
489 variable_type: Ty<'tcx>,
490 scope_metadata: &'ll DIScope,
491 variable_access: VariableAccess<'_, 'll>,
492 variable_kind: VariableKind,
495 assert!(!dbg_context.get_ref(span).source_locations_enabled.get());
498 let file = span_start(cx, span).file;
499 let file_metadata = file_metadata(cx,
501 dbg_context.get_ref(span).defining_crate);
503 let loc = span_start(cx, span);
504 let type_metadata = type_metadata(cx, variable_type, span);
506 let (argument_index, dwarf_tag) = match variable_kind {
507 ArgumentVariable(index) => (index as c_uint, DW_TAG_arg_variable),
508 LocalVariable => (0, DW_TAG_auto_variable)
510 let align = cx.align_of(variable_type);
512 let name = SmallCStr::new(&variable_name.as_str());
513 match (variable_access, &[][..]) {
514 (DirectVariable { alloca }, address_operations) |
515 (IndirectVariable {alloca, address_operations}, _) => {
516 let metadata = unsafe {
517 llvm::LLVMRustDIBuilderCreateVariable(
525 cx.sess().opts.optimize != config::OptLevel::No,
531 source_loc::set_debug_location(bx,
532 InternalDebugLocation::new(scope_metadata, loc.line, loc.col.to_usize()));
534 let debug_loc = llvm::LLVMGetCurrentDebugLocation(bx.llbuilder);
535 let instr = llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
539 address_operations.as_ptr(),
540 address_operations.len() as c_uint,
544 llvm::LLVMSetInstDebugLocation(bx.llbuilder, instr);
546 source_loc::set_debug_location(bx, UnknownLocation);