1 // See doc.rs for documentation.
4 use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
6 use self::metadata::{file_metadata, type_metadata, TypeMap, UNKNOWN_LINE_NUMBER};
7 use self::namespace::mangled_name_of_instance;
8 use self::type_names::compute_debuginfo_type_name;
9 use self::utils::{create_DIArray, is_node_local_to_unit, DIB};
11 use crate::abi::FnAbi;
12 use crate::builder::Builder;
13 use crate::common::CodegenCx;
15 use crate::llvm::debuginfo::{
16 DIArray, DIBuilder, DIFile, DIFlags, DILexicalBlock, DISPFlags, DIScope, DIType, DIVariable,
18 use crate::value::Value;
20 use rustc_codegen_ssa::debuginfo::type_names;
21 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
22 use rustc_codegen_ssa::traits::*;
23 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
24 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
25 use rustc_index::vec::IndexVec;
26 use rustc_middle::mir;
27 use rustc_middle::ty::layout::HasTyCtxt;
28 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
29 use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeFoldable};
30 use rustc_session::config::{self, DebugInfo};
31 use rustc_span::symbol::Symbol;
32 use rustc_span::{self, BytePos, Span};
33 use rustc_target::abi::{LayoutOf, Primitive, Size};
36 use smallvec::SmallVec;
37 use std::cell::RefCell;
47 pub use self::create_scope_map::compute_mir_scopes;
48 pub use self::metadata::create_global_var_metadata;
49 pub use self::metadata::extend_scope_to_file;
51 #[allow(non_upper_case_globals)]
52 const DW_TAG_auto_variable: c_uint = 0x100;
53 #[allow(non_upper_case_globals)]
54 const DW_TAG_arg_variable: c_uint = 0x101;
56 /// A context object for maintaining all state needed by the debuginfo module.
57 pub struct CrateDebugContext<'a, 'tcx> {
58 llcontext: &'a llvm::Context,
59 llmod: &'a llvm::Module,
60 builder: &'a mut DIBuilder<'a>,
61 created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
62 created_enum_disr_types: RefCell<FxHashMap<(DefId, Primitive), &'a DIType>>,
64 type_map: RefCell<TypeMap<'a, 'tcx>>,
65 namespace_map: RefCell<DefIdMap<&'a DIScope>>,
67 // This collection is used to assert that composite types (structs, enums,
68 // ...) have their members only set once:
69 composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
72 impl Drop for CrateDebugContext<'a, 'tcx> {
75 llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
80 impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
81 pub fn new(llmod: &'a llvm::Module) -> Self {
82 debug!("CrateDebugContext::new");
83 let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
84 // DIBuilder inherits context from the module, so we'd better use the same one
85 let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
90 created_files: Default::default(),
91 created_enum_disr_types: Default::default(),
92 type_map: Default::default(),
93 namespace_map: RefCell::new(Default::default()),
94 composite_types_completed: Default::default(),
99 /// Creates any deferred debug metadata nodes
100 pub fn finalize(cx: &CodegenCx<'_, '_>) {
101 if cx.dbg_cx.is_none() {
107 if gdb::needs_gdb_debug_scripts_section(cx) {
108 // Add a .debug_gdb_scripts section to this compile-unit. This will
109 // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
110 // which activates the Rust pretty printers for binary this section is
112 gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
116 llvm::LLVMRustDIBuilderFinalize(DIB(cx));
117 // Debuginfo generation in LLVM by default uses a higher
118 // version of dwarf than macOS currently understands. We can
119 // instruct LLVM to emit an older version of dwarf, however,
120 // for macOS to understand. For more info see #11352
121 // This can be overridden using --llvm-opts -dwarf-version,N.
122 // Android has the same issue (#22398)
123 if cx.sess().target.target.options.is_like_osx
124 || cx.sess().target.target.options.is_like_android
126 llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
129 // Indicate that we want CodeView debug information on MSVC
130 if cx.sess().target.target.options.is_like_msvc {
131 llvm::LLVMRustAddModuleFlag(cx.llmod, "CodeView\0".as_ptr().cast(), 1)
134 // Prevent bitcode readers from deleting the debug info.
135 let ptr = "Debug Info Version\0".as_ptr();
136 llvm::LLVMRustAddModuleFlag(cx.llmod, ptr.cast(), llvm::LLVMRustDebugMetadataVersion());
140 impl DebugInfoBuilderMethods for Builder<'a, 'll, 'tcx> {
141 // FIXME(eddyb) find a common convention for all of the debuginfo-related
142 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
145 dbg_var: &'ll DIVariable,
146 scope_metadata: &'ll DIScope,
147 variable_alloca: Self::Value,
149 indirect_offsets: &[Size],
154 // Convert the direct and indirect offsets to address ops.
155 // FIXME(eddyb) use `const`s instead of getting the values via FFI,
156 // the values should match the ones in the DWARF standard anyway.
157 let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() };
158 let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() };
159 let mut addr_ops = SmallVec::<[_; 8]>::new();
161 if direct_offset.bytes() > 0 {
162 addr_ops.push(op_plus_uconst());
163 addr_ops.push(direct_offset.bytes() as i64);
165 for &offset in indirect_offsets {
166 addr_ops.push(op_deref());
167 if offset.bytes() > 0 {
168 addr_ops.push(op_plus_uconst());
169 addr_ops.push(offset.bytes() as i64);
173 // FIXME(eddyb) maybe this information could be extracted from `dbg_var`,
174 // to avoid having to pass it down in both places?
175 // NB: `var` doesn't seem to know about the column, so that's a limitation.
176 let dbg_loc = cx.create_debug_loc(scope_metadata, span);
178 // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
179 llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
184 addr_ops.len() as c_uint,
191 fn set_source_location(&mut self, scope: &'ll DIScope, span: Span) {
192 debug!("set_source_location: {}", self.sess().source_map().span_to_string(span));
194 let dbg_loc = self.cx().create_debug_loc(scope, span);
197 llvm::LLVMSetCurrentDebugLocation(self.llbuilder, dbg_loc);
200 fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
201 gdb::insert_reference_to_gdb_debug_scripts_section_global(self)
204 fn set_var_name(&mut self, value: &'ll Value, name: &str) {
205 // Avoid wasting time if LLVM value names aren't even enabled.
206 if self.sess().fewer_names() {
210 // Only function parameters and instructions are local to a function,
211 // don't change the name of anything else (e.g. globals).
212 let param_or_inst = unsafe {
213 llvm::LLVMIsAArgument(value).is_some() || llvm::LLVMIsAInstruction(value).is_some()
219 // Avoid replacing the name if it already exists.
220 // While we could combine the names somehow, it'd
221 // get noisy quick, and the usefulness is dubious.
222 if llvm::get_value_name(value).is_empty() {
223 llvm::set_value_name(value, name.as_bytes());
228 impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
229 fn create_function_debug_context(
231 instance: Instance<'tcx>,
232 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
235 ) -> Option<FunctionDebugContext<&'ll DIScope>> {
236 if self.sess().opts.debuginfo == DebugInfo::None {
242 // This can be the case for functions inlined from another crate
244 // FIXME(simulacrum): Probably can't happen; remove.
248 let def_id = instance.def_id();
249 let containing_scope = get_containing_scope(self, instance);
250 let loc = self.lookup_debug_loc(span.lo());
251 let file_metadata = file_metadata(self, &loc.file, def_id.krate);
253 let function_type_metadata = unsafe {
254 let fn_signature = get_function_signature(self, fn_abi);
255 llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(self), fn_signature)
258 // Find the enclosing function, in case this is a closure.
259 let def_key = self.tcx().def_key(def_id);
260 let mut name = def_key.disambiguated_data.data.to_string();
262 let enclosing_fn_def_id = self.tcx().closure_base_def_id(def_id);
264 // Get_template_parameters() will append a `<...>` clause to the function
265 // name if necessary.
266 let generics = self.tcx().generics_of(enclosing_fn_def_id);
267 let substs = instance.substs.truncate_to(self.tcx(), generics);
268 let template_parameters = get_template_parameters(self, &generics, substs, &mut name);
270 let linkage_name = &mangled_name_of_instance(self, instance).name;
271 // Omit the linkage_name if it is the same as subprogram name.
272 let linkage_name = if &name == linkage_name { "" } else { linkage_name };
274 // FIXME(eddyb) does this need to be separate from `loc.line` for some reason?
275 let scope_line = loc.line;
277 let mut flags = DIFlags::FlagPrototyped;
279 if fn_abi.ret.layout.abi.is_uninhabited() {
280 flags |= DIFlags::FlagNoReturn;
283 let mut spflags = DISPFlags::SPFlagDefinition;
284 if is_node_local_to_unit(self, def_id) {
285 spflags |= DISPFlags::SPFlagLocalToUnit;
287 if self.sess().opts.optimize != config::OptLevel::No {
288 spflags |= DISPFlags::SPFlagOptimized;
290 if let Some((id, _)) = self.tcx.entry_fn(LOCAL_CRATE) {
291 if id.to_def_id() == def_id {
292 spflags |= DISPFlags::SPFlagMainSubprogram;
296 let fn_metadata = unsafe {
297 llvm::LLVMRustDIBuilderCreateFunction(
300 name.as_ptr().cast(),
302 linkage_name.as_ptr().cast(),
305 loc.line.unwrap_or(UNKNOWN_LINE_NUMBER),
306 function_type_metadata,
307 scope_line.unwrap_or(UNKNOWN_LINE_NUMBER),
316 // Initialize fn debug context (including scopes).
317 // FIXME(eddyb) figure out a way to not need `Option` for `scope_metadata`.
318 let null_scope = DebugScope {
319 scope_metadata: None,
320 file_start_pos: BytePos(0),
321 file_end_pos: BytePos(0),
323 let mut fn_debug_context = FunctionDebugContext {
324 scopes: IndexVec::from_elem(null_scope, &mir.source_scopes),
325 defining_crate: def_id.krate,
328 // Fill in all the scopes, with the information from the MIR body.
329 compute_mir_scopes(self, mir, fn_metadata, &mut fn_debug_context);
331 return Some(fn_debug_context);
333 fn get_function_signature<'ll, 'tcx>(
334 cx: &CodegenCx<'ll, 'tcx>,
335 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
337 if cx.sess().opts.debuginfo == DebugInfo::Limited {
338 return create_DIArray(DIB(cx), &[]);
341 let mut signature = Vec::with_capacity(fn_abi.args.len() + 1);
343 // Return type -- llvm::DIBuilder wants this at index 0
344 signature.push(if fn_abi.ret.is_ignore() {
347 Some(type_metadata(cx, fn_abi.ret.layout.ty, rustc_span::DUMMY_SP))
351 if cx.sess().target.target.options.is_like_msvc {
353 // There is a bug in MSDIA that leads to a crash when it encounters
354 // a fixed-size array of `u8` or something zero-sized in a
355 // function-type (see #40477).
356 // As a workaround, we replace those fixed-size arrays with a
357 // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
358 // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
359 // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
360 // This transformed type is wrong, but these function types are
361 // already inaccurate due to ABI adjustments (see #42800).
362 signature.extend(fn_abi.args.iter().map(|arg| {
363 let t = arg.layout.ty;
364 let t = match t.kind() {
366 if (*ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() =>
368 cx.tcx.mk_imm_ptr(ct)
372 Some(type_metadata(cx, t, rustc_span::DUMMY_SP))
379 .map(|arg| Some(type_metadata(cx, arg.layout.ty, rustc_span::DUMMY_SP))),
383 create_DIArray(DIB(cx), &signature[..])
386 fn get_template_parameters<'ll, 'tcx>(
387 cx: &CodegenCx<'ll, 'tcx>,
388 generics: &ty::Generics,
389 substs: SubstsRef<'tcx>,
390 name_to_append_suffix_to: &mut String,
392 if substs.types().next().is_none() {
393 return create_DIArray(DIB(cx), &[]);
396 name_to_append_suffix_to.push('<');
397 for (i, actual_type) in substs.types().enumerate() {
399 name_to_append_suffix_to.push_str(",");
403 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
404 // Add actual type name to <...> clause of function name
405 let actual_type_name = compute_debuginfo_type_name(cx.tcx(), actual_type, true);
406 name_to_append_suffix_to.push_str(&actual_type_name[..]);
408 name_to_append_suffix_to.push('>');
410 // Again, only create type information if full debuginfo is enabled
411 let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
412 let names = get_parameter_names(cx, generics);
416 .filter_map(|(kind, name)| {
417 if let GenericArgKind::Type(ty) = kind.unpack() {
419 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
420 let actual_type_metadata =
421 type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
422 let name = name.as_str();
424 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
427 name.as_ptr().cast(),
429 actual_type_metadata,
441 create_DIArray(DIB(cx), &template_params[..])
444 fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
445 let mut names = generics
447 .map_or(vec![], |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
448 names.extend(generics.params.iter().map(|param| param.name));
452 fn get_containing_scope<'ll, 'tcx>(
453 cx: &CodegenCx<'ll, 'tcx>,
454 instance: Instance<'tcx>,
456 // First, let's see if this is a method within an inherent impl. Because
457 // if yes, we want to make the result subroutine DIE a child of the
458 // subroutine's self-type.
459 let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
460 // If the method does *not* belong to a trait, proceed
461 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
462 let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
464 ty::ParamEnv::reveal_all(),
465 &cx.tcx.type_of(impl_def_id),
468 // Only "class" methods are generally understood by LLVM,
469 // so avoid methods on other types (e.g., `<*mut T>::null`).
470 match impl_self_ty.kind() {
471 ty::Adt(def, ..) if !def.is_box() => {
472 // Again, only create type information if full debuginfo is enabled
473 if cx.sess().opts.debuginfo == DebugInfo::Full
474 && !impl_self_ty.needs_subst()
476 Some(type_metadata(cx, impl_self_ty, rustc_span::DUMMY_SP))
478 Some(namespace::item_namespace(cx, def.did))
484 // For trait method impls we still use the "parallel namespace"
490 self_type.unwrap_or_else(|| {
491 namespace::item_namespace(
494 krate: instance.def_id().krate,
497 .def_key(instance.def_id())
499 .expect("get_containing_scope: missing parent?"),
506 fn create_vtable_metadata(&self, ty: Ty<'tcx>, vtable: Self::Value) {
507 metadata::create_vtable_metadata(self, ty, vtable)
510 fn extend_scope_to_file(
512 scope_metadata: &'ll DIScope,
513 file: &rustc_span::SourceFile,
514 defining_crate: CrateNum,
515 ) -> &'ll DILexicalBlock {
516 metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
519 fn debuginfo_finalize(&self) {
523 // FIXME(eddyb) find a common convention for all of the debuginfo-related
524 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
527 dbg_context: &FunctionDebugContext<&'ll DIScope>,
528 variable_name: Symbol,
529 variable_type: Ty<'tcx>,
530 scope_metadata: &'ll DIScope,
531 variable_kind: VariableKind,
533 ) -> &'ll DIVariable {
534 let loc = self.lookup_debug_loc(span.lo());
535 let file_metadata = file_metadata(self, &loc.file, dbg_context.defining_crate);
537 let type_metadata = type_metadata(self, variable_type, span);
539 let (argument_index, dwarf_tag) = match variable_kind {
540 ArgumentVariable(index) => (index as c_uint, DW_TAG_arg_variable),
541 LocalVariable => (0, DW_TAG_auto_variable),
543 let align = self.align_of(variable_type);
545 let name = variable_name.as_str();
547 llvm::LLVMRustDIBuilderCreateVariable(
551 name.as_ptr().cast(),
554 loc.line.unwrap_or(UNKNOWN_LINE_NUMBER),
559 align.bytes() as u32,