1 // See doc.rs for documentation.
4 use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
6 use self::metadata::{file_metadata, type_metadata, TypeMap};
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, span_start, DIB};
12 use crate::llvm::debuginfo::{
13 DIArray, DIBuilder, DIFile, DIFlags, DILexicalBlock, DISPFlags, DIScope, DIType, DIVariable,
15 use rustc::middle::codegen_fn_attrs::CodegenFnAttrFlags;
16 use rustc::ty::subst::{GenericArgKind, SubstsRef};
17 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
19 use crate::abi::FnAbi;
20 use crate::builder::Builder;
21 use crate::common::CodegenCx;
22 use crate::value::Value;
24 use rustc::session::config::{self, DebugInfo};
25 use rustc::ty::{self, Instance, InstanceDef, ParamEnv, Ty};
26 use rustc_codegen_ssa::debuginfo::type_names;
27 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
28 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
29 use rustc_data_structures::small_c_str::SmallCStr;
30 use rustc_index::vec::IndexVec;
34 use std::cell::RefCell;
35 use std::ffi::CString;
37 use rustc::ty::layout::{self, HasTyCtxt, LayoutOf, Size};
38 use rustc_codegen_ssa::traits::*;
39 use rustc_span::symbol::Symbol;
40 use rustc_span::{self, BytePos, Span};
41 use smallvec::SmallVec;
51 pub use self::create_scope_map::compute_mir_scopes;
52 pub use self::metadata::create_global_var_metadata;
53 pub use self::metadata::extend_scope_to_file;
54 pub use self::source_loc::set_source_location;
56 #[allow(non_upper_case_globals)]
57 const DW_TAG_auto_variable: c_uint = 0x100;
58 #[allow(non_upper_case_globals)]
59 const DW_TAG_arg_variable: c_uint = 0x101;
61 /// A context object for maintaining all state needed by the debuginfo module.
62 pub struct CrateDebugContext<'a, 'tcx> {
63 llcontext: &'a llvm::Context,
64 llmod: &'a llvm::Module,
65 builder: &'a mut DIBuilder<'a>,
66 created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
67 created_enum_disr_types: RefCell<FxHashMap<(DefId, layout::Primitive), &'a DIType>>,
69 type_map: RefCell<TypeMap<'a, 'tcx>>,
70 namespace_map: RefCell<DefIdMap<&'a DIScope>>,
72 // This collection is used to assert that composite types (structs, enums,
73 // ...) have their members only set once:
74 composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
77 impl Drop for CrateDebugContext<'a, 'tcx> {
80 llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
85 impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
86 pub fn new(llmod: &'a llvm::Module) -> Self {
87 debug!("CrateDebugContext::new");
88 let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
89 // DIBuilder inherits context from the module, so we'd better use the same one
90 let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
95 created_files: Default::default(),
96 created_enum_disr_types: Default::default(),
97 type_map: Default::default(),
98 namespace_map: RefCell::new(Default::default()),
99 composite_types_completed: Default::default(),
104 /// Creates any deferred debug metadata nodes
105 pub fn finalize(cx: &CodegenCx<'_, '_>) {
106 if cx.dbg_cx.is_none() {
112 if gdb::needs_gdb_debug_scripts_section(cx) {
113 // Add a .debug_gdb_scripts section to this compile-unit. This will
114 // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
115 // which activates the Rust pretty printers for binary this section is
117 gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
121 llvm::LLVMRustDIBuilderFinalize(DIB(cx));
122 // Debuginfo generation in LLVM by default uses a higher
123 // version of dwarf than macOS currently understands. We can
124 // instruct LLVM to emit an older version of dwarf, however,
125 // for macOS to understand. For more info see #11352
126 // This can be overridden using --llvm-opts -dwarf-version,N.
127 // Android has the same issue (#22398)
128 if cx.sess().target.target.options.is_like_osx
129 || cx.sess().target.target.options.is_like_android
131 llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
134 // Indicate that we want CodeView debug information on MSVC
135 if cx.sess().target.target.options.is_like_msvc {
136 llvm::LLVMRustAddModuleFlag(cx.llmod, "CodeView\0".as_ptr().cast(), 1)
139 // Prevent bitcode readers from deleting the debug info.
140 let ptr = "Debug Info Version\0".as_ptr();
141 llvm::LLVMRustAddModuleFlag(cx.llmod, ptr.cast(), llvm::LLVMRustDebugMetadataVersion());
145 impl DebugInfoBuilderMethods for Builder<'a, 'll, 'tcx> {
146 // FIXME(eddyb) find a common convention for all of the debuginfo-related
147 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
150 dbg_var: &'ll DIVariable,
151 scope_metadata: &'ll DIScope,
152 variable_alloca: Self::Value,
154 indirect_offsets: &[Size],
159 // Convert the direct and indirect offsets to address ops.
160 // FIXME(eddyb) use `const`s instead of getting the values via FFI,
161 // the values should match the ones in the DWARF standard anyway.
162 let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() };
163 let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() };
164 let mut addr_ops = SmallVec::<[_; 8]>::new();
166 if direct_offset.bytes() > 0 {
167 addr_ops.push(op_plus_uconst());
168 addr_ops.push(direct_offset.bytes() as i64);
170 for &offset in indirect_offsets {
171 addr_ops.push(op_deref());
172 if offset.bytes() > 0 {
173 addr_ops.push(op_plus_uconst());
174 addr_ops.push(offset.bytes() as i64);
178 // FIXME(eddyb) maybe this information could be extracted from `dbg_var`,
179 // to avoid having to pass it down in both places?
180 // NB: `var` doesn't seem to know about the column, so that's a limitation.
181 let dbg_loc = cx.create_debug_loc(scope_metadata, span);
183 // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
184 llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
189 addr_ops.len() as c_uint,
196 fn set_source_location(
198 debug_context: &mut FunctionDebugContext<&'ll DIScope>,
202 set_source_location(debug_context, &self, scope, span)
204 fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
205 gdb::insert_reference_to_gdb_debug_scripts_section_global(self)
208 fn set_var_name(&mut self, value: &'ll Value, name: &str) {
209 // Avoid wasting time if LLVM value names aren't even enabled.
210 if self.sess().fewer_names() {
214 // Only function parameters and instructions are local to a function,
215 // don't change the name of anything else (e.g. globals).
216 let param_or_inst = unsafe {
217 llvm::LLVMIsAArgument(value).is_some() || llvm::LLVMIsAInstruction(value).is_some()
223 // Avoid replacing the name if it already exists.
224 // While we could combine the names somehow, it'd
225 // get noisy quick, and the usefulness is dubious.
226 if llvm::get_value_name(value).is_empty() {
227 llvm::set_value_name(value, name.as_bytes());
232 impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
233 fn create_function_debug_context(
235 instance: Instance<'tcx>,
236 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
239 ) -> Option<FunctionDebugContext<&'ll DIScope>> {
240 if self.sess().opts.debuginfo == DebugInfo::None {
244 if let InstanceDef::Item(def_id) = instance.def {
245 if self.tcx().codegen_fn_attrs(def_id).flags.contains(CodegenFnAttrFlags::NO_DEBUG) {
252 // This can be the case for functions inlined from another crate
254 // FIXME(simulacrum): Probably can't happen; remove.
258 let def_id = instance.def_id();
259 let containing_scope = get_containing_scope(self, instance);
260 let loc = span_start(self, span);
261 let file_metadata = file_metadata(self, &loc.file.name, def_id.krate);
263 let function_type_metadata = unsafe {
264 let fn_signature = get_function_signature(self, fn_abi);
265 llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(self), file_metadata, fn_signature)
268 // Find the enclosing function, in case this is a closure.
269 let def_key = self.tcx().def_key(def_id);
270 let mut name = def_key.disambiguated_data.data.to_string();
272 let enclosing_fn_def_id = self.tcx().closure_base_def_id(def_id);
274 // Get_template_parameters() will append a `<...>` clause to the function
275 // name if necessary.
276 let generics = self.tcx().generics_of(enclosing_fn_def_id);
277 let substs = instance.substs.truncate_to(self.tcx(), generics);
278 let template_parameters =
279 get_template_parameters(self, &generics, substs, file_metadata, &mut name);
281 // Get the linkage_name, which is just the symbol name
282 let linkage_name = mangled_name_of_instance(self, instance);
284 // FIXME(eddyb) does this need to be separate from `loc.line` for some reason?
285 let scope_line = loc.line;
287 let function_name = CString::new(name).unwrap();
288 let linkage_name = SmallCStr::new(&linkage_name.name.as_str());
290 let mut flags = DIFlags::FlagPrototyped;
292 if fn_abi.ret.layout.abi.is_uninhabited() {
293 flags |= DIFlags::FlagNoReturn;
296 let mut spflags = DISPFlags::SPFlagDefinition;
297 if is_node_local_to_unit(self, def_id) {
298 spflags |= DISPFlags::SPFlagLocalToUnit;
300 if self.sess().opts.optimize != config::OptLevel::No {
301 spflags |= DISPFlags::SPFlagOptimized;
303 if let Some((id, _)) = self.tcx.entry_fn(LOCAL_CRATE) {
305 spflags |= DISPFlags::SPFlagMainSubprogram;
309 let fn_metadata = unsafe {
310 llvm::LLVMRustDIBuilderCreateFunction(
313 function_name.as_ptr(),
314 linkage_name.as_ptr(),
317 function_type_metadata,
318 scope_line as c_uint,
327 // Initialize fn debug context (including scopes).
328 // FIXME(eddyb) figure out a way to not need `Option` for `scope_metadata`.
329 let null_scope = DebugScope {
330 scope_metadata: None,
331 file_start_pos: BytePos(0),
332 file_end_pos: BytePos(0),
334 let mut fn_debug_context = FunctionDebugContext {
335 scopes: IndexVec::from_elem(null_scope, &mir.source_scopes),
336 source_locations_enabled: false,
337 defining_crate: def_id.krate,
340 // Fill in all the scopes, with the information from the MIR body.
341 compute_mir_scopes(self, mir, fn_metadata, &mut fn_debug_context);
343 return Some(fn_debug_context);
345 fn get_function_signature<'ll, 'tcx>(
346 cx: &CodegenCx<'ll, 'tcx>,
347 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
349 if cx.sess().opts.debuginfo == DebugInfo::Limited {
350 return create_DIArray(DIB(cx), &[]);
353 let mut signature = Vec::with_capacity(fn_abi.args.len() + 1);
355 // Return type -- llvm::DIBuilder wants this at index 0
356 signature.push(if fn_abi.ret.is_ignore() {
359 Some(type_metadata(cx, fn_abi.ret.layout.ty, rustc_span::DUMMY_SP))
363 if cx.sess().target.target.options.is_like_msvc {
365 // There is a bug in MSDIA that leads to a crash when it encounters
366 // a fixed-size array of `u8` or something zero-sized in a
367 // function-type (see #40477).
368 // As a workaround, we replace those fixed-size arrays with a
369 // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
370 // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
371 // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
372 // This transformed type is wrong, but these function types are
373 // already inaccurate due to ABI adjustments (see #42800).
374 signature.extend(fn_abi.args.iter().map(|arg| {
375 let t = arg.layout.ty;
376 let t = match t.kind {
378 if (ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() =>
380 cx.tcx.mk_imm_ptr(ct)
384 Some(type_metadata(cx, t, rustc_span::DUMMY_SP))
391 .map(|arg| Some(type_metadata(cx, arg.layout.ty, rustc_span::DUMMY_SP))),
395 create_DIArray(DIB(cx), &signature[..])
398 fn get_template_parameters<'ll, 'tcx>(
399 cx: &CodegenCx<'ll, 'tcx>,
400 generics: &ty::Generics,
401 substs: SubstsRef<'tcx>,
402 file_metadata: &'ll DIFile,
403 name_to_append_suffix_to: &mut String,
405 if substs.types().next().is_none() {
406 return create_DIArray(DIB(cx), &[]);
409 name_to_append_suffix_to.push('<');
410 for (i, actual_type) in substs.types().enumerate() {
412 name_to_append_suffix_to.push_str(",");
416 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
417 // Add actual type name to <...> clause of function name
418 let actual_type_name = compute_debuginfo_type_name(cx.tcx(), actual_type, true);
419 name_to_append_suffix_to.push_str(&actual_type_name[..]);
421 name_to_append_suffix_to.push('>');
423 // Again, only create type information if full debuginfo is enabled
424 let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
425 let names = get_parameter_names(cx, generics);
429 .filter_map(|(kind, name)| {
430 if let GenericArgKind::Type(ty) = kind.unpack() {
432 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
433 let actual_type_metadata =
434 type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
435 let name = SmallCStr::new(&name.as_str());
437 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
441 actual_type_metadata,
456 return create_DIArray(DIB(cx), &template_params[..]);
459 fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
460 let mut names = generics
462 .map_or(vec![], |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
463 names.extend(generics.params.iter().map(|param| param.name));
467 fn get_containing_scope<'ll, 'tcx>(
468 cx: &CodegenCx<'ll, 'tcx>,
469 instance: Instance<'tcx>,
471 // First, let's see if this is a method within an inherent impl. Because
472 // if yes, we want to make the result subroutine DIE a child of the
473 // subroutine's self-type.
474 let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
475 // If the method does *not* belong to a trait, proceed
476 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
477 let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
479 ty::ParamEnv::reveal_all(),
480 &cx.tcx.type_of(impl_def_id),
483 // Only "class" methods are generally understood by LLVM,
484 // so avoid methods on other types (e.g., `<*mut T>::null`).
485 match impl_self_ty.kind {
486 ty::Adt(def, ..) if !def.is_box() => {
487 Some(type_metadata(cx, impl_self_ty, rustc_span::DUMMY_SP))
492 // For trait method impls we still use the "parallel namespace"
498 self_type.unwrap_or_else(|| {
499 namespace::item_namespace(
502 krate: instance.def_id().krate,
505 .def_key(instance.def_id())
507 .expect("get_containing_scope: missing parent?"),
514 fn create_vtable_metadata(&self, ty: Ty<'tcx>, vtable: Self::Value) {
515 metadata::create_vtable_metadata(self, ty, vtable)
518 fn extend_scope_to_file(
520 scope_metadata: &'ll DIScope,
521 file: &rustc_span::SourceFile,
522 defining_crate: CrateNum,
523 ) -> &'ll DILexicalBlock {
524 metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
527 fn debuginfo_finalize(&self) {
531 // FIXME(eddyb) find a common convention for all of the debuginfo-related
532 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
535 dbg_context: &FunctionDebugContext<&'ll DIScope>,
536 variable_name: ast::Name,
537 variable_type: Ty<'tcx>,
538 scope_metadata: &'ll DIScope,
539 variable_kind: VariableKind,
541 ) -> &'ll DIVariable {
542 let loc = span_start(self, span);
543 let file_metadata = file_metadata(self, &loc.file.name, dbg_context.defining_crate);
545 let type_metadata = type_metadata(self, variable_type, span);
547 let (argument_index, dwarf_tag) = match variable_kind {
548 ArgumentVariable(index) => (index as c_uint, DW_TAG_arg_variable),
549 LocalVariable => (0, DW_TAG_auto_variable),
551 let align = self.align_of(variable_type);
553 let name = SmallCStr::new(&variable_name.as_str());
555 llvm::LLVMRustDIBuilderCreateVariable(
563 self.sess().opts.optimize != config::OptLevel::No,
566 align.bytes() as u32,