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;
55 #[allow(non_upper_case_globals)]
56 const DW_TAG_auto_variable: c_uint = 0x100;
57 #[allow(non_upper_case_globals)]
58 const DW_TAG_arg_variable: c_uint = 0x101;
60 /// A context object for maintaining all state needed by the debuginfo module.
61 pub struct CrateDebugContext<'a, 'tcx> {
62 llcontext: &'a llvm::Context,
63 llmod: &'a llvm::Module,
64 builder: &'a mut DIBuilder<'a>,
65 created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
66 created_enum_disr_types: RefCell<FxHashMap<(DefId, layout::Primitive), &'a DIType>>,
68 type_map: RefCell<TypeMap<'a, 'tcx>>,
69 namespace_map: RefCell<DefIdMap<&'a DIScope>>,
71 // This collection is used to assert that composite types (structs, enums,
72 // ...) have their members only set once:
73 composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
76 impl Drop for CrateDebugContext<'a, 'tcx> {
79 llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
84 impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
85 pub fn new(llmod: &'a llvm::Module) -> Self {
86 debug!("CrateDebugContext::new");
87 let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
88 // DIBuilder inherits context from the module, so we'd better use the same one
89 let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
94 created_files: Default::default(),
95 created_enum_disr_types: Default::default(),
96 type_map: Default::default(),
97 namespace_map: RefCell::new(Default::default()),
98 composite_types_completed: Default::default(),
103 /// Creates any deferred debug metadata nodes
104 pub fn finalize(cx: &CodegenCx<'_, '_>) {
105 if cx.dbg_cx.is_none() {
111 if gdb::needs_gdb_debug_scripts_section(cx) {
112 // Add a .debug_gdb_scripts section to this compile-unit. This will
113 // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
114 // which activates the Rust pretty printers for binary this section is
116 gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
120 llvm::LLVMRustDIBuilderFinalize(DIB(cx));
121 // Debuginfo generation in LLVM by default uses a higher
122 // version of dwarf than macOS currently understands. We can
123 // instruct LLVM to emit an older version of dwarf, however,
124 // for macOS to understand. For more info see #11352
125 // This can be overridden using --llvm-opts -dwarf-version,N.
126 // Android has the same issue (#22398)
127 if cx.sess().target.target.options.is_like_osx
128 || cx.sess().target.target.options.is_like_android
130 llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
133 // Indicate that we want CodeView debug information on MSVC
134 if cx.sess().target.target.options.is_like_msvc {
135 llvm::LLVMRustAddModuleFlag(cx.llmod, "CodeView\0".as_ptr().cast(), 1)
138 // Prevent bitcode readers from deleting the debug info.
139 let ptr = "Debug Info Version\0".as_ptr();
140 llvm::LLVMRustAddModuleFlag(cx.llmod, ptr.cast(), llvm::LLVMRustDebugMetadataVersion());
144 impl DebugInfoBuilderMethods for Builder<'a, 'll, 'tcx> {
145 // FIXME(eddyb) find a common convention for all of the debuginfo-related
146 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
149 dbg_var: &'ll DIVariable,
150 scope_metadata: &'ll DIScope,
151 variable_alloca: Self::Value,
153 indirect_offsets: &[Size],
158 // Convert the direct and indirect offsets to address ops.
159 // FIXME(eddyb) use `const`s instead of getting the values via FFI,
160 // the values should match the ones in the DWARF standard anyway.
161 let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() };
162 let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() };
163 let mut addr_ops = SmallVec::<[_; 8]>::new();
165 if direct_offset.bytes() > 0 {
166 addr_ops.push(op_plus_uconst());
167 addr_ops.push(direct_offset.bytes() as i64);
169 for &offset in indirect_offsets {
170 addr_ops.push(op_deref());
171 if offset.bytes() > 0 {
172 addr_ops.push(op_plus_uconst());
173 addr_ops.push(offset.bytes() as i64);
177 // FIXME(eddyb) maybe this information could be extracted from `dbg_var`,
178 // to avoid having to pass it down in both places?
179 // NB: `var` doesn't seem to know about the column, so that's a limitation.
180 let dbg_loc = cx.create_debug_loc(scope_metadata, span);
182 // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
183 llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
188 addr_ops.len() as c_uint,
195 fn set_source_location(&mut self, scope: &'ll DIScope, span: Span) {
196 debug!("set_source_location: {}", self.sess().source_map().span_to_string(span));
198 let dbg_loc = self.cx().create_debug_loc(scope, span);
201 llvm::LLVMSetCurrentDebugLocation(self.llbuilder, dbg_loc);
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 defining_crate: def_id.krate,
339 // Fill in all the scopes, with the information from the MIR body.
340 compute_mir_scopes(self, mir, fn_metadata, &mut fn_debug_context);
342 return Some(fn_debug_context);
344 fn get_function_signature<'ll, 'tcx>(
345 cx: &CodegenCx<'ll, 'tcx>,
346 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
348 if cx.sess().opts.debuginfo == DebugInfo::Limited {
349 return create_DIArray(DIB(cx), &[]);
352 let mut signature = Vec::with_capacity(fn_abi.args.len() + 1);
354 // Return type -- llvm::DIBuilder wants this at index 0
355 signature.push(if fn_abi.ret.is_ignore() {
358 Some(type_metadata(cx, fn_abi.ret.layout.ty, rustc_span::DUMMY_SP))
362 if cx.sess().target.target.options.is_like_msvc {
364 // There is a bug in MSDIA that leads to a crash when it encounters
365 // a fixed-size array of `u8` or something zero-sized in a
366 // function-type (see #40477).
367 // As a workaround, we replace those fixed-size arrays with a
368 // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
369 // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
370 // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
371 // This transformed type is wrong, but these function types are
372 // already inaccurate due to ABI adjustments (see #42800).
373 signature.extend(fn_abi.args.iter().map(|arg| {
374 let t = arg.layout.ty;
375 let t = match t.kind {
377 if (ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() =>
379 cx.tcx.mk_imm_ptr(ct)
383 Some(type_metadata(cx, t, rustc_span::DUMMY_SP))
390 .map(|arg| Some(type_metadata(cx, arg.layout.ty, rustc_span::DUMMY_SP))),
394 create_DIArray(DIB(cx), &signature[..])
397 fn get_template_parameters<'ll, 'tcx>(
398 cx: &CodegenCx<'ll, 'tcx>,
399 generics: &ty::Generics,
400 substs: SubstsRef<'tcx>,
401 file_metadata: &'ll DIFile,
402 name_to_append_suffix_to: &mut String,
404 if substs.types().next().is_none() {
405 return create_DIArray(DIB(cx), &[]);
408 name_to_append_suffix_to.push('<');
409 for (i, actual_type) in substs.types().enumerate() {
411 name_to_append_suffix_to.push_str(",");
415 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
416 // Add actual type name to <...> clause of function name
417 let actual_type_name = compute_debuginfo_type_name(cx.tcx(), actual_type, true);
418 name_to_append_suffix_to.push_str(&actual_type_name[..]);
420 name_to_append_suffix_to.push('>');
422 // Again, only create type information if full debuginfo is enabled
423 let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
424 let names = get_parameter_names(cx, generics);
428 .filter_map(|(kind, name)| {
429 if let GenericArgKind::Type(ty) = kind.unpack() {
431 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
432 let actual_type_metadata =
433 type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
434 let name = SmallCStr::new(&name.as_str());
436 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
440 actual_type_metadata,
455 return create_DIArray(DIB(cx), &template_params[..]);
458 fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
459 let mut names = generics
461 .map_or(vec![], |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
462 names.extend(generics.params.iter().map(|param| param.name));
466 fn get_containing_scope<'ll, 'tcx>(
467 cx: &CodegenCx<'ll, 'tcx>,
468 instance: Instance<'tcx>,
470 // First, let's see if this is a method within an inherent impl. Because
471 // if yes, we want to make the result subroutine DIE a child of the
472 // subroutine's self-type.
473 let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
474 // If the method does *not* belong to a trait, proceed
475 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
476 let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
478 ty::ParamEnv::reveal_all(),
479 &cx.tcx.type_of(impl_def_id),
482 // Only "class" methods are generally understood by LLVM,
483 // so avoid methods on other types (e.g., `<*mut T>::null`).
484 match impl_self_ty.kind {
485 ty::Adt(def, ..) if !def.is_box() => {
486 Some(type_metadata(cx, impl_self_ty, rustc_span::DUMMY_SP))
491 // For trait method impls we still use the "parallel namespace"
497 self_type.unwrap_or_else(|| {
498 namespace::item_namespace(
501 krate: instance.def_id().krate,
504 .def_key(instance.def_id())
506 .expect("get_containing_scope: missing parent?"),
513 fn create_vtable_metadata(&self, ty: Ty<'tcx>, vtable: Self::Value) {
514 metadata::create_vtable_metadata(self, ty, vtable)
517 fn extend_scope_to_file(
519 scope_metadata: &'ll DIScope,
520 file: &rustc_span::SourceFile,
521 defining_crate: CrateNum,
522 ) -> &'ll DILexicalBlock {
523 metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
526 fn debuginfo_finalize(&self) {
530 // FIXME(eddyb) find a common convention for all of the debuginfo-related
531 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
534 dbg_context: &FunctionDebugContext<&'ll DIScope>,
535 variable_name: ast::Name,
536 variable_type: Ty<'tcx>,
537 scope_metadata: &'ll DIScope,
538 variable_kind: VariableKind,
540 ) -> &'ll DIVariable {
541 let loc = span_start(self, span);
542 let file_metadata = file_metadata(self, &loc.file.name, dbg_context.defining_crate);
544 let type_metadata = type_metadata(self, variable_type, span);
546 let (argument_index, dwarf_tag) = match variable_kind {
547 ArgumentVariable(index) => (index as c_uint, DW_TAG_arg_variable),
548 LocalVariable => (0, DW_TAG_auto_variable),
550 let align = self.align_of(variable_type);
552 let name = SmallCStr::new(&variable_name.as_str());
554 llvm::LLVMRustDIBuilderCreateVariable(
565 align.bytes() as u32,