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::ty::subst::{GenericArgKind, SubstsRef};
16 use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
18 use crate::abi::FnAbi;
19 use crate::builder::Builder;
20 use crate::common::CodegenCx;
21 use crate::value::Value;
23 use rustc::session::config::{self, DebugInfo};
24 use rustc::ty::{self, Instance, ParamEnv, Ty};
25 use rustc_codegen_ssa::debuginfo::type_names;
26 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
27 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
28 use rustc_data_structures::small_c_str::SmallCStr;
29 use rustc_index::vec::IndexVec;
33 use std::cell::RefCell;
34 use std::ffi::CString;
36 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;
50 pub use self::create_scope_map::compute_mir_scopes;
51 pub use self::metadata::create_global_var_metadata;
52 pub use self::metadata::extend_scope_to_file;
54 #[allow(non_upper_case_globals)]
55 const DW_TAG_auto_variable: c_uint = 0x100;
56 #[allow(non_upper_case_globals)]
57 const DW_TAG_arg_variable: c_uint = 0x101;
59 /// A context object for maintaining all state needed by the debuginfo module.
60 pub struct CrateDebugContext<'a, 'tcx> {
61 llcontext: &'a llvm::Context,
62 llmod: &'a llvm::Module,
63 builder: &'a mut DIBuilder<'a>,
64 created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
65 created_enum_disr_types: RefCell<FxHashMap<(DefId, layout::Primitive), &'a DIType>>,
67 type_map: RefCell<TypeMap<'a, 'tcx>>,
68 namespace_map: RefCell<DefIdMap<&'a DIScope>>,
70 // This collection is used to assert that composite types (structs, enums,
71 // ...) have their members only set once:
72 composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
75 impl Drop for CrateDebugContext<'a, 'tcx> {
78 llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
83 impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
84 pub fn new(llmod: &'a llvm::Module) -> Self {
85 debug!("CrateDebugContext::new");
86 let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
87 // DIBuilder inherits context from the module, so we'd better use the same one
88 let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
93 created_files: Default::default(),
94 created_enum_disr_types: Default::default(),
95 type_map: Default::default(),
96 namespace_map: RefCell::new(Default::default()),
97 composite_types_completed: Default::default(),
102 /// Creates any deferred debug metadata nodes
103 pub fn finalize(cx: &CodegenCx<'_, '_>) {
104 if cx.dbg_cx.is_none() {
110 if gdb::needs_gdb_debug_scripts_section(cx) {
111 // Add a .debug_gdb_scripts section to this compile-unit. This will
112 // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
113 // which activates the Rust pretty printers for binary this section is
115 gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
119 llvm::LLVMRustDIBuilderFinalize(DIB(cx));
120 // Debuginfo generation in LLVM by default uses a higher
121 // version of dwarf than macOS currently understands. We can
122 // instruct LLVM to emit an older version of dwarf, however,
123 // for macOS to understand. For more info see #11352
124 // This can be overridden using --llvm-opts -dwarf-version,N.
125 // Android has the same issue (#22398)
126 if cx.sess().target.target.options.is_like_osx
127 || cx.sess().target.target.options.is_like_android
129 llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
132 // Indicate that we want CodeView debug information on MSVC
133 if cx.sess().target.target.options.is_like_msvc {
134 llvm::LLVMRustAddModuleFlag(cx.llmod, "CodeView\0".as_ptr().cast(), 1)
137 // Prevent bitcode readers from deleting the debug info.
138 let ptr = "Debug Info Version\0".as_ptr();
139 llvm::LLVMRustAddModuleFlag(cx.llmod, ptr.cast(), llvm::LLVMRustDebugMetadataVersion());
143 impl DebugInfoBuilderMethods for Builder<'a, 'll, 'tcx> {
144 // FIXME(eddyb) find a common convention for all of the debuginfo-related
145 // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
148 dbg_var: &'ll DIVariable,
149 scope_metadata: &'ll DIScope,
150 variable_alloca: Self::Value,
152 indirect_offsets: &[Size],
157 // Convert the direct and indirect offsets to address ops.
158 // FIXME(eddyb) use `const`s instead of getting the values via FFI,
159 // the values should match the ones in the DWARF standard anyway.
160 let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() };
161 let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() };
162 let mut addr_ops = SmallVec::<[_; 8]>::new();
164 if direct_offset.bytes() > 0 {
165 addr_ops.push(op_plus_uconst());
166 addr_ops.push(direct_offset.bytes() as i64);
168 for &offset in indirect_offsets {
169 addr_ops.push(op_deref());
170 if offset.bytes() > 0 {
171 addr_ops.push(op_plus_uconst());
172 addr_ops.push(offset.bytes() as i64);
176 // FIXME(eddyb) maybe this information could be extracted from `dbg_var`,
177 // to avoid having to pass it down in both places?
178 // NB: `var` doesn't seem to know about the column, so that's a limitation.
179 let dbg_loc = cx.create_debug_loc(scope_metadata, span);
181 // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
182 llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
187 addr_ops.len() as c_uint,
194 fn set_source_location(&mut self, scope: &'ll DIScope, span: Span) {
195 debug!("set_source_location: {}", self.sess().source_map().span_to_string(span));
197 let dbg_loc = self.cx().create_debug_loc(scope, span);
200 llvm::LLVMSetCurrentDebugLocation(self.llbuilder, dbg_loc);
203 fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
204 gdb::insert_reference_to_gdb_debug_scripts_section_global(self)
207 fn set_var_name(&mut self, value: &'ll Value, name: &str) {
208 // Avoid wasting time if LLVM value names aren't even enabled.
209 if self.sess().fewer_names() {
213 // Only function parameters and instructions are local to a function,
214 // don't change the name of anything else (e.g. globals).
215 let param_or_inst = unsafe {
216 llvm::LLVMIsAArgument(value).is_some() || llvm::LLVMIsAInstruction(value).is_some()
222 // Avoid replacing the name if it already exists.
223 // While we could combine the names somehow, it'd
224 // get noisy quick, and the usefulness is dubious.
225 if llvm::get_value_name(value).is_empty() {
226 llvm::set_value_name(value, name.as_bytes());
231 impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
232 fn create_function_debug_context(
234 instance: Instance<'tcx>,
235 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
238 ) -> Option<FunctionDebugContext<&'ll DIScope>> {
239 if self.sess().opts.debuginfo == DebugInfo::None {
245 // This can be the case for functions inlined from another crate
247 // FIXME(simulacrum): Probably can't happen; remove.
251 let def_id = instance.def_id();
252 let containing_scope = get_containing_scope(self, instance);
253 let loc = span_start(self, span);
254 let file_metadata = file_metadata(self, &loc.file.name, def_id.krate);
256 let function_type_metadata = unsafe {
257 let fn_signature = get_function_signature(self, fn_abi);
258 llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(self), file_metadata, fn_signature)
261 // Find the enclosing function, in case this is a closure.
262 let def_key = self.tcx().def_key(def_id);
263 let mut name = def_key.disambiguated_data.data.to_string();
265 let enclosing_fn_def_id = self.tcx().closure_base_def_id(def_id);
267 // Get_template_parameters() will append a `<...>` clause to the function
268 // name if necessary.
269 let generics = self.tcx().generics_of(enclosing_fn_def_id);
270 let substs = instance.substs.truncate_to(self.tcx(), generics);
271 let template_parameters =
272 get_template_parameters(self, &generics, substs, file_metadata, &mut name);
274 // Get the linkage_name, which is just the symbol name
275 let linkage_name = mangled_name_of_instance(self, instance);
277 // FIXME(eddyb) does this need to be separate from `loc.line` for some reason?
278 let scope_line = loc.line;
280 let function_name = CString::new(name).unwrap();
281 let linkage_name = SmallCStr::new(&linkage_name.name.as_str());
283 let mut flags = DIFlags::FlagPrototyped;
285 if fn_abi.ret.layout.abi.is_uninhabited() {
286 flags |= DIFlags::FlagNoReturn;
289 let mut spflags = DISPFlags::SPFlagDefinition;
290 if is_node_local_to_unit(self, def_id) {
291 spflags |= DISPFlags::SPFlagLocalToUnit;
293 if self.sess().opts.optimize != config::OptLevel::No {
294 spflags |= DISPFlags::SPFlagOptimized;
296 if let Some((id, _)) = self.tcx.entry_fn(LOCAL_CRATE) {
298 spflags |= DISPFlags::SPFlagMainSubprogram;
302 let fn_metadata = unsafe {
303 llvm::LLVMRustDIBuilderCreateFunction(
306 function_name.as_ptr(),
307 linkage_name.as_ptr(),
310 function_type_metadata,
311 scope_line as c_uint,
320 // Initialize fn debug context (including scopes).
321 // FIXME(eddyb) figure out a way to not need `Option` for `scope_metadata`.
322 let null_scope = DebugScope {
323 scope_metadata: None,
324 file_start_pos: BytePos(0),
325 file_end_pos: BytePos(0),
327 let mut fn_debug_context = FunctionDebugContext {
328 scopes: IndexVec::from_elem(null_scope, &mir.source_scopes),
329 defining_crate: def_id.krate,
332 // Fill in all the scopes, with the information from the MIR body.
333 compute_mir_scopes(self, mir, fn_metadata, &mut fn_debug_context);
335 return Some(fn_debug_context);
337 fn get_function_signature<'ll, 'tcx>(
338 cx: &CodegenCx<'ll, 'tcx>,
339 fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
341 if cx.sess().opts.debuginfo == DebugInfo::Limited {
342 return create_DIArray(DIB(cx), &[]);
345 let mut signature = Vec::with_capacity(fn_abi.args.len() + 1);
347 // Return type -- llvm::DIBuilder wants this at index 0
348 signature.push(if fn_abi.ret.is_ignore() {
351 Some(type_metadata(cx, fn_abi.ret.layout.ty, rustc_span::DUMMY_SP))
355 if cx.sess().target.target.options.is_like_msvc {
357 // There is a bug in MSDIA that leads to a crash when it encounters
358 // a fixed-size array of `u8` or something zero-sized in a
359 // function-type (see #40477).
360 // As a workaround, we replace those fixed-size arrays with a
361 // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
362 // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
363 // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
364 // This transformed type is wrong, but these function types are
365 // already inaccurate due to ABI adjustments (see #42800).
366 signature.extend(fn_abi.args.iter().map(|arg| {
367 let t = arg.layout.ty;
368 let t = match t.kind {
370 if (ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() =>
372 cx.tcx.mk_imm_ptr(ct)
376 Some(type_metadata(cx, t, rustc_span::DUMMY_SP))
383 .map(|arg| Some(type_metadata(cx, arg.layout.ty, rustc_span::DUMMY_SP))),
387 create_DIArray(DIB(cx), &signature[..])
390 fn get_template_parameters<'ll, 'tcx>(
391 cx: &CodegenCx<'ll, 'tcx>,
392 generics: &ty::Generics,
393 substs: SubstsRef<'tcx>,
394 file_metadata: &'ll DIFile,
395 name_to_append_suffix_to: &mut String,
397 if substs.types().next().is_none() {
398 return create_DIArray(DIB(cx), &[]);
401 name_to_append_suffix_to.push('<');
402 for (i, actual_type) in substs.types().enumerate() {
404 name_to_append_suffix_to.push_str(",");
408 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
409 // Add actual type name to <...> clause of function name
410 let actual_type_name = compute_debuginfo_type_name(cx.tcx(), actual_type, true);
411 name_to_append_suffix_to.push_str(&actual_type_name[..]);
413 name_to_append_suffix_to.push('>');
415 // Again, only create type information if full debuginfo is enabled
416 let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
417 let names = get_parameter_names(cx, generics);
421 .filter_map(|(kind, name)| {
422 if let GenericArgKind::Type(ty) = kind.unpack() {
424 cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
425 let actual_type_metadata =
426 type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
427 let name = SmallCStr::new(&name.as_str());
429 Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
433 actual_type_metadata,
448 return create_DIArray(DIB(cx), &template_params[..]);
451 fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
452 let mut names = generics
454 .map_or(vec![], |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
455 names.extend(generics.params.iter().map(|param| param.name));
459 fn get_containing_scope<'ll, 'tcx>(
460 cx: &CodegenCx<'ll, 'tcx>,
461 instance: Instance<'tcx>,
463 // First, let's see if this is a method within an inherent impl. Because
464 // if yes, we want to make the result subroutine DIE a child of the
465 // subroutine's self-type.
466 let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
467 // If the method does *not* belong to a trait, proceed
468 if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
469 let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
471 ty::ParamEnv::reveal_all(),
472 &cx.tcx.type_of(impl_def_id),
475 // Only "class" methods are generally understood by LLVM,
476 // so avoid methods on other types (e.g., `<*mut T>::null`).
477 match impl_self_ty.kind {
478 ty::Adt(def, ..) if !def.is_box() => {
479 Some(type_metadata(cx, impl_self_ty, rustc_span::DUMMY_SP))
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: ast::Name,
529 variable_type: Ty<'tcx>,
530 scope_metadata: &'ll DIScope,
531 variable_kind: VariableKind,
533 ) -> &'ll DIVariable {
534 let loc = span_start(self, span);
535 let file_metadata = file_metadata(self, &loc.file.name, 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 = SmallCStr::new(&variable_name.as_str());
547 llvm::LLVMRustDIBuilderCreateVariable(
558 align.bytes() as u32,