Importing rustc-1.48.0
Bug: 173721343
Change-Id: Ie8184d9a685086ca8a77266d6c608843f40dc9e1
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
new file mode 100644
index 0000000..7cdd366
--- /dev/null
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs
@@ -0,0 +1,563 @@
+// See doc.rs for documentation.
+mod doc;
+
+use rustc_codegen_ssa::mir::debuginfo::VariableKind::*;
+
+use self::metadata::{file_metadata, type_metadata, TypeMap, UNKNOWN_LINE_NUMBER};
+use self::namespace::mangled_name_of_instance;
+use self::type_names::compute_debuginfo_type_name;
+use self::utils::{create_DIArray, is_node_local_to_unit, DIB};
+
+use crate::abi::FnAbi;
+use crate::builder::Builder;
+use crate::common::CodegenCx;
+use crate::llvm;
+use crate::llvm::debuginfo::{
+ DIArray, DIBuilder, DIFile, DIFlags, DILexicalBlock, DISPFlags, DIScope, DIType, DIVariable,
+};
+use crate::value::Value;
+
+use rustc_codegen_ssa::debuginfo::type_names;
+use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
+use rustc_codegen_ssa::traits::*;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, LOCAL_CRATE};
+use rustc_index::vec::IndexVec;
+use rustc_middle::mir;
+use rustc_middle::ty::layout::HasTyCtxt;
+use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
+use rustc_middle::ty::{self, Instance, ParamEnv, Ty, TypeFoldable};
+use rustc_session::config::{self, DebugInfo};
+use rustc_span::symbol::Symbol;
+use rustc_span::{self, BytePos, Span};
+use rustc_target::abi::{LayoutOf, Primitive, Size};
+
+use libc::c_uint;
+use smallvec::SmallVec;
+use std::cell::RefCell;
+use tracing::debug;
+
+mod create_scope_map;
+pub mod gdb;
+pub mod metadata;
+mod namespace;
+mod source_loc;
+mod utils;
+
+pub use self::create_scope_map::compute_mir_scopes;
+pub use self::metadata::create_global_var_metadata;
+pub use self::metadata::extend_scope_to_file;
+
+#[allow(non_upper_case_globals)]
+const DW_TAG_auto_variable: c_uint = 0x100;
+#[allow(non_upper_case_globals)]
+const DW_TAG_arg_variable: c_uint = 0x101;
+
+/// A context object for maintaining all state needed by the debuginfo module.
+pub struct CrateDebugContext<'a, 'tcx> {
+ llcontext: &'a llvm::Context,
+ llmod: &'a llvm::Module,
+ builder: &'a mut DIBuilder<'a>,
+ created_files: RefCell<FxHashMap<(Option<String>, Option<String>), &'a DIFile>>,
+ created_enum_disr_types: RefCell<FxHashMap<(DefId, Primitive), &'a DIType>>,
+
+ type_map: RefCell<TypeMap<'a, 'tcx>>,
+ namespace_map: RefCell<DefIdMap<&'a DIScope>>,
+
+ // This collection is used to assert that composite types (structs, enums,
+ // ...) have their members only set once:
+ composite_types_completed: RefCell<FxHashSet<&'a DIType>>,
+}
+
+impl Drop for CrateDebugContext<'a, 'tcx> {
+ fn drop(&mut self) {
+ unsafe {
+ llvm::LLVMRustDIBuilderDispose(&mut *(self.builder as *mut _));
+ }
+ }
+}
+
+impl<'a, 'tcx> CrateDebugContext<'a, 'tcx> {
+ pub fn new(llmod: &'a llvm::Module) -> Self {
+ debug!("CrateDebugContext::new");
+ let builder = unsafe { llvm::LLVMRustDIBuilderCreate(llmod) };
+ // DIBuilder inherits context from the module, so we'd better use the same one
+ let llcontext = unsafe { llvm::LLVMGetModuleContext(llmod) };
+ CrateDebugContext {
+ llcontext,
+ llmod,
+ builder,
+ created_files: Default::default(),
+ created_enum_disr_types: Default::default(),
+ type_map: Default::default(),
+ namespace_map: RefCell::new(Default::default()),
+ composite_types_completed: Default::default(),
+ }
+ }
+}
+
+/// Creates any deferred debug metadata nodes
+pub fn finalize(cx: &CodegenCx<'_, '_>) {
+ if cx.dbg_cx.is_none() {
+ return;
+ }
+
+ debug!("finalize");
+
+ if gdb::needs_gdb_debug_scripts_section(cx) {
+ // Add a .debug_gdb_scripts section to this compile-unit. This will
+ // cause GDB to try and load the gdb_load_rust_pretty_printers.py file,
+ // which activates the Rust pretty printers for binary this section is
+ // contained in.
+ gdb::get_or_insert_gdb_debug_scripts_section_global(cx);
+ }
+
+ unsafe {
+ llvm::LLVMRustDIBuilderFinalize(DIB(cx));
+ // Debuginfo generation in LLVM by default uses a higher
+ // version of dwarf than macOS currently understands. We can
+ // instruct LLVM to emit an older version of dwarf, however,
+ // for macOS to understand. For more info see #11352
+ // This can be overridden using --llvm-opts -dwarf-version,N.
+ // Android has the same issue (#22398)
+ if cx.sess().target.target.options.is_like_osx
+ || cx.sess().target.target.options.is_like_android
+ {
+ llvm::LLVMRustAddModuleFlag(cx.llmod, "Dwarf Version\0".as_ptr().cast(), 2)
+ }
+
+ // Indicate that we want CodeView debug information on MSVC
+ if cx.sess().target.target.options.is_like_msvc {
+ llvm::LLVMRustAddModuleFlag(cx.llmod, "CodeView\0".as_ptr().cast(), 1)
+ }
+
+ // Prevent bitcode readers from deleting the debug info.
+ let ptr = "Debug Info Version\0".as_ptr();
+ llvm::LLVMRustAddModuleFlag(cx.llmod, ptr.cast(), llvm::LLVMRustDebugMetadataVersion());
+ };
+}
+
+impl DebugInfoBuilderMethods for Builder<'a, 'll, 'tcx> {
+ // FIXME(eddyb) find a common convention for all of the debuginfo-related
+ // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
+ fn dbg_var_addr(
+ &mut self,
+ dbg_var: &'ll DIVariable,
+ scope_metadata: &'ll DIScope,
+ variable_alloca: Self::Value,
+ direct_offset: Size,
+ indirect_offsets: &[Size],
+ span: Span,
+ ) {
+ let cx = self.cx();
+
+ // Convert the direct and indirect offsets to address ops.
+ // FIXME(eddyb) use `const`s instead of getting the values via FFI,
+ // the values should match the ones in the DWARF standard anyway.
+ let op_deref = || unsafe { llvm::LLVMRustDIBuilderCreateOpDeref() };
+ let op_plus_uconst = || unsafe { llvm::LLVMRustDIBuilderCreateOpPlusUconst() };
+ let mut addr_ops = SmallVec::<[_; 8]>::new();
+
+ if direct_offset.bytes() > 0 {
+ addr_ops.push(op_plus_uconst());
+ addr_ops.push(direct_offset.bytes() as i64);
+ }
+ for &offset in indirect_offsets {
+ addr_ops.push(op_deref());
+ if offset.bytes() > 0 {
+ addr_ops.push(op_plus_uconst());
+ addr_ops.push(offset.bytes() as i64);
+ }
+ }
+
+ // FIXME(eddyb) maybe this information could be extracted from `dbg_var`,
+ // to avoid having to pass it down in both places?
+ // NB: `var` doesn't seem to know about the column, so that's a limitation.
+ let dbg_loc = cx.create_debug_loc(scope_metadata, span);
+ unsafe {
+ // FIXME(eddyb) replace `llvm.dbg.declare` with `llvm.dbg.addr`.
+ llvm::LLVMRustDIBuilderInsertDeclareAtEnd(
+ DIB(cx),
+ variable_alloca,
+ dbg_var,
+ addr_ops.as_ptr(),
+ addr_ops.len() as c_uint,
+ dbg_loc,
+ self.llbb(),
+ );
+ }
+ }
+
+ fn set_source_location(&mut self, scope: &'ll DIScope, span: Span) {
+ debug!("set_source_location: {}", self.sess().source_map().span_to_string(span));
+
+ let dbg_loc = self.cx().create_debug_loc(scope, span);
+
+ unsafe {
+ llvm::LLVMSetCurrentDebugLocation(self.llbuilder, dbg_loc);
+ }
+ }
+ fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
+ gdb::insert_reference_to_gdb_debug_scripts_section_global(self)
+ }
+
+ fn set_var_name(&mut self, value: &'ll Value, name: &str) {
+ // Avoid wasting time if LLVM value names aren't even enabled.
+ if self.sess().fewer_names() {
+ return;
+ }
+
+ // Only function parameters and instructions are local to a function,
+ // don't change the name of anything else (e.g. globals).
+ let param_or_inst = unsafe {
+ llvm::LLVMIsAArgument(value).is_some() || llvm::LLVMIsAInstruction(value).is_some()
+ };
+ if !param_or_inst {
+ return;
+ }
+
+ // Avoid replacing the name if it already exists.
+ // While we could combine the names somehow, it'd
+ // get noisy quick, and the usefulness is dubious.
+ if llvm::get_value_name(value).is_empty() {
+ llvm::set_value_name(value, name.as_bytes());
+ }
+ }
+}
+
+impl DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
+ fn create_function_debug_context(
+ &self,
+ instance: Instance<'tcx>,
+ fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
+ llfn: &'ll Value,
+ mir: &mir::Body<'_>,
+ ) -> Option<FunctionDebugContext<&'ll DIScope>> {
+ if self.sess().opts.debuginfo == DebugInfo::None {
+ return None;
+ }
+
+ let span = mir.span;
+
+ // This can be the case for functions inlined from another crate
+ if span.is_dummy() {
+ // FIXME(simulacrum): Probably can't happen; remove.
+ return None;
+ }
+
+ let def_id = instance.def_id();
+ let containing_scope = get_containing_scope(self, instance);
+ let loc = self.lookup_debug_loc(span.lo());
+ let file_metadata = file_metadata(self, &loc.file, def_id.krate);
+
+ let function_type_metadata = unsafe {
+ let fn_signature = get_function_signature(self, fn_abi);
+ llvm::LLVMRustDIBuilderCreateSubroutineType(DIB(self), fn_signature)
+ };
+
+ // Find the enclosing function, in case this is a closure.
+ let def_key = self.tcx().def_key(def_id);
+ let mut name = def_key.disambiguated_data.data.to_string();
+
+ let enclosing_fn_def_id = self.tcx().closure_base_def_id(def_id);
+
+ // Get_template_parameters() will append a `<...>` clause to the function
+ // name if necessary.
+ let generics = self.tcx().generics_of(enclosing_fn_def_id);
+ let substs = instance.substs.truncate_to(self.tcx(), generics);
+ let template_parameters = get_template_parameters(self, &generics, substs, &mut name);
+
+ let linkage_name = &mangled_name_of_instance(self, instance).name;
+ // Omit the linkage_name if it is the same as subprogram name.
+ let linkage_name = if &name == linkage_name { "" } else { linkage_name };
+
+ // FIXME(eddyb) does this need to be separate from `loc.line` for some reason?
+ let scope_line = loc.line;
+
+ let mut flags = DIFlags::FlagPrototyped;
+
+ if fn_abi.ret.layout.abi.is_uninhabited() {
+ flags |= DIFlags::FlagNoReturn;
+ }
+
+ let mut spflags = DISPFlags::SPFlagDefinition;
+ if is_node_local_to_unit(self, def_id) {
+ spflags |= DISPFlags::SPFlagLocalToUnit;
+ }
+ if self.sess().opts.optimize != config::OptLevel::No {
+ spflags |= DISPFlags::SPFlagOptimized;
+ }
+ if let Some((id, _)) = self.tcx.entry_fn(LOCAL_CRATE) {
+ if id.to_def_id() == def_id {
+ spflags |= DISPFlags::SPFlagMainSubprogram;
+ }
+ }
+
+ let fn_metadata = unsafe {
+ llvm::LLVMRustDIBuilderCreateFunction(
+ DIB(self),
+ containing_scope,
+ name.as_ptr().cast(),
+ name.len(),
+ linkage_name.as_ptr().cast(),
+ linkage_name.len(),
+ file_metadata,
+ loc.line.unwrap_or(UNKNOWN_LINE_NUMBER),
+ function_type_metadata,
+ scope_line.unwrap_or(UNKNOWN_LINE_NUMBER),
+ flags,
+ spflags,
+ llfn,
+ template_parameters,
+ None,
+ )
+ };
+
+ // Initialize fn debug context (including scopes).
+ // FIXME(eddyb) figure out a way to not need `Option` for `scope_metadata`.
+ let null_scope = DebugScope {
+ scope_metadata: None,
+ file_start_pos: BytePos(0),
+ file_end_pos: BytePos(0),
+ };
+ let mut fn_debug_context = FunctionDebugContext {
+ scopes: IndexVec::from_elem(null_scope, &mir.source_scopes),
+ defining_crate: def_id.krate,
+ };
+
+ // Fill in all the scopes, with the information from the MIR body.
+ compute_mir_scopes(self, mir, fn_metadata, &mut fn_debug_context);
+
+ return Some(fn_debug_context);
+
+ fn get_function_signature<'ll, 'tcx>(
+ cx: &CodegenCx<'ll, 'tcx>,
+ fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
+ ) -> &'ll DIArray {
+ if cx.sess().opts.debuginfo == DebugInfo::Limited {
+ return create_DIArray(DIB(cx), &[]);
+ }
+
+ let mut signature = Vec::with_capacity(fn_abi.args.len() + 1);
+
+ // Return type -- llvm::DIBuilder wants this at index 0
+ signature.push(if fn_abi.ret.is_ignore() {
+ None
+ } else {
+ Some(type_metadata(cx, fn_abi.ret.layout.ty, rustc_span::DUMMY_SP))
+ });
+
+ // Arguments types
+ if cx.sess().target.target.options.is_like_msvc {
+ // FIXME(#42800):
+ // There is a bug in MSDIA that leads to a crash when it encounters
+ // a fixed-size array of `u8` or something zero-sized in a
+ // function-type (see #40477).
+ // As a workaround, we replace those fixed-size arrays with a
+ // pointer-type. So a function `fn foo(a: u8, b: [u8; 4])` would
+ // appear as `fn foo(a: u8, b: *const u8)` in debuginfo,
+ // and a function `fn bar(x: [(); 7])` as `fn bar(x: *const ())`.
+ // This transformed type is wrong, but these function types are
+ // already inaccurate due to ABI adjustments (see #42800).
+ signature.extend(fn_abi.args.iter().map(|arg| {
+ let t = arg.layout.ty;
+ let t = match t.kind() {
+ ty::Array(ct, _)
+ if (*ct == cx.tcx.types.u8) || cx.layout_of(ct).is_zst() =>
+ {
+ cx.tcx.mk_imm_ptr(ct)
+ }
+ _ => t,
+ };
+ Some(type_metadata(cx, t, rustc_span::DUMMY_SP))
+ }));
+ } else {
+ signature.extend(
+ fn_abi
+ .args
+ .iter()
+ .map(|arg| Some(type_metadata(cx, arg.layout.ty, rustc_span::DUMMY_SP))),
+ );
+ }
+
+ create_DIArray(DIB(cx), &signature[..])
+ }
+
+ fn get_template_parameters<'ll, 'tcx>(
+ cx: &CodegenCx<'ll, 'tcx>,
+ generics: &ty::Generics,
+ substs: SubstsRef<'tcx>,
+ name_to_append_suffix_to: &mut String,
+ ) -> &'ll DIArray {
+ if substs.types().next().is_none() {
+ return create_DIArray(DIB(cx), &[]);
+ }
+
+ name_to_append_suffix_to.push('<');
+ for (i, actual_type) in substs.types().enumerate() {
+ if i != 0 {
+ name_to_append_suffix_to.push_str(",");
+ }
+
+ let actual_type =
+ cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), actual_type);
+ // Add actual type name to <...> clause of function name
+ let actual_type_name = compute_debuginfo_type_name(cx.tcx(), actual_type, true);
+ name_to_append_suffix_to.push_str(&actual_type_name[..]);
+ }
+ name_to_append_suffix_to.push('>');
+
+ // Again, only create type information if full debuginfo is enabled
+ let template_params: Vec<_> = if cx.sess().opts.debuginfo == DebugInfo::Full {
+ let names = get_parameter_names(cx, generics);
+ substs
+ .iter()
+ .zip(names)
+ .filter_map(|(kind, name)| {
+ if let GenericArgKind::Type(ty) = kind.unpack() {
+ let actual_type =
+ cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), ty);
+ let actual_type_metadata =
+ type_metadata(cx, actual_type, rustc_span::DUMMY_SP);
+ let name = name.as_str();
+ Some(unsafe {
+ Some(llvm::LLVMRustDIBuilderCreateTemplateTypeParameter(
+ DIB(cx),
+ None,
+ name.as_ptr().cast(),
+ name.len(),
+ actual_type_metadata,
+ ))
+ })
+ } else {
+ None
+ }
+ })
+ .collect()
+ } else {
+ vec![]
+ };
+
+ create_DIArray(DIB(cx), &template_params[..])
+ }
+
+ fn get_parameter_names(cx: &CodegenCx<'_, '_>, generics: &ty::Generics) -> Vec<Symbol> {
+ let mut names = generics
+ .parent
+ .map_or(vec![], |def_id| get_parameter_names(cx, cx.tcx.generics_of(def_id)));
+ names.extend(generics.params.iter().map(|param| param.name));
+ names
+ }
+
+ fn get_containing_scope<'ll, 'tcx>(
+ cx: &CodegenCx<'ll, 'tcx>,
+ instance: Instance<'tcx>,
+ ) -> &'ll DIScope {
+ // First, let's see if this is a method within an inherent impl. Because
+ // if yes, we want to make the result subroutine DIE a child of the
+ // subroutine's self-type.
+ let self_type = cx.tcx.impl_of_method(instance.def_id()).and_then(|impl_def_id| {
+ // If the method does *not* belong to a trait, proceed
+ if cx.tcx.trait_id_of_impl(impl_def_id).is_none() {
+ let impl_self_ty = cx.tcx.subst_and_normalize_erasing_regions(
+ instance.substs,
+ ty::ParamEnv::reveal_all(),
+ &cx.tcx.type_of(impl_def_id),
+ );
+
+ // Only "class" methods are generally understood by LLVM,
+ // so avoid methods on other types (e.g., `<*mut T>::null`).
+ match impl_self_ty.kind() {
+ ty::Adt(def, ..) if !def.is_box() => {
+ // Again, only create type information if full debuginfo is enabled
+ if cx.sess().opts.debuginfo == DebugInfo::Full
+ && !impl_self_ty.needs_subst()
+ {
+ Some(type_metadata(cx, impl_self_ty, rustc_span::DUMMY_SP))
+ } else {
+ Some(namespace::item_namespace(cx, def.did))
+ }
+ }
+ _ => None,
+ }
+ } else {
+ // For trait method impls we still use the "parallel namespace"
+ // strategy
+ None
+ }
+ });
+
+ self_type.unwrap_or_else(|| {
+ namespace::item_namespace(
+ cx,
+ DefId {
+ krate: instance.def_id().krate,
+ index: cx
+ .tcx
+ .def_key(instance.def_id())
+ .parent
+ .expect("get_containing_scope: missing parent?"),
+ },
+ )
+ })
+ }
+ }
+
+ fn create_vtable_metadata(&self, ty: Ty<'tcx>, vtable: Self::Value) {
+ metadata::create_vtable_metadata(self, ty, vtable)
+ }
+
+ fn extend_scope_to_file(
+ &self,
+ scope_metadata: &'ll DIScope,
+ file: &rustc_span::SourceFile,
+ defining_crate: CrateNum,
+ ) -> &'ll DILexicalBlock {
+ metadata::extend_scope_to_file(&self, scope_metadata, file, defining_crate)
+ }
+
+ fn debuginfo_finalize(&self) {
+ finalize(self)
+ }
+
+ // FIXME(eddyb) find a common convention for all of the debuginfo-related
+ // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.).
+ fn create_dbg_var(
+ &self,
+ dbg_context: &FunctionDebugContext<&'ll DIScope>,
+ variable_name: Symbol,
+ variable_type: Ty<'tcx>,
+ scope_metadata: &'ll DIScope,
+ variable_kind: VariableKind,
+ span: Span,
+ ) -> &'ll DIVariable {
+ let loc = self.lookup_debug_loc(span.lo());
+ let file_metadata = file_metadata(self, &loc.file, dbg_context.defining_crate);
+
+ let type_metadata = type_metadata(self, variable_type, span);
+
+ let (argument_index, dwarf_tag) = match variable_kind {
+ ArgumentVariable(index) => (index as c_uint, DW_TAG_arg_variable),
+ LocalVariable => (0, DW_TAG_auto_variable),
+ };
+ let align = self.align_of(variable_type);
+
+ let name = variable_name.as_str();
+ unsafe {
+ llvm::LLVMRustDIBuilderCreateVariable(
+ DIB(self),
+ dwarf_tag,
+ scope_metadata,
+ name.as_ptr().cast(),
+ name.len(),
+ file_metadata,
+ loc.line.unwrap_or(UNKNOWN_LINE_NUMBER),
+ type_metadata,
+ true,
+ DIFlags::FlagZero,
+ argument_index,
+ align.bytes() as u32,
+ )
+ }
+ }
+}
