compiler/rustc_codegen_gcc/src/debuginfo.rs - third_party/rust - Git at Google

 use std::ops::Range;

 use gccjit::{Location, RValue};
 use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
 use rustc_codegen_ssa::traits::{DebugInfoBuilderMethods, DebugInfoCodegenMethods};
 use rustc_data_structures::sync::Lrc;
 use rustc_index::bit_set::BitSet;
 use rustc_index::{Idx, IndexVec};
 use rustc_middle::mir::{self, Body, SourceScope};
 use rustc_middle::ty::{Instance, PolyExistentialTraitRef, Ty};
 use rustc_session::config::DebugInfo;
 use rustc_span::{BytePos, Pos, SourceFile, SourceFileAndLine, Span, Symbol};
 use rustc_target::abi::call::FnAbi;
 use rustc_target::abi::Size;

 use crate::builder::Builder;
 use crate::context::CodegenCx;

 pub(super) const UNKNOWN_LINE_NUMBER: u32 = 0;
 pub(super) const UNKNOWN_COLUMN_NUMBER: u32 = 0;

 impl<'a, 'gcc, 'tcx> DebugInfoBuilderMethods for Builder<'a, 'gcc, '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: Self::DIVariable,
         _dbg_loc: Self::DILocation,
         _variable_alloca: Self::Value,
         _direct_offset: Size,
         _indirect_offsets: &[Size],
         _fragment: Option<Range<Size>>,
     ) {
         // FIXME(tempdragon): Not sure if this is correct, probably wrong but still keep it here.
         #[cfg(feature = "master")]
         _variable_alloca.set_location(_dbg_loc);
     }

     fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
         // TODO(antoyo): insert reference to gdb debug scripts section global.
     }

     /// FIXME(tempdragon): Currently, this function is not yet implemented. It seems that the
     /// debug name and the mangled name should both be included in the LValues.
     /// Besides, a function to get the rvalue type(m_is_lvalue) should also be included.
     fn set_var_name(&mut self, _value: RValue<'gcc>, _name: &str) {}

     fn set_dbg_loc(&mut self, dbg_loc: Self::DILocation) {
         self.location = Some(dbg_loc);
     }

     fn clear_dbg_loc(&mut self) {
         self.location = None;
     }
 }

 /// Generate the `debug_context` in an MIR Body.
 /// # Souce of Origin
 /// Copied from `create_scope_map.rs` of rustc_codegen_llvm
 fn compute_mir_scopes<'gcc, 'tcx>(
     cx: &CodegenCx<'gcc, 'tcx>,
     instance: Instance<'tcx>,
     mir: &Body<'tcx>,
     debug_context: &mut FunctionDebugContext<'tcx, (), Location<'gcc>>,
 ) {
     // Find all scopes with variables defined in them.
     let variables = if cx.sess().opts.debuginfo == DebugInfo::Full {
         let mut vars = BitSet::new_empty(mir.source_scopes.len());
         // FIXME(eddyb) take into account that arguments always have debuginfo,
         // irrespective of their name (assuming full debuginfo is enabled).
         // NOTE(eddyb) actually, on second thought, those are always in the
         // function scope, which always exists.
         for var_debug_info in &mir.var_debug_info {
             vars.insert(var_debug_info.source_info.scope);
         }
         Some(vars)
     } else {
         // Nothing to emit, of course.
         None
     };
     let mut instantiated = BitSet::new_empty(mir.source_scopes.len());
     // Instantiate all scopes.
     for idx in 0..mir.source_scopes.len() {
         let scope = SourceScope::new(idx);
         make_mir_scope(cx, instance, mir, &variables, debug_context, &mut instantiated, scope);
     }
     assert!(instantiated.count() == mir.source_scopes.len());
 }

 /// Update the `debug_context`, adding new scope to it,
 /// if it's not added as is denoted in `instantiated`.
 ///
 /// # Souce of Origin
 /// Copied from `create_scope_map.rs` of rustc_codegen_llvm
 /// FIXME(tempdragon/?): Add Scope Support Here.
 fn make_mir_scope<'gcc, 'tcx>(
     cx: &CodegenCx<'gcc, 'tcx>,
     _instance: Instance<'tcx>,
     mir: &Body<'tcx>,
     variables: &Option<BitSet<SourceScope>>,
     debug_context: &mut FunctionDebugContext<'tcx, (), Location<'gcc>>,
     instantiated: &mut BitSet<SourceScope>,
     scope: SourceScope,
 ) {
     if instantiated.contains(scope) {
         return;
     }

     let scope_data = &mir.source_scopes[scope];
     let parent_scope = if let Some(parent) = scope_data.parent_scope {
         make_mir_scope(cx, _instance, mir, variables, debug_context, instantiated, parent);
         debug_context.scopes[parent]
     } else {
         // The root is the function itself.
         let file = cx.sess().source_map().lookup_source_file(mir.span.lo());
         debug_context.scopes[scope] = DebugScope {
             file_start_pos: file.start_pos,
             file_end_pos: file.end_position(),
             ..debug_context.scopes[scope]
         };
         instantiated.insert(scope);
         return;
     };

     if let Some(ref vars) = *variables {
         if !vars.contains(scope) && scope_data.inlined.is_none() {
             // Do not create a DIScope if there are no variables defined in this
             // MIR `SourceScope`, and it's not `inlined`, to avoid debuginfo bloat.
             debug_context.scopes[scope] = parent_scope;
             instantiated.insert(scope);
             return;
         }
     }

     let loc = cx.lookup_debug_loc(scope_data.span.lo());

     // FIXME(tempdragon): Add the scope related code here if the scope is supported.
     let dbg_scope = ();

     let inlined_at = scope_data.inlined.map(|(_, callsite_span)| {
         // FIXME(eddyb) this doesn't account for the macro-related
         // `Span` fixups that `rustc_codegen_ssa::mir::debuginfo` does.

         // TODO(tempdragon): Add scope support and then revert to cg_llvm version of this closure
         // NOTE: These variables passed () here.
         // Changed to comply to clippy.

         /* let callsite_scope =  */
         parent_scope.adjust_dbg_scope_for_span(cx, callsite_span);
         cx.dbg_loc(/* callsite_scope */ (), parent_scope.inlined_at, callsite_span)
     });
     let p_inlined_at = parent_scope.inlined_at;
     // TODO(tempdragon): dbg_scope: Add support for scope extension here.
     inlined_at.or(p_inlined_at);

     debug_context.scopes[scope] = DebugScope {
         dbg_scope,
         inlined_at,
         file_start_pos: loc.file.start_pos,
         file_end_pos: loc.file.end_position(),
     };
     instantiated.insert(scope);
 }

 /// A source code location used to generate debug information.
 // FIXME(eddyb) rename this to better indicate it's a duplicate of
 // `rustc_span::Loc` rather than `DILocation`, perhaps by making
 // `lookup_char_pos` return the right information instead.
 pub struct DebugLoc {
     /// Information about the original source file.
     pub file: Lrc<SourceFile>,
     /// The (1-based) line number.
     pub line: u32,
     /// The (1-based) column number.
     pub col: u32,
 }

 impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
     /// Looks up debug source information about a `BytePos`.
     // FIXME(eddyb) rename this to better indicate it's a duplicate of
     // `lookup_char_pos` rather than `dbg_loc`, perhaps by making
     // `lookup_char_pos` return the right information instead.
     // Source of Origin: cg_llvm
     pub fn lookup_debug_loc(&self, pos: BytePos) -> DebugLoc {
         let (file, line, col) = match self.sess().source_map().lookup_line(pos) {
             Ok(SourceFileAndLine { sf: file, line }) => {
                 let line_pos = file.lines()[line];

                 // Use 1-based indexing.
                 let line = (line + 1) as u32;
                 let col = (file.relative_position(pos) - line_pos).to_u32() + 1;

                 (file, line, col)
             }
             Err(file) => (file, UNKNOWN_LINE_NUMBER, UNKNOWN_COLUMN_NUMBER),
         };

         // For MSVC, omit the column number.
         // Otherwise, emit it. This mimics clang behaviour.
         // See discussion in https://github.com/rust-lang/rust/issues/42921
         if self.sess().target.is_like_msvc {
             DebugLoc { file, line, col: UNKNOWN_COLUMN_NUMBER }
         } else {
             DebugLoc { file, line, col }
         }
     }
 }

 impl<'gcc, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
     fn create_vtable_debuginfo(
         &self,
         _ty: Ty<'tcx>,
         _trait_ref: Option<PolyExistentialTraitRef<'tcx>>,
         _vtable: Self::Value,
     ) {
         // TODO(antoyo)
     }

     fn create_function_debug_context(
         &self,
         instance: Instance<'tcx>,
         fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         llfn: RValue<'gcc>,
         mir: &mir::Body<'tcx>,
     ) -> Option<FunctionDebugContext<'tcx, Self::DIScope, Self::DILocation>> {
         if self.sess().opts.debuginfo == DebugInfo::None {
             return None;
         }

         // Initialize fn debug context (including scopes).
         let empty_scope = DebugScope {
             dbg_scope: self.dbg_scope_fn(instance, fn_abi, Some(llfn)),
             inlined_at: None,
             file_start_pos: BytePos(0),
             file_end_pos: BytePos(0),
         };
         let mut fn_debug_context = FunctionDebugContext {
             scopes: IndexVec::from_elem(empty_scope, mir.source_scopes.as_slice()),
             inlined_function_scopes: Default::default(),
         };

         // Fill in all the scopes, with the information from the MIR body.
         compute_mir_scopes(self, instance, mir, &mut fn_debug_context);

         Some(fn_debug_context)
     }

     fn extend_scope_to_file(
         &self,
         _scope_metadata: Self::DIScope,
         _file: &SourceFile,
     ) -> Self::DIScope {
         // TODO(antoyo): implement.
     }

     fn debuginfo_finalize(&self) {
         self.context.set_debug_info(true)
     }

     fn create_dbg_var(
         &self,
         _variable_name: Symbol,
         _variable_type: Ty<'tcx>,
         _scope_metadata: Self::DIScope,
         _variable_kind: VariableKind,
         _span: Span,
     ) -> Self::DIVariable {
     }

     fn dbg_scope_fn(
         &self,
         _instance: Instance<'tcx>,
         _fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
         _maybe_definition_llfn: Option<RValue<'gcc>>,
     ) -> Self::DIScope {
         // TODO(antoyo): implement.
     }

     fn dbg_loc(
         &self,
         _scope: Self::DIScope,
         _inlined_at: Option<Self::DILocation>,
         span: Span,
     ) -> Self::DILocation {
         let pos = span.lo();
         let DebugLoc { file, line, col } = self.lookup_debug_loc(pos);
         let loc = match file.name {
             rustc_span::FileName::Real(ref name) => match *name {
                 rustc_span::RealFileName::LocalPath(ref name) => {
                     if let Some(name) = name.to_str() {
                         self.context.new_location(name, line as i32, col as i32)
                     } else {
                         Location::null()
                     }
                 }
                 rustc_span::RealFileName::Remapped {
                     ref local_path,
                     virtual_name: ref _unused,
                 } => {
                     if let Some(name) = local_path.as_ref() {
                         if let Some(name) = name.to_str() {
                             self.context.new_location(name, line as i32, col as i32)
                         } else {
                             Location::null()
                         }
                     } else {
                         Location::null()
                     }
                 }
             },
             _ => Location::null(),
         };
         loc
     }
 }
	use std::ops::Range;

	use gccjit::{Location, RValue};
	use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext, VariableKind};
	use rustc_codegen_ssa::traits::{DebugInfoBuilderMethods, DebugInfoCodegenMethods};
	use rustc_data_structures::sync::Lrc;
	use rustc_index::bit_set::BitSet;
	use rustc_index::{Idx, IndexVec};
	use rustc_middle::mir::{self, Body, SourceScope};
	use rustc_middle::ty::{Instance, PolyExistentialTraitRef, Ty};
	use rustc_session::config::DebugInfo;
	use rustc_span::{BytePos, Pos, SourceFile, SourceFileAndLine, Span, Symbol};
	use rustc_target::abi::call::FnAbi;
	use rustc_target::abi::Size;

	use crate::builder::Builder;
	use crate::context::CodegenCx;

	pub(super) const UNKNOWN_LINE_NUMBER: u32 = 0;
	pub(super) const UNKNOWN_COLUMN_NUMBER: u32 = 0;

	impl<'a, 'gcc, 'tcx> DebugInfoBuilderMethods for Builder<'a, 'gcc, '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: Self::DIVariable,
	_dbg_loc: Self::DILocation,
	_variable_alloca: Self::Value,
	_direct_offset: Size,
	_indirect_offsets: &[Size],
	_fragment: Option<Range<Size>>,
	) {
	// FIXME(tempdragon): Not sure if this is correct, probably wrong but still keep it here.
	#[cfg(feature = "master")]
	_variable_alloca.set_location(_dbg_loc);
	}

	fn insert_reference_to_gdb_debug_scripts_section_global(&mut self) {
	// TODO(antoyo): insert reference to gdb debug scripts section global.
	}

	/// FIXME(tempdragon): Currently, this function is not yet implemented. It seems that the
	/// debug name and the mangled name should both be included in the LValues.
	/// Besides, a function to get the rvalue type(m_is_lvalue) should also be included.
	fn set_var_name(&mut self, _value: RValue<'gcc>, _name: &str) {}

	fn set_dbg_loc(&mut self, dbg_loc: Self::DILocation) {
	self.location = Some(dbg_loc);
	}

	fn clear_dbg_loc(&mut self) {
	self.location = None;
	}
	}

	/// Generate the `debug_context` in an MIR Body.
	/// # Souce of Origin
	/// Copied from `create_scope_map.rs` of rustc_codegen_llvm
	fn compute_mir_scopes<'gcc, 'tcx>(
	cx: &CodegenCx<'gcc, 'tcx>,
	instance: Instance<'tcx>,
	mir: &Body<'tcx>,
	debug_context: &mut FunctionDebugContext<'tcx, (), Location<'gcc>>,
	) {
	// Find all scopes with variables defined in them.
	let variables = if cx.sess().opts.debuginfo == DebugInfo::Full {
	let mut vars = BitSet::new_empty(mir.source_scopes.len());
	// FIXME(eddyb) take into account that arguments always have debuginfo,
	// irrespective of their name (assuming full debuginfo is enabled).
	// NOTE(eddyb) actually, on second thought, those are always in the
	// function scope, which always exists.
	for var_debug_info in &mir.var_debug_info {
	vars.insert(var_debug_info.source_info.scope);
	}
	Some(vars)
	} else {
	// Nothing to emit, of course.
	None
	};
	let mut instantiated = BitSet::new_empty(mir.source_scopes.len());
	// Instantiate all scopes.
	for idx in 0..mir.source_scopes.len() {
	let scope = SourceScope::new(idx);
	make_mir_scope(cx, instance, mir, &variables, debug_context, &mut instantiated, scope);
	}
	assert!(instantiated.count() == mir.source_scopes.len());
	}

	/// Update the `debug_context`, adding new scope to it,
	/// if it's not added as is denoted in `instantiated`.
	///
	/// # Souce of Origin
	/// Copied from `create_scope_map.rs` of rustc_codegen_llvm
	/// FIXME(tempdragon/?): Add Scope Support Here.
	fn make_mir_scope<'gcc, 'tcx>(
	cx: &CodegenCx<'gcc, 'tcx>,
	_instance: Instance<'tcx>,
	mir: &Body<'tcx>,
	variables: &Option<BitSet<SourceScope>>,
	debug_context: &mut FunctionDebugContext<'tcx, (), Location<'gcc>>,
	instantiated: &mut BitSet<SourceScope>,
	scope: SourceScope,
	) {
	if instantiated.contains(scope) {
	return;
	}

	let scope_data = &mir.source_scopes[scope];
	let parent_scope = if let Some(parent) = scope_data.parent_scope {
	make_mir_scope(cx, _instance, mir, variables, debug_context, instantiated, parent);
	debug_context.scopes[parent]
	} else {
	// The root is the function itself.
	let file = cx.sess().source_map().lookup_source_file(mir.span.lo());
	debug_context.scopes[scope] = DebugScope {
	file_start_pos: file.start_pos,
	file_end_pos: file.end_position(),
	..debug_context.scopes[scope]
	};
	instantiated.insert(scope);
	return;
	};

	if let Some(ref vars) = *variables {
	if !vars.contains(scope) && scope_data.inlined.is_none() {
	// Do not create a DIScope if there are no variables defined in this
	// MIR `SourceScope`, and it's not `inlined`, to avoid debuginfo bloat.
	debug_context.scopes[scope] = parent_scope;
	instantiated.insert(scope);
	return;
	}
	}

	let loc = cx.lookup_debug_loc(scope_data.span.lo());

	// FIXME(tempdragon): Add the scope related code here if the scope is supported.
	let dbg_scope = ();

	let inlined_at = scope_data.inlined.map(\|(_, callsite_span)\| {
	// FIXME(eddyb) this doesn't account for the macro-related
	// `Span` fixups that `rustc_codegen_ssa::mir::debuginfo` does.

	// TODO(tempdragon): Add scope support and then revert to cg_llvm version of this closure
	// NOTE: These variables passed () here.
	// Changed to comply to clippy.

	/* let callsite_scope = */
	parent_scope.adjust_dbg_scope_for_span(cx, callsite_span);
	cx.dbg_loc(/* callsite_scope */ (), parent_scope.inlined_at, callsite_span)
	});
	let p_inlined_at = parent_scope.inlined_at;
	// TODO(tempdragon): dbg_scope: Add support for scope extension here.
	inlined_at.or(p_inlined_at);

	debug_context.scopes[scope] = DebugScope {
	dbg_scope,
	inlined_at,
	file_start_pos: loc.file.start_pos,
	file_end_pos: loc.file.end_position(),
	};
	instantiated.insert(scope);
	}

	/// A source code location used to generate debug information.
	// FIXME(eddyb) rename this to better indicate it's a duplicate of
	// `rustc_span::Loc` rather than `DILocation`, perhaps by making
	// `lookup_char_pos` return the right information instead.
	pub struct DebugLoc {
	/// Information about the original source file.
	pub file: Lrc<SourceFile>,
	/// The (1-based) line number.
	pub line: u32,
	/// The (1-based) column number.
	pub col: u32,
	}

	impl<'gcc, 'tcx> CodegenCx<'gcc, 'tcx> {
	/// Looks up debug source information about a `BytePos`.
	// FIXME(eddyb) rename this to better indicate it's a duplicate of
	// `lookup_char_pos` rather than `dbg_loc`, perhaps by making
	// `lookup_char_pos` return the right information instead.
	// Source of Origin: cg_llvm
	pub fn lookup_debug_loc(&self, pos: BytePos) -> DebugLoc {
	let (file, line, col) = match self.sess().source_map().lookup_line(pos) {
	Ok(SourceFileAndLine { sf: file, line }) => {
	let line_pos = file.lines()[line];

	// Use 1-based indexing.
	let line = (line + 1) as u32;
	let col = (file.relative_position(pos) - line_pos).to_u32() + 1;

	(file, line, col)
	}
	Err(file) => (file, UNKNOWN_LINE_NUMBER, UNKNOWN_COLUMN_NUMBER),
	};

	// For MSVC, omit the column number.
	// Otherwise, emit it. This mimics clang behaviour.
	// See discussion in https://github.com/rust-lang/rust/issues/42921
	if self.sess().target.is_like_msvc {
	DebugLoc { file, line, col: UNKNOWN_COLUMN_NUMBER }
	} else {
	DebugLoc { file, line, col }
	}
	}
	}

	impl<'gcc, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
	fn create_vtable_debuginfo(
	&self,
	_ty: Ty<'tcx>,
	_trait_ref: Option<PolyExistentialTraitRef<'tcx>>,
	_vtable: Self::Value,
	) {
	// TODO(antoyo)
	}

	fn create_function_debug_context(
	&self,
	instance: Instance<'tcx>,
	fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
	llfn: RValue<'gcc>,
	mir: &mir::Body<'tcx>,
	) -> Option<FunctionDebugContext<'tcx, Self::DIScope, Self::DILocation>> {
	if self.sess().opts.debuginfo == DebugInfo::None {
	return None;
	}

	// Initialize fn debug context (including scopes).
	let empty_scope = DebugScope {
	dbg_scope: self.dbg_scope_fn(instance, fn_abi, Some(llfn)),
	inlined_at: None,
	file_start_pos: BytePos(0),
	file_end_pos: BytePos(0),
	};
	let mut fn_debug_context = FunctionDebugContext {
	scopes: IndexVec::from_elem(empty_scope, mir.source_scopes.as_slice()),
	inlined_function_scopes: Default::default(),
	};

	// Fill in all the scopes, with the information from the MIR body.
	compute_mir_scopes(self, instance, mir, &mut fn_debug_context);

	Some(fn_debug_context)
	}

	fn extend_scope_to_file(
	&self,
	_scope_metadata: Self::DIScope,
	_file: &SourceFile,
	) -> Self::DIScope {
	// TODO(antoyo): implement.
	}

	fn debuginfo_finalize(&self) {
	self.context.set_debug_info(true)
	}

	fn create_dbg_var(
	&self,
	_variable_name: Symbol,
	_variable_type: Ty<'tcx>,
	_scope_metadata: Self::DIScope,
	_variable_kind: VariableKind,
	_span: Span,
	) -> Self::DIVariable {
	}

	fn dbg_scope_fn(
	&self,
	_instance: Instance<'tcx>,
	_fn_abi: &FnAbi<'tcx, Ty<'tcx>>,
	_maybe_definition_llfn: Option<RValue<'gcc>>,
	) -> Self::DIScope {
	// TODO(antoyo): implement.
	}

	fn dbg_loc(
	&self,
	_scope: Self::DIScope,
	_inlined_at: Option<Self::DILocation>,
	span: Span,
	) -> Self::DILocation {
	let pos = span.lo();
	let DebugLoc { file, line, col } = self.lookup_debug_loc(pos);
	let loc = match file.name {
	rustc_span::FileName::Real(ref name) => match *name {
	rustc_span::RealFileName::LocalPath(ref name) => {
	if let Some(name) = name.to_str() {
	self.context.new_location(name, line as i32, col as i32)
	} else {
	Location::null()
	}
	}
	rustc_span::RealFileName::Remapped {
	ref local_path,
	virtual_name: ref _unused,
	} => {
	if let Some(name) = local_path.as_ref() {
	if let Some(name) = name.to_str() {
	self.context.new_location(name, line as i32, col as i32)
	} else {
	Location::null()
	}
	} else {
	Location::null()
	}
	}
	},
	_ => Location::null(),
	};
	loc
	}
	}