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Merged
P-E-P merged 6 commits into from
Jan 6, 2026
Merged

Improved Expr parser errors #4330

P-E-P merged 6 commits into from
Jan 6, 2026
+1,473 −1,185

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@P-E-P P-E-P commented Dec 10, 2025

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@P-E-P P-E-P force-pushed the improved_parser_errors branch from 6af4be8 to adf8940 Compare December 12, 2025 13:16
CohenArthur
CohenArthur approved these changes Dec 17, 2025
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Looks good to me!

@P-E-P P-E-P marked this pull request as draft December 17, 2025 10:25
P-E-P added 3 commits January 5, 2026 14:38
@P-E-P
Move old parser error classes to error header
d555134 
A parser error header with Parse::Error namespace has recently been
introduced. Move some old parser error classes to this namespace.

gcc/rust/ChangeLog:

	* parse/rust-parse.h (class ParseLifetimeParamError): Move error from
	here ...
	(class ParseLifetimeError): Likewise.
	(enum class): Likewise.
	* parse/rust-parse-error.h (class LifetimeParam): ... to here.
	here.
	(class Lifetime): Likewise.
	(enum class): Likewise.
	(struct LoopLabel): Likewise and make it a full struct with ctors.
	(struct Self): Likewise.
	* parse/rust-parse-impl-expr.hxx: Make error point to new namespace.
	* parse/rust-parse-impl.hxx: Likewise.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P
Use error collector in the parser
c1021b4 
Errors in the parser needs to be collected instead of emitted directly.

gcc/rust/ChangeLog:

	* parse/rust-parse-impl.hxx: Collect errors instead of emitting them.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P
Use tl::expected for parse_block_expr results
3ce4f7b 
gcc/rust/ChangeLog:

	* parse/rust-parse-error.h (struct BlockExpr): Add BlockExpr error type
	* parse/rust-parse-impl-expr.hxx: Update return types.
	* parse/rust-parse-impl.hxx: Likewise.
	* parse/rust-parse.h: Update function prototypes.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P P-E-P force-pushed the improved_parser_errors branch 4 times, most recently from 88b3510 to 7d5edde Compare January 5, 2026 21:53
P-E-P added 3 commits January 5, 2026 23:14
@P-E-P
Remove redundant error types
81f048d 
Some error types in the parser had the exact same meaning and could be
grouped under one same type.

gcc/rust/ChangeLog:

	* ast/rust-ast.cc (AttributeParser::parse_meta_item_lit): Use
	tl::expected
	* expand/rust-macro-builtins-helpers.cc (parse_single_string_literal):
	Likewise.
	* expand/rust-macro-expand.cc (MacroExpander::match_fragment):
	Likewise.
	* parse/rust-cfg-parser.cc (parse_cfg_option): Likewise.
	* parse/rust-parse-error.h (struct SimplePath): Remove error type.
	(struct DelimTokenTree): Likewise.
	(struct Token): Likewise.
	(struct TokenTree): Likewise.
	(class LifetimeParam): Move from here ...
	(struct LifetimeParam): ... to here. Add ctor.
	(class Lifetime): Add error type.
	(enum class): Remove AnonConst.
	(struct BlockExpr): Change BlockExpr to generic node error.
	* parse/rust-parse-impl-expr.hxx: Use tl::expected for errors.
	* parse/rust-parse-impl-path.hxx: Likewise.
	* parse/rust-parse-impl-ttree.hxx: Likewise.
	* parse/rust-parse-impl.hxx: Likewise.
	* parse/rust-parse.h: Update function return types with tl::expected
	to propagate errors.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P
Use error wrapper when required instead of nullptr
139fd36 
gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit): Update function
	name.
	* ast/rust-ast-pointer-visitor.cc (PointerVisitor::visit): Likewise.
	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit): Likewise.
	* ast/rust-ast.cc (BreakExpr::as_string): Use getter function.
	(AttributeParser::parse_path_meta_item): Convert to expected type.
	(ReturnExpr::as_string): Change access to returned expr.
	* ast/rust-desugar-for-loops.cc (DesugarForLoops::DesugarCtx::make_break_arm):
	Likewise.
	* ast/rust-expr.h (class BreakExpr): Make expr in break optional.
	(class ReturnExpr): Make returned expr explicitely optional. Change the
	getters and introduce a  const getter.
	* expand/rust-cfg-strip.cc (CfgStrip::visit): Convert to expected type.
	* expand/rust-macro-builtins-asm.cc (parse_reg_operand_in): Update
	constructor call to new expected types.
	(parse_reg_operand_out): Likewise.
	(parse_reg_operand_inout): Likewise.
	(parse_llvm_operands): Likewise.
	* expand/rust-macro-builtins-format-args.cc (format_args_parse_expr):
	Likewise.
	(format_args_parse_arguments): Likewise.
	* expand/rust-macro-builtins-helpers.cc (try_expand_many_expr): Update
	value for tl::expected.
	* expand/rust-macro-builtins-include.cc (MacroBuiltin::include_handler):
	Likewise.
	* expand/rust-macro-expand.cc (transcribe_expression): Update
	constructor call with expected value.
	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): Likewise.
	* parse/rust-parse-error.h (enum class): Add new error types for Expr
	and StructExprField.
	* parse/rust-parse-impl-expr.hxx: Explicitely handle return expr
	parsing failure. Update to fit new expected types.
	* parse/rust-parse-impl.hxx: Likewise.
	* resolve/rust-late-name-resolver-2.0.cc (Late::visit): Adapt to
	tl::expected.
	* ast/rust-desugar-while-let.cc (DesugarWhileLet::DesugarCtx::make_break_arm):
	Use optional for break expressions when missing instead of nullptr.
	* parse/rust-parse.h: Change function return type with expected. Remove
	error state from ExprOrStmt.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P
Explicitely specify templates for GCC5
dfc822a 
GCC5 does not infer correctly the type to use within the template.

gcc/rust/ChangeLog:

	* parse/rust-parse-impl-expr.hxx: Use explicit template.
	* parse/rust-parse-impl-path.hxx: Likewise.
	* parse/rust-parse-impl-ttree.hxx: Likewise.
	* parse/rust-parse-impl.hxx: Likewise.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>
@P-E-P P-E-P force-pushed the improved_parser_errors branch from 7d5edde to dfc822a Compare January 6, 2026 00:30
@P-E-P P-E-P marked this pull request as ready for review January 6, 2026 10:05
@P-E-P P-E-P added this pull request to the merge queue Jan 6, 2026
@P-E-P P-E-P changed the title Improved parser errors Improved Expr parser errors Jan 6, 2026
Merged via the queue into Rust-GCC:master with commit 13d989d Jan 6, 2026
12 checks passed
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