ansi-c: support qualified __auto_type#9053
Open
tautschnig wants to merge 1 commit into
Open
Conversation
tautschnig
requested review from
kroening,
peterschrammel and
remi-delmas-3000
as code owners
Collaborator
|
All tests for |
There was a problem hiding this comment.
Pull request overview
Note
Copilot was unable to run its full agentic suite in this review.
This PR updates the ANSI-C parser to accept GCC’s qualified __auto_type declarations (e.g., const __auto_type x = init;) by treating them as qualified typeof(initializer) types, and adds a regression test to prevent future breakage.
Changes:
- Extend
declaring_listto parsetype_qualifier_list TOK_GCC_AUTO_TYPE ... = initializerand build atypeof(initializer)type merged with qualifiers. - Add a regression test that exercises
const __auto_typeand expects successful verification without parsing errors.
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| src/ansi-c/parser.y | Adds a new grammar production + semantic action to support qualified __auto_type by rewriting to qualified typeof(initializer). |
| regression/ansi-c/auto_type_qualified/test.desc | Defines a regression test that must not emit parsing errors and must verify successfully. |
| regression/ansi-c/auto_type_qualified/main.c | Minimal C program using const __auto_type to validate parsing and type deduction. |
💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.
Comment on lines
+1125
to
+1128
| parser_stack($2).id(ID_typeof); | ||
| parser_stack($2).copy_to_operands(parser_stack($6)); | ||
| // Merge qualifiers into the typeof type. | ||
| $2 = merge($1, $2); |
Comment on lines
+1117
to
+1136
| | type_qualifier_list TOK_GCC_AUTO_TYPE declarator | ||
| post_declarator_attributes_opt '=' initializer | ||
| { | ||
| // Qualified __auto_type: 'const/volatile/... __auto_type | ||
| // var = initializer;' is equivalent to | ||
| // '<qualifiers> typeof(initializer) var = initializer;'. | ||
| // Build the typeof-of-initializer node, then wrap it with | ||
| // the qualifiers. | ||
| parser_stack($2).id(ID_typeof); | ||
| parser_stack($2).copy_to_operands(parser_stack($6)); | ||
| // Merge qualifiers into the typeof type. | ||
| $2 = merge($1, $2); | ||
|
|
||
| $3 = merge($4, $3); | ||
|
|
||
| init($$, ID_declaration); | ||
| parser_stack($$).type().swap(parser_stack($2)); | ||
| PARSER.add_declarator(parser_stack($$), parser_stack($3)); | ||
| to_ansi_c_declaration(parser_stack($$)).add_initializer(parser_stack($6)); | ||
| } |
tautschnig
force-pushed
the
extract/ansi-c-parser-compat
branch
from
00e1abf to
e0ecfdc
Compare
tautschnig
force-pushed
the
extract/ansi-c-parser-compat
branch
from
e0ecfdc to
715f9ab
Compare
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## develop #9053 +/- ##
========================================
Coverage 80.68% 80.68%
========================================
Files 1714 1714
Lines 189501 189510 +9
Branches 73 73
========================================
+ Hits 152902 152914 +12
+ Misses 36599 36596 -3 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
|
GCC allows __auto_type with type qualifiers, e.g.
const __auto_type x = init;
which is equivalent to
const typeof(init) x = init;
The parser only had a production for the unqualified '__auto_type var =
init;' form, so a qualified __auto_type -- as used by the Linux 6.12
kernel in arch/x86/include/asm/string_64.h -- failed with a syntax
error.
Add a declaring_list production for
type_qualifier_list TOK_GCC_AUTO_TYPE declarator
post_declarator_attributes_opt '=' initializer
whose semantic action builds the typeof-of-initializer node and merges
the qualifier list into it, mirroring GCC's documented semantics.
Co-authored-by: Kiro <kiro-agent@users.noreply.github.com>
tautschnig
force-pushed
the
extract/ansi-c-parser-compat
branch
from
715f9ab to
b657866
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
GCC allows __auto_type with type qualifiers, e.g.
const __auto_type x = init;
which is equivalent to
const typeof(init) x = init;
The parser only had a production for the unqualified '__auto_type var = init;' form, so a qualified __auto_type -- as used by the Linux 6.12 kernel in arch/x86/include/asm/string_64.h -- failed with a syntax error.
Add a declaring_list production for
type_qualifier_list TOK_GCC_AUTO_TYPE declarator
post_declarator_attributes_opt '=' initializer
whose semantic action builds the typeof-of-initializer node and merges the qualifier list into it, mirroring GCC's documented semantics.