[COMMITTED 24/77] gccrs: Add compatible version option
arthur.cohen@embecosm.com
arthur.cohen@embecosm.com
Fri Aug 7 12:39:15 GMT 2026
From: Owen Avery <powerboat9.gamer@gmail.com>
GCCRS targets version 1.49 of rust. However, rust for linux expects rust
1.78 or later (soon 1.85 or later) and we will want to bump our main
target version from 1.49 eventually. This patch adds an option for the
user to specify a rust version to target for compatibility, so that
we can account for backwards incompatible behavior between rust
versions.
This should allow libcore 1.49 to compile without explicitly enabling
post-1.49 features.
gcc/rust/ChangeLog:
* checks/errors/feature/rust-feature-collector.cc: Include
"rust-session-manager.h".
(FeatureCollector::collect): Automatically enable
EXTENDED_KEY_VALUE_ATTRIBUTES when targeting compatibility with
rust versions before 1.50.
* expand/rust-macro-expand.cc: Include "rust-session-manager.h".
(MacroExpander::expand_invoc): Use Session to determine whether
offset_of is supported.
* lang.opt (frust-assume-builtin-offset-of): Remove option,
superseded by...
(frust-compat-version): ...new option.
* resolve/rust-early-name-resolver-2.0.cc: Include
"rust-session-manager.h".
(Early::visit (MacroInvocation)): Use Session to determine
whether offset_of is supported.
* rust-session-manager.cc (Session::handle_option): Handle
frust-compat-version.
* rust-session-manager.h (CompileOptions::compat_version): New
member variable.
(CompileOptions::set_compat_version): New member function.
(CompileOptions::get_compat_version): Likewise.
(Session::get_compat_version): Likewise.
(Session::should_support_offset_of): Likewise.
gcc/testsuite/ChangeLog:
* rust/compile/early_feature_gate_in_macro.rs: Change test
options.
* rust/compile/offset_of1.rs: Likewise.
* rust/compile/offset_of2.rs: Likewise.
* rust/compile/parse_time_feature_gate.rs: Likewise.
* rust/execute/torture/offset_of1.rs: Likewise.
Signed-off-by: Owen Avery <powerboat9.gamer@gmail.com>
---
.../errors/feature/rust-feature-collector.cc | 6 ++++
gcc/rust/expand/rust-macro-expand.cc | 3 +-
gcc/rust/lang.opt | 6 ++--
.../resolve/rust-early-name-resolver-2.0.cc | 5 ++--
gcc/rust/rust-session-manager.cc | 3 ++
gcc/rust/rust-session-manager.h | 30 +++++++++++++++++++
.../compile/early_feature_gate_in_macro.rs | 1 +
gcc/testsuite/rust/compile/offset_of1.rs | 2 +-
gcc/testsuite/rust/compile/offset_of2.rs | 2 +-
.../rust/compile/parse_time_feature_gate.rs | 1 +
.../rust/execute/torture/offset_of1.rs | 2 +-
11 files changed, 52 insertions(+), 9 deletions(-)
diff --git a/gcc/rust/checks/errors/feature/rust-feature-collector.cc b/gcc/rust/checks/errors/feature/rust-feature-collector.cc
index 6a3a1479227..bd5a910d96c 100644
--- a/gcc/rust/checks/errors/feature/rust-feature-collector.cc
+++ b/gcc/rust/checks/errors/feature/rust-feature-collector.cc
@@ -18,6 +18,7 @@
#include "rust-feature-collector.h"
#include "rust-attribute-values.h"
+#include "rust-session-manager.h"
namespace Rust {
namespace Features {
@@ -32,6 +33,11 @@ FeatureCollector::collect (AST::Crate &crate)
features.valid_lib_features.clear ();
features.crate_id = crate.get_node_id ();
+ // TODO: this is a hack, remove when possible
+ if (Session::get_instance ().get_compat_version () < 50)
+ features.valid_lang_features.insert (
+ Feature::Name::EXTENDED_KEY_VALUE_ATTRIBUTES);
+
visit (crate);
return features;
diff --git a/gcc/rust/expand/rust-macro-expand.cc b/gcc/rust/expand/rust-macro-expand.cc
index c06290cdfda..2ab9d2541dc 100644
--- a/gcc/rust/expand/rust-macro-expand.cc
+++ b/gcc/rust/expand/rust-macro-expand.cc
@@ -29,6 +29,7 @@
#include "rust-cfg-strip.h"
#include "rust-proc-macro.h"
#include "rust-token-tree-desugar.h"
+#include "rust-session-manager.h"
namespace Rust {
@@ -311,7 +312,7 @@ MacroExpander::expand_invoc (AST::MacroInvocation &invoc,
// We special case the `offset_of!()` macro if the flag is here and manually
// resolve to the builtin transcriber we have specified
auto assume_builtin_offset_of
- = flag_assume_builtin_offset_of
+ = Session::get_instance ().should_support_offset_of ()
&& (invoc.get_invoc_data ().get_path ().as_string () == "offset_of")
&& !rules_def;
diff --git a/gcc/rust/lang.opt b/gcc/rust/lang.opt
index 1d38fec8635..f996ec0f0a5 100644
--- a/gcc/rust/lang.opt
+++ b/gcc/rust/lang.opt
@@ -229,9 +229,9 @@ frust-overflow-checks
Rust Var(flag_overflow_checks) Init(1)
Enable the overflow checks in code generation.
-frust-assume-builtin-offset-of
-Rust Var(flag_assume_builtin_offset_of)
-Define a built-in offset_of macro in the compiler and assume it is present.
+frust-compat-version=
+Rust Joined RejectNegative Var(flag_rust_compat_version)
+Select a version of rust to target for compatibility. Must be of form '1.x' or 'max'.
frust-unused-check-2.0
Rust Var(flag_unused_check_2_0)
diff --git a/gcc/rust/resolve/rust-early-name-resolver-2.0.cc b/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
index 0c5422d2c43..854102ff90b 100644
--- a/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
+++ b/gcc/rust/resolve/rust-early-name-resolver-2.0.cc
@@ -30,6 +30,7 @@
#include "rust-finalize-imports-2.0.h"
#include "rust-attribute-values.h"
#include "rust-identifier-path.h"
+#include "rust-session-manager.h"
namespace Rust {
namespace Resolver2_0 {
@@ -318,8 +319,8 @@ Early::visit (AST::MacroInvocation &invoc)
// We special case the `offset_of!()` macro if the flag is here, otherwise
// we accept whatever `offset_of!()` definition we resolved to.
- auto resolve_offset_of
- = flag_assume_builtin_offset_of && (path.as_string () == "offset_of");
+ auto resolve_offset_of = Session::get_instance ().should_support_offset_of ()
+ && (path.as_string () == "offset_of");
if (invoc.get_kind () == AST::MacroInvocation::InvocKind::Builtin)
for (auto &pending_invoc : invoc.get_pending_eager_invocations ())
diff --git a/gcc/rust/rust-session-manager.cc b/gcc/rust/rust-session-manager.cc
index 011ca8b99e8..6a56c956d9e 100644
--- a/gcc/rust/rust-session-manager.cc
+++ b/gcc/rust/rust-session-manager.cc
@@ -289,6 +289,9 @@ Session::handle_option (
case OPT_frust_edition_:
options.set_edition (flag_rust_edition);
break;
+ case OPT_frust_compat_version_:
+ options.set_compat_version (flag_rust_compat_version);
+ break;
case OPT_frust_compile_until_:
options.set_compile_step (flag_rust_compile_until);
break;
diff --git a/gcc/rust/rust-session-manager.h b/gcc/rust/rust-session-manager.h
index 930012a7bd7..af5a700b84b 100644
--- a/gcc/rust/rust-session-manager.h
+++ b/gcc/rust/rust-session-manager.h
@@ -242,6 +242,8 @@ struct CompileOptions
bool debug_assertions = false;
std::string metadata_output_path;
+ int compat_version = 49;
+
/** Structure containing additional attributes to be injected within the
* compiled crate from the command line instead of the source code.
*
@@ -344,6 +346,30 @@ struct CompileOptions
const Edition &get_edition () const { return edition; }
+ void set_compat_version (const char *version)
+ {
+ if (!strcmp (version, "max"))
+ {
+ compat_version = INT_MAX;
+ return;
+ }
+
+ long res;
+ char *end_ptr;
+ if (version[0] != '1' || version[1] != '.' || version[2] == '\0'
+ || (res = strtol (version + 2, &end_ptr, 10), *end_ptr) || res < 0
+ || res > INT_MAX)
+ {
+ rust_error_at (UNKNOWN_LOCATION,
+ "compat version must be of form 1.x or be \"max\"");
+ return;
+ }
+
+ compat_version = res;
+ }
+
+ int get_compat_version () const { return compat_version; }
+
void set_crate_type (int raw_type) { target_data.set_crate_type (raw_type); }
bool is_proc_macro () const
@@ -474,6 +500,10 @@ public:
tl::expected<LoadedCrate, LoadingError>
load_extern_crate (const std::string &crate_name, location_t locus);
+ int get_compat_version () const { return options.get_compat_version (); }
+
+ bool should_support_offset_of () const { return get_compat_version () >= 71; }
+
private:
Session () : mappings (Analysis::Mappings::get ()) {}
void compile_crate (const char *filename);
diff --git a/gcc/testsuite/rust/compile/early_feature_gate_in_macro.rs b/gcc/testsuite/rust/compile/early_feature_gate_in_macro.rs
index 9e2a51027aa..dd68b920e71 100644
--- a/gcc/testsuite/rust/compile/early_feature_gate_in_macro.rs
+++ b/gcc/testsuite/rust/compile/early_feature_gate_in_macro.rs
@@ -1,3 +1,4 @@
+// { dg-additional-options "-frust-compat-version=1.50" }
#![feature(rustc_attrs)]
#![feature(lang_items)]
#![feature(no_core)]
diff --git a/gcc/testsuite/rust/compile/offset_of1.rs b/gcc/testsuite/rust/compile/offset_of1.rs
index 2fca6d5eed2..ff1bd4a2150 100644
--- a/gcc/testsuite/rust/compile/offset_of1.rs
+++ b/gcc/testsuite/rust/compile/offset_of1.rs
@@ -1,4 +1,4 @@
-// { dg-additional-options "-frust-compile-until=lowering -frust-assume-builtin-offset-of" }
+// { dg-additional-options "-frust-compile-until=lowering -frust-compat-version=1.71" }
#![feature(no_core)]
#![no_core]
diff --git a/gcc/testsuite/rust/compile/offset_of2.rs b/gcc/testsuite/rust/compile/offset_of2.rs
index 2f2fa00a305..143aab1e0eb 100644
--- a/gcc/testsuite/rust/compile/offset_of2.rs
+++ b/gcc/testsuite/rust/compile/offset_of2.rs
@@ -1,4 +1,4 @@
-// { dg-additional-options "-frust-compile-until=compilation -frust-assume-builtin-offset-of" }
+// { dg-additional-options "-frust-compile-until=compilation -frust-compat-version=1.71" }
#![feature(no_core)]
#![no_core]
diff --git a/gcc/testsuite/rust/compile/parse_time_feature_gate.rs b/gcc/testsuite/rust/compile/parse_time_feature_gate.rs
index 907ac0c519b..1affcd81a5a 100644
--- a/gcc/testsuite/rust/compile/parse_time_feature_gate.rs
+++ b/gcc/testsuite/rust/compile/parse_time_feature_gate.rs
@@ -1,3 +1,4 @@
+// { dg-additional-options "-frust-compat-version=1.50" }
#![feature(no_core)]
#![no_core]
#![feature(rustc_attrs)]
diff --git a/gcc/testsuite/rust/execute/torture/offset_of1.rs b/gcc/testsuite/rust/execute/torture/offset_of1.rs
index d8ab9eba4d3..9d17b2bb2cf 100644
--- a/gcc/testsuite/rust/execute/torture/offset_of1.rs
+++ b/gcc/testsuite/rust/execute/torture/offset_of1.rs
@@ -1,5 +1,5 @@
// { dg-do run { target x86_64*-*-* } }
-// { dg-additional-options "-frust-assume-builtin-offset-of" }
+// { dg-additional-options "-frust-compat-version=1.71" }
#![feature(no_core)]
#![no_core]
--
2.50.1
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