From 86451badf1113c6b6de99043e3abb87d7021d7e7 Mon Sep 17 00:00:00 2001 From: "Celina G. Val" Date: Fri, 15 Dec 2023 13:18:41 -0800 Subject: [PATCH] Add a method to check if type is a CStr --- compiler/rustc_smir/src/rustc_smir/context.rs | 6 +++++ compiler/stable_mir/src/compiler_interface.rs | 3 +++ compiler/stable_mir/src/ty.rs | 6 +++++ .../stable-mir/check_allocation.rs | 22 +++++++++++++++++++ 4 files changed, 37 insertions(+) diff --git a/compiler/rustc_smir/src/rustc_smir/context.rs b/compiler/rustc_smir/src/rustc_smir/context.rs index 70313cc021e..ae47f767f93 100644 --- a/compiler/rustc_smir/src/rustc_smir/context.rs +++ b/compiler/rustc_smir/src/rustc_smir/context.rs @@ -220,6 +220,12 @@ fn adt_is_simd(&self, def: AdtDef) -> bool { def.internal(&mut *tables).repr().simd() } + fn adt_is_cstr(&self, def: AdtDef) -> bool { + let mut tables = self.0.borrow_mut(); + let def_id = def.0.internal(&mut *tables); + tables.tcx.lang_items().c_str() == Some(def_id) + } + fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig { let mut tables = self.0.borrow_mut(); let def_id = def.0.internal(&mut *tables); diff --git a/compiler/stable_mir/src/compiler_interface.rs b/compiler/stable_mir/src/compiler_interface.rs index 2fac59e71fd..57c60b70d8a 100644 --- a/compiler/stable_mir/src/compiler_interface.rs +++ b/compiler/stable_mir/src/compiler_interface.rs @@ -72,6 +72,9 @@ pub trait Context { /// Returns whether this ADT is simd. fn adt_is_simd(&self, def: AdtDef) -> bool; + /// Returns whether this definition is a C string. + fn adt_is_cstr(&self, def: AdtDef) -> bool; + /// Retrieve the function signature for the given generic arguments. fn fn_sig(&self, def: FnDef, args: &GenericArgs) -> PolyFnSig; diff --git a/compiler/stable_mir/src/ty.rs b/compiler/stable_mir/src/ty.rs index 3d5e264104b..4807a9028eb 100644 --- a/compiler/stable_mir/src/ty.rs +++ b/compiler/stable_mir/src/ty.rs @@ -316,6 +316,12 @@ pub fn is_str(&self) -> bool { *self == TyKind::RigidTy(RigidTy::Str) } + #[inline] + pub fn is_cstr(&self) -> bool { + let TyKind::RigidTy(RigidTy::Adt(def, _)) = self else { return false }; + with(|cx| cx.adt_is_cstr(*def)) + } + #[inline] pub fn is_slice(&self) -> bool { matches!(self, TyKind::RigidTy(RigidTy::Slice(_))) diff --git a/tests/ui-fulldeps/stable-mir/check_allocation.rs b/tests/ui-fulldeps/stable-mir/check_allocation.rs index 88c41537d9f..8554630e9c9 100644 --- a/tests/ui-fulldeps/stable-mir/check_allocation.rs +++ b/tests/ui-fulldeps/stable-mir/check_allocation.rs @@ -33,6 +33,7 @@ use std::assert_matches::assert_matches; use std::cmp::{max, min}; use std::collections::HashMap; +use std::ffi::CStr; use std::io::Write; use std::ops::ControlFlow; @@ -45,6 +46,7 @@ fn test_stable_mir(_tcx: TyCtxt<'_>) -> ControlFlow<()> { check_foo(*get_item(&items, (ItemKind::Static, "FOO")).unwrap()); check_bar(*get_item(&items, (ItemKind::Static, "BAR")).unwrap()); check_len(*get_item(&items, (ItemKind::Static, "LEN")).unwrap()); + check_cstr(*get_item(&items, (ItemKind::Static, "C_STR")).unwrap()); check_other_consts(*get_item(&items, (ItemKind::Fn, "other_consts")).unwrap()); check_type_id(*get_item(&items, (ItemKind::Fn, "check_type_id")).unwrap()); ControlFlow::Continue(()) @@ -86,6 +88,24 @@ fn check_bar(item: CrateItem) { assert_eq!(std::str::from_utf8(&allocation.raw_bytes().unwrap()), Ok("Bar")); } +/// Check the allocation data for static `C_STR`. +/// +/// ```no_run +/// static C_STR: &core::ffi::cstr = c"cstr"; +/// ``` +fn check_cstr(item: CrateItem) { + let def = StaticDef::try_from(item).unwrap(); + let alloc = def.eval_initializer().unwrap(); + assert_eq!(alloc.provenance.ptrs.len(), 1); + let deref = item.ty().kind().builtin_deref(true).unwrap(); + assert!(deref.ty.kind().is_cstr(), "Expected CStr, but got: {:?}", item.ty()); + + let alloc_id_0 = alloc.provenance.ptrs[0].1.0; + let GlobalAlloc::Memory(allocation) = GlobalAlloc::from(alloc_id_0) else { unreachable!() }; + assert_eq!(allocation.bytes.len(), 5); + assert_eq!(CStr::from_bytes_until_nul(&allocation.raw_bytes().unwrap()), Ok(c"cstr")); +} + /// Check the allocation data for constants used in `other_consts` function. fn check_other_consts(item: CrateItem) { // Instance body will force constant evaluation. @@ -206,6 +226,7 @@ fn main() { generate_input(&path).unwrap(); let args = vec![ "rustc".to_string(), + "--edition=2021".to_string(), "--crate-name".to_string(), CRATE_NAME.to_string(), path.to_string(), @@ -224,6 +245,7 @@ fn generate_input(path: &str) -> std::io::Result<()> { static LEN: usize = 2; static FOO: [&str; 2] = ["hi", "there"]; static BAR: &str = "Bar"; + static C_STR: &std::ffi::CStr = c"cstr"; const NULL: *const u8 = std::ptr::null(); const TUPLE: (u32, u32) = (10, u32::MAX);