rustc_codegen_llvm/back/
owned_target_machine.rs

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1use std::ffi::{CStr, c_char};
2use std::marker::PhantomData;
3use std::ptr::NonNull;
4
5use rustc_data_structures::small_c_str::SmallCStr;
6
7use crate::errors::LlvmError;
8use crate::llvm;
9
10/// Responsible for safely creating and disposing llvm::TargetMachine via ffi functions.
11/// Not cloneable as there is no clone function for llvm::TargetMachine.
12#[repr(transparent)]
13pub struct OwnedTargetMachine {
14    tm_unique: NonNull<llvm::TargetMachine>,
15    phantom: PhantomData<llvm::TargetMachine>,
16}
17
18impl OwnedTargetMachine {
19    pub(crate) fn new(
20        triple: &CStr,
21        cpu: &CStr,
22        features: &CStr,
23        abi: &CStr,
24        model: llvm::CodeModel,
25        reloc: llvm::RelocModel,
26        level: llvm::CodeGenOptLevel,
27        float_abi: llvm::FloatAbi,
28        function_sections: bool,
29        data_sections: bool,
30        unique_section_names: bool,
31        trap_unreachable: bool,
32        singlethread: bool,
33        verbose_asm: bool,
34        emit_stack_size_section: bool,
35        relax_elf_relocations: bool,
36        use_init_array: bool,
37        split_dwarf_file: &CStr,
38        output_obj_file: &CStr,
39        debug_info_compression: &CStr,
40        use_emulated_tls: bool,
41        args_cstr_buff: &[u8],
42    ) -> Result<Self, LlvmError<'static>> {
43        assert!(args_cstr_buff.len() > 0);
44        assert!(
45            *args_cstr_buff.last().unwrap() == 0,
46            "The last character must be a null terminator."
47        );
48
49        // SAFETY: llvm::LLVMRustCreateTargetMachine copies pointed to data
50        let tm_ptr = unsafe {
51            llvm::LLVMRustCreateTargetMachine(
52                triple.as_ptr(),
53                cpu.as_ptr(),
54                features.as_ptr(),
55                abi.as_ptr(),
56                model,
57                reloc,
58                level,
59                float_abi,
60                function_sections,
61                data_sections,
62                unique_section_names,
63                trap_unreachable,
64                singlethread,
65                verbose_asm,
66                emit_stack_size_section,
67                relax_elf_relocations,
68                use_init_array,
69                split_dwarf_file.as_ptr(),
70                output_obj_file.as_ptr(),
71                debug_info_compression.as_ptr(),
72                use_emulated_tls,
73                args_cstr_buff.as_ptr() as *const c_char,
74                args_cstr_buff.len(),
75            )
76        };
77
78        NonNull::new(tm_ptr)
79            .map(|tm_unique| Self { tm_unique, phantom: PhantomData })
80            .ok_or_else(|| LlvmError::CreateTargetMachine { triple: SmallCStr::from(triple) })
81    }
82
83    /// Returns inner `llvm::TargetMachine` type.
84    ///
85    /// This could be a `Deref` implementation, but `llvm::TargetMachine` is an extern type and
86    /// `Deref::Target: ?Sized`.
87    pub fn raw(&self) -> &llvm::TargetMachine {
88        // SAFETY: constructing ensures we have a valid pointer created by
89        // llvm::LLVMRustCreateTargetMachine.
90        unsafe { self.tm_unique.as_ref() }
91    }
92}
93
94impl Drop for OwnedTargetMachine {
95    fn drop(&mut self) {
96        // SAFETY: constructing ensures we have a valid pointer created by
97        // llvm::LLVMRustCreateTargetMachine OwnedTargetMachine is not copyable so there is no
98        // double free or use after free.
99        unsafe {
100            llvm::LLVMRustDisposeTargetMachine(self.tm_unique.as_mut());
101        }
102    }
103}
rustc_codegen_llvm/back/owned_target_machine.rs

rustc_codegen_llvm/back/
owned_target_machine.rs
