rustc_codegen_llvm/back/
owned_target_machine.rs

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1use std::ffi::{CStr, c_char};
2use std::marker::PhantomData;
3use std::ops::Deref;
4use std::ptr::NonNull;
5
6use rustc_data_structures::small_c_str::SmallCStr;
7
8use crate::errors::LlvmError;
9use crate::llvm;
10
11/// Responsible for safely creating and disposing llvm::TargetMachine via ffi functions.
12/// Not cloneable as there is no clone function for llvm::TargetMachine.
13#[repr(transparent)]
14pub struct OwnedTargetMachine {
15    tm_unique: NonNull<llvm::TargetMachine>,
16    phantom: PhantomData<llvm::TargetMachine>,
17}
18
19impl OwnedTargetMachine {
20    pub(crate) fn new(
21        triple: &CStr,
22        cpu: &CStr,
23        features: &CStr,
24        abi: &CStr,
25        model: llvm::CodeModel,
26        reloc: llvm::RelocModel,
27        level: llvm::CodeGenOptLevel,
28        float_abi: llvm::FloatAbi,
29        function_sections: bool,
30        data_sections: bool,
31        unique_section_names: bool,
32        trap_unreachable: bool,
33        singlethread: bool,
34        verbose_asm: bool,
35        emit_stack_size_section: bool,
36        relax_elf_relocations: bool,
37        use_init_array: bool,
38        split_dwarf_file: &CStr,
39        output_obj_file: &CStr,
40        debug_info_compression: &CStr,
41        use_emulated_tls: bool,
42        args_cstr_buff: &[u8],
43    ) -> Result<Self, LlvmError<'static>> {
44        assert!(args_cstr_buff.len() > 0);
45        assert!(
46            *args_cstr_buff.last().unwrap() == 0,
47            "The last character must be a null terminator."
48        );
49
50        // SAFETY: llvm::LLVMRustCreateTargetMachine copies pointed to data
51        let tm_ptr = unsafe {
52            llvm::LLVMRustCreateTargetMachine(
53                triple.as_ptr(),
54                cpu.as_ptr(),
55                features.as_ptr(),
56                abi.as_ptr(),
57                model,
58                reloc,
59                level,
60                float_abi,
61                function_sections,
62                data_sections,
63                unique_section_names,
64                trap_unreachable,
65                singlethread,
66                verbose_asm,
67                emit_stack_size_section,
68                relax_elf_relocations,
69                use_init_array,
70                split_dwarf_file.as_ptr(),
71                output_obj_file.as_ptr(),
72                debug_info_compression.as_ptr(),
73                use_emulated_tls,
74                args_cstr_buff.as_ptr() as *const c_char,
75                args_cstr_buff.len(),
76            )
77        };
78
79        NonNull::new(tm_ptr)
80            .map(|tm_unique| Self { tm_unique, phantom: PhantomData })
81            .ok_or_else(|| LlvmError::CreateTargetMachine { triple: SmallCStr::from(triple) })
82    }
83}
84
85impl Deref for OwnedTargetMachine {
86    type Target = llvm::TargetMachine;
87
88    fn deref(&self) -> &Self::Target {
89        // SAFETY: constructing ensures we have a valid pointer created by
90        // llvm::LLVMRustCreateTargetMachine.
91        unsafe { self.tm_unique.as_ref() }
92    }
93}
94
95impl Drop for OwnedTargetMachine {
96    fn drop(&mut self) {
97        // SAFETY: constructing ensures we have a valid pointer created by
98        // llvm::LLVMRustCreateTargetMachine OwnedTargetMachine is not copyable so there is no
99        // double free or use after free.
100        unsafe {
101            llvm::LLVMRustDisposeTargetMachine(self.tm_unique.as_mut());
102        }
103    }
104}
rustc_codegen_llvm/back/owned_target_machine.rs

rustc_codegen_llvm/back/
owned_target_machine.rs
