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Avoid a bunch of unnecessary unsafe blocks in cg_llvm

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This commit is contained in:
Oli Scherer
2025-07-09 09:12:42 +00:00
parent ad635e5d06
commit d3d51b4fdb
8 changed files with 52 additions and 63 deletions
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73
compiler/rustc_codegen_llvm/src/back/write.rs
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@@ -879,9 +879,7 @@ pub(crate) fn codegen(
.generic_activity_with_arg("LLVM_module_codegen_embed_bitcode", &*module.name);
let thin_bc =
module.thin_lto_buffer.as_deref().expect("cannot find embedded bitcode");
unsafe {
embed_bitcode(cgcx, llcx, llmod, &config.bc_cmdline, &thin_bc);
}
embed_bitcode(cgcx, llcx, llmod, &config.bc_cmdline, &thin_bc);
}
}
@@ -945,7 +943,7 @@ pub(crate) fn codegen(
// binaries. So we must clone the module to produce the asm output
// if we are also producing object code.
let llmod = if let EmitObj::ObjectCode(_) = config.emit_obj {
unsafe { llvm::LLVMCloneModule(llmod) }
llvm::LLVMCloneModule(llmod)
} else {
llmod
};
@@ -1073,7 +1071,7 @@ pub(crate) fn bitcode_section_name(cgcx: &CodegenContext<LlvmCodegenBackend>) ->
}
/// Embed the bitcode of an LLVM module for LTO in the LLVM module itself.
unsafe fn embed_bitcode(
fn embed_bitcode(
cgcx: &CodegenContext<LlvmCodegenBackend>,
llcx: &llvm::Context,
llmod: &llvm::Module,
@@ -1115,43 +1113,40 @@ unsafe fn embed_bitcode(
// Unfortunately, LLVM provides no way to set custom section flags. For ELF
// and COFF we emit the sections using module level inline assembly for that
// reason (see issue #90326 for historical background).
unsafe {
if cgcx.target_is_like_darwin
|| cgcx.target_is_like_aix
|| cgcx.target_arch == "wasm32"
|| cgcx.target_arch == "wasm64"
{
// We don't need custom section flags, create LLVM globals.
let llconst = common::bytes_in_context(llcx, bitcode);
let llglobal =
llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.module");
llvm::set_initializer(llglobal, llconst);
llvm::set_section(llglobal, bitcode_section_name(cgcx));
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
if cgcx.target_is_like_darwin
|| cgcx.target_is_like_aix
|| cgcx.target_arch == "wasm32"
|| cgcx.target_arch == "wasm64"
{
// We don't need custom section flags, create LLVM globals.
let llconst = common::bytes_in_context(llcx, bitcode);
let llglobal = llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.module");
llvm::set_initializer(llglobal, llconst);
let llconst = common::bytes_in_context(llcx, cmdline.as_bytes());
let llglobal =
llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.cmdline");
llvm::set_initializer(llglobal, llconst);
let section = if cgcx.target_is_like_darwin {
c"__LLVM,__cmdline"
} else if cgcx.target_is_like_aix {
c".info"
} else {
c".llvmcmd"
};
llvm::set_section(llglobal, section);
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
llvm::set_section(llglobal, bitcode_section_name(cgcx));
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
llvm::LLVMSetGlobalConstant(llglobal, llvm::True);
let llconst = common::bytes_in_context(llcx, cmdline.as_bytes());
let llglobal = llvm::add_global(llmod, common::val_ty(llconst), c"rustc.embedded.cmdline");
llvm::set_initializer(llglobal, llconst);
let section = if cgcx.target_is_like_darwin {
c"__LLVM,__cmdline"
} else if cgcx.target_is_like_aix {
c".info"
} else {
// We need custom section flags, so emit module-level inline assembly.
let section_flags = if cgcx.is_pe_coff { "n" } else { "e" };
let asm = create_section_with_flags_asm(".llvmbc", section_flags, bitcode);
llvm::append_module_inline_asm(llmod, &asm);
let asm = create_section_with_flags_asm(".llvmcmd", section_flags, cmdline.as_bytes());
llvm::append_module_inline_asm(llmod, &asm);
}
c".llvmcmd"
};
llvm::set_section(llglobal, section);
llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage);
} else {
// We need custom section flags, so emit module-level inline assembly.
let section_flags = if cgcx.is_pe_coff { "n" } else { "e" };
let asm = create_section_with_flags_asm(".llvmbc", section_flags, bitcode);
llvm::append_module_inline_asm(llmod, &asm);
let asm = create_section_with_flags_asm(".llvmcmd", section_flags, cmdline.as_bytes());
llvm::append_module_inline_asm(llmod, &asm);
}
}