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Make sure we prepare for thin LTO whenever we are emitting bitcode

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Emitting LLVM bitcode uses ThinLTOBuffers, so we need to prepare for
thin LTO or we will likely cause errors in LLVM.
This commit is contained in:
Colin Pronovost 2018-05-30 16:46:56 -04:00
parent 02190f397e
commit 3da7c65e92
4 changed files with 34 additions and 3 deletions
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31
src/librustc_codegen_llvm/back/write.rs
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@ -541,11 +541,23 @@ unsafe fn optimize(cgcx: &CodegenContext,
};
if config.verify_llvm_ir { assert!(addpass("verify")); }
// Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
// to make sure we run LLVM's NameAnonGlobals pass when emitting bitcode; otherwise
// we'll get errors in LLVM.
let using_thin_buffers = llvm::LLVMRustThinLTOAvailable() && (config.emit_bc
|| config.obj_is_bitcode || config.emit_bc_compressed || config.embed_bitcode);
let mut have_name_anon_globals_pass = false;
if !config.no_prepopulate_passes {
llvm::LLVMRustAddAnalysisPasses(tm, fpm, llmod);
llvm::LLVMRustAddAnalysisPasses(tm, mpm, llmod);
let opt_level = config.opt_level.unwrap_or(llvm::CodeGenOptLevel::None);
let prepare_for_thin_lto = cgcx.lto == Lto::Thin || cgcx.lto == Lto::ThinLocal;
have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
if using_thin_buffers && !prepare_for_thin_lto {
assert!(addpass("name-anon-globals"));
have_name_anon_globals_pass = true;
}
with_llvm_pmb(llmod, &config, opt_level, prepare_for_thin_lto, &mut |b| {
llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(b, fpm);
llvm::LLVMPassManagerBuilderPopulateModulePassManager(b, mpm);
@ -557,6 +569,9 @@ unsafe fn optimize(cgcx: &CodegenContext,
diag_handler.warn(&format!("unknown pass `{}`, ignoring",
pass));
}
if pass == "name-anon-globals" {
have_name_anon_globals_pass = true;
}
}
for pass in &cgcx.plugin_passes {
@ -565,6 +580,22 @@ unsafe fn optimize(cgcx: &CodegenContext,
`{}` but LLVM does not \
recognize it", pass));
}
if pass == "name-anon-globals" {
have_name_anon_globals_pass = true;
}
}
if using_thin_buffers && !have_name_anon_globals_pass {
// As described above, this will probably cause an error in LLVM
if config.no_prepopulate_passes {
diag_handler.err("The current compilation is going to use thin LTO buffers \
without running LLVM's NameAnonGlobals pass. \
This will likely cause errors in LLVM. Consider adding \
-C passes=name-anon-globals to the compiler command line.");
} else {
bug!("We are using thin LTO buffers without running the NameAnonGlobals pass. \
This will likely cause errors in LLVM and shoud never happen.");
}
}
}