Rollup merge of rust-lang#101997 - cuviper:drop-legacy-pm, r=nikic

Remove support for legacy PM This removes support for optimizing with LLVM's legacy pass manager, as well as the unstable `-Znew-llvm-pass-manager` option. We have been defaulting to the new PM since LLVM 13 (except for s390x that waited for 14), and LLVM 15 removed support altogether. The only place we still use the legacy PM is for writing the output file, just like `llc` does. cc rust-lang#74705 r? ``@nikic``
fee1-dead-contrib · Sep 25, 2022 · 07467c5 · 07467c5
2 parents da884d2 + 00bb9fc
commit 07467c5
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Showing 15 changed files with 28 additions and 685 deletions.
diff --git a/Cargo.lock b/Cargo.lock
@@ -3263,7 +3263,6 @@ dependencies = [
  "bitflags",
  "cstr",
  "libc",
- "libloading",
  "measureme",
  "object 0.29.0",
  "rustc-demangle",

diff --git a/compiler/rustc_codegen_llvm/Cargo.toml b/compiler/rustc_codegen_llvm/Cargo.toml
@@ -11,7 +11,6 @@ doctest = false
 bitflags = "1.0"
 cstr = "0.2"
 libc = "0.2"
-libloading = "0.7.1"
 measureme = "10.0.0"
 object = { version = "0.29.0", default-features = false, features = ["std", "read_core", "archive", "coff", "elf", "macho", "pe"] }
 tracing = "0.1"

diff --git a/compiler/rustc_codegen_llvm/src/back/lto.rs b/compiler/rustc_codegen_llvm/src/back/lto.rs
@@ -1,8 +1,6 @@
-use crate::back::write::{
-    self, save_temp_bitcode, to_llvm_opt_settings, with_llvm_pmb, DiagnosticHandlers,
-};
-use crate::llvm::{self, build_string, False, True};
-use crate::{llvm_util, LlvmCodegenBackend, ModuleLlvm};
+use crate::back::write::{self, save_temp_bitcode, DiagnosticHandlers};
+use crate::llvm::{self, build_string};
+use crate::{LlvmCodegenBackend, ModuleLlvm};
 use object::read::archive::ArchiveFile;
 use rustc_codegen_ssa::back::lto::{LtoModuleCodegen, SerializedModule, ThinModule, ThinShared};
 use rustc_codegen_ssa::back::symbol_export;
@@ -597,61 +595,9 @@ pub(crate) fn run_pass_manager(
                 1,
             );
         }
-        if llvm_util::should_use_new_llvm_pass_manager(
-            &config.new_llvm_pass_manager,
-            &cgcx.target_arch,
-        ) {
-            let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO };
-            let opt_level = config.opt_level.unwrap_or(config::OptLevel::No);
-            write::optimize_with_new_llvm_pass_manager(
-                cgcx,
-                diag_handler,
-                module,
-                config,
-                opt_level,
-                opt_stage,
-            )?;
-            debug!("lto done");
-            return Ok(());
-        }
-
-        let pm = llvm::LLVMCreatePassManager();
-        llvm::LLVMAddAnalysisPasses(module.module_llvm.tm, pm);
-
-        if config.verify_llvm_ir {
-            let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        let opt_level = config
-            .opt_level
-            .map(|x| to_llvm_opt_settings(x).0)
-            .unwrap_or(llvm::CodeGenOptLevel::None);
-        with_llvm_pmb(module.module_llvm.llmod(), config, opt_level, false, &mut |b| {
-            if thin {
-                llvm::LLVMRustPassManagerBuilderPopulateThinLTOPassManager(b, pm);
-            } else {
-                llvm::LLVMRustPassManagerBuilderPopulateLTOPassManager(
-                    b, pm, /* Internalize = */ False, /* RunInliner = */ True,
-                );
-            }
-        });
-
-        // We always generate bitcode through ThinLTOBuffers,
-        // which do not support anonymous globals
-        if config.bitcode_needed() {
-            let pass = llvm::LLVMRustFindAndCreatePass("name-anon-globals\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        if config.verify_llvm_ir {
-            let pass = llvm::LLVMRustFindAndCreatePass("verify\0".as_ptr().cast());
-            llvm::LLVMRustAddPass(pm, pass.unwrap());
-        }
-
-        llvm::LLVMRunPassManager(pm, module.module_llvm.llmod());
-
-        llvm::LLVMDisposePassManager(pm);
+        let opt_stage = if thin { llvm::OptStage::ThinLTO } else { llvm::OptStage::FatLTO };
+        let opt_level = config.opt_level.unwrap_or(config::OptLevel::No);
+        write::llvm_optimize(cgcx, diag_handler, module, config, opt_level, opt_stage)?;
     }
     debug!("lto done");
     Ok(())