Rollup merge of #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 #74705
r? ``@nikic``

1 files changed, 9 insertions, 250 deletions

diff --git a/compiler/rustc_codegen_llvm/src/back/write.rs b/compiler/rustc_codegen_llvm/src/back/write.rs
index a695df8409b..db526746fa7 100644
--- a/compiler/rustc_codegen_llvm/src/back/write.rs
+++ b/compiler/rustc_codegen_llvm/src/back/write.rs
@@ -21,7 +21,6 @@ use rustc_data_structures::profiling::SelfProfilerRef;
 use rustc_data_structures::small_c_str::SmallCStr;
 use rustc_errors::{FatalError, Handler, Level};
 use rustc_fs_util::{link_or_copy, path_to_c_string};
-use rustc_middle::bug;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{self, Lto, OutputType, Passes, SplitDwarfKind, SwitchWithOptPath};
 use rustc_session::Session;
@@ -417,7 +416,7 @@ fn get_instr_profile_output_path(config: &ModuleConfig) -> Option<CString> {
     }
 }
 
-pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
+pub(crate) unsafe fn llvm_optimize(
     cgcx: &CodegenContext<LlvmCodegenBackend>,
     diag_handler: &Handler,
     module: &ModuleCodegen<ModuleLlvm>,
@@ -465,7 +464,7 @@ pub(crate) unsafe fn optimize_with_new_llvm_pass_manager(
     // FIXME: NewPM doesn't provide a facility to pass custom InlineParams.
     // We would have to add upstream support for this first, before we can support
     // config.inline_threshold and our more aggressive default thresholds.
-    let result = llvm::LLVMRustOptimizeWithNewPassManager(
+    let result = llvm::LLVMRustOptimize(
         module.module_llvm.llmod(),
         &*module.module_llvm.tm,
         to_pass_builder_opt_level(opt_level),
@@ -509,18 +508,11 @@ pub(crate) unsafe fn optimize(
 
     let llmod = module.module_llvm.llmod();
     let llcx = &*module.module_llvm.llcx;
-    let tm = &*module.module_llvm.tm;
     let _handlers = DiagnosticHandlers::new(cgcx, diag_handler, llcx);
 
     let module_name = module.name.clone();
     let module_name = Some(&module_name[..]);
 
-    if let Some(false) = config.new_llvm_pass_manager && llvm_util::get_version() >= (15, 0, 0) {
-        diag_handler.warn(
-            "ignoring `-Z new-llvm-pass-manager=no`, which is no longer supported with LLVM 15",
-        );
-    }
-
     if config.emit_no_opt_bc {
         let out = cgcx.output_filenames.temp_path_ext("no-opt.bc", module_name);
         let out = path_to_c_string(&out);
@@ -528,184 +520,17 @@ pub(crate) unsafe fn optimize(
     }
 
     if let Some(opt_level) = config.opt_level {
-        if llvm_util::should_use_new_llvm_pass_manager(
-            &config.new_llvm_pass_manager,
-            &cgcx.target_arch,
-        ) {
-            let opt_stage = match cgcx.lto {
-                Lto::Fat => llvm::OptStage::PreLinkFatLTO,
-                Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO,
-                _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO,
-                _ => llvm::OptStage::PreLinkNoLTO,
-            };
-            return optimize_with_new_llvm_pass_manager(
-                cgcx,
-                diag_handler,
-                module,
-                config,
-                opt_level,
-                opt_stage,
-            );
-        }
-
-        if cgcx.prof.llvm_recording_enabled() {
-            diag_handler
-                .warn("`-Z self-profile-events = llvm` requires `-Z new-llvm-pass-manager`");
-        }
-
-        // Create the two optimizing pass managers. These mirror what clang
-        // does, and are by populated by LLVM's default PassManagerBuilder.
-        // Each manager has a different set of passes, but they also share
-        // some common passes.
-        let fpm = llvm::LLVMCreateFunctionPassManagerForModule(llmod);
-        let mpm = llvm::LLVMCreatePassManager();
-
-        {
-            let find_pass = |pass_name: &str| {
-                let pass_name = SmallCStr::new(pass_name);
-                llvm::LLVMRustFindAndCreatePass(pass_name.as_ptr())
-            };
-
-            if config.verify_llvm_ir {
-                // Verification should run as the very first pass.
-                llvm::LLVMRustAddPass(fpm, find_pass("verify").unwrap());
-            }
-
-            let mut extra_passes = Vec::new();
-            let mut have_name_anon_globals_pass = false;
-
-            for pass_name in &config.passes {
-                if pass_name == "lint" {
-                    // Linting should also be performed early, directly on the generated IR.
-                    llvm::LLVMRustAddPass(fpm, find_pass("lint").unwrap());
-                    continue;
-                }
-
-                if let Some(pass) = find_pass(pass_name) {
-                    extra_passes.push(pass);
-                } else {
-                    diag_handler.warn(&format!("unknown pass `{}`, ignoring", pass_name));
-                }
-
-                if pass_name == "name-anon-globals" {
-                    have_name_anon_globals_pass = true;
-                }
-            }
-
-            // Instrumentation must be inserted before optimization,
-            // otherwise LLVM may optimize some functions away which
-            // breaks llvm-cov.
-            //
-            // This mirrors what Clang does in lib/CodeGen/BackendUtil.cpp.
-            if config.instrument_gcov {
-                llvm::LLVMRustAddPass(mpm, find_pass("insert-gcov-profiling").unwrap());
-            }
-            if config.instrument_coverage {
-                llvm::LLVMRustAddPass(mpm, find_pass("instrprof").unwrap());
-            }
-            if config.debug_info_for_profiling {
-                llvm::LLVMRustAddPass(mpm, find_pass("add-discriminators").unwrap());
-            }
-
-            add_sanitizer_passes(config, &mut extra_passes);
-
-            // 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 = config.bitcode_needed();
-            if !config.no_prepopulate_passes {
-                llvm::LLVMAddAnalysisPasses(tm, fpm);
-                llvm::LLVMAddAnalysisPasses(tm, mpm);
-                let opt_level = to_llvm_opt_settings(opt_level).0;
-                let prepare_for_thin_lto = cgcx.lto == Lto::Thin
-                    || cgcx.lto == Lto::ThinLocal
-                    || (cgcx.lto != Lto::Fat && cgcx.opts.cg.linker_plugin_lto.enabled());
-                with_llvm_pmb(llmod, config, opt_level, prepare_for_thin_lto, &mut |b| {
-                    llvm::LLVMRustAddLastExtensionPasses(
-                        b,
-                        extra_passes.as_ptr(),
-                        extra_passes.len() as size_t,
-                    );
-                    llvm::LLVMRustPassManagerBuilderPopulateFunctionPassManager(b, fpm);
-                    llvm::LLVMRustPassManagerBuilderPopulateModulePassManager(b, mpm);
-                });
-
-                have_name_anon_globals_pass = have_name_anon_globals_pass || prepare_for_thin_lto;
-                if using_thin_buffers && !prepare_for_thin_lto {
-                    llvm::LLVMRustAddPass(mpm, find_pass("name-anon-globals").unwrap());
-                    have_name_anon_globals_pass = true;
-                }
-            } else {
-                // If we don't use the standard pipeline, directly populate the MPM
-                // with the extra passes.
-                for pass in extra_passes {
-                    llvm::LLVMRustAddPass(mpm, pass);
-                }
-            }
-
-            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 should never happen."
-                    );
-                }
-            }
-        }
-
-        diag_handler.abort_if_errors();
-
-        // Finally, run the actual optimization passes
-        {
-            let _timer = cgcx.prof.extra_verbose_generic_activity(
-                "LLVM_module_optimize_function_passes",
-                &*module.name,
-            );
-            llvm::LLVMRustRunFunctionPassManager(fpm, llmod);
-        }
-        {
-            let _timer = cgcx.prof.extra_verbose_generic_activity(
-                "LLVM_module_optimize_module_passes",
-                &*module.name,
-            );
-            llvm::LLVMRunPassManager(mpm, llmod);
-        }
-
-        // Deallocate managers that we're now done with
-        llvm::LLVMDisposePassManager(fpm);
-        llvm::LLVMDisposePassManager(mpm);
+        let opt_stage = match cgcx.lto {
+            Lto::Fat => llvm::OptStage::PreLinkFatLTO,
+            Lto::Thin | Lto::ThinLocal => llvm::OptStage::PreLinkThinLTO,
+            _ if cgcx.opts.cg.linker_plugin_lto.enabled() => llvm::OptStage::PreLinkThinLTO,
+            _ => llvm::OptStage::PreLinkNoLTO,
+        };
+        return llvm_optimize(cgcx, diag_handler, module, config, opt_level, opt_stage);
     }
     Ok(())
 }
 
-unsafe fn add_sanitizer_passes(config: &ModuleConfig, passes: &mut Vec<&'static mut llvm::Pass>) {
-    if config.sanitizer.contains(SanitizerSet::ADDRESS) {
-        let recover = config.sanitizer_recover.contains(SanitizerSet::ADDRESS);
-        passes.push(llvm::LLVMRustCreateAddressSanitizerFunctionPass(recover));
-        passes.push(llvm::LLVMRustCreateModuleAddressSanitizerPass(recover));
-    }
-    if config.sanitizer.contains(SanitizerSet::MEMORY) {
-        let track_origins = config.sanitizer_memory_track_origins as c_int;
-        let recover = config.sanitizer_recover.contains(SanitizerSet::MEMORY);
-        passes.push(llvm::LLVMRustCreateMemorySanitizerPass(track_origins, recover));
-    }
-    if config.sanitizer.contains(SanitizerSet::THREAD) {
-        passes.push(llvm::LLVMRustCreateThreadSanitizerPass());
-    }
-    if config.sanitizer.contains(SanitizerSet::HWADDRESS) {
-        let recover = config.sanitizer_recover.contains(SanitizerSet::HWADDRESS);
-        passes.push(llvm::LLVMRustCreateHWAddressSanitizerPass(recover));
-    }
-}
-
 pub(crate) fn link(
     cgcx: &CodegenContext<LlvmCodegenBackend>,
     diag_handler: &Handler,
@@ -1072,72 +897,6 @@ unsafe fn embed_bitcode(
     }
 }
 
-pub unsafe fn with_llvm_pmb(
-    llmod: &llvm::Module,
-    config: &ModuleConfig,
-    opt_level: llvm::CodeGenOptLevel,
-    prepare_for_thin_lto: bool,
-    f: &mut dyn FnMut(&llvm::PassManagerBuilder),
-) {
-    use std::ptr;
-
-    // Create the PassManagerBuilder for LLVM. We configure it with
-    // reasonable defaults and prepare it to actually populate the pass
-    // manager.
-    let builder = llvm::LLVMRustPassManagerBuilderCreate();
-    let opt_size = config.opt_size.map_or(llvm::CodeGenOptSizeNone, |x| to_llvm_opt_settings(x).1);
-    let inline_threshold = config.inline_threshold;
-    let pgo_gen_path = get_pgo_gen_path(config);
-    let pgo_use_path = get_pgo_use_path(config);
-    let pgo_sample_use_path = get_pgo_sample_use_path(config);
-
-    llvm::LLVMRustConfigurePassManagerBuilder(
-        builder,
-        opt_level,
-        config.merge_functions,
-        config.vectorize_slp,
-        config.vectorize_loop,
-        prepare_for_thin_lto,
-        pgo_gen_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
-        pgo_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
-        pgo_sample_use_path.as_ref().map_or(ptr::null(), |s| s.as_ptr()),
-        opt_size as c_int,
-    );
-
-    llvm::LLVMRustAddBuilderLibraryInfo(builder, llmod, config.no_builtins);
-
-    // Here we match what clang does (kinda). For O0 we only inline
-    // always-inline functions (but don't add lifetime intrinsics), at O1 we
-    // inline with lifetime intrinsics, and O2+ we add an inliner with a
-    // thresholds copied from clang.
-    match (opt_level, opt_size, inline_threshold) {
-        (.., Some(t)) => {
-            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, t);
-        }
-        (llvm::CodeGenOptLevel::Aggressive, ..) => {
-            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 275);
-        }
-        (_, llvm::CodeGenOptSizeDefault, _) => {
-            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 75);
-        }
-        (_, llvm::CodeGenOptSizeAggressive, _) => {
-            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 25);
-        }
-        (llvm::CodeGenOptLevel::None, ..) => {
-            llvm::LLVMRustAddAlwaysInlinePass(builder, config.emit_lifetime_markers);
-        }
-        (llvm::CodeGenOptLevel::Less, ..) => {
-            llvm::LLVMRustAddAlwaysInlinePass(builder, config.emit_lifetime_markers);
-        }
-        (llvm::CodeGenOptLevel::Default, ..) => {
-            llvm::LLVMRustPassManagerBuilderUseInlinerWithThreshold(builder, 225);
-        }
-    }
-
-    f(builder);
-    llvm::LLVMRustPassManagerBuilderDispose(builder);
-}
-
 // Create a `__imp_<symbol> = &symbol` global for every public static `symbol`.
 // This is required to satisfy `dllimport` references to static data in .rlibs
 // when using MSVC linker.  We do this only for data, as linker can fix up