Use new pass manager

This appears to produce miscompilation in the aya integration tests.

Cargo.toml

@@ -38,3 +38,6 @@ rust-llvm = [
     "llvm-sys/disable-alltargets-init"
 ]
 default = ["rust-llvm"]
+
+[patch.crates-io]
+aya-rustc-llvm-proxy = { git = "https://github.com/aya-rs/rustc-llvm-proxy.git" }

src/llvm/mod.rs

@@ -18,8 +18,7 @@ use llvm_sys::prelude::*;
 use llvm_sys::support::LLVMParseCommandLineOptions;
 use llvm_sys::target::*;
 use llvm_sys::target_machine::*;
-use llvm_sys::transforms::ipo::*;
-use llvm_sys::transforms::pass_manager_builder::*;
+use llvm_sys::transforms::pass_builder::*;
 use llvm_sys::LLVMAttributeFunctionIndex;
 use llvm_sys::{LLVMLinkage, LLVMVisibility};
 use log::*;
@@ -178,69 +177,48 @@ pub unsafe fn optimize(
         LLVMSetModuleInlineAsm2(module, ptr::null_mut(), 0);
     }
 
-    let mpm = LLVMCreatePassManager();
-    let fpm = LLVMCreateFunctionPassManagerForModule(module);
-
-    LLVMAddAnalysisPasses(tm, mpm);
-    LLVMAddAnalysisPasses(tm, fpm);
-
-    // even with -O0 and without LTO we still want to avoid linking in unused code from core etc
-    LLVMAddGlobalDCEPass(mpm);
-
-    let pmb = LLVMPassManagerBuilderCreate();
-
-    use OptLevel::*;
-    let (inline_threshold, opt) = match opt_level {
-        No | SizeMin => (0, 1), // Pretty much nothing compiles with -O0 s∫o make it an alias for -O1
-        Less => (25, 1),
-        Default => (225, 2),
-        Aggressive => (275, 3),
-        Size => (25, 0),
-    };
-    LLVMPassManagerBuilderSetOptLevel(pmb, opt);
-    LLVMPassManagerBuilderSetSizeLevel(
-        pmb,
-        match opt_level {
-            Size => 1,
-            SizeMin => 2,
-            _ => 0,
-        },
-    );
-    LLVMPassManagerBuilderUseInlinerWithThreshold(pmb, inline_threshold);
-
-    // populate the pass managers
-    LLVMPassManagerBuilderPopulateFunctionPassManager(pmb, fpm);
-    LLVMPassManagerBuilderPopulateModulePassManager(pmb, mpm);
-
     for sym in module.globals_iter() {
         internalize(sym, &symbol_name(sym), export_symbols);
     }
     for sym in module.global_aliases_iter() {
         internalize(sym, &symbol_name(sym), export_symbols);
     }
 
-    debug!("running function passes");
-    LLVMInitializeFunctionPassManager(fpm);
     for function in module.functions_iter() {
         let name = symbol_name(function);
         if !name.starts_with("llvm.") {
             if ignore_inline_never {
                 remove_attribute(function, "noinline");
             }
             internalize(function, &name, export_symbols);
-            if LLVMIsDeclaration(function) == 0 {
-                LLVMRunFunctionPassManager(fpm, function);
-            }
         }
     }
-    LLVMFinalizeFunctionPassManager(fpm);
-
-    debug!("running module passes");
-    LLVMRunPassManager(mpm, module);
 
     // Some debug info generated by rustc seems to trigger a segfault in the
     // BTF code in llvm, so strip it until that is fixed
     LLVMStripModuleDebugInfo(module);
+
+    let options = LLVMCreatePassBuilderOptions();
+
+    // even with -O0 and without LTO we still want to avoid linking in unused code from core etc
+    let dce = CString::new("dce").unwrap();
+    debug!("running dce passe");
+    LLVMRunPasses(module, dce.as_ptr(), tm, options);
+
+    let opt = CString::new(match opt_level {
+        // Pretty much nothing compiles with -O0 so make it an alias for -O1
+        OptLevel::No | OptLevel::Less => "default<O1>",
+        OptLevel::Default => "default<O2>",
+        OptLevel::Aggressive => "default<O3>",
+        OptLevel::Size => "default<Os>",
+        OptLevel::SizeMin => "default<Oz>",
+    })
+    .unwrap();
+
+    debug!("running optimization pass");
+    LLVMRunPasses(module, opt.as_ptr(), tm, options);
+
+    LLVMDisposePassBuilderOptions(options);
 }
 
 unsafe fn module_asm_is_probestack(module: LLVMModuleRef) -> bool {