Better way to expose julia meta-pass

In the previous iteration of this code, timing would be double counted.
This way, the individual passes are correctly registered with the
top level manager, so timing works properly. It's a bit hacky but
with the legacy pass manager, there's not much else to be done.

src/jitlayers.cpp

@@ -55,6 +55,8 @@ namespace llvm {
 #include <llvm/Bitcode/BitcodeWriterPass.h>
 #endif
 
+#include <llvm/IR/LegacyPassManagers.h>
+#include <llvm/IR/IRPrintingPasses.h>
 #include <llvm/Transforms/Utils/Cloning.h>
 #include <llvm/ExecutionEngine/JITEventListener.h>
 
@@ -109,7 +111,7 @@ void jl_init_jit(Type *T_pjlvalue_)
 
 // this defines the set of optimization passes defined for Julia at various optimization levels
 #if JL_LLVM_VERSION >= 30700
-void addOptimizationPasses(legacy::PassManager *PM, int opt_level)
+void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level)
 #else
 void addOptimizationPasses(PassManager *PM, int opt_level)
 #endif
@@ -1432,20 +1434,24 @@ GlobalVariable *jl_get_global_for(const char *cname, void *addr, Module *M)
 // An LLVM module pass that just runs all julia passes in order. Useful for
 // debugging
 extern "C" void jl_init_codegen(void);
-class JuliaPipeline : public ModulePass {
+class JuliaPipeline : public Pass {
 public:
     static char ID;
-    JuliaPipeline() : ModulePass(ID) {}
-    virtual bool runOnModule(Module &M) {
+    // A bit of a hack, but works
+    struct TPMAdapter : public PassManagerBase {
+        PMTopLevelManager *TPM;
+        TPMAdapter(PMTopLevelManager *TPM) : TPM(TPM) {}
+        void add(Pass *P) { TPM->schedulePass(P); }
+    };
+    void preparePassManager(PMStack &Stack) override {
         (void)jl_init_llvm();
-#if JL_LLVM_VERSION >= 30700
-        legacy::PassManager PM;
-#else
-        PassManager PM;
-#endif
-        addOptimizationPasses(&PM, 3);
-        PM.run(M);
-        return true;
+        PMTopLevelManager *TPM = Stack.top()->getTopLevelManager();
+        TPMAdapter Adapter(TPM);
+        addOptimizationPasses(&Adapter, 3);
+    }
+    JuliaPipeline() : Pass(PT_PassManager, ID) {}
+    Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const {
+        return createPrintModulePass(O, Banner);
     }
 };
 char JuliaPipeline::ID = 0;

src/jitlayers.h

@@ -61,7 +61,7 @@ extern size_t jltls_offset_idx;
 typedef struct {Value *gv; int32_t index;} jl_value_llvm; // uses 1-based indexing
 
 #if JL_LLVM_VERSION >= 30700
-void addOptimizationPasses(legacy::PassManager *PM, int opt_level);
+void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level);
 #else
 void addOptimizationPasses(PassManager *PM, int opt_level);
 #endif