xo-jit: refactor: Jit::mangle() -> std::string_view

include/xo/jit/Jit.hpp

@@ -133,8 +133,10 @@ namespace xo {
             /** intern @p symbol, binding it to address @p dest **/
             template <typename T>
             llvm::Error intern_symbol(const std::string & symbol, T * dest) {
+                auto mangled_sym = mangler_(symbol);
+
                 llvm::orc::SymbolMap symbol_map;
-                symbol_map[mangler_(symbol)]
+                symbol_map[mangled_sym]
                     = llvm::orc::ExecutorSymbolDef(llvm::orc::ExecutorAddr::fromPtr(dest),
                                                    llvm::JITSymbolFlags());
 
@@ -144,8 +146,10 @@ namespace xo {
             } /*intern_symbol*/
 
             /** report mangled symbol name **/
-            auto mangle(StringRef name) {
-                return this->mangler_(name.str());
+            std::string_view mangle(StringRef name) {
+                auto tmp = *(this->mangler_(name.str()));
+
+                return std::string_view(tmp.data(), tmp.size());
             }
 
             llvm::Expected<ExecutorSymbolDef> lookup(StringRef name) {

include/xo/jit/MachPipeline.hpp

@@ -108,8 +108,8 @@ namespace xo {
             /** dump text description of module contents to console **/
             void dump_current_module();
 
-            /** report mangle symbol **/
-            std::string mangle(const std::string & x) const;
+            /** report mangled symbol for @p x **/
+            std::string_view mangle(const std::string & x) const;
 
             /** lookup symbol in jit-associated output library **/
             llvm::Expected<llvm::orc::ExecutorAddr> lookup_symbol(const std::string & x);

src/jit/MachPipeline.cpp

@@ -308,9 +308,11 @@ namespace xo {
         llvm::Function *
         MachPipeline::codegen_primitive(ref::brw<PrimitiveInterface> expr)
         {
-            //constexpr bool c_debug_flag = true;
+            constexpr bool c_debug_flag = true;
             using xo::scope;
 
+            scope log(XO_DEBUG(c_debug_flag));
+
             /** note: documentation (such as it is) for llvm::Function here:
              *
              *  https://llvm.org/doxygenL/classllvm_1_1Function.html
@@ -359,8 +361,13 @@ namespace xo {
             if (expr->explicit_symbol_def()) {
                 static llvm::ExitOnError llvm_exit_on_err;
 
-                llvm_exit_on_err(this->jit_->intern_symbol(expr->name(),
-                                                           expr->function_address()));
+                auto name = expr->name();
+                auto fn_addr = expr->function_address();
+
+                log && log(xtag("sym", name),
+                           xtag("mangled_sym", this->jit_->mangle(name)));
+
+                llvm_exit_on_err(this->jit_->intern_symbol(name, fn_addr));
 
 #ifdef NOT_USING
                 if (!llvm_result) {
@@ -373,6 +380,8 @@ namespace xo {
                     return nullptr;
                 }
 #endif
+            } else {
+                log && log("not requiring absolute address", xtag("sym", expr->name()));
             }
 
 #ifdef OBSOLETE
@@ -987,17 +996,10 @@ namespace xo {
             this->recreate_llvm_ir_pipeline();
         } /*machgen_current_module*/
 
-        std::string
+        std::string_view
         MachPipeline::mangle(const std::string & sym) const
         {
-            auto p = this->jit_->mangle(sym);
-
-            if (p)
-                return (*p).str();
-
-            throw std::runtime_error(tostr("MachPipeline::mangle"
-                                           ": mangle(sym) returned empty pointer",
-                                           xtag("sym", sym)));
+            return this->jit_->mangle(sym);
         } /*mangle*/
 
         llvm::Expected<llvm::orc::ExecutorAddr>