Read template parameters for function types

Read DW_TAG_template_type_parameter and apply to function types.

Closes llvm#5

Author: tromey

lldb/include/lldb/Symbol/RustASTContext.h

@@ -112,7 +112,8 @@ class RustASTContext : public TypeSystem {
 
   CompilerType CreateFunctionType(const lldb_private::ConstString &name,
                                   const CompilerType &return_type,
-                                  const std::vector<CompilerType> &&params);
+                                  const std::vector<CompilerType> &&params,
+				  const std::vector<CompilerType> &&template_params);
 
   CompilerType CreateStructType(const ConstString &name, uint32_t byte_size,
                                 bool has_discriminant);

lldb/packages/Python/lldbsuite/test/lang/rust/types/TestRustASTContext.py

@@ -179,3 +179,7 @@ def check_generics(self):
         self.assertEqual(1, t.num_template_args)
         self.assertEqual('T', t.template_args[0].name)
         self.assertEqual('i32', t.template_args[0].GetTypedefedType().name)
+        t = self.frame().EvaluateExpression("generic_function<i32>").GetType().GetPointeeType()
+        self.assertEqual(1, t.num_template_args)
+        self.assertEqual('T', t.template_args[0].name)
+        self.assertEqual('i32', t.template_args[0].GetTypedefedType().name)

lldb/packages/Python/lldbsuite/test/lang/rust/types/main.rs

@@ -34,6 +34,8 @@ pub enum OptimizedEnum {
 
 pub struct Generic<T>(T);
 
+fn generic_function<T>(arg: T) { }
+
 fn main() {
     let vbool: bool = true;
 
@@ -75,6 +77,7 @@ fn main() {
     let voptenum2 = OptimizedEnum::NonNull(Box::new(7));
 
     let vgeneric = Generic(23i32);
+    generic_function(vgeneric.0);
 
     do_nothing();               // breakpoint
 }

lldb/source/Plugins/ExpressionParser/Rust/RustParse.cpp

@@ -1284,7 +1284,8 @@ RustFunctionTypeExpression::Evaluate(ExecutionContext &exe_ctx, Status &error) {
     args.push_back(argtype);
   }
 
-  return context->CreateFunctionType(ConstString(""), ret, std::move(args));
+  std::vector<CompilerType> empty;
+  return context->CreateFunctionType(ConstString(""), ret, std::move(args), std::move(empty));
 }
 
 CompilerType

lldb/source/Plugins/SymbolFile/DWARF/DWARFASTParserRust.cpp

@@ -372,7 +372,9 @@ TypeSP DWARFASTParserRust::ParseFunctionType(const DWARFDIE &die) {
     return_type = m_ast.CreateVoidType();
   }
 
+  SymbolFileDWARF *dwarf = die.GetDWARF();
   std::vector<CompilerType> function_param_types;
+  std::vector<CompilerType> template_params;
   for (auto &&child_die : IterableDIEChildren(die)) {
     if (child_die.Tag() == DW_TAG_formal_parameter) {
       for (auto &&attr : IterableDIEAttrs(child_die)) {
@@ -384,13 +386,18 @@ TypeSP DWARFASTParserRust::ParseFunctionType(const DWARFDIE &die) {
 	  break;
 	}
       }
+    } else if (child_die.Tag() == DW_TAG_template_type_parameter) {
+      Type *param_type = dwarf->ResolveTypeUID(child_die, true);
+      if (param_type) {
+	template_params.push_back(param_type->GetForwardCompilerType());
+      }
     }
   }
 
   CompilerType compiler_type = m_ast.CreateFunctionType(type_name_const_str, return_type,
-							std::move(function_param_types));
+							std::move(function_param_types),
+							std::move(template_params));
 
-  SymbolFileDWARF *dwarf = die.GetDWARF();
   TypeSP type_sp(new Type(die.GetID(), dwarf, type_name_const_str, 0, NULL,
 			  LLDB_INVALID_UID, Type::eEncodingIsUID, &decl,
 			  compiler_type, Type::eResolveStateFull));

lldb/source/Symbol/RustASTContext.cpp

@@ -712,11 +712,13 @@ class RustFunction : public RustType {
 public:
   RustFunction (const ConstString &name, uint64_t byte_size,
                 const CompilerType &return_type,
-                const std::vector<CompilerType> &&arguments)
+                const std::vector<CompilerType> &&arguments,
+                const std::vector<CompilerType> &&template_arguments)
     : RustType(name),
       m_byte_size(byte_size),
       m_return_type(return_type),
-      m_arguments(std::move(arguments))
+      m_arguments(std::move(arguments)),
+      m_template_args(std::move(template_arguments))
   {
   }
   DISALLOW_COPY_AND_ASSIGN(RustFunction);
@@ -763,11 +765,20 @@ class RustFunction : public RustType {
     return result + ")";
   }
 
+  size_t GetNumTemplateArguments() const {
+    return m_template_args.size();
+  }
+
+  CompilerType GetTypeTemplateArgument(size_t idx) const {
+    return m_template_args[idx];
+  }
+
 private:
 
   uint64_t m_byte_size;
   CompilerType m_return_type;
   std::vector<CompilerType> m_arguments;
+  std::vector<CompilerType> m_template_args;
 };
 
 class RustTypedef : public RustType {
@@ -1921,8 +1932,10 @@ void RustASTContext::AddFieldToStruct(const CompilerType &struct_type,
 CompilerType
 RustASTContext::CreateFunctionType(const lldb_private::ConstString &name,
                                    const CompilerType &return_type,
-                                   const std::vector<CompilerType> &&params) {
-  RustType *type = new RustFunction(name, m_pointer_byte_size, return_type, std::move(params));
+                                   const std::vector<CompilerType> &&params,
+                                   const std::vector<CompilerType> &&template_params) {
+  RustType *type = new RustFunction(name, m_pointer_byte_size, return_type, std::move(params),
+				    std::move(template_params));
   return CacheType(type);
 }
 
@@ -2168,6 +2181,8 @@ CompilerType RustASTContext::GetTypeTemplateArgument(lldb::opaque_compiler_type_
     RustType *t = static_cast<RustType *>(type);
     if (RustAggregateBase *a = t->AsAggregate()) {
       return a->GetTypeTemplateArgument(idx);
+    } else if (RustFunction *f = t->AsFunction()) {
+      return f->GetTypeTemplateArgument(idx);
     }
   }
   return CompilerType();
@@ -2178,6 +2193,8 @@ size_t RustASTContext::GetNumTemplateArguments(lldb::opaque_compiler_type_t type
     RustType *t = static_cast<RustType *>(type);
     if (RustAggregateBase *a = t->AsAggregate()) {
       return a->GetNumTemplateArguments();
+    } else if (RustFunction *f = t->AsFunction()) {
+      return f->GetNumTemplateArguments();
     }
   }
   return 0;