CppAst.NET

CppAst provides a C/C++ parser for header files with access to the full AST, comments and macros for .NET Framework and .NET Core

Purpose

The target primary usage of this library is to serve as a simple foundation for domain oriented PInvoke/Interop codegen

Features

• Compatible with .NET Standard 2.0+
• Using Clang/libclang 15.0.2
• Allow to parse in-memory C/C++ text and C/C++ files from the disk
• Simple AST model
• Full type system
• Provides basic access to attributes (_declspec(...) or __attribute__((...)))
• Provides access to attached comments
• Provides access to expressions for variable and parameter init value (e.g const int x = (1 + 2) << 1 the (1 + 2) << 1 will be retrievable as a binary expression from the AST)
• Provides access to macro definitions, including tokens via the option CppParserOptions.ParseMacros (default is false)

Documentation

Check the user guide documentation from the doc/ folder.

Usage Example

Setup

After installing the NuGet package, you need to modify your csproj to select a Platform RID via the RuntimeIdentifier property:

  <PropertyGroup>
    <!-- Workaround for issue https://github.com/microsoft/ClangSharp/issues/129 -->
    <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == '' AND '$(PackAsTool)' != 'true'">$(NETCoreSdkRuntimeIdentifier)</RuntimeIdentifier>
  </PropertyGroup>

Code

You can jump-start with the CppParser.Parse method:

// Parse a C++ files
var compilation = CppParser.Parse(@"
enum MyEnum { MyEnum_0, MyEnum_1 };
void function0(int a, int b);
struct MyStruct { int field0; int field1;};
typedef MyStruct* MyStructPtr;
"
);
// Print diagnostic messages
foreach (var message in compilation.Diagnostics.Messages)
    Console.WriteLine(message);

// Print All enums
foreach (var cppEnum in compilation.Enums)
    Console.WriteLine(cppEnum);

// Print All functions
foreach (var cppFunction in compilation.Functions)
    Console.WriteLine(cppFunction);

// Print All classes, structs
foreach (var cppClass in compilation.Classes)
    Console.WriteLine(cppClass);

// Print All typedefs
foreach (var cppTypedef in compilation.Typedefs)
    Console.WriteLine(cppTypedef);

Prints the following result:

enum MyEnum {...}
void function0(int a, int b)
struct MyStruct { ... }
typedef MyStruct* MyStructPtr

Binaries

This library is distributed as a NuGet package

Known issues

The library libclang used by this project has some known issues and limitations:

• Attributes are not fully exposed (e.g in function parameters, on typedefs...)
• Generic instance types are not fully exposed (e.g used as parameters, or as base types...)

License

This software is released under the BSD-Clause 2 license.

Credits

• ClangSharp: .NET managed wrapper around Clang/libclang

Related

The C++ project cppast serves similar purpose although CppAst.NET does not share API or any implementation details.

Author

Alexandre Mutel aka xoofx.