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MacroCodeGenModule

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Julien SOYSOUVANH edited this page Nov 26, 2021 · 4 revisions

Introduction

The MacroCodeGenModule inherits from the CodeGenModule class. It only accepts MacroPropertyCodeGen, and provides a few more methods to override to generate code.

Create a MacroCodeGenModule

To create a new MacroCodeGenModule, you must inherit from MacroCodeGenModule instead of CodeGenModule:

#include <Kodgen/CodeGen/Macro/MacroCodeGenModule.h>

class ExampleCGM : public kodgen::MacroCodeGenModule
{
};

Override methods

clone

Same as CodeGenModule::clone

getGenerationOrder

Same as CodeGenModule::getGenerationOrder.

initialGenerateCode

The initialGenerateCode method is sealed in the MacroCodeGenModule implementation. Instead, 3 methods are called once to initially generate code in each location:

  • initialGenerateHeaderFileHeaderCode
  • initialGenerateHeaderFileFooterCode
  • initialGenerateSourceFileHeaderCode
bool initialGenerateHeaderFileHeaderCode(kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate code at the beginning of the generated header file header
    //...

    return true;
}

finalGenerateCode

The finalGenerateCode method is sealed in the MacroCodeGenModule implementation. Instead, 3 methods are called once to generate code in each location:

  • finalGenerateHeaderFileHeaderCode
  • finalGenerateHeaderFileFooterCode
  • finalGenerateSourceFileHeaderCode
bool finalGenerateHeaderFileHeaderCode(kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate code at the end of the generated header file header
    //...

    return true;
}

preGenerateCodeForEntity

Called once before generating code for each entity. Returns false to abort the code generation for the running CodeGenUnit.

bool preGenerateCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& data) noexcept override
{
    //Do some stuff
    return true; //return false if you want to abort the code generation for the running unit
}

postGenerateCodeForEntity

Called once after generating code for each entity. Returns false to abort the code generation for the running CodeGenUnit.

bool postGenerateCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& data) noexcept override
{
    //Do some stuff
    return true; //return false if you want to abort the code generation for the running unit
}

generateHeaderFileHeaderCodeForEntity

This method generates code for the given entity in the HeaderFileHeader location.
Check the CodeGenModule::generateCodeForEntity method documentation for more info on the returned value.

kodgen::ETraversalBehaviour generateHeaderFileHeaderCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate some code here by appending it to inout_result
    return kodgen::ETraversalBehaviour::Recurse;
}

generateClassFooterCodeForEntity

This method generates code for the given entity in the ClassFooter location.
Check the CodeGenModule::generateCodeForEntity method documentation for more info on the returned value.

kodgen::ETraversalBehaviour generateClassFooterCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate some code here by appending it to inout_result
    return kodgen::ETraversalBehaviour::Recurse;
}

generateHeaderFileFooterCodeForEntity

This method generates code for the given entity in the HeaderFileFooter location.
Check the CodeGenModule::generateCodeForEntity method documentation for more info on the returned value.

kodgen::ETraversalBehaviour generateHeaderFileFooterCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate some code here by appending it to inout_result
    return kodgen::ETraversalBehaviour::Recurse;
}

generateSourceFileHeaderCodeForEntity

This method generates code for the given entity in the SourceFileHeader location.
Check the CodeGenModule::generateCodeForEntity method documentation for more info on the returned value.

kodgen::ETraversalBehaviour generateSourceFileHeaderCodeForEntity(kodgen::EntityInfo const& entity, kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    //Generate some code here by appending it to inout_result
    return kodgen::ETraversalBehaviour::Recurse;
}

Tips

Tip 1

You can use the MacroCodeGenEnv::getSeparator() method to insert spaces and generate human-readable (and more easily debuggable) code. It basically returns a backspace or backspace + \ depending on the generation location (if the code is generated in a macro, backspace + \ is returned).

kodgen::ETraversalBehaviour generateClassFooterCode(kodgen::EntityInfo const* entity, kodgen::MacroCodeGenEnv& env, std::string& inout_result) noexcept override
{
    inout_result += "void someFunction(){}";
    inout_result += "void someFunction2(){}";

    return kodgen::ETraversalBehaviour::Recurse;
}

The above would generate something like:

#define GENERATED_MACRO \
  void someFunction(){}void someFunction2(){}

Now, if we decide to use separators:

kodgen::ETraversalBehaviour generateClassFooterCode(kodgen::EntityInfo const* entity, kodgen::MacroCodeGenEnv& env , std::string& inout_result) noexcept override
{
    inout_result += "void someFunction(){}" + env.getSeparator();
    inout_result += "void someFunction2(){}";

    return kodgen::ETraversalBehaviour::Recurse;
}
#define GENERATED_MACRO \
  void someFunction(){} \
  void someFunction2(){}

Tip 2

The default implementation for the 4 code generation methods return ETraversalBehaviour::Break, so one must override at least one of generateHeaderFileHeaderCode, generateClassFooterCode, generateHeaderFileFooterCode or generateSourceFileHeaderCode to give a specific traversal behaviour to the module. The less restrictive returned traversal behaviour will always have the priority over the others.

The priority order is: AbortWithFailure > AbortWithSuccess > Recurse > Continue > Break.

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