Source/WebGPU/WGSL/CallGraph.cpp

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#include "config.h"
#include "CallGraph.h"

#include "AST.h"
#include "ASTVisitor.h"
#include "WGSLShaderModule.h"

namespace WGSL {

CallGraph::CallGraph(ShaderModule& shaderModule)
    : m_ast(shaderModule)
{
}

class CallGraphBuilder : public AST::Visitor {
public:
    CallGraphBuilder(ShaderModule& shaderModule)
        : m_callGraph(shaderModule)
    {
    }

    CallGraph build();

    // FIXME: we also need to visit function calls when we add support for them
    void visit(AST::Function&) override;

private:
    void initializeMappings();

    CallGraph m_callGraph;
    AST::Function* m_currentFunction;
};

CallGraph CallGraphBuilder::build()
{
    initializeMappings();
    return m_callGraph;
}

void CallGraphBuilder::initializeMappings()
{
    for (auto& functionDecl : m_callGraph.m_ast.functions()) {
        const auto& name = functionDecl.name();
        {
            auto result = m_callGraph.m_functionsByName.add(name, &functionDecl);
            ASSERT_UNUSED(result, result.isNewEntry);
        }

        {
            auto result = m_callGraph.m_callees.add(&functionDecl, Vector<CallGraph::Callee>());
            ASSERT_UNUSED(result, result.isNewEntry);
        }

        for (auto& attribute : functionDecl.attributes()) {
            if (is<AST::StageAttribute>(attribute)) {
                auto stage = downcast<AST::StageAttribute>(attribute).stage();
                m_callGraph.m_entrypoints.append({ functionDecl, stage });
                break;
            }
        }
    }
}

void CallGraphBuilder::visit(AST::Function& functionDecl)
{
    m_currentFunction = &functionDecl;
    checkErrorAndVisit(functionDecl.body());
    m_currentFunction = nullptr;
}

CallGraph buildCallGraph(ShaderModule& shaderModule)
{
    return CallGraphBuilder(shaderModule).build();
}

} // namespace WGSL