Use of Natvis framework to observe value pointed by pointer-CodePudding

My goal is to observe a container of value which is pointed by a pointer. I am recommended to use natvis for this purpose. I am using VSCode to develop my project in Linux system. Unfortunately, I am not succeeded to get the desired value. I can only see the first address and value pointed by the pointer.

Sample code I am giving here.

foo.h

#include <iostream>

class FOO
{
    public:
        FOO(uint32_t a_, uint32_t b_) : a{a_}, b{b_}
                                        {}

        void Print_Value();
        uint32_t *pointer_array;

    protected:
        uint32_t a, b;

};

foo.cpp

#include "foo.h"

void FOO :: Print_Value()
{
    std::cout << "a: " << a << std::endl
              << "b: " << b << std::endl;
}

main.cpp

#include "foo.h"

int main()
{
    FOO obj_1(58,9);
    obj_1.Print_Value();

    uint32_t foo_array[5] = {5,15,96,8,77};
    obj_1.pointer_array = foo_array;


    return 0;
}

natvis file I have tried to create

<?xml version="1.0" encoding="utf-8"?>
<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
    <Type Name="FOO">
        <DisplayString>Test</DisplayString>
        <Expand>
            <Item Name="[pointer_array]">pointer_array</Item>
        </Expand>
    </Type>
</AutoVisualizer>

I have also tried the following but failed. Moreover, here I am not understanding how can I include the other items (a,b). Syntax is not clear to me.

<?xml version="1.0" encoding="utf-8"?>
<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
    <Type Name="FOO::pointer_array">
        <DisplayString>Test</DisplayString>
        <Expand>
            <CustomListItems>
                <Variable Name="pointer_array" InitialValue="0" />
                <Size>5</Size>
                <Loop Condition="pointer_array &lt; 5">
                  <Item Name="{pointer_array}"> 1 </Item>
                  <Exec>   pointer_array </Exec>
                </Loop>
              </CustomListItems>
        </Expand>
    </Type>
</AutoVisualizer>

Added line in the launch.json file

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "(gdb) Launch",
            "type": "cppdbg",
            "request": "launch",
            "program": "${workspaceFolder}/bin/foo_example",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}/bin/",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "visualizerFile": "${workspaceFolder}/natvis_file/file.natvis",
            "showDisplayString": true,
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                },
                {
                    "description":  "Set Disassembly Flavor to Intel",
                    "text": "-gdb-set disassembly-flavor intel",
                    "ignoreFailures": true
                }
            ]
        }
    ]
}

What I expect

In my debug window, I can see the value of the foo_array with the index.
I would also like to observe the value by using the class member pointer_array
I am recommended to use natvis to achieve this goal. I have tried by following 1 but failed.
My idea/ understanding regarding natvis is not so much clear. I guess I have to use CustomListItems to achieve the goal where suing Loop I can display the value pointed by the pointer but found this, this where it has told that using VSCode it is not possible. Though, I am not sure whether I am walking in right track or not.

My queries

If I want to display the value pointed by the pointer in the debug window, what/how I have to write my natvis file? If a working example is given would be really helpful to understand.
If it is not possible, is there any way to achieve it in VSCode?

CodePudding user response：

Finally, found the solution though came lots of other questions which will post in new post. I was wrongly interpreting the syntax.

file.natvis

<?xml version="1.0" encoding="utf-8"?>
<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
    <Type Name="FOO">
        <DisplayString>Test</DisplayString>
        <Expand>
        <Item Name="[a]">a</Item>
        <ArrayItems>
            <Size>5</Size>
            <ValuePointer>pointer_array</ValuePointer>
        </ArrayItems>
        </Expand>
    </Type>
</AutoVisualizer>

The pointer is pointed to the array. So, iteration through the array will reveal the pointed value by the pointer. For this, natvis has the ArrayItems element.