A source to source transformation tool for C language using clang LibTooling, LibASTMatchers and RecursiveASTVisitor, 
creates a new source file which support nested functions (as labeled blocks).

LLVM Version
============
I developed the code for LLVM 11.0.0

HOW TO COMPILE AND RUN
======================
* Add the folder "clang-nested-func" to llvm-project/clang/tools.
* Add the line "add_clang_subdirectory(clang-nested-func)" to llvm-project/clang/tools/CMakeLists.txt
* cd build 
* cmake -DLLVM_ENABLE_PROJECTS=clang -G "Unix Makefiles" ../llvm
* make
* A new executable "clang-nested-func" will be created in llvm-project/build/bin
* Invoke the tool using llvm-project/build/bin/clang-nested-func testfile --
* The tool prints the rewritten code to stdout.

HOW TO RUN TEST PROGRAMS
========================
* test_programs folder contain runAll.sh script.
* This script invokes clang-nested-func tool on test programs stored in test_files folder and stores the transformed 
    source code in output_files folder.

FILES IN DIRECTORY clang-nested-func
====================================
* clang-nested-func.cpp : This file contain the code for source to source transformation of a C program to support
nested functions (as labeled blocks).
* CMakeLists.txt : CMake file to build clang-nested-func.cpp

Answers to asked questions
==========================
0. test0.c contain the code sent along with assignment. test0_output.c contain the transformed code.
1. Does your implementation handle recursively nested function blocks?
    Yes, test1.c demonstrate it.
2. Does your implementation handle structs that are locally defined (i.e. defined inside the function)?
    Yes, test2.c demonstrate it.
3. If I have a local captured variable (i.e. the var is defined inside the function and used inside the closure) 
and a global var with same name, will your code still work?
    Yes, global and local var are handled accordingly. test3.c demonstrate it.
4. Do you pass all the variables to every closure or only the captured vars?
    My solution defines global structure for every function/labeled block containing pointer to local variables
    in that function/labeled block. 
5. Can you handle multiple closures in same/different functions (not necessarily nested)?
    Yes, test4.c demonstrate it.
6. Do you explicitly pass global vars to the closure as well? Note that you don't need that.
    No
7. In addition, if your implementation has any extra features, please  mention these and add tests for them.
    My solution supports 1D arrays other than int, float and struct. test5.c demonstrate it.