ADD: `dbg` C++ debugger program.

META: Ran format command with correct C++ extensions.

Signed-off-by: Amlal <amlal.elmahrouss@icloud.com>

3 files changed, 158 insertions, 1 deletions

diff --git a/tools/dbg.cc b/tools/dbg.cc
new file mode 100644
index 0000000..40769a6
--- /dev/null
+++ b/tools/dbg.cc
@@ -0,0 +1,154 @@
+/***
+	(C) 2025 Amlal El Mahrouss
+ */
+
+#include <iostream>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/user.h>
+#include <unistd.h>
+#include <unordered_map>
+#include <stdint.h>
+
+namespace Dbg
+{
+	/// \brief Debug Interface class in C++
+	/// \author Amlal El Mahrouss
+	class Interface final
+	{
+	public:
+		Interface()	 = default;
+		~Interface() = default;
+
+		Interface& operator=(const Interface&) = default;
+		Interface(const Interface&)			   = default;
+
+		void Attach(pid_t pid)
+		{
+			this->pid = pid;
+
+			if (ptrace(PTRACE_ATTACH, this->pid, nullptr, nullptr) == -1)
+			{
+				perror("DBG: Attach");
+				exit(1);
+			}
+
+			waitpid(pid, nullptr, 0);
+			std::cout << "[+] Attached to process: " << pid << std::endl;
+		}
+
+		void SetBreakpoint(void* addr)
+		{
+			long original_data = ptrace(PTRACE_PEEKTEXT, pid, addr, nullptr);
+			if (original_data == -1)
+			{
+				perror("DBG: Peek");
+				exit(1);
+			}
+
+			long data_with_int3 = (original_data & ~0xFF) | 0xCC; // Insert INT3 (0xCC)
+			if (ptrace(PTRACE_POKETEXT, pid, addr, data_with_int3) == -1)
+			{
+				perror("DBG: Poke");
+				exit(1);
+			}
+
+			std::cout << "[+] Breakpoint set at: " << addr << std::endl;
+			breakpoints[reinterpret_cast<uintptr_t>(addr)] = original_data; // Store original data
+		}
+
+		void ContinueExecution()
+		{
+			if (ptrace(PTRACE_CONT, pid, nullptr, nullptr) == -1)
+			{
+				perror("DBG: Cont");
+				exit(1);
+			}
+
+			int status;
+			waitpid(pid, &status, 0);
+
+			if (WIFSTOPPED(status) && WSTOPSIG(status) == SIGTRAP)
+			{
+				std::cout << "[!] Breakpoint hit!" << std::endl;
+			}
+		}
+
+		void Detach()
+		{
+			if (ptrace(PTRACE_DETACH, pid, nullptr, nullptr) == -1)
+			{
+				perror("DBG: Detach");
+				exit(1);
+			}
+
+			std::cout << "[-] Detached from process: " << pid << std::endl;
+		}
+
+		std::unordered_map<uintptr_t, long>& Breakpoints()
+		{
+			return breakpoints;
+		}
+
+	private:
+		pid_t								pid;
+		std::unordered_map<uintptr_t, long> breakpoints;
+	};
+} // namespace Dbg
+
+int main(int argc, char* argv[])
+{
+	if (!argv[1])
+	{
+		std::cout << "[?] Attach to process using it's PID.\n";
+		return EXIT_FAILURE;
+	}
+
+	pid_t pid = std::stoi(argv[1]);
+
+	Dbg::Interface debugger;
+	debugger.Attach(pid);
+
+	while (true)
+	{
+		std::string cmd;
+		std::getline(std::cin, cmd);
+
+		if (cmd == "c" ||
+			cmd == "cont")
+			debugger.ContinueExecution();
+
+		if (cmd == "d" ||
+			cmd == "detach")
+			debugger.Detach();
+
+		if (cmd == "attach")
+		{
+			std::cout << "[?] Enter a PID to attach on: ";
+
+			std::getline(std::cin, cmd);
+			pid = std::stoi(argv[1]);
+			debugger.Attach(pid);
+		}
+
+		if (cmd == "exit")
+		{
+			std::exit(0);
+		}
+
+		if (cmd == "b" ||
+			cmd == "break")
+		{
+			std::cout << "[?] Enter an address to break on: ";
+
+			std::getline(std::cin, cmd);
+			void* breakpoint_addr = reinterpret_cast<void*>(std::stoul(cmd.c_str(), nullptr, 16));
+
+			if (breakpoint_addr)
+				debugger.SetBreakpoint(breakpoint_addr);
+		}
+	}
+
+	return 0;
+}
diff --git a/tools/dbg.sh b/tools/dbg.sh
new file mode 100755
index 0000000..8624b93
--- /dev/null
+++ b/tools/dbg.sh
@@ -0,0 +1,2 @@
+#!/bin/sh
+g++ dbg.cc -o dbg
diff --git a/tools/necc.cc b/tools/necc.cc
index 9e59f48..56dd5cc 100644
--- a/tools/necc.cc
+++ b/tools/necc.cc
@@ -59,7 +59,8 @@ int main(int argc, char const* argv[])
 				arg += ".pp";
 
 				args_list_cxx.push_back(arg);
-			} else if (strstr(argv[index_arg], ".c"))
+			}
+			else if (strstr(argv[index_arg], ".c"))
 			{
 				std::printf("necc: error: C is not ready yet.\n");
 				return EXIT_FAILURE;