From f6f5f31067cdee2d7003d8209361ac9e5b6975c5 Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Sun, 13 Jun 2021 12:42:52 +0200
Subject: Use vfork/exec instead of system for compiler invocation.

---
 task.cc | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 74 insertions(+), 10 deletions(-)

(limited to 'task.cc')

diff --git a/task.cc b/task.cc
index 29e18cb..030932e 100644
--- a/task.cc
+++ b/task.cc
@@ -2,6 +2,11 @@
 
 #include <iostream>
 #include <fstream>
+#include <unistd.h>
+#include <cstring>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <spawn.h>
 
 #include "libcppbuild.h"
 #include "settings.h"
@@ -143,6 +148,17 @@ bool Task::dirty()
 	return false;
 }
 
+int parent_waitpid(pid_t pid)
+{
+	int status;
+
+	if(waitpid(pid, &status, 0) != pid)
+	{
+		return 1;
+	}
+
+	return status;
+}
 int Task::run()
 {
 	if(!std::filesystem::exists(sourceFile))
@@ -151,24 +167,72 @@ int Task::run()
 		return 1;
 	}
 
-	std::string comp = "g++";
-	std::string flags = config.cxxflags;
+	std::string comp = "/usr/bin/g++";
+	auto flags = config.cxxflags;
 	if(std::string(sourceFile.extension()) == ".c")
 	{
-		comp = "gcc";
+		comp = "/usr/bin/gcc";
 		flags = config.cflags;
 	}
-	std::string cmd = comp +
-		" -MMD -c " + std::string(sourceFile) + " " +
-		flags + " " +
-		"-o " + std::string(targetFile);
+
+	char source[256];
+	strcpy(source, std::string(sourceFile).data());
+	char target[256];
+	strcpy(target, std::string(targetFile).data());
+	char pwd[256];
+	strcpy(pwd, std::string(std::filesystem::current_path()).data());
+	std::vector<const char*> argv;
+	//args.push_back("/bin/echo");
+	if(comp == "/usr/bin/gcc")
+	{
+		argv.push_back("/usr/bin/gcc");
+	}
+	else
+	{
+		argv.push_back("/usr/bin/g++");
+	}
+
+	argv.push_back("-MMD");
+	argv.push_back("-c");
+	argv.push_back(source);
+	argv.push_back("-o");
+	argv.push_back(target);
+
+	for(const auto& flag : flags)
+	{
+		argv.push_back(flag.data());
+	}
+
+	std::string cmd;
+	for(const auto& arg : argv)
+	{
+		if(arg == nullptr)
+		{
+			break;
+		}
+		if(!cmd.empty())
+		{
+			cmd += " ";
+		}
+		cmd += arg;
+	}
 	std::cout << cmd << "\n";
 
-	if(system(cmd.data()))
+#if 0
+	auto pid = vfork();
+	if(pid == 0)
 	{
-		return 1;
+		execv(comp.data(), (char**)argv.data());
 	}
-	return 0;
+#else
+	pid_t pid;
+	if(posix_spawn(&pid, comp.data(), nullptr, nullptr, (char**)argv.data(), nullptr))
+	{
+		return 1;//exit(1);
+	}
+#endif
+
+	return parent_waitpid(pid);
 }
 
 int Task::clean()
-- 
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