refactor: Move system from util to common library

Since the kernel library no longer depends on the system file, move it
to the common library instead in accordance to the diagram in
doc/design/libraries.md.

src/common/system.cpp

@@ -0,0 +1,107 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2022 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <common/system.h>
+
+#include <logging.h>
+#include <util/string.h>
+#include <util/time.h>
+
+#ifndef WIN32
+#include <sys/stat.h>
+#else
+#include <codecvt>
+#endif
+
+#ifdef HAVE_MALLOPT_ARENA_MAX
+#include <malloc.h>
+#endif
+
+#include <cstdlib>
+#include <locale>
+#include <stdexcept>
+#include <string>
+#include <thread>
+
+// Application startup time (used for uptime calculation)
+const int64_t nStartupTime = GetTime();
+
+#ifndef WIN32
+std::string ShellEscape(const std::string& arg)
+{
+    std::string escaped = arg;
+    ReplaceAll(escaped, "'", "'\"'\"'");
+    return "'" + escaped + "'";
+}
+#endif
+
+#if HAVE_SYSTEM
+void runCommand(const std::string& strCommand)
+{
+    if (strCommand.empty()) return;
+#ifndef WIN32
+    int nErr = ::system(strCommand.c_str());
+#else
+    int nErr = ::_wsystem(std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t>().from_bytes(strCommand).c_str());
+#endif
+    if (nErr)
+        LogPrintf("runCommand error: system(%s) returned %d\n", strCommand, nErr);
+}
+#endif
+
+void SetupEnvironment()
+{
+#ifdef HAVE_MALLOPT_ARENA_MAX
+    // glibc-specific: On 32-bit systems set the number of arenas to 1.
+    // By default, since glibc 2.10, the C library will create up to two heap
+    // arenas per core. This is known to cause excessive virtual address space
+    // usage in our usage. Work around it by setting the maximum number of
+    // arenas to 1.
+    if (sizeof(void*) == 4) {
+        mallopt(M_ARENA_MAX, 1);
+    }
+#endif
+    // On most POSIX systems (e.g. Linux, but not BSD) the environment's locale
+    // may be invalid, in which case the "C.UTF-8" locale is used as fallback.
+#if !defined(WIN32) && !defined(MAC_OSX) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
+    try {
+        std::locale(""); // Raises a runtime error if current locale is invalid
+    } catch (const std::runtime_error&) {
+        setenv("LC_ALL", "C.UTF-8", 1);
+    }
+#elif defined(WIN32)
+    // Set the default input/output charset is utf-8
+    SetConsoleCP(CP_UTF8);
+    SetConsoleOutputCP(CP_UTF8);
+#endif
+
+#ifndef WIN32
+    constexpr mode_t private_umask = 0077;
+    umask(private_umask);
+#endif
+}
+
+bool SetupNetworking()
+{
+#ifdef WIN32
+    // Initialize Windows Sockets
+    WSADATA wsadata;
+    int ret = WSAStartup(MAKEWORD(2,2), &wsadata);
+    if (ret != NO_ERROR || LOBYTE(wsadata.wVersion ) != 2 || HIBYTE(wsadata.wVersion) != 2)
+        return false;
+#endif
+    return true;
+}
+
+int GetNumCores()
+{
+    return std::thread::hardware_concurrency();
+}
+
+// Obtain the application startup time (used for uptime calculation)
+int64_t GetStartupTime()
+{
+    return nStartupTime;
+}