From 4eb967b5ebd5ca7a00049c7f958011e54b975040 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Tue, 14 Jul 2020 16:41:59 -0400
Subject: [PATCH] LibC+Kernel: Start implementing sysconf

For now, only the non-standard _SC_NPROCESSORS_CONF and
_SC_NPROCESSORS_ONLN are implemented.

Use them to make ninja pick a better default -j value.
While here, make the ninja package script not fail if
no other port has been built yet.
---
 Kernel/API/Syscall.h            |  3 ++-
 Kernel/Arch/i386/CPU.h          |  2 ++
 Kernel/Process.cpp              | 11 +++++++++++
 Kernel/Process.h                |  1 +
 Kernel/UnixTypes.h              |  5 +++++
 Libraries/LibC/unistd.cpp       |  6 ++++++
 Libraries/LibC/unistd.h         |  6 ++++++
 Ports/ninja/package.sh          |  1 +
 Ports/ninja/patches/nproc.patch | 13 -------------
 9 files changed, 34 insertions(+), 14 deletions(-)
 delete mode 100644 Ports/ninja/patches/nproc.patch

diff --git a/Kernel/API/Syscall.h b/Kernel/API/Syscall.h
index 8c11349c16..8412971bf6 100644
--- a/Kernel/API/Syscall.h
+++ b/Kernel/API/Syscall.h
@@ -191,7 +191,8 @@ namespace Kernel {
     __ENUMERATE_SYSCALL(ptrace)             \
     __ENUMERATE_SYSCALL(minherit)           \
     __ENUMERATE_SYSCALL(sendfd)             \
-    __ENUMERATE_SYSCALL(recvfd)
+    __ENUMERATE_SYSCALL(recvfd)             \
+    __ENUMERATE_SYSCALL(sysconf)
 
 namespace Syscall {
 
diff --git a/Kernel/Arch/i386/CPU.h b/Kernel/Arch/i386/CPU.h
index 95f8980a50..de90cd6dc9 100644
--- a/Kernel/Arch/i386/CPU.h
+++ b/Kernel/Arch/i386/CPU.h
@@ -744,6 +744,8 @@ public:
 
     static Processor& by_id(u32 cpu);
 
+    static size_t processor_count() { return processors().size(); }
+
     template<typename Callback>
     static inline IterationDecision for_each(Callback callback)
     {
diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 3bb727452e..a051e8145b 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -5308,4 +5308,15 @@ int Process::sys$recvfd(int sockfd)
     m_fds[new_fd].set(*received_descriptor_or_error.value(), 0);
     return new_fd;
 }
+
+long Process::sys$sysconf(int name)
+{
+    switch (name) {
+    case _SC_NPROCESSORS_CONF:
+    case _SC_NPROCESSORS_ONLN:
+        return Processor::processor_count();
+    default:
+        return -EINVAL;
+    }
+}
 }
diff --git a/Kernel/Process.h b/Kernel/Process.h
index 48d386c6aa..ebec0c73ea 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -327,6 +327,7 @@ public:
     int sys$ptrace(const Syscall::SC_ptrace_params*);
     int sys$sendfd(int sockfd, int fd);
     int sys$recvfd(int sockfd);
+    long sys$sysconf(int name);
 
     template<bool sockname, typename Params>
     int get_sock_or_peer_name(const Params&);
diff --git a/Kernel/UnixTypes.h b/Kernel/UnixTypes.h
index a07ebf4f57..9115c22daa 100644
--- a/Kernel/UnixTypes.h
+++ b/Kernel/UnixTypes.h
@@ -55,6 +55,11 @@
 #define MS_RDONLY (1 << 4)
 #define MS_REMOUNT (1 << 5)
 
+enum {
+    _SC_NPROCESSORS_CONF,
+    _SC_NPROCESSORS_ONLN,
+};
+
 #define PERF_EVENT_MALLOC 1
 #define PERF_EVENT_FREE 2
 
diff --git a/Libraries/LibC/unistd.cpp b/Libraries/LibC/unistd.cpp
index 80b05a16af..30929d47c1 100644
--- a/Libraries/LibC/unistd.cpp
+++ b/Libraries/LibC/unistd.cpp
@@ -722,4 +722,10 @@ char* getpass(const char* prompt)
     dbg() << "FIXME: getpass(\"" << prompt << "\")";
     ASSERT_NOT_REACHED();
 }
+
+long sysconf(int name)
+{
+    int rc = syscall(SC_sysconf, name);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
 }
diff --git a/Libraries/LibC/unistd.h b/Libraries/LibC/unistd.h
index 8a9687dc39..5836018975 100644
--- a/Libraries/LibC/unistd.h
+++ b/Libraries/LibC/unistd.h
@@ -172,4 +172,10 @@ enum {
 #define _POSIX_PRIORITY_SCHEDULING
 #define _POSIX_VDISABLE '\0'
 
+enum {
+    _SC_NPROCESSORS_CONF,
+    _SC_NPROCESSORS_ONLN,
+};
+long sysconf(int name);
+
 __END_DECLS
diff --git a/Ports/ninja/package.sh b/Ports/ninja/package.sh
index 6f56af4fde..977a95aa6e 100755
--- a/Ports/ninja/package.sh
+++ b/Ports/ninja/package.sh
@@ -13,5 +13,6 @@ build() {
 }
 
 install() {
+    mkdir -p "${SERENITY_ROOT}/Build/Root/usr/local/bin"
     cp "${workdir}/ninja" "${SERENITY_ROOT}/Build/Root/usr/local/bin/ninja"
 }
diff --git a/Ports/ninja/patches/nproc.patch b/Ports/ninja/patches/nproc.patch
deleted file mode 100644
index 0e383c0ef2..0000000000
--- a/Ports/ninja/patches/nproc.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-diff --git a/src/util.cc b/src/util.cc
-index ae94d34..72cf501 100644
---- a/src/util.cc
-+++ b/src/util.cc
-@@ -476,7 +476,7 @@ int GetProcessorCount() {
-   GetNativeSystemInfo(&info);
-   return info.dwNumberOfProcessors;
- #else
--  return sysconf(_SC_NPROCESSORS_ONLN);
-+  return 1;  // FIXME: serenity way of saying sysconf(_SC_NPROCESSORS_ONLN);
- #endif
- }
-