Build: Include headers from LibC, LibM, and LibPthread with -isystem

Make sure that userspace is always referencing "system" headers in a way
that would build on target :). This means removing the explicit
include_directories of Libraries/LibC in favor of having it export its
headers as SYSTEM. Also remove a redundant include_directories of
Libraries in the 'serenity build' part of the build script. It's already
set at the top.

This causes issues for the Kernel, and for crt0.o. These special cases
are handled individually.

Applications/Debugger/main.cpp

@@ -30,7 +30,6 @@
 #include <AK/LogStream.h>
 #include <AK/StringBuilder.h>
 #include <AK/kmalloc.h>
-#include <LibC/sys/arch/i386/regs.h>
 #include <LibCore/File.h>
 #include <LibDebug/DebugInfo.h>
 #include <LibDebug/DebugSession.h>
@@ -41,6 +40,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/arch/i386/regs.h>
 #include <unistd.h>
 
 static Line::Editor editor {};

CMakeLists.txt

@@ -52,6 +52,7 @@ function(serenity_libc target_name fs_name)
     add_library(${target_name} ${SOURCES})
     install(TARGETS ${target_name} ARCHIVE DESTINATION usr/lib)
     set_target_properties(${target_name} PROPERTIES OUTPUT_NAME ${fs_name})
+    target_include_directories(${target_name} SYSTEM PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
     target_link_directories(LibC PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
 endfunction()
 
@@ -101,8 +102,9 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Os -Wno-sized-deallocation -fno-sized-d
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DDEBUG -DSANITIZE_PTRS")
 add_link_options(--sysroot ${CMAKE_BINARY_DIR}/Root)
 
-include_directories(Libraries/LibC)
+# Source directory relative service headers
 include_directories(Services)
+# Generated Service/Library Headers
 include_directories(${CMAKE_CURRENT_BINARY_DIR}/Services)
 include_directories(${CMAKE_CURRENT_BINARY_DIR}/Libraries)
 

Kernel/CMakeLists.txt

@@ -161,6 +161,9 @@ if (${CMAKE_HOST_SYSTEM_NAME} MATCHES SerenityOS)
 else()
     include_directories(../Toolchain/Local/i686-pc-serenity/include/c++/10.1.0/)
     include_directories(../Toolchain/Local/i686-pc-serenity/include/c++/10.1.0/i686-pc-serenity/)
+    # FIXME: Many files include <LibC/sys/ioctl_numbers.h> and <LibC/errno_numbers.h>
+    #     With -nostdinc, this makes it interesting to include these headers properly
+    include_directories(../Libraries/LibC)
 endif()
 
 add_executable(Kernel ${SOURCES})

Libraries/LibC/CMakeLists.txt

@@ -52,6 +52,8 @@ file(GLOB ELF_SOURCES "../LibELF/*.cpp")
 set(ELF_SOURCES ${ELF_SOURCES} ../LibELF/Arch/i386/plt_trampoline.S)
 
 add_library(crt0 STATIC crt0.cpp)
+# We need include headers from LibC in crt0. namely, <assert.h>
+target_include_directories(crt0 PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 add_custom_command(
     TARGET crt0
     COMMAND install -D $<TARGET_OBJECTS:crt0> ${CMAKE_INSTALL_PREFIX}/usr/lib/crt0.o

Libraries/LibDebug/DebugSession.h

@@ -33,11 +33,11 @@
 #include <AK/Optional.h>
 #include <AK/OwnPtr.h>
 #include <AK/String.h>
-#include <LibC/sys/arch/i386/regs.h>
 #include <LibDebug/DebugInfo.h>
 #include <LibELF/Loader.h>
 #include <signal.h>
 #include <stdio.h>
+#include <sys/arch/i386/regs.h>
 #include <sys/ptrace.h>
 #include <sys/wait.h>
 #include <unistd.h>

Libraries/LibM/CMakeLists.txt

@@ -3,5 +3,4 @@ set(SOURCES
 )
 
 serenity_libc(LibM m)
-target_include_directories(LibM PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(LibM LibC)

Libraries/LibM/math.cpp

@@ -24,8 +24,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <LibC/assert.h>
-#include <LibM/math.h>
+#include <assert.h>
+#include <math.h>
 #include <stdint.h>
 #include <stdlib.h>
 

Libraries/LibPthread/CMakeLists.txt

@@ -4,4 +4,3 @@ set(SOURCES
 
 serenity_libc(LibPthread pthread)
 target_link_libraries(LibPthread LibC)
-target_include_directories(LibPthread PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

Userland/functrace.cpp

@@ -33,7 +33,6 @@
 #include <AK/StringBuilder.h>
 #include <AK/kmalloc.h>
 #include <Kernel/Syscall.h>
-#include <LibC/sys/arch/i386/regs.h>
 #include <LibCore/File.h>
 #include <LibDebug/DebugSession.h>
 #include <LibELF/Image.h>
@@ -44,6 +43,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/arch/i386/regs.h>
 #include <unistd.h>
 
 static int usage()

Userland/strace.cpp

@@ -28,11 +28,11 @@
 #include <AK/LogStream.h>
 #include <AK/Types.h>
 #include <Kernel/Syscall.h>
-#include <LibC/sys/arch/i386/regs.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/arch/i386/regs.h>
 #include <sys/ptrace.h>
 #include <sys/wait.h>
 #include <unistd.h>

Userland/test-crypto.cpp

@@ -24,7 +24,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <LibC/limits.h>
 #include <LibCore/ArgsParser.h>
 #include <LibCore/EventLoop.h>
 #include <LibCore/File.h>
@@ -37,6 +36,7 @@
 #include <LibCrypto/PK/RSA.h>
 #include <LibLine/Editor.h>
 #include <LibTLS/TLSv12.h>
+#include <limits.h>
 #include <stdio.h>
 #include <time.h>