Fix raidfile tests on 32-bit Linux

A recent fix for Solaris (commit 81e9aa6545f7f19124c9f5e88982b867d8732965)
broke support for 32-bit Linux (which wasn't spotted because we didn't have any
32-bit builders). Try a different approach: detect whether the lseek syscall
takes a 64-bit integer offset, and use that if possible.

CMake: reimplement autoconf tests for 64-bit lseek

(cherry picked from commit 138ea5d174f146f14d91a16bf5d1ce8e479d2024)

1 files changed, 96 insertions, 0 deletions

diff --git a/infrastructure/cmake/CMakeLists.txt b/infrastructure/cmake/CMakeLists.txt
index 65f59eb8..a00e10d7 100644
--- a/infrastructure/cmake/CMakeLists.txt
+++ b/infrastructure/cmake/CMakeLists.txt
@@ -363,6 +363,7 @@ target_compile_definitions(lib_common PUBLIC $<$<CONFIG:Release>:BOX_RELEASE_BUI
 
 include(CheckCXXCompilerFlag)
 include(CheckCXXSourceCompiles)
+include(CheckCXXSourceRuns)
 include(CheckFunctionExists)
 include(CheckIncludeFiles)
 include(CheckLibraryExists)
@@ -610,6 +611,7 @@ CHECK_CXX_SOURCE_COMPILES([=[
 	}
 	]=] "HAVE_STRUCT_STATFS_F_MNTONNAME")
 file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_STRUCT_STATFS_F_MNTONNAME\n")
+
 CHECK_CXX_SOURCE_COMPILES([=[
 	#include "BoxConfig.cmake.h"
 	#ifdef HAVE_SYS_PARAM_H
@@ -623,6 +625,7 @@ CHECK_CXX_SOURCE_COMPILES([=[
 	}
 	]=] "HAVE_STRUCT_STATVFS_F_MNTONNAME")
 file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_STRUCT_STATVFS_F_MNTONNAME\n")
+
 if(HAVE_STRUCT_STATFS_F_MNTONNAME OR
 	HAVE_STRUCT_STATVFS_F_MNTONNAME OR
 	HAVE_STRUCT_MNTENT_MNT_DIR OR
@@ -649,6 +652,34 @@ file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_RANDOM_DEVICE\n")
 # Build an intermediate version of BoxConfig.cmake.h for use in the following tests:
 configure_file("${boxconfig_h_file}" "${boxconfig_cmake_h_dir}/BoxConfig.cmake.h")
 
+# Emulate ax_func_syscall.m4: Autoconf's AC_CHECK_FUNC (which we emulate above,
+# using check_function_exists) defines the function when testing for its
+# presence, so HAVE___SYSCALL will be true even if __syscall has no definition
+# in the system libraries, and this is precisely the case that we want to test
+# for, so now we test whether a test program compiles with no explicit
+# definition (only the system headers) and if that fails, we set
+# HAVE___SYSCALL_NEED_DEFN to 1.
+
+CHECK_CXX_SOURCE_COMPILES(
+	[=[
+		#include "BoxConfig.cmake.h"
+
+		#ifdef HAVE_SYS_SYSCALL_H
+		#	include <sys/syscall.h>
+		#endif
+
+		int main()
+		{
+			__syscall(SYS_exit, 0);
+			return 0;
+		}
+	]=] HAVE___SYSCALL_NO_DEFN)
+set(HAVE___SYSCALL_NEED_DEFN !HAVE___SYSCALL_NO_DEFN)
+file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE___SYSCALL_NEED_DEFN\n")
+
+# Build an intermediate version of BoxConfig.cmake.h for use in the following tests:
+configure_file("${boxconfig_h_file}" "${boxconfig_cmake_h_dir}/BoxConfig.cmake.h")
+
 foreach(struct_member_name "struct ucred.uid" "struct ucred.cr_uid")
 	string(REGEX MATCH "(.*)\\.(.*)" dummy_var ${struct_member_name})
 	set(struct_name "${CMAKE_MATCH_1}")
@@ -684,6 +715,71 @@ foreach(struct_member_name "struct ucred.uid" "struct ucred.cr_uid")
 		]=] "HAVE_${platform_var_name}")
 	file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_${platform_var_name}\n")
 endforeach()
+
+function(AX_TRY_RUN_FD code var)
+	CHECK_CXX_SOURCE_RUNS([=[
+		#include "BoxConfig.cmake.h"
+		#include <fcntl.h>
+		#include <unistd.h>
+		#include <sys/syscall.h>
+		#include <sys/types.h>
+
+		#ifdef HAVE___SYSCALL_NEED_DEFN
+		extern "C" off_t __syscall(quad_t number, ...);
+		#endif
+
+		#ifdef HAVE___SYSCALL // always use it if we have it
+		#	undef syscall
+		#	define syscall __syscall
+		#endif
+
+		int main()
+		{
+			int fd = creat("lseektest", 0600);
+			int res = 1;
+			if(fd>=0)
+			{
+				${code}
+				close(fd);
+			}
+			unlink("lseektest");
+			return res;
+		}
+		]=] ${var})
+	file(APPEND "${boxconfig_h_file}" "#cmakedefine ${var}\n")
+endfunction()
+
+AX_TRY_RUN_FD(
+	[=[
+		// This test tries first to seek to position 0, with NO "dummy
+		// argument". If lseek does actually require a dummy argument,
+		// then it will eat SEEK_SET for the offset and try to use 99
+		// as whence, which is invalid, so res will be 0, the program
+		// will return 0 and we will define HAVE_LSEEK_DUMMY_PARAM
+		// (whew! that took 1 hour to figure out) The "dummy argument"
+		// probably means that it takes a 64-bit offset.
+		res = (syscall(SYS_lseek, fd, (int32_t)10, SEEK_SET, 99) == 10) ? 2 : 0;
+	]=] HAVE_LSEEK_DUMMY_PARAM)
+
+AX_TRY_RUN_FD(
+	[=[
+		// Try to seek to a position that requires a 64-bit
+		// representation, and check the return value, which is the
+		// current position.
+		if(syscall(SYS_lseek, fd, (int64_t)5, SEEK_SET) != 5)
+		{
+			res = 2;
+		}
+		else if(syscall(SYS_lseek, fd, (int64_t)10, SEEK_CUR) != 15)
+		{
+			res = 3;
+		}
+		else
+		{
+			res = 0;
+		}
+	]=] HAVE_LSEEK_64_BIT)
+
 set(CMAKE_REQUIRED_INCLUDES "")
 
 # Build the final version of BoxConfig.cmake.h, as a temporary file.