Merge pull request #26 from boxbackup/fix_raidfile_i386

Fix raidfile tests on 32-bit Linux.

A recent fix for Solaris (commit 81e9aa6545f7f19124c9f5e88982b867d8732965) broke support for 32-bit Linux (which wasn't spotted at the time, because we didn't have any 32-bit builders). Try a different approach: detect explicitly whether the `lseek` syscall takes a 64-bit integer offset, regardless of the size of `off_t` in user space.
    
CMake: Add support for M4 CXX flag detection in CMakeLists. Reimplement autoconf tests for 64-bit lseek.

Fix error in t-gdb when no debugger is detected.

Thanks to Reinhard Tartler (our Debian package maintainer) for pointing out the error, and James O'Gorman for setting up i386 builders to ensure that it's fixed and cannot recur.

1 files changed, 113 insertions, 1 deletions

diff --git a/infrastructure/cmake/CMakeLists.txt b/infrastructure/cmake/CMakeLists.txt
index 65f59eb8..e6f46148 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)
@@ -477,7 +478,7 @@ move_file_if_exists(
 	"${boxconfig_cmake_h_dir}/BoxConfig.cmake.h.bak")
 
 foreach(m4_filename boxbackup_tests.m4 ax_check_mount_point.m4 ax_func_syscall.m4)
-	file(STRINGS "${base_dir}/infrastructure/m4/${m4_filename}" m4_functions REGEX "^ *AC[_A-Z]+\\(.*\\)$")
+	file(STRINGS "${base_dir}/infrastructure/m4/${m4_filename}" m4_functions REGEX "^ *(AC|AX|BOX)_[A-Z_]+\\(.*\\)$")
 	foreach(m4_function ${m4_functions})
 		if(DEBUG)
 			message(STATUS "Processing m4_function: ${m4_function}")
@@ -559,6 +560,22 @@ foreach(m4_filename boxbackup_tests.m4 ax_check_mount_point.m4 ax_func_syscall.m
 				}
 				]=] "HAVE_${platform_var_name}")
 			file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_${platform_var_name}\n")
+		elseif(m4_function MATCHES "^ *BOX_CHECK_CXX_FLAG\\((-[A-Za-z_,=-]+)\\)")
+			if(DEBUG)
+				message(STATUS "Processing BOX_CHECK_CXX_FLAG: ${CMAKE_MATCH_1}")
+			endif()
+
+			if(NOT CMAKE_MATCH_1 STREQUAL "-Wall")
+				set(flag "${CMAKE_MATCH_1}")
+				string(TOLOWER "have_flag_${flag}" have_flag_var_name)
+				string(REGEX REPLACE "[^a-z_]" "_" have_flag_var_name ${have_flag_var_name})
+				string(REGEX REPLACE "__+" "_" have_flag_var_name ${have_flag_var_name})
+
+				CHECK_CXX_COMPILER_FLAG(${flag} ${have_flag_var_name})
+				if(${have_flag_var_name})
+					add_definitions("${flag}")
+				endif()
+			endif()
 		endif()
 	endforeach()
 
@@ -610,6 +627,7 @@ CHECK_CXX_SOURCE_COMPILES([=[
 	}
 	]=] "HAVE_STRUCT_STATFS_F_MNTONNAME")
 file(APPEND "${boxconfig_h_file}" "#cmakedefine HAVE_STRUCT_STATFS_F_MNTONNAME\n")
+
 CHECK_CXX_SOURCE_COMPILES([=[
 	#include "BoxConfig.cmake.h"
 	#ifdef HAVE_SYS_PARAM_H
@@ -623,6 +641,7 @@ CHECK_CXX_SOURCE_COMPILES([=[
 	}
 	]=] "HAVE_STRUCT_STATVFS_F_MNTONNAME")
 file(APPEND "${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 +668,34 @@ 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 +731,71 @@ 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.