error test: check that return code is as expected

Author: scivision

README.md

@@ -16,13 +16,9 @@ For example:
 
 Demonstrate linking of
 
-* C++ calling Fortran
-* Fortran calling C++
-* Fortran calling C
+* C and C++ program calling Fortran libraries
+* Fortran program calling C and C++ libraries
 
-https://stackoverflow.com/tags/fortran-iso-c-binding/info
-
-In general, CMake >= 3.14 has better link resolution than CMake 3.13.
 In general, strongly avoid the FortranCInterface of CMake and mangling function names--just use Fortran 2003 standard `bind(C)`
 
 ## build
@@ -42,13 +38,19 @@ be sure you have in ~/.zshrc like the following:
 (check directory / versions on your Mac)
 
 ```sh
-export LIBRARY_PATH=$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/lib
-export CPLUS_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX11.1.sdk/usr/include
+export LIBRARY_PATH=$LIBRARY_PATH:/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/lib
+export CPLUS_INCLUDE_PATH=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include
 export CXXFLAGS=-I$CPLUS_INCLUDE_PATH
 export CFLAGS=$CXXFLAGS
 ```
 
 ## Error handling in Fortran with C/C++ main program
 
-Using Fortran statement "stop" or "error stop" with a C/C++ main program results in segmentation fault across compilers and operating systems.
-Instead, return an error code from Fortran subroutine to the C/C++ main program, and let C/C++ handle the error.
+Using Fortran statement "stop" or "error stop" with a C/C++ main program works like with a Fortran main program.
+The "error*" examples show this.
+
+
+## References
+
+* [StackOverflow](
+https://stackoverflow.com/tags/fortran-iso-c-binding/info)

cmake/test_error.cmake

@@ -0,0 +1,7 @@
+execute_process(COMMAND ${exe}
+  RESULT_VARIABLE ret
+)
+
+if(NOT ret EQUAL exp_code)
+  message(FATAL_ERROR "Expected ${exe} code ${exp_code} but got ${ret}")
+endif()

src/CMakeLists.txt

@@ -21,7 +21,9 @@ add_executable(c_fortran_error c/error_main.c)
 target_link_libraries(c_fortran_error PRIVATE error_fortran)
 # LINKER_LANGUAGE option is necessary for ifort at least
 set_target_properties(c_fortran_error PROPERTIES LINKER_LANGUAGE C)
-add_test(NAME C_Fortran_error COMMAND c_fortran_error)
+add_test(NAME C_Fortran_error
+  COMMAND ${CMAKE_COMMAND} -Dexe=$<TARGET_FILE:c_fortran_error> -Dexp_code=42 -P ${PROJECT_SOURCE_DIR}/cmake/test_error.cmake
+)
 
 # -- C++ calling Fortran
 add_executable(cxx_call_fortran cxx/main.cxx)
@@ -32,12 +34,11 @@ add_executable(cxx_fortran_error cxx/error_main.cxx)
 target_link_libraries(cxx_fortran_error PRIVATE error_fortran)
 # LINKER_LANGUAGE option is necessary for ifort at least
 set_target_properties(cxx_fortran_error PROPERTIES LINKER_LANGUAGE CXX)
-add_test(NAME C++_Fortran_error COMMAND cxx_fortran_error)
+add_test(NAME C++_Fortran_error
+  COMMAND ${CMAKE_COMMAND} -Dexe=$<TARGET_FILE:cxx_fortran_error> -Dexp_code=42 -P ${PROJECT_SOURCE_DIR}/cmake/test_error.cmake
+)
 
 # -- test wrapup
-
-set_tests_properties(C++_Fortran_error C_Fortran_error PROPERTIES WILL_FAIL TRUE)
-
 set_tests_properties(C++_Fortran_math C++_Fortran_error Fortran_call_C Fortran_call_C++ PROPERTIES
 TIMEOUT 5
 )