Return program's exit code on unsuccessful command (#852)

Author: perazz

ci/run_tests.sh

@@ -158,5 +158,41 @@ pushd cpp_files
 "$fpm" test
 popd
 
+# Test app exit codes
+pushd fpm_test_exit_code
+"$fpm" build
+
+# odd number -> success!
+EXIT_CODE=0
+"$fpm" run -- 1 || EXIT_CODE=$?
+test $EXIT_CODE -eq 0
+
+# even number -> error 3
+EXIT_CODE=0
+"$fpm" run -- 512 || EXIT_CODE=$?
+test $EXIT_CODE -eq 3
+
+# even number -> error 3
+EXIT_CODE=0
+"$fpm" run -- 0 || EXIT_CODE=$?
+test $EXIT_CODE -eq 3
+
+# not an integer -> error 2
+EXIT_CODE=0
+"$fpm" run -- 3.1415 || EXIT_CODE=$?
+test $EXIT_CODE -eq 2
+
+# not a number -> error 2
+EXIT_CODE=0
+"$fpm" run -- notanumber || EXIT_CODE=$?
+test $EXIT_CODE -eq 2
+
+# no arguments -> error 1
+EXIT_CODE=0
+"$fpm" run || EXIT_CODE=$?
+test $EXIT_CODE -eq 1
+popd
+
+
 # Cleanup
 rm -rf ./*/build

example_packages/fpm_test_exit_code/README.md

@@ -0,0 +1,6 @@
+# fpm_test_exit_code
+Test program for application exit codes
+see https://github.com/fortran-lang/fpm/issues/848
+
+This app expects to receive an integer command line argument, to check whether it is odd or even.
+It returns 0 on success (odd input), or among a few error codes otherwise.

example_packages/fpm_test_exit_code/app/main.f90

@@ -0,0 +1,42 @@
+! Test program for application exit codes
+! see https://github.com/fortran-lang/fpm/issues/848
+
+! This app expects to receive an integer command line argument, to check whether it is odd or even.
+! It returns 0 on success (odd input), or among a few error codes otherwise.
+
+program check_odd_number
+    implicit none
+
+    integer, parameter :: SUCCESS          = 0
+    integer, parameter :: INVALID_ARGUMENT = 1
+    integer, parameter :: NOT_AN_INTEGER   = 2
+    integer, parameter :: NOT_ODD          = 3
+
+    character(len=1024) :: buffer
+    integer :: ierr,ln,the_number
+
+    ! If the argument is missing or not an integer, return an error flag
+    if (command_argument_count()/=1) stop INVALID_ARGUMENT
+
+    ! Get command argument
+    call get_command_argument(1,value=buffer,length=ln,status=ierr)
+
+    ! On invalid string
+    if (ln<1 .or. ierr/=0) stop INVALID_ARGUMENT
+
+    ! Read to int
+    read(buffer(:ln),*,iostat=ierr) the_number
+
+    ! On invalid integer
+    if (ierr/=0) stop NOT_AN_INTEGER
+
+    ! Check if it is odd or even
+    if (mod(the_number,2)==0) then
+        ! Is even
+        stop NOT_ODD
+    else
+        ! Is odd
+        stop SUCCESS
+    end if
+
+end program check_odd_number

example_packages/fpm_test_exit_code/fpm.toml

@@ -0,0 +1,10 @@
+name = "fpm_test_exit_code"
+version = "0.1.0"
+license = "license"
+author = "Federico Perini"
+maintainer = "[email protected]"
+copyright = "Copyright 2023, Jane Doe"
+[build]
+auto-executables = true
+[install]
+library = false

src/fpm.f90

@@ -445,7 +445,7 @@ subroutine cmd_run(settings,test)
     type(string_t), allocatable :: executables(:)
     type(build_target_t), pointer :: exe_target
     type(srcfile_t), pointer :: exe_source
-    integer :: run_scope
+    integer :: run_scope,firsterror
     integer, allocatable :: stat(:)
     character(len=:),allocatable :: line
     logical :: toomany
@@ -590,10 +590,12 @@ subroutine cmd_run(settings,test)
         if (any(stat /= 0)) then
             do i=1,size(stat)
                 if (stat(i) /= 0) then
-                    write(stderr,'(*(g0:,1x))') '<ERROR> Execution failed for object "',basename(executables(i)%s),'"'
+                    write(stderr,'(*(g0:,1x))') '<ERROR> Execution for object "',basename(executables(i)%s),&
+                                                '" returned exit code ',stat(i)
                 end if
             end do
-            call fpm_stop(1,'*cmd_run*:stopping due to failed executions')
+            firsterror = findloc(stat/=0,value=.true.,dim=1)
+            call fpm_stop(stat(firsterror),'*cmd_run*:stopping due to failed executions')
         end if
 
     endif

src/fpm_filesystem.F90

@@ -924,10 +924,8 @@ subroutine run(cmd,echo,exitstat,verbose,redirect)
 
     if (present(exitstat)) then
         exitstat = stat
-    else
-        if (stat /= 0) then
-            call fpm_stop(1,'*run*:Command failed')
-        end if
+    elseif (stat /= 0) then
+        call fpm_stop(stat,'*run*: Command '//cmd//redirect_str//' returned a non-zero status code')
     end if
 
 end subroutine run