Add: error handling to source parsing

2 files changed, 151 insertions, 31 deletions

diff --git a/fpm/src/fpm/error.f90 b/fpm/src/fpm/error.f90
index aebd7e4..ba47034 100644
--- a/fpm/src/fpm/error.f90
+++ b/fpm/src/fpm/error.f90
@@ -5,6 +5,7 @@ module fpm_error
 
     public :: error_t
     public :: fatal_error, syntax_error, file_not_found_error
+    public :: file_parse_error
 
 
     !> Data type defining an error
@@ -55,4 +56,30 @@ contains
     end subroutine file_not_found_error
 
 
+    !> Error created when file parsing fails
+    subroutine file_parse_error(error, file_name, line, message)
+
+        !> Instance of the error data
+        type(error_t), allocatable, intent(out) :: error
+
+        !> Name of file
+        character(len=*), intent(in) :: file_name
+
+        !> Line number of parse error
+        integer, intent(in) :: line
+
+        !> Parse error message
+        character(len=*), intent(in) :: message
+
+        character(50) :: line_no_string
+
+        write(line_no_string,'(I0)') line
+
+        allocate(error)
+        error%message = 'Error while parsing file "'//file_name//'" on line '// &
+                        trim(line_no_string)//': '//message
+
+    end subroutine file_parse_error
+
+
 end module fpm_error
diff --git a/fpm/src/fpm_sources.f90 b/fpm/src/fpm_sources.f90
index f2418b5..ac483f2 100644
--- a/fpm/src/fpm_sources.f90
+++ b/fpm/src/fpm_sources.f90
@@ -1,4 +1,5 @@
 module fpm_sources
+use fpm_error, only: error_t, file_parse_error
 use fpm_model, only: srcfile_ptr, srcfile_t, fpm_model_t, &
                     FPM_UNIT_UNKNOWN, FPM_UNIT_PROGRAM, FPM_UNIT_MODULE, &
                     FPM_UNIT_SUBMODULE, FPM_UNIT_SUBPROGRAM, &
@@ -9,7 +10,8 @@ use fpm_manifest_executable, only: executable_t
 implicit none
 
 private
-public :: add_sources_from_dir, add_executable_sources, resolve_module_dependencies
+public :: add_sources_from_dir, add_executable_sources
+public :: parse_f_source, parse_c_source, resolve_module_dependencies
 
 character(15), parameter :: INTRINSIC_MODULE_NAMES(*) =  &
                              ['iso_c_binding  ', &
@@ -26,6 +28,7 @@ subroutine add_sources_from_dir(sources,directory,with_executables)
     type(srcfile_t), allocatable, intent(inout), target :: sources(:)
     character(*), intent(in) :: directory
     logical, intent(in), optional :: with_executables
+    type(error_t), allocatable :: error
 
     integer :: i, j
     logical, allocatable :: is_source(:), exclude_source(:)
@@ -48,12 +51,12 @@ subroutine add_sources_from_dir(sources,directory,with_executables)
     do i = 1, size(src_file_names)
 
         if (str_ends_with(lower(src_file_names(i)%s), ".f90")) then
-            dir_sources(i) = parse_f_source(src_file_names(i)%s)
+            dir_sources(i) = parse_f_source(src_file_names(i)%s, error)
         end if
 
         if (str_ends_with(lower(src_file_names(i)%s), ".c") .or. &
             str_ends_with(lower(src_file_names(i)%s), ".h")) then
-            dir_sources(i) = parse_c_source(src_file_names(i)%s)
+            dir_sources(i) = parse_c_source(src_file_names(i)%s,error)
         end if
 
         ! Exclude executables unless specified otherwise
@@ -157,16 +160,17 @@ subroutine get_executable_source_dirs(exe_dirs,executables)
 end subroutine get_executable_source_dirs
 
 
-function parse_f_source(f_filename) result(f_source)
+function parse_f_source(f_filename,error) result(f_source)
     ! Rudimentary scan of Fortran source file and 
     !  extract program unit name and use/include dependencies
     !
     character(*), intent(in) :: f_filename
     type(srcfile_t) :: f_source
+    type(error_t), allocatable, intent(out) :: error
 
+    integer :: stat
     integer :: fh, n_use, n_include, n_mod, i, j, ic, pass
     type(string_t), allocatable :: file_lines(:)
-    character(:), allocatable :: line_parts(:)
     character(:), allocatable :: temp_string, mod_name
 
     f_source%file_name = f_filename
@@ -199,16 +203,31 @@ function parse_f_source(f_filename) result(f_source)
 
                 if (index(file_lines(i)%s,'::') > 0) then
 
-                    call split(file_lines(i)%s,line_parts,delimiters=':')
-                    temp_string = trim(line_parts(2))
-                    call split(temp_string,line_parts,delimiters=' ,')
-                    mod_name = trim(lower(line_parts(1)))
+                    temp_string = split_n(file_lines(i)%s,delims=':',n=2,stat=stat)
+                    if (stat /= 0) then
+                        call file_parse_error(error,f_filename,i, &
+                                message='unable to find used module name')
+                        return
+                    end if
+
+                    mod_name = split_n(temp_string,delims=' ,',n=1,stat=stat)
+                    if (stat /= 0) then
+                        call file_parse_error(error,f_filename,i, &
+                                 message='unable to find used module name')
+                        return
+                    end if
+                    mod_name = lower(mod_name)
 
                 else
 
-                    call split(file_lines(i)%s,line_parts,delimiters=' ,')
-                    mod_name = trim(lower(line_parts(2)))
-    
+                    mod_name = split_n(file_lines(i)%s,n=2,delims=' ,',stat=stat)
+                    if (stat /= 0) then
+                        call file_parse_error(error,f_filename,i, &
+                                message='unable to find used module name')
+                        return
+                    end if
+                    mod_name = lower(mod_name)
+
                 end if
 
                 if (.not.validate_name(mod_name)) then
@@ -236,8 +255,13 @@ function parse_f_source(f_filename) result(f_source)
                 n_include = n_include + 1
 
                 if (pass == 2) then
-                    call split(file_lines(i)%s,line_parts,delimiters="'"//'"')
-                    f_source%include_dependencies(n_include)%s = trim(line_parts(2))
+                    f_source%include_dependencies(n_include)%s = &
+                     & split_n(file_lines(i)%s,n=2,delims="'"//'"',stat=stat)
+                    if (stat /= 0) then
+                        call file_parse_error(error,f_filename,i, &
+                              message='unable to find include file name')
+                        return
+                    end if
                 end if
 
             end if
@@ -245,12 +269,24 @@ function parse_f_source(f_filename) result(f_source)
             ! Extract name of module if is module
             if (index(adjustl(lower(file_lines(i)%s)),'module ') == 1) then
 
-                call split(file_lines(i)%s,line_parts,delimiters=' ')
+                mod_name = lower(split_n(file_lines(i)%s,n=2,delims=' ',stat=stat))
+                if (stat /= 0) then
+                    call file_parse_error(error,f_filename,i, &
+                          message='unable to find module name')
+                    return
+                end if
 
-                mod_name = adjustl(trim(lower(line_parts(2))))
+                if (mod_name == 'procedure' .or. &
+                    mod_name == 'subroutine' .or. &
+                    mod_name == 'function') then
+                    ! Ignore these cases
+                    cycle
+                end if
 
                 if (.not.validate_name(mod_name)) then
-                    cycle
+                    call file_parse_error(error,f_filename,i, &
+                          message='empty or invalid name for module')
+                    return
                 end if
 
                 n_mod = n_mod + 1
@@ -266,7 +302,12 @@ function parse_f_source(f_filename) result(f_source)
             ! Extract name of submodule if is submodule
             if (index(adjustl(lower(file_lines(i)%s)),'submodule') == 1) then
 
-                call split(file_lines(i)%s,line_parts,delimiters=' ()')
+                temp_string = split_n(file_lines(i)%s,n=2,delims='()',stat=stat)
+                if (stat /= 0) then
+                    call file_parse_error(error,f_filename,i, &
+                          message='unable to get submodule ancestry')
+                    return
+                end if
 
                 f_source%unit_type = FPM_UNIT_SUBMODULE
 
@@ -274,13 +315,19 @@ function parse_f_source(f_filename) result(f_source)
 
                 if (pass == 2) then
 
-                    if (index(line_parts(2),':') > 0) then
-
-                        line_parts(2) = line_parts(2)(index(line_parts(2),':')+1:)
+                    if (index(temp_string,':') > 0) then
 
+                        temp_string = temp_string(index(temp_string,':')+1:)
+                        
                     end if
 
-                    f_source%modules_used(n_use)%s = adjustl(trim(lower(line_parts(2))))
+                    f_source%modules_used(n_use)%s = lower(temp_string)
+
+                    if (.not.validate_name(temp_string)) then
+                        call file_parse_error(error,f_filename,i, &
+                          message='empty or invalid name for submodule parent')
+                        return
+                    end if
 
                 end if
 
@@ -317,10 +364,7 @@ function parse_f_source(f_filename) result(f_source)
 
         integer :: i
 
-        if (trim(lower(name)) == 'procedure' .or. &
-            trim(lower(name)) == 'subroutine' .or. &
-            trim(lower(name)) == 'function') then
-
+        if (len_trim(name) < 1) then
             valid = .false.
             return
         end if
@@ -353,16 +397,16 @@ function parse_f_source(f_filename) result(f_source)
 end function parse_f_source
 
 
-function parse_c_source(c_filename) result(c_source)
+function parse_c_source(c_filename,error) result(c_source)
     ! Rudimentary scan of c source file and 
     !  extract include dependencies
     !
     character(*), intent(in) :: c_filename
     type(srcfile_t) :: c_source
+    type(error_t), allocatable, intent(out) :: error
 
-    integer :: fh, n_include, i, pass
+    integer :: fh, n_include, i, pass, stat
     type(string_t), allocatable :: file_lines(:)
-    character(:), allocatable :: line_parts(:)
 
     c_source%file_name = c_filename
 
@@ -394,8 +438,15 @@ function parse_c_source(c_filename) result(c_source)
                 n_include = n_include + 1
 
                 if (pass == 2) then
-                    call split(file_lines(i)%s,line_parts,delimiters='"')
-                    c_source%include_dependencies(n_include)%s = trim(line_parts(2))
+
+                    c_source%include_dependencies(n_include)%s = &
+                     &   split_n(file_lines(i)%s,n=2,delims='"',stat=stat)
+                    if (stat /= 0) then
+                        call file_parse_error(error,c_filename,i, &
+                            message='unable to get c include file')
+                        return
+                    end if
+
                 end if
 
             end if
@@ -411,6 +462,48 @@ function parse_c_source(c_filename) result(c_source)
 end function parse_c_source
 
 
+function split_n(string,delims,n,stat) result(substring)
+    ! Split a string on one or more delimeters
+    !  and return the nth substring if it exists
+    !
+    ! n=0  will return the last item
+    ! n=-1 will return the penultimate item etc.
+    !
+    ! stat = 1 on return if the index 
+    !  is not found
+    !
+    character(*), intent(in) :: string
+    character(*), intent(in) :: delims
+    integer, intent(in) :: n
+    integer, intent(out) :: stat
+    character(:), allocatable :: substring
+
+    integer :: i
+    character(:), allocatable :: string_parts(:)
+
+    call split(string,string_parts,delims)
+
+    if (n<1) then
+        i = size(string_parts) + n
+        if (i < 1) then
+            stat = 1
+            return
+        end if
+    else
+        i = n
+    end if
+
+    if (i>size(string_parts)) then
+        stat = 1
+        return
+    end if
+
+    substring = trim(string_parts(i))
+    stat = 0
+
+end function split_n
+
+
 subroutine resolve_module_dependencies(sources)
     ! After enumerating all source files: resolve file dependencies
     !  by searching on module names