Update: file_parse_error with more context output

Allows optional line number, line string value and line column output.

2 files changed, 78 insertions, 26 deletions

diff --git a/fpm/src/fpm/error.f90 b/fpm/src/fpm/error.f90
index ba47034..e69ff1e 100644
--- a/fpm/src/fpm/error.f90
+++ b/fpm/src/fpm/error.f90
@@ -57,7 +57,8 @@ contains
 
 
     !> Error created when file parsing fails
-    subroutine file_parse_error(error, file_name, line, message)
+    subroutine file_parse_error(error, file_name, message, line_num, &
+                                 line_string, line_col)
 
         !> Instance of the error data
         type(error_t), allocatable, intent(out) :: error
@@ -65,19 +66,61 @@ contains
         !> 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
+        !> Line number of parse error
+        integer, intent(in), optional :: line_num
+
+        !> Line context string
+        character(len=*), intent(in), optional :: line_string
+
+        !> Line context column
+        integer, intent(in), optional :: line_col
 
-        write(line_no_string,'(I0)') line
+        character(50) :: temp_string
 
         allocate(error)
-        error%message = 'Error while parsing file "'//file_name//'" on line '// &
-                        trim(line_no_string)//': '//message
+        error%message = 'Parse error: '//message//new_line('a')
+        
+        error%message = error%message//file_name
+        
+        if (present(line_num)) then
+
+            write(temp_string,'(I0)') line_num
+
+            error%message = error%message//':'//trim(temp_string)
+
+        end if
+
+        if (present(line_col)) then
+
+            if (line_col > 0) then
+
+                write(temp_string,'(I0)') line_col
+                error%message = error%message//':'//trim(temp_string)
+
+            end if
+
+        end if
+
+        if (present(line_string)) then
+
+            error%message = error%message//new_line('a')
+            error%message = error%message//'   | '//line_string
+
+            if (present(line_col)) then
+
+                if (line_col > 0) then
+
+                    error%message = error%message//new_line('a')
+                    error%message = error%message//'   | '//repeat(' ',line_col-1)//'^'
+                
+                end if
+                
+            end if
+
+        end if
 
     end subroutine file_parse_error
 
diff --git a/fpm/src/fpm_sources.f90 b/fpm/src/fpm_sources.f90
index 3c8a3cf..787efff 100644
--- a/fpm/src/fpm_sources.f90
+++ b/fpm/src/fpm_sources.f90
@@ -224,15 +224,17 @@ function parse_f_source(f_filename,error) result(f_source)
 
                     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')
+                        call file_parse_error(error,f_filename, &
+                                'unable to find used module name',i, &
+                                file_lines(i)%s,index(file_lines(i)%s,'::'))
                         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')
+                        call file_parse_error(error,f_filename, &
+                                 'unable to find used module name',i, &
+                                 file_lines(i)%s)
                         return
                     end if
                     mod_name = lower(mod_name)
@@ -241,8 +243,9 @@ function parse_f_source(f_filename,error) result(f_source)
 
                     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')
+                        call file_parse_error(error,f_filename, &
+                                'unable to find used module name',i, &
+                                file_lines(i)%s)
                         return
                     end if
                     mod_name = lower(mod_name)
@@ -277,8 +280,9 @@ function parse_f_source(f_filename,error) result(f_source)
                     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')
+                        call file_parse_error(error,f_filename, &
+                              'unable to find include file name',i, &
+                              file_lines(i)%s)
                         return
                     end if
                 end if
@@ -290,8 +294,9 @@ function parse_f_source(f_filename,error) result(f_source)
 
                 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')
+                    call file_parse_error(error,f_filename, &
+                          'unable to find module name',i, &
+                          file_lines(i)%s)
                     return
                 end if
 
@@ -303,8 +308,9 @@ function parse_f_source(f_filename,error) result(f_source)
                 end if
 
                 if (.not.validate_name(mod_name)) then
-                    call file_parse_error(error,f_filename,i, &
-                          message='empty or invalid name for module')
+                    call file_parse_error(error,f_filename, &
+                          'empty or invalid name for module',i, &
+                          file_lines(i)%s)
                     return
                 end if
 
@@ -323,8 +329,9 @@ function parse_f_source(f_filename,error) result(f_source)
 
                 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')
+                    call file_parse_error(error,f_filename, &
+                          'unable to get submodule ancestry',i, &
+                          file_lines(i)%s)
                     return
                 end if
 
@@ -343,8 +350,9 @@ function parse_f_source(f_filename,error) result(f_source)
                     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')
+                        call file_parse_error(error,f_filename, &
+                          'empty or invalid name for submodule parent',i, &
+                          file_lines(i)%s, index(file_lines(i)%s,temp_string))
                         return
                     end if
 
@@ -461,8 +469,9 @@ function parse_c_source(c_filename,error) result(c_source)
                     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')
+                        call file_parse_error(error,c_filename, &
+                            'unable to get c include file',i, &
+                            file_lines(i)%s,index(file_lines(i)%s,'"'))
                         return
                     end if