40-better-messages.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>
        * automake.in (&variable_dump): If a variable is undefined, say
        it.
        (&check_ambiguous_conditional): Give finer error messages.
        (&variable_define): Check that a `+=' variable is not set with `='.
        Check for ambiguous definitions each time you _set_ (even with `+=')
        a variable.
        (&read_main_am_file): Perform a deep copy of %conditional.
        
        
Index: automake.in
--- automake.in Sun, 11 Mar 2001 11:12:08 +0100 akim (am/f/39_automake.i 1.160 
755)
+++ automake.in Sun, 11 Mar 2001 12:49:08 +0100 akim (am/f/39_automake.i 1.160 
755)
@@ -5480,19 +5480,25 @@ sub variable_dump ($)
 {
   my ($var)= @_;
 
-  my $var_is_am = $var_is_am{$var} ? "Automake" : "User";
-  my $where = (defined $content_lines{$var}
-              ? $content_lines{$var} : "undefined");
-  my $pluseq = ((defined $var_was_plus_eq{$var} && $var_was_plus_eq{$var})
-               ? "+=" : "=");
-
-  print STDERR "  $var ($var_is_am, where = $where) $pluseq\n";
-  print STDERR "  {\n";
-  foreach my $vcond (sort by_condition keys %{$conditional{$var}})
+  if (!exists $conditional{$var})
     {
-      print STDERR "    $vcond => $conditional{$var}{$vcond}\n";
+      print STDERR "  $var does not exist\n";
+    }
+  else
+    {
+      my $var_is_am = $var_is_am{$var} ? "Automake" : "User";
+      my $where = (defined $content_lines{$var}
+                  ? $content_lines{$var} : "undefined");
+      my $pluseq = ((defined $var_was_plus_eq{$var} && $var_was_plus_eq{$var})
+                   ? "+=" : "=");
+      print STDERR "  $var ($var_is_am, where = $where) $pluseq\n";
+      print STDERR "  {\n";
+      foreach my $vcond (sort by_condition keys %{$conditional{$var}})
+       {
+         print STDERR "    $vcond => $conditional{$var}{$vcond}\n";
+       }
+      print STDERR "  }\n";
     }
-  print STDERR "  }\n";
 }
 
 
@@ -5591,14 +5597,25 @@ sub check_ambiguous_conditional ($$)
     my ($var, $cond) = @_;
     foreach my $vcond (keys %{$conditional{$var}})
     {
-       if (&conditional_true_when ($vcond, $cond)
-           || &conditional_true_when ($cond, $vcond))
-       {
-           &am_line_error ($var,
-                           "$var multiply defined in condition $cond");
-           variable_dump ($var);
-       }
-    }
+       my $message;
+       if ($vcond eq $cond)
+       {
+          $message = "$var multiply defined in condition $cond";
+       }
+       elsif (&conditional_true_when ($vcond, $cond))
+       {
+        $message = "$var was already defined in condition $vcond, which 
implies condition $cond";
+       }
+       elsif (&conditional_true_when ($cond, $vcond))
+       {
+          $message = "$var was already defined in condition $vcond, which is 
implied by condition $cond";
+       }
+       if ($message)
+       {
+          &am_line_error ($var, $message);
+          variable_dump ($var);
+       }
+   }
 }
 
 
@@ -5617,40 +5634,36 @@ sub variable_define ($$$$$$)
 
   $cond ||= 'TRUE';
 
-  check_ambiguous_conditional ($var, $cond)
-    unless $type eq '+';
-
-  if (! defined $conditional{$var}{$cond})
+  # A variable which was `+=' must not be `='.
+  if (defined $var_was_plus_eq{$var})
+    {
+      if ($var_was_plus_eq{$var} && $type ne '+')
+       {
+         am_line_error ($var,
+                        ("$var was set with `+=' "
+                         . "and is now set with `$type='"));
+       }
+    }
+  else
     {
-      # Initialize: we rely on defined.
-      $conditional{$var}{$cond} = '';
-
-      # The first assignment to a macro sets the line number.  Ideally
-      # I suppose we would associate line numbers with random bits of
-      # text.
-      # FIXME: We sometimes redefine some variables, but we want to keep
-      # the original location.  More subs are needed to handle properly
-      # variables.  Once this done, remove this hack.
-      $content_lines{$var} = $where
-       unless defined $content_lines{$var};
-
-      # If first assignment, set `+=' indicator.
       $var_was_plus_eq{$var} = $type eq '+' && ! $var_is_am{$var};
     }
 
+  # An Automake variable can be given to the user, but not the converse.
   if (! defined $var_is_am{$var} || !$var_is_am)
     {
       $var_is_am{$var} = $var_is_am;
     }
 
-  if ($type eq '+')
+  # Differentiate the first assignment (including with `+=').
+  if ($type eq '+' && defined $conditional{$var}{$cond})
     {
       if (substr ($conditional{$var}{$cond}, -1) eq "\n")
-       {
-         # Insert a backslash before a trailing newline.
-         $conditional{$var}{$cond} =
-          substr ($conditional{$var}{$cond}, 0, -1) . "\\\n";
-       }
+       {
+         # Insert a backslash before a trailing newline.
+         $conditional{$var}{$cond} =
+           substr ($conditional{$var}{$cond}, 0, -1) . "\\\n";
+       }
       elsif ($conditional{$var}{$cond})
        {
          # Insert a separator.
@@ -5660,6 +5673,16 @@ sub variable_define ($$$$$$)
     }
   else
     {
+      # The first assignment to a macro sets the line number.  Ideally I
+      # suppose we would associate line numbers with random bits of text.
+      # FIXME: We sometimes redefine some variables, but we want to keep
+      # the original location.  More subs are needed to handle
+      # properly variables.  Once this done, remove this hack.
+      $content_lines{$var} = $where
+       unless defined $content_lines{$var};
+
+      # There must be no previous value.
+      check_ambiguous_conditional ($var, $cond);
       $conditional{$var}{$cond} = $value;
     }
 
@@ -6567,7 +6590,16 @@ sub read_main_am_file
 
     # First pass.
     &define_standard_variables;
-    my %saved_conditional = %conditional;
+    # Deep copy. With `%saved_conditional = %conditional' modifying
+    # one modifes the other.
+    my %saved_conditional;
+    foreach my $var (keys %conditional)
+      {
+       foreach my $cond (keys %{$conditional{$var}})
+         {
+           $saved_conditional{$var}{$cond} = $conditional{$var}{$cond};
+         }
+      }
 
     # Read user file, but discard text of variable assignments we just
     # made.