Add new warnings invalid-var and invalid-ref

The "invalid-var" warning triggers if the makefile attempts to assign
a value to an invalid variable name (a name containing whitespace).
The "invalid-ref" warning triggers if the makefile attempts to
reference an invalid variable name.  Both new warnings have a default
action of "warn".

* NEWS: Add these new warnings.
* doc/make.1: Document them in the man page.
* doc/make.texi (Warnings): Document them in the user's manual.
* src/warning.h: Add enum values for the new warning types.
* src/main.c (initialize_warnings): Initialize the new warnings.
* src/variable.h (undefine_variable_in_set, undefine_variable_global):
Ask callers to provide a struct floc specifying where the variable
is undefined.
* src/read.c (do_undefine): Pass floc when undefining.
* src/variable.c (check_valid_name): If invalid-var is enabled, check
the variable name.
(define_variable_in_set): Call it.
(undefine_variable_in_set): Ditto.
(check_variable_reference): If invalid-ref is enabled, check the
variable reference.
(lookup_variable): Call it.
(lookup_variable_in_set): Ditto.
* tests/scripts/options/warn: Add tests for the new warning types.

1 files changed, 66 insertions, 2 deletions

diff --git a/tests/scripts/options/warn b/tests/scripts/options/warn
index 98155d46..f41f84ff 100644
--- a/tests/scripts/options/warn
+++ b/tests/scripts/options/warn
@@ -5,8 +5,8 @@ $description = "Test the --warn option.";
 my %warn_test = (
     '--warn' => '', '--warn=warn' => '', '--warn=error --warn=warn' => '',
     '--warn --warn=error' => '=error',
-    '--warn=ignore --warn=error --warn=ignore --warn=undefined-var' => '=ignore,undefined-var',
-    '--warn=undefined-var:error --warn' => '=warn,undefined-var:error'
+    '--warn=ignore --warn=error --warn=ignore --warn=invalid-var,invalid-ref,undefined-var' => '=ignore,invalid-var,invalid-ref,undefined-var',
+    '--warn=invalid-ref:ignore --warn=error --warn=invalid-var:warn,,,,,undefined-var:error,,,,,' => '=error,invalid-var,invalid-ref:ignore,undefined-var:error'
 );
 
 # Verify the deprecated --warn-undefined-variables option
@@ -83,4 +83,68 @@ ref");
 run_make_test(undef, '--warn=undefined-var:error',
               "#MAKEFILE#:7: *** reference to undefined variable 'UNDEFINED'.  Stop.", 512);
 
+# Check invalid variable reference warnings
+
+# With no options we still check for invalid references
+run_make_test('
+IREF = $(bad variable)
+SIREF := $(IREF)
+
+define nl
+
+
+endef
+
+all: ; @echo ref $(also$(nl)bad) $(IREF) $(SIREF)',
+              '', "#MAKEFILE#:2: invalid variable reference 'bad variable'
+#MAKEFILE#:10: invalid variable reference 'also\nbad'
+#MAKEFILE#:2: invalid variable reference 'bad variable'
+ref");
+
+run_make_test(undef, '--warn=ignore', 'ref');
+
+run_make_test(undef, '--warn=invalid-ref:ignore', 'ref');
+
+# Check and errors
+run_make_test(undef, '--warn=invalid-ref:error',
+              "#MAKEFILE#:2: *** invalid variable reference 'bad variable'.  Stop.", 512);
+
+# Check invalid variable name warnings
+
+# With no options we still check for invalid references
+run_make_test('
+EMPTY =
+SPACE = $(EMPTY) $(EMPTY)
+BAD$(SPACE)VAR = foo
+
+define nl
+
+
+endef
+
+NL$(nl)VAR = bar
+
+define BAD$(SPACE)DEF :=
+foo
+endef
+
+define NL$(nl)DEF :=
+foo
+endef
+
+all: ; @echo ref',
+              '', "#MAKEFILE#:4: invalid variable name 'BAD VAR'
+#MAKEFILE#:11: invalid variable name 'NL\nVAR'
+#MAKEFILE#:13: invalid variable name 'BAD DEF'
+#MAKEFILE#:17: invalid variable name 'NL\nDEF'
+ref");
+
+run_make_test(undef, '--warn=ignore', 'ref');
+
+run_make_test(undef, '--warn=invalid-var:ignore', 'ref');
+
+# Check and errors
+run_make_test(undef, '--warn=invalid-var:error',
+              "#MAKEFILE#:4: *** invalid variable name 'BAD VAR'.  Stop.", 512);
+
 1;