* module/language/tree-il/analyze.scm (&syntax-error): New variable.
(format-string-argument-count): Throw to &SYNTAX-ERROR when a syntax
error in a format string is encountered.
(format-analysis): Catch &SYNTAX-ERROR and convert as a warning of the
appropriate type.
* module/system/base/message.scm (%warning-types)[format]: Handle
`syntax-error' warnings.
* test-suite/tests/tree-il.test
("warnings")["conditionals"]("unterminated", "unexpected ~;",
"unexpected ~]"): New tests.
["unterminated ~{...~}"]: New test.
* module/language/tree-il/analyze.scm (format-analysis): Add new
sub-warnings: `wrong-port', `wrong-format-string',
`non-literal-format-string', and `wrong-num-args'.
* module/system/base/message.scm (%warning-types)[format]: Handle
them.
* test-suite/tests/tree-il.test ("warnings")["wrong port arg",
"wrong format string", "non-literal format string",
"wrong number of args"]: New tests.
* module/language/tree-il/analyze.scm (format-string-argument-count):
Return two values, the minimum and maximum number of arguments.
Add support for most of `format' escapes, including conditionals.
(format-analysis): Adjust accordingly.
* module/system/base/message.scm (%warning-types)[format]: Take two
arguments, MIN and MAX, instead of EXPECTED. Display warning
accordingly.
* test-suite/tests/tree-il.test ("warnings")["format"]("~%, ~~, ~&, ~t,
~_, and ~\\n", "~{...~}", "~{...~}, too many args", "~@{...~}",
"~@{...~}, too few args", "~(...~)", "~v", "~v:@y", "~*", "~?",
"complex 1", "complex 2", "complex 3"): New tests.
("conditionals"): New test prefix.
* module/language/tree-il/analyze.scm (<reference-dag>): New record
type.
(dag-reachable-nodes, dag-reachable-nodes*, unused-variable-analysis):
New variables.
(unbound-variable-analysis): Slightly simplify the `up' procedure.
* module/language/tree-il/compile-glil.scm (%warning-passes): Add
`unused-toplevel'.
* module/system/base/message.scm (%warning-types): Likewise.
* test-suite/tests/tree-il.test (%opts-w-unused-toplevel): New variable.
("warnings")["unused-toplevel"]: New test prefix.
* module/language/tree-il/analyze.scm (<arity-info>): New record type.
(validate-arity, arity-analysis): New variables.
* module/language/tree-il/compile-glil.scm (%warning-passes): Add
`arity-mismatch'.
* module/system/base/message.scm (%warning-types): Likewise.
* test-suite/tests/tree-il.test (read-and-compile): Remove, as it's now
public.
(%opts-w-arity): New.
("warnings")["arity mismatch"]: New test prefix.
