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Fix the bugs were exposed by my pre-dummy-type-diff cleanup of polymorphism.m.
This diff deleted a "semidet_fail" in the predicate that tested whether a
foreign_proc used a variable, making the test a real test, not a dummy.
The main bugs were in unused_args.m, polymorphism.m and ml_unify_gen.m.
compiler/unused_args.m:
Fix the mismatch between the analysis and fixup passes' treatment of
foreign_procs. The analysis pass says that variables representing
unnamed foreign_proc arguments are unused, and therefore the code
generating them can be optimized away, but the fixup pass used to leave
those arguments unchanged. This is usually fine, but there was a
problem if a variable had two or more such conjoined consumers but no
other consumers. It then had its generator optimized away, but the
variable was left in the nonlocal set of each consumer, which meant
that the code generator aborted when trying to save the value of the
variable after the first consumer.
The fix is to rename unnamed foreign proc args, ensuring that they are
local to the foreign_proc they appear in. The code generators can
already handle such arguments.
compiler/typecheck.m:
Detect foreign_procs that are supposed to bind type_info variables,
but don't, and generate error messages for them. This is now necessary,
since if we accept such predicates, unused_args.m will now rename apart
the unused type_info argument, and the code generator will abort
due to the type_info missing its generator.
compiler/typecheck_errors.m:
Add a predicate for reporting the error.
compiler/goal_util.m:
Add a utility predicate and export some previously internal predicates
for use by unused_args.m.
Delete redundant module prefixes on predicate names to avoid having to
split long lines.
compiler/polymorphism.m:
Ensure that all arguments of import foreign_procs are considered used,
since our contract with foreign language code prevents us from
optimizing them away.
Redefine a predicate using the new utility predicate in goal_util.m.
compiler/pragma_c_gen.m:
Ensure that all arguments of import foreign_procs are considered used,
since our contract with foreign language code prevents us from
optimizing them away. This is a belt-and-suspenders fix: the change to
polymorphism.m should be sufficient to ensure this objective by itself.
compiler/ml_unify_gen.m:
The mark_static_terms pass was assuming that if X is a static term,
then after the assignment unification Y = X Y is also a static term.
However, when processing such assignments, the code generator here
neglected to copy over the part of the X's state that says what static
term it is to become part of Y's state. This diff fixes that neglect.
compiler/ml_code_util.m:
We used to identify MLDS variables holding static terms by a sequence
number, and then create a name from the number by tacking on the name
of the HLDS variable referring to it at each reference. This worked
because each static term was referred to by only one HLDS variable;
but after the diff to ml_unify_gen, this is no longer the case.
We therefore now construct the MLDS variable's name when the static
term is created, and use that name as the translation of all the HLDS
variables referring to that static term.
compiler/add_pragma.m:
Minor cleanup.
library/rtti_implementation.m:
library/store.m:
In some predicates that don't define type_infos for existentially typed
arguments, mention the type_info that *should* be defined there in
comments to avoid the error now generated by typecheck.m.
browser/Mercury.options:
deep_profiler/Mercury.options:
Undo the workaround for the fixed bug.
tests/existential_type_classes.m:
In predicates that don't define type_infos for existentially typed
arguments, mention the type_info that *should* be defined there in
comments to avoid the error now generated by typecheck.m.
tests/existential_type_classes.exp:
Conform to the changed line numbers in existential_type_classes.m.
tests/invalid/exist_foreign_error.{m,exp}:
New test case for the error now detected by typecheck.m.
tests/invalid/Mmakefile:
Enable the new test case.
