Estimated hours taken: 12
Bug fixes.
tests/term/arit_exp.m still fails with --intermodule-optimization
due to a slightly different (but correct) trans_opt file being produced.
compiler/simplify.m
Don't produce singleton disjunctions, since the code generator
barfs on them. Use a `some' instead.
Test case: tests/general/partition.m compiled with --deforestation.
compiler/unused_args.m
Deconstructions where the arguments included `any' insts were
not being handled correctly, due to inst_matches_binding
failing for any->any.
Test case: extras/trailed_update/samples/vqueens.m at -O3.
Don't warn about predicates from `.opt' files having unused
arguments, because in most cases the warning will be generated
when compiling the imported module.
compiler/higher_order.m
Fix a bug that caused compiler/modules.m to be miscompiled at
-O3 --intermodule-optimization, due to curried arguments for
multiple known higher-order arguments being passed to a
specialised version in the wrong order.
Test case: tests/hard_coded/ho_order2.m
compiler/mercury_compile.m
Call intermod__update_pred_import_status when compiling to
C at the same stage of the compilation as the `.opt' file
was written to ensure that the same information is being used.
Test case: tests/hard_coded/rational_test.m compiled with
--intermodule-optimization failed because of a link error.
Make sure polymorphism has been run before doing unused argument
checking with --errorcheck-only. Otherwise the argument indices
read in from `.opt' files are incorrect.
compiler/intermod.m
Use code_util__compiler_generated to test if a called predicate
is compiler generated, rather than looking for a call_unify_context
(function calls have a call_unify_context).
Add a progress message for updating the import status of predicates
exported to `.opt' files.
Fix a bug where the unused_args pragmas read in from the current
module's `.opt' file were given an import_status of `imported' rather
than `opt_imported' resulting in an error message from make_hlds.m.
compiler/dead_proc_elim.m
Ensure that predicates used by instance declarations and
`:- pragma export's are not eliminated by the dead_pred_elim
pass before typechecking.
Test case: most of the typeclass tests compiled with
--intermodule-optimization.
compiler/hlds_goal.m
Remove obsolete comments about the modes of a higher-order
unification being incorrect after polymorphism, since that
was fixed months ago.
compiler/options.m
Reenable deforestation.
Enable --intermodule-optimization and --intermod-unused-args
at -O5 so they get tested occasionally.
compiler/handle_options.m
Disable deforestation if --typeinfo-liveness is set, since
there are bugs in the folding code if extra typeinfos are
added to a new predicate's arguments by hlds_pred__define_new_pred.
Disable higher_order.m if --typeinfo-liveness is set, since
higher_order.m currently does not pass all necessary typeinfos
to specialised versions or update the typeinfo_varmap of
specialised versions.
Test case: tests/valid/agc_ho_pred.m
tests/hard_coded/ho_order2.m
tests/hard_coded/ho_order2.exp
Test case for higher_order.m.
tools/test_mercury
Added --intermod-unused-args to the options for murlibobo.
extras/trailed_update/{samples,tests}/Mmakefile
Add "-I.." to MGNUCFLAGS so gcc can find unsafe.h which
is #included in c_header_code read from unsafe.opt.
Estimated hours taken: 3
Allow a predicate to have matching `cc' and `non-cc' modes.
compiler/det_analysis.m:
If there is a call to a cc procedure in a non-cc context,
then search for a mode of that predicate which is
identical to the called mode except that it is not cc.
If such a mode is found, use it, rather than reporting
an error.
compiler/modecheck_call.m:
Add predicate modes_are_identical_bar_cc, for use by
det_analysis.m.
NEWS:
LIMITATIONS:
doc/reference_manual.texi:
Document the new feature and delete documentation about the
lack of this feature.
tests/hard_coded/Mmakefile:
tests/hard_coded/cc_and_non_cc_test.m:
tests/hard_coded/cc_and_non_cc_test.exp:
Add a test case for the new feature.
Estimated hours taken: 6
Add Mmake support for nested sub-modules.
compiler/mercury_compile.m:
compiler/modules.m:
compiler/intermod.m:
Pass down the source file name to various places.
Store the source file name in the module_imports data structure.
In various places, use this source file name instead of assuming
that the source file name can be obtained from the module name.
compiler/modules.m:
Change the generated .d and .dep files to use the source file names.
Add hard-coded rules in the .d files if the source file name does not
match the form expected by the pattern rules in scripts/Mmake.rules.
XXX unfortunately the rules don't work right for parallel makes of
nested modules
scripts/Mmake.rules:
Add a comment saying that any changes here might need to
be duplicated in compiler/modules.m.
tests/hard_coded/Mmakefile:
tests/hard_coded/nested.m:
tests/hard_coded/nested2.m:
tests/hard_coded/nested.exp:
tests/hard_coded/nested2.exp:
Add a couple of test cases for nested modules (XXX not enabled,
due to the above-mentioned problem with parallel makes).
doc/reference_manual.texi:
Update the "implementation bugs and limitations" section.
NEWS:
Update the news about nested modules.
Estimated hours taken: 6
compiler/mercury_to_mercury.m:
compiler/mode_errors.m:
Make the code a little bit more readable:
use specific types rather than `bool' in a few places.
compiler/mercury_to_mercury.m:
Fix bugs in the generation of interface files where it was
outputting certain graphic tokens incorrectly. In particular,
it was outputting things like `module:?' without any parentheses,
space, or quotes to separate the `:' as module qualifier from
the symbol name.
tests/hard_coded/Mmakefile:
tests/hard_coded/quoting_bug.m:
tests/hard_coded/quoting_bug_test.m:
tests/hard_coded/quoting_bug_test.exp:
Add some tests for the above-mentioned bug fix.
tests/term/*.trans_opt_exp:
tests/misc_tests/pretty_print_test.exp:
Update expected output for these tests to reflect the
above changes.
Estimated hours taken: 1
tests/hard_coded/Mmakefile
Disable cycles.m since it triggers a bug in code generation
for disjunctions when compiled in a non-GC grade with --deforestation.
tests/hard_coded/cycles2.m
cycles.m expanded so that deforestation is not needed to produce
the problem.
Estimated hours taken: 0.25
tests/hard_coded/Mmakefile:
Add `--gc conservative' to the GRADEFLAGS settings for
integer_test and rational_test, since these test cases both use
enough memory that they require some kind of GC -- without it
the test fails because it runs out of heap space.
Estimated hours taken: 0.1
Moved tests of library/{integer,rational}.m from tests/general to
tests/hard_coded since the library modules and their tests cannot
be compiled under NU-Prolog.
general/Mmakefile:
general/.cvsignore:
Removed references to integer_test and rational_test.
general/integer_test.m:
general/integer_test.exp:
general/rational_test.exp:
general/rational_test.m:
File removed.
hard_coded/Mmakefile:
hard_coded/.cvsignore:
Added references to integer_test and rational_test.
hard_coded/integer_test.m:
hard_coded/integer_test.exp:
hard_coded/rational_test.exp:
hard_coded/rational_test.m:
File added.
Estimated hours taken: 0.5
Make another small fix to mmake.in and add more empty definitions for various
Mmake variables to avoid spurious warnings.
scripts/mmake.in:
Add `*clean*' to the patterns for which we do not
pass `--warn-undefined-variables'.
scripts/Mmake.rules:
When invoking make recursively, pass $(MFLAGS) rather than
$(MAKEOVERRIDES). This avoids a warning, and is probably the
right thing to do anyway (I'm not sure why I used MAKEOVERRIDES
in the first place).
boehm_gc/Mmakefile:
tests/hard_coded/Mmakefile:
Add empty definition for `MMAKEFLAGS'.
Estimated hours taken: 0.2
tests/general/Mmakefile:
tests/general/rtc_bug.m:
tests/general/rtc_bug.exp:
tests/general/.cvsignore:
tests/hard_coded/Mmakefile:
tests/hard_coded/rtc_bug.m:
tests/hard_coded/rtc_bug.exp:
tests/hard_coded/.cvsignore:
Move the `rtc_bug' test case from the `general'
directory to the `hard_coded' directory, since it doesn't
work in Prolog.
Estimated hours taken: 0.25
tests/general/Mmakefile:
tests/general/relation_test.m:
tests/general/relation_test.exp:
tests/hard_coded/Mmakefile:
tests/hard_coded/relation_test.m:
tests/hard_coded/relation_test.exp:
Move the `relation_test' test case from the `general'
directory to the `hard_coded' directory, since it doesn't
work in Prolog.
Estimated hours taken: 1
library/string.m:
Fix a bug in string__base_string_to_int:
it was handling MININT incorrectly.
tests/hard_coded/Mmakefile:
tests/hard_coded/minint_bug.m:
tests/hard_coded/minint_bug.exp:
Regression test.
Estimated hours taken: 0.25
tests/hard_coded/Mmakefile:
tests/hard_coded/rev_arith.m:
tests/hard_coded/rev_arith.exp:
Change the `rev_arith.m' test so that it only tests
for the things which we actually support, and enable it.
Estimated hours taken: 0.25
tests/general/Mmakefile:
tests/general/common_type_cast.m:
tests/general/common_type_cast.exp:
tests/hard_coded/Mmakefile:
tests/hard_coded/common_type_cast.m:
tests/hard_coded/common_type_cast.exp:
Move the `common_type_cast' test from the `general' directory
to the `hard_coded' directory. The reason for this was that
the output under Mercury is slightly different to the output
under NU-Prolog (the difference being trailing zeroes on
floating point numbers); moving the test to the `hard_coded'
directory was the simplest way of fixing this.
Estimated hours taken: 50
Add support for nested modules.
- module names may themselves be module-qualified
- modules may contain `:- include_module' declarations
which name sub-modules
- a sub-module has access to all the declarations in the
parent module (including its implementation section).
This support is not yet complete; see the BUGS and LIMITATIONS below.
LIMITATIONS
- source file names must match module names
(just as they did previously)
- mmc doesn't allow path names on the command line any more
(e.g. `mmc --make-int ../library/foo.m').
- import_module declarations must use the fully-qualified module name
- module qualifiers must use the fully-qualified module name
- no support for root-qualified module names
(e.g. `:parent:child' instead of `parent:child').
- modules may not be physically nested (only logical nesting, via
`include_module').
BUGS
- doesn't check that the parent module is imported/used before allowing
import/use of its sub-modules.
- doesn't check that there is an include_module declaration in the
parent for each module claiming to be a child of that parent
- privacy of private modules is not enforced
-------------------
NEWS:
Mention that we support nested modules.
library/ops.m:
library/nc_builtin.nl:
library/sp_builtin.nl:
compiler/mercury_to_mercury.m:
Add `include_module' as a new prefix operator.
Change the associativity of `:' from xfy to yfx
(since this made parsing module qualifiers slightly easier).
compiler/prog_data.m:
Add new `include_module' declaration.
Change the `module_name' and `module_specifier' types
from strings to sym_names, so that module names can
themselves be module qualified.
compiler/modules.m:
Add predicates module_name_to_file_name/2 and
file_name_to_module_name/2.
Lots of changes to handle parent module dependencies,
to create parent interface (`.int0') files, to read them in,
to output correct dependencies information for them to the
`.d' and `.dep' files, etc.
Rewrite a lot of the code to improve the readability
(add comments, use subroutines, better variable names).
Also fix a couple of bugs:
- generate_dependencies was using the transitive implementation
dependencies rather than the transitive interface dependencies
to compute the `.int3' dependencies when writing `.d' files
(this bug was introduced during crs's changes to support
`.trans_opt' files)
- when creating the `.int' file, it was reading in the
interfaces for modules imported in the implementation section,
not just those in the interface section.
This meant that the compiler missed a lot of errors.
library/graph.m:
library/lexer.m:
library/term.m:
library/term_io.m:
library/varset.m:
compiler/*.m:
Add `:- import_module' declarations to the interface needed
by declarations in the interface. (The previous version
of the compiler did not detect these missing interface imports,
due to the above-mentioned bug in modules.m.)
compiler/mercury_compile.m:
compiler/intermod.m:
Change mercury_compile__maybe_grab_optfiles and
intermod__grab_optfiles so that they grab the opt files for
parent modules as well as the ones for imported modules.
compiler/mercury_compile.m:
Minor changes to handle parent module dependencies.
(Also improve the wording of the warning about trans-opt
dependencies.)
compiler/make_hlds.m:
compiler/module_qual.m:
Ignore `:- include_module' declarations.
compiler/module_qual.m:
A couple of small changes to handle nested module names.
compiler/prog_out.m:
compiler/prog_util.m:
Add new predicates string_to_sym_name/3 (prog_util.m) and
sym_name_to_string/{2,3} (prog_out.m).
compiler/*.m:
Replace many occurrences of `string' with `module_name'.
Change code that prints out module names or converts
them to strings or filenames to handle the fact that
module names are now sym_names intead of strings.
Also change a few places (e.g. in intermod.m, hlds_module.m)
where the code assumed that any qualified symbol was
fully-qualified.
compiler/prog_io.m:
compiler/prog_io_goal.m:
Move sym_name_and_args/3, parse_qualified_term/4 and
parse_qualified_term/5 preds from prog_io_goal.m to prog_io.m,
since they are very similar to the parse_symbol_name/2 predicate
already in prog_io.m. Rewrite these predicates, both
to improve maintainability, and to handle the newly
allowed syntax (module-qualified module names).
Rename parse_qualified_term/5 as `parse_implicit_qualified_term'.
compiler/prog_io.m:
Rewrite the handling of `:- module' and `:- end_module'
declarations, so that it can handle nested modules.
Add code to parse `include_module' declarations.
compiler/prog_util.m:
compiler/*.m:
Add new predicates mercury_public_builtin_module/1 and
mercury_private_builtin_module/1 in prog_util.m.
Change most of the hard-coded occurrences of "mercury_builtin"
to call mercury_private_builtin_module/1 or
mercury_public_builtin_module/1 or both.
compiler/llds_out.m:
Add llds_out__sym_name_mangle/2, for mangling module names.
compiler/special_pred.m:
compiler/mode_util.m:
compiler/clause_to_proc.m:
compiler/prog_io_goal.m:
compiler/lambda.m:
compiler/polymorphism.m:
Move the predicates in_mode/1, out_mode/1, and uo_mode/1
from special_pred.m to mode_util.m, and change various
hard-coded definitions to instead call these predicates.
compiler/polymorphism.m:
Ensure that the type names `type_info' and `typeclass_info' are
module-qualified in the generated code. This avoids a problem
where the code generated by polymorphism.m was not considered
type-correct, due to the type `type_info' not matching
`mercury_builtin:type_info'.
compiler/check_typeclass.m:
Simplify the code for check_instance_pred and
get_matching_instance_pred_ids.
compiler/mercury_compile.m:
compiler/modules.m:
Disallow directory names in command-line arguments.
compiler/options.m:
compiler/handle_options.m:
compiler/mercury_compile.m:
compiler/modules.m:
Add a `--make-private-interface' option.
The private interface file `<module>.int0' contains
all the declarations in the module; it is used for
compiling sub-modules.
scripts/Mmake.rules:
scripts/Mmake.vars.in:
Add support for creating `.int0' and `.date0' files
by invoking mmc with `--make-private-interface'.
doc/user_guide.texi:
Document `--make-private-interface' and the `.int0'
and `.date0' file extensions.
doc/reference_manual.texi:
Document nested modules.
util/mdemangle.c:
profiler/demangle.m:
Demangle names with multiple module qualifiers.
tests/general/Mmakefile:
tests/general/string_format_test.m:
tests/general/string_format_test.exp:
tests/general/string__format_test.m:
tests/general/string__format_test.exp:
tests/general/.cvsignore:
Change the `:- module string__format_test' declaration in
`string__format_test.m' to `:- module string_format_test',
because with the original declaration the `__' was taken
as a module qualifier, which lead to an error message.
Hence rename the file accordingly, to avoid the warning
about file name not matching module name.
tests/invalid/Mmakefile:
tests/invalid/missing_interface_import.m:
tests/invalid/missing_interface_import.err_exp:
Regression test to check that the compiler reports
errors for missing `import_module' in the interface section.
tests/invalid/*.err_exp:
tests/warnings/unused_args_test.exp:
tests/warnings/unused_import.exp:
Update the expected diagnostics output for the test cases to
reflect a few minor changes to the warning messages.
tests/hard_coded/Mmakefile:
tests/hard_coded/parent.m:
tests/hard_coded/parent.child.m:
tests/hard_coded/parent.exp:
tests/hard_coded/parent2.m:
tests/hard_coded/parent2.child.m:
tests/hard_coded/parent2.exp:
Two simple tests case for the use of nested modules with
separate compilation.
Estimated hours taken: 0.75
compiler/modecheck_unify.m:
Fix a bug which caused the compiler to generate incorrect
code for the case where a function had the same name and arity
as a data constructor (but a different return type),
and the data constructor was used with an explicit module
qualifier -- it incorrectly ignored the types and chose
the function rather than the data constructor.
tests/hard_coded/Mmakefile:
tests/hard_coded/func_ctor_ambig.m:
tests/hard_coded/func_ctor_ambig.exp:
Regression test.
Estimated hours taken: 3
Fix a bug that broke Tom's implementation of a random number generator at -O6.
The bug appeared only if value numbering is run for a second time after most
other low-level optimizations have been repeated several times. The problem
was that the first invocation of value numbering introduces a temp variable,
and the second one deletes the assignment to the temp variable because an
if_val with a liveness annotation comes between this assignment and the
first use of the temp variable.
compiler/livemap.m:
When an if_val is preceded by a livevals annotation,
do not replace the current liveness with the contents
of the annotation. Instead, just include the contents
of the annotation in the current set of live lvals.
tests/hard_coded/rnd.{m,exp}:
Tom's test case.
tests/hard_coded/Mmakefile:
Always run Tom's test case at -O6.
Estimated hours taken: 0.25
tests/hard_coded/Mmakefile:
Fix another bug in the handling of the `typeclasses'
subdirectory: ensure that variables are quoted when
passing them down to make subdirectories, so that it
works for settings such as EXTRA_MCFLAGS="-O2 --opt-space"
which contain embedded spaces.
Estimated hours taken: 0.5
tests/hard_coded/Mmakefile:
Link the `mode_choice' test with `--no-strip', to
work around a probably bug in the Solaris linker.
Estimated hours taken: 0.5
tests/hard_coded/Mmakefile:
Fix a couple of bugs introduced when dgj added a `typeclasses'
subdirectory:
- ensure that `mmake clean' and `mmake realclean' recursively
clean the subdirectories
- when recursively invoking the Mmakefiles in subdirectories,
make sure we pass down the values of the GRADE, EXTRA_CFLAGS
and EXTRA_MCFLAGS variables.
Estimated hours taken: 0.05
tests/hard_coded/Mmakefile:
Remove typeclass_test_* from the Mmakefile, as these tests now reside
in the tyepclasses directory.
Estimated hours taken: 3 (plus 1 from dgj)
compiler/polymorphism.m:
For calls to class methods, if the particular class instance is
known at the call site, then specialize the code by generating
a direct call to the method for that instance.
tests/invalid/Mmakefile:
tests/invalid/typeclass_test_{1,2,3,4}.m:
tests/invalid/typeclass_test_{1,2,3,4}.err_exp:
tests/hard_coded/Mmakefile:
tests/hard_coded/typeclass_test_{5,6}.m:
tests/hard_coded/typeclass_test_{5,6}.exp:
Some test cases for type classes, including one for the above change.
Estimated hours taken: 0.25
Fix a bug reported by Mark Brown that caused type_to_term
to fail when used for values of type `character'.
library/mercury_builtin.m:
Fix a bug in the hand-coded base_type_info for the
"character" type -- it had the type name as "char", not
"character"
tests/hard_coded/Mmakefile:
tests/hard_coded/ground_dd.m:
tests/hard_coded/ground_dd.exp:
Regression test.
Estimated hours taken: 0.5
library/io.m:
Fix a bug in io__remove_file_2 that was spotted by
Thomas By <T.By@dcs.shef.ac.uk>: a call to strcpy()
in the pragma c_code had the wrong argument, causing
it to do the wrong thing in the case where io__remove_file
returned an error.
tests/hard_coded/Mmakefile:
tests/hard_coded/remove_file.m:
tests/hard_coded/remove_file.exp:
Regression test.
Estimated hours taken: 4
Fix a bug that caused the compiler to report spurious unique mode
errors for cases involving nested conjunctions, reordering, and
unique modes.
compiler/modes.m:
When modechecking conjunctions, if the conjunction as a whole
delays, make sure that we restore the original live_vars set.
compiler/mode_info.m:
Add mode_info_get_live_vars/2 and mode_info_set_live_vars/3,
for use by modes.m.
tests/hard_coded/Mmakefile:
tests/hard_coded/reorder_di.m:
tests/hard_coded/reorder_di.exp:
Regression test for the above-mentioned bug.
Estimated hours taken: 8
compiler/pragma_c_gen.m:
Fix a bug where semidet pragma c_codes didn't work in non-gc grades.
The problem was that in the following code fragment
{ <the c code itself> }
#ifndef CONSERVATIVE_GC
restore_registers();
#endif
if (r1) ...
the C code would assign to SUCCESS_INDICATOR, which is #defined
to `r1', and then the call to restore_registers() would clobber r1.
In the process of fixing the bug, reorganize the code for
generating ordinary (det/semi) pragma_c so that it more closely
matches the layout of the code it generates, and add a few comments.
compiler/dupelim.m:
Fix a bug in dupelim__build_maps: a lambda expression was using
the same variable name (`Label') as the code outside it,
resulting in it accidentally capturing that variable rather
than being a fresh variable.
compiler/frameopt.m:
Fix a bug in possible_targets/2: the possible targets for
a `pragma_c' instruction include the label, if it has one.
compiler/opt_util.m:
Update the comments for component_can_branch_away/2
to reflect the fact that pragma_c_raw_code components for
semidet pragma c_codes can branch away. Also check for the
special case of an empty string in pragma_c_raw_code.
tests/hard_coded/Mmakefile:
Re-enable the `pragma_import' test which uncovered this bug.
Estimated hours taken: 0.5
tests/hard_coded/Mmakefile:
Add `GRADEFLAGS-pragma_import = --gc conservative',
because the `pragma_import' test currently does not
work in non-gc grades.
Estimated hours taken: 20
Add support for `pragma import', which is a simplified form of
`pragma c_code'. With `pragma import', the user specifies only
the C function name, rather than a C code fragment, and the
Mercury compiler handles the argument-passing automatically.
TODO
- add documentation to doc/reference_manual.texi.
WISHLIST
- change `pragma import' and `pragma export'
to take an additional parameter indicating the language
(e.g. C, Prolog, Ada, Fortran, etc.) and/or calling
convention
compiler/prog_data.m:
Add `pragma import' to the parse tree data structure.
compiler/prog_io_pragma.m:
Add code to parse `pragma import' declarations.
compiler/mercury_to_mercury.m:
Add code to pretty-print `pragma import' declarations.
compiler/module_qual.m:
Add code to module-qualify `pragma import' declarations.
compiler/make_hlds.m:
Add code to process `pragma import' declarations,
by converting them to clauses with HLDS `c_code' instructions.
compiler/export.m:
Declare `export__exclude_argument_type' in the interface,
for use by the code for handling `pragma import' in make_hlds.m.
Change the documentation to say that this procedure is used for
both exported and imported procedures.
compiler/notes/compiler_design.html:
Document how the compiler handles `pragma import' declarations.
tests/hard_coded/Mmakefile:
tests/hard_coded/pragma_import.m:
tests/hard_coded/pragma_import.exp:
Add some test cases for `pragma import'.
Estimated hours taken: 5
library/std_util.m:
Fix a bug in ML_create_type_info():
when searching for type parameters to substituting with their
corresponding values, they were only looking at the top level
of the type. To get correct results, it is necessary to
traverse recursively through all levels of the type.
runtime/mercury_deep_copy.c:
Fix a bug similar to the one above in make_type_info().
The fix is a bit more complicated, due to memory management
issues --- we need to keep a linked list of all the memory
cells we allocate so that we can free them when we're done.
Also avoid some duplicated code in mercury_deep_copy.c
by introducing a new function deep_copy_arg().
And fix a bug in deep_copy_type_info(): it should be
allocating memory using incr_saved_hp(), not using
make(). make() calls newmem(), which in non-conservative GC
grades calls malloc(), which results in a memory leak;
whereas incr_saved_hp() allocates on the Mercury heap,
which is (in accurate gc grades) subject to garbage collection.
tests/hard_coded/Mmakefile:
tests/hard_coded/eqv_type_bug.m:
tests/hard_coded/eqv_type_bug.exp:
Regression test for the above-mentioned bug in ML_create_type_info().
The purpose of this diff is to allow Mercury programs to contain
impure Mercury code without the compiler changing its behavior
inappropriately, while still allowing the compiler to aggressively
optimize pure code. To do this, we require impure predicates to be so
declared, and calls to impure predicates to be flagged as such. We
also allow predicates implemented in terms of impure predicates to be
promised to be pure; lacking such a promise, any predicate that calls
an impure predicate is assumed to be impure.
At the moment, we don't allow impure functions (only predicates),
though some of the work necessary to support them has been done.
Note that to make the operators work properly, the precedence of the
`pred' and `func' operators has been changed from 1199 to 800.
Estimated hours taken: 150
compiler/purity.m:
New compiler pass for purity checking.
compiler/hlds_goal.m:
Add `impure' and `semipure' to the goal_feature enum.
compiler/hlds_out.m:
compiler/typecheck.m:
compiler/special_pred.m:
Fixed code that prints predicate name to write something more
helpful for special (compiler-generated) predicates. Added
code to print new markers. Added purity argument to
mercury_output_pred_type. New public predicate
special_pred_description/2 provides an english description for
each compiler-generated predicate.
compiler/hlds_pred.m:
Add `impure' and `semipure' to marker enum. Added new
public predicates to get predicate purity and whether or not
it's promised to be pure.
compiler/prog_data.m:
compiler/mercury_to_mercury.m:
compiler/prog_io.m:
compiler/prog_io_goal.m:
compiler/prog_io_pragma.m:
compiler/prog_io_dcg.m:
compiler/prog_util.m:
compiler/equiv_type.m:
compiler/intermod.m:
compiler/mercury_to_c.m:
compiler/module_qual.m:
Add purity argument to pred and func items. Add new `impure'
and `semipure' operators. Add promise_pure pragma. Add
purity/2 wrapper to goal_expr type.
compiler/make_hlds.m:
compiler/mercury_to_goedel.m:
Added purity argument to module_add_{pred,func},
clauses_info_add_pragma_c_code, and to pred and func items.
Handle promise_pure pragma. Handle purity/2 wrapper used to
handle user-written impurity annotations on goals.
compiler/mercury_compile.m:
Add purity checking pass between type and mode checking.
compiler/mode_errors.m:
Distinguish mode errors caused by impure goals preventing
goals being delayed.
compiler/modes.m:
Don't delay impure goals, and ensure before scheduling an
impure goal that no goals are delayed. Actually, we go ahead
and try to schedule goals even if impurity causes a problem,
and then if it still doesn't mode check, then we report an
ordinary mode error. Only if the clause would be mode correct
except for an impure goal do we report it as an impurity problem.
compiler/simplify.m:
Don't optimize away non-pure duplicate calls. We could do
better and still optimize duplicate semipure goals without an
intervening impure goal, but it's probably not worth the
trouble. Also don't eliminate impure goals on a failing branch.
compiler/notes/compiler_design.html:
Documented purity checking pass.
doc/reference_manual.texi:
Document purity system.
doc/transition_guide.texi:
library/nc_builtin.nl:
library/ops.m:
library/sp_builtin.nl:
New operators and new precdence for `pred' and `func'
operators.
tests/hard_coded/purity.m
tests/hard_coded/purity.exp
tests/hard_coded/Mmakefile:
tests/invalid/purity.m
tests/invalid/purity_nonsense.m
tests/invalid/purity.err_exp
tests/invalid/purity_nonsense.err_exp
tests/invalid/Mmakefile:
Test cases for purity.
Estimated hours taken: 6
Change the way mode analysis chooses which mode of a predicate to call.
If there are multiple matching modes, choose the best one, rather
than just the first one. "Best" is determined by comparing the
argument insts and livenesses, and (if that fails) determinism
of all the modes which do match. If two modes are equal, or
incomparable, in this partial ordering, we choose the first one
(according to the order in which they were declared).
Still to do (will be committed seperately): delete the hacks in make_hlds.m
etc. that assign mode numbers with a priority based on determinism.
compiler/modecheck_call.m:
For calls to predicates with multiple modes, find all the modes
which match and select the best one, rather than just picking
the first one that matches.
compiler/det_report.m:
Export compare_determinism/3, for use by modecheck_call.m.
NEWS:
LIMITATIONS:
We've fixed one of the limitations: unique mode declarations
no longer have to precede non-unique mode declarations.
tests/hard_coded/Mmakefile:
tests/hard_coded/mode_choice.m:
tests/hard_coded/mode_choice.exp:
Some tests cases for this change.
