[merge] You can now set compiler flags in BUILD.plz files

* build_compiler_opts:
  [build] Gracefully error when a module has conflicting compiler options
  [build] Add a compiler_opts field to program entrie
  [build] Fix indentation in ninja rules
  [build] Simplify error message creation for interpreting TOML files
  [build] Add a utility function for default results from TOML searches
  [build] Refactor the TOML search_result type
  [build] Refactor how modules are processed
  [build] rename the pc/pl flags ninja variables

src/context.m

@@ -44,6 +44,10 @@
     %
 :- func context_string(string, context) = string.
 
+%-----------------------------------------------------------------------%
+
+:- func context_earliest(context, context) = context.
+
 %-----------------------------------------------------------------------%
 %-----------------------------------------------------------------------%
 
@@ -88,5 +92,9 @@
         Pretty = format("%s:%d", [s(File), i(Line)])
     ).
 
+%-----------------------------------------------------------------------%
+
+context_earliest(C1, C2) = ( if compare((<), C1, C2) then C1 else C2 ).
+
 %-----------------------------------------------------------------------%
 %-----------------------------------------------------------------------%

src/util.mercury.m

@@ -15,6 +15,7 @@
 :- import_module getopt.
 :- import_module io.
 :- import_module list.
+:- import_module map.
 :- import_module maybe.
 :- import_module pair.
 :- import_module set.
@@ -111,6 +112,11 @@
 
 :- func handle_bool_option(option_table(O), O, T, T) = T.
 
+%-----------------------------------------------------------------------%
+
+:- pred map_set_or_update(func(V) = V, K, V, map(K, V), map(K, V)).
+:- mode map_set_or_update(in, in, in, in, out) is det.
+
 %-----------------------------------------------------------------------%
 %-----------------------------------------------------------------------%
 :- implementation.
@@ -347,5 +353,14 @@
         Result = False
     ).
 
+%-----------------------------------------------------------------------%
+
+map_set_or_update(UpdateFn, Key, Value, !Map) :-
+    ( if search(!.Map, Key, OldValue) then
+        det_update(Key, UpdateFn(OldValue), !Map)
+    else
+        set(Key, Value, !Map)
+    ).
+
 %-----------------------------------------------------------------------%
 %-----------------------------------------------------------------------%

src/util.result.m

@@ -16,6 +16,7 @@
 :- import_module io.
 :- import_module cord.
 :- import_module list.
+:- import_module map.
 :- import_module maybe.
 
 :- import_module context.
@@ -97,6 +98,23 @@ func error_or_warning(E) = error_or_warning
 
 :- func result_map((func(T) = U), result(T, E)) = result(U, E).
 
+%-----------------------------------------------------------------------%
+
+    % foldl over a list except the accumulator includes a result that must
+    % be unpact before processing the next item.  If mercury had monads this
+    % would be bind.
+    %
+:- pred foldl_result(pred(X, A, result(A, E)), list(X),
+    A, result(A, E)).
+:- mode foldl_result(pred(in, in, out) is det, in, in, out) is det.
+
+    % Set or update the value within a map at the given key.  if the update
+    % function fails then return that error.
+    %
+:- pred map_set_or_update_result(func(V) = result(V, E),
+    K, V, map(K, V), result(map(K, V), E)).
+:- mode map_set_or_update_result(in, in, in, in, out) is det.
+
 %-----------------------------------------------------------------------%
 
 :- func errors_map((func(E1) = E2), errors(E1)) = errors(E2).
@@ -205,6 +223,33 @@ func error_or_warning(E) = error_or_warning
 
 %-----------------------------------------------------------------------%
 
+foldl_result(_, [], Acc, ok(Acc)).
+foldl_result(Pred, [X | Xs], Acc0, MaybeAcc) :-
+    Pred(X, Acc0, MaybeAcc1),
+    ( MaybeAcc1 = ok(Acc1),
+        foldl_result(Pred, Xs, Acc1, MaybeAcc)
+    ; MaybeAcc1 = errors(Error),
+        MaybeAcc = errors(Error)
+    ).
+
+%-----------------------------------------------------------------------%
+
+map_set_or_update_result(UpdateFn, Key, Value, !.Map, MaybeMap) :-
+    ( if search(!.Map, Key, Old) then
+        MaybeNew = UpdateFn(Old),
+        ( MaybeNew = ok(New),
+            det_update(Key, New, !Map),
+            MaybeMap = ok(!.Map)
+        ; MaybeNew = errors(Error),
+            MaybeMap = errors(Error)
+        )
+    else
+        set(Key, Value, !Map),
+        MaybeMap = ok(!.Map)
+    ).
+
+%-----------------------------------------------------------------------%
+
 errors_map(Func, Errors) = map(error_map(Func), Errors).
 
 :- func error_map((func(E1) = E2), error(E1)) = error(E2).

tests/build/options_compiler_01.build

@@ -0,0 +1,8 @@
+# This is free and unencumbered software released into the public domain.
+# See ../LICENSE.unlicense
+
+[options_compiler_01]
+type = program
+modules = [ OptionsCompiler01 ]
+compiler_opts = "--no-simplify"
+

tests/build/options_compiler_01.exp

@@ -0,0 +1 @@
+Hello world

tests/build/options_compiler_01.p

@@ -0,0 +1,15 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module OptionsCompiler01
+
+entrypoint
+func hello() uses IO -> Int {
+    print!("Hello world\n")
+
+    return 0
+}
+

tests/build/options_compiler_02.build

@@ -0,0 +1,10 @@
+# This is free and unencumbered software released into the public domain.
+# See ../LICENSE.unlicense
+
+# PLZTEST type compile_failure
+
+[options_compiler_02]
+type = program
+modules = [ OptionsCompiler02 ]
+compiler_opts = "--nonexistant-option"
+

tests/build/options_compiler_02.exp

@@ -0,0 +1 @@
+Error processing command line options: unrecognized option `--nonexistant-option'

tests/build/options_compiler_02.p

@@ -0,0 +1,15 @@
+/*
+ * vim: ft=plasma
+ * This is free and unencumbered software released into the public domain.
+ * See ../LICENSE.unlicense
+ */
+
+module OptionsCompiler02
+
+entrypoint
+func hello() uses IO -> Int {
+    print!("Hello world\n")
+
+    return 0
+}
+

tests/build/options_compiler_03.build

@@ -0,0 +1,17 @@
+# This is free and unencumbered software released into the public domain.
+# See ../LICENSE.unlicense
+
+# PLZTEST type compile_failure
+
+# This test asks the build system to build the same module with different
+# settings, it should fail.
+
+[options_compiler_03a]
+type = program
+modules = [ OptionsCompiler03a, OptionsCompiler03 ]
+compiler_opts = "--no-simplify"
+
+[options_compiler_03b]
+type = program
+modules = [ OptionsCompiler03b, OptionsCompiler03 ]
+

tests/build/options_compiler_03.exp

@@ -0,0 +1,2 @@
+options_compiler_03.build:11: Flags set for the same module in different
+                              programs do not match