Profiling code with lots of lambda goals was painful, because the names

Estimated hours taken: 1.5

Profiling code with lots of lambda goals was painful, because the names
of the predicates contained no information about which piece of the source
they correspond to. This change corrects this problem by enabling the
profiler to produce output such as:

... 0.00     0.00 <pred/func goal from lp:'pivot', line 362> [10]
... 0.00     0.00 <pred/func goal from lp:'pivot', line 356> [11]
... 0.00     0.00 <pred/func goal from lp:'simplex', line 262> [12]

compiler/lambda.m:
compiler/polymorphism.m:
	construct more meaningful predicate names for lambda predicates.
	this required adding the name of the predicate that contained the
	lambda goal to the info structures that gets threaded through
	these modules.

profiler/demangle.m:
util/mdemangle.c:
	demangle the names for lambda goals.

compiler/lambda.m

@@ -41,11 +41,11 @@
 :- pred lambda__process_pred(pred_id, module_info, module_info).
 :- mode lambda__process_pred(in, in, out) is det.
 
-:- pred lambda__transform_lambda(pred_or_func, list(var), list(mode), 
+:- pred lambda__transform_lambda(pred_or_func, string, list(var), list(mode), 
 		determinism, set(var), hlds_goal, unification,
 		varset, map(var, type), tvarset, map(tvar, var), module_info,
 		unify_rhs, unification, module_info).
-:- mode lambda__transform_lambda(in, in, in, in, in, in, in, in, in, in, in,
+:- mode lambda__transform_lambda(in, in, in, in, in, in, in, in, in, in, in, in,
 		in, out, out, out) is det.
 
 	% Permute the list of variables so that inputs come before outputs.
@@ -69,6 +69,8 @@
 			map(var, type),		% from the proc_info
 			tvarset,		% from the proc_info
 			map(tvar, var),		% from the proc_info (typeinfos)
+			pred_or_func,
+			string,			% pred/func name
 			module_info
 		).
 
@@ -115,6 +117,8 @@ lambda__process_proc(PredId, ProcId, ModuleInfo0, ModuleInfo) :-
 lambda__process_proc_2(ProcInfo0, PredInfo0, ModuleInfo0,
 				ProcInfo, PredInfo, ModuleInfo) :-
 	% grab the appropriate fields from the pred_info and proc_info
+	pred_info_name(PredInfo0, PredName),
+	pred_info_get_is_pred_or_func(PredInfo0, PredOrFunc),
 	pred_info_typevarset(PredInfo0, TypeVarSet0),
 	proc_info_variables(ProcInfo0, VarSet0),
 	proc_info_vartypes(ProcInfo0, VarTypes0),
@@ -123,9 +127,11 @@ lambda__process_proc_2(ProcInfo0, PredInfo0, ModuleInfo0,
 
 	% process the goal
 	Info0 = lambda_info(VarSet0, VarTypes0, TypeVarSet0, TVarMap0, 
+		PredOrFunc, PredName,
 		ModuleInfo0),
 	lambda__process_goal(Goal0, Goal, Info0, Info),
 	Info = lambda_info(VarSet, VarTypes, TypeVarSet, TVarMap, 
+		_, _,
 		ModuleInfo),
 
 	% set the new values of the fields in proc_info and pred_info
@@ -219,16 +225,18 @@ lambda__process_cases([case(ConsId, Goal0) | Cases0],
 lambda__process_lambda(PredOrFunc, Vars, Modes, Det, OrigNonLocals0, LambdaGoal,
 		Unification0, Functor, Unification, LambdaInfo0, LambdaInfo) :-
 	LambdaInfo0 = lambda_info(VarSet, VarTypes, TVarSet, TVarMap, 
-			ModuleInfo0),
-	lambda__transform_lambda(PredOrFunc, Vars, Modes, Det, OrigNonLocals0, 
-		LambdaGoal, Unification0, VarSet, VarTypes, TVarSet, TVarMap, 
-		ModuleInfo0, Functor, Unification, ModuleInfo),
+			POF, PredName, ModuleInfo0),
+	lambda__transform_lambda(PredOrFunc, PredName, Vars, Modes, Det,
+		OrigNonLocals0, LambdaGoal, Unification0, VarSet, VarTypes,
+		TVarSet, TVarMap, ModuleInfo0, Functor,
+		Unification, ModuleInfo),
 	LambdaInfo = lambda_info(VarSet, VarTypes, TVarSet, TVarMap, 
-		ModuleInfo).
+			POF, PredName, ModuleInfo).
 
-lambda__transform_lambda(PredOrFunc, Vars, Modes, Detism, OrigNonLocals0, 
-		LambdaGoal, Unification0, VarSet, VarTypes, TVarSet, TVarMap, 
-		ModuleInfo0, Functor, Unification, ModuleInfo) :-
+lambda__transform_lambda(PredOrFunc, OrigPredName, Vars, Modes, Detism,
+		OrigNonLocals0, LambdaGoal, Unification0, VarSet, VarTypes,
+		TVarSet, TVarMap, ModuleInfo0, Functor,
+		Unification, ModuleInfo) :-
 	(
 		Unification0 = construct(Var0, _, _, UniModes0)
 	->
@@ -308,10 +316,10 @@ lambda__transform_lambda(PredOrFunc, Vars, Modes, Detism, OrigNonLocals0,
 		module_info_name(ModuleInfo0, ModuleName),
 		module_info_next_lambda_count(ModuleInfo0, LambdaCount,
 					ModuleInfo1),
-		string__int_to_string(LambdaCount, LambdaCountStr),
-		string__append("__LambdaGoal__", LambdaCountStr, PName0),
-		string__append(ModuleName, PName0, PName),
-		PredName = qualified(ModuleName, PName),
+		goal_info_get_context(LambdaGoalInfo, OrigContext),
+		term__context_line(OrigContext, OrigLine),
+		make_lambda_name(ModuleName, PredOrFunc, OrigPredName,
+			OrigLine, LambdaCount, PredName),
 		goal_info_get_context(LambdaGoalInfo, LambdaContext),
 		% the TVarSet is a superset of what it really ought be,
 		% but that shouldn't matter
@@ -370,6 +378,21 @@ lambda__transform_lambda(PredOrFunc, Vars, Modes, Detism, OrigNonLocals0,
 	ConsId = pred_const(PredId, ProcId),
 	Unification = construct(Var, ConsId, ArgVars, UniModes).
 
+:- pred make_lambda_name(string, pred_or_func, string, int, int, sym_name).
+:- mode make_lambda_name(in, in, in, in, in, out) is det.
+
+make_lambda_name(ModuleName, PredOrFunc, PredName, Line, Counter, SymName) :-
+	(
+		PredOrFunc = predicate,
+		PFS = "pred"
+	;
+		PredOrFunc = function,
+		PFS = "func"
+	),
+	string__format("IntroducedFrom__%s__%s__%d__%d",
+		[s(PFS), s(PredName), i(Line), i(Counter)], Name),
+		SymName = qualified(ModuleName, Name).
+
 :- pred lambda__uni_modes_to_modes(list(uni_mode), list(mode)).
 :- mode lambda__uni_modes_to_modes(in, out) is det.