Add ShowUsedInfoClasses

doc/ref/debug.xml

@@ -106,6 +106,8 @@ algorithms for the computation of a subgroup lattice.
 Note that not all info classes defined in the ⪆ library are currently
 documented.  Many ⪆ packages define additional info classes, which are
 typically documented in the corresponding package documentation.
+The function <Ref Func="ShowUsedInfoClasses"/> will show all info classes which
+&GAP; considers while executing code.
 <P/>
 The amount of information to be displayed by each info class can be separately
 specified by the user. This is done by selecting a non-negative integer
@@ -158,6 +160,35 @@ returns the info level of <A>infoclass</A>.
 </Description>
 </ManSection>
 <P/>
+<ManSection>
+<Func Name="ShowUsedInfoClasses" Arg='infoclass'/>
+
+<Description>
+Called with argument <K>true</K>, this makes &GAP; print the info class and level of
+ any executed <Ref Func="Info"/> statement. Calling with the argument <K>false</K> stops this
+ printing.
+
+Each level of each InfoClass is only printed once. The history of printed
+info classes and levels is reset whenever <K>true</K> is passed.
+<P/>
+
+<Example><![CDATA[
+gap> ShowUsedInfoClasses(true);
+gap> Intersection(Group((1,3,2,4,5,6)), Group((1,2,3,4,5,6)));
+#I Would print info with SetInfoLevel(InfoOptions,1)
+#I Would print info with SetInfoLevel(InfoBckt,1)
+#I Would print info with SetInfoLevel(InfoBckt,3)
+#I Would print info with SetInfoLevel(InfoBckt,5)
+Group(())
+gap> Intersection(Group((1,3,2,4,5,6)), Group((1,2,3,4,5,6)));
+Group(())
+gap> ShowUsedInfoClasses(false);
+]]></Example>
+
+</Description>
+</ManSection>
+<P/>
+
 <ManSection>
 <Func Name="Info" Arg='infoclass, level, info[, moreinfo ...]'/>
 

lib/info.gd

@@ -131,6 +131,7 @@ DeclareOperation("InfoLevel", [IsInfoClass]);
 DeclareGlobalFunction("SetInfoHandler");
 DeclareGlobalFunction("DefaultInfoHandler");
 
+
 #############################################################################
 ##
 ##  

lib/info.gi

@@ -315,6 +315,43 @@ BIND_GLOBAL( "InfoDecision", function(selectors, level)
 end );
 
 
+#############################################################################
+##
+## The following functions are used by ShowUsedInfoClasses
+##
+## SHOWN_USED_INFO_CLASSES contains the InfoClasses which have been printed
+## out by ShowUsedInfoClasses.
+## RESET_SHOW_USED_INFO_CLASSES and SHOW_USED_INFO_CLASSES are called from
+## the kernel.
+
+SHOWN_USED_INFO_CLASSES := [];
+
+if IsHPCGAP then
+    ShareInternalObj(INFO_CLASSES);
+fi;
+
+
+BIND_GLOBAL("RESET_SHOW_USED_INFO_CLASSES", function()
+    atomic readwrite SHOWN_USED_INFO_CLASSES do
+        SHOWN_USED_INFO_CLASSES := [];
+    od;
+end);
+
+BIND_GLOBAL("SHOW_USED_INFO_CLASSES", function(selectors, level)
+    local selector;
+    # Handle selectors possibly being a list
+    selectors := Flat([selectors]);
+    atomic readwrite SHOWN_USED_INFO_CLASSES do
+        for selector in selectors do
+            if not [selector, level] in SHOWN_USED_INFO_CLASSES then
+                Add(SHOWN_USED_INFO_CLASSES, [selector, level]);
+                Print("#I Would print info with SetInfoLevel(",
+                    selector, ",", level, ")\n");
+            fi;
+        od;
+    od;
+end);
+
 #############################################################################
 ##
 #V  InfoDebug

src/gapstate.h

@@ -104,6 +104,9 @@ typedef struct GAPState {
     Int PrintObjIndex;
     Int PrintObjDepth;
 
+    /* From info.c */
+    Int ShowUsedInfoClassesActive;
+
     UInt1 StateSlots[STATE_SLOTS_SIZE];
 
 /* Allocation */

src/info.c

@@ -15,6 +15,8 @@
 
 #include "bool.h"
 #include "calls.h"
+#include "error.h"
+#include "gapstate.h"
 #include "gvars.h"
 #include "modules.h"
 #include "plist.h"
@@ -34,6 +36,24 @@ enum {
 static Obj InfoDecision;
 static Obj IsInfoClassListRep;
 static Obj DefaultInfoHandler;
+static Obj ResetShowUsedInfoClassesHandler;
+static Obj ShowUsedInfoClassesHandler;
+
+
+Obj FuncShowUsedInfoClasses(Obj self, Obj choice)
+{
+    if (choice == True) {
+        STATE(ShowUsedInfoClassesActive) = 1;
+        CALL_0ARGS(ResetShowUsedInfoClassesHandler);
+    }
+    else if (choice == False) {
+        STATE(ShowUsedInfoClassesActive) = 0;
+    }
+    else {
+        ErrorMayQuit("<setting> should be true or false", 0, 0);
+    }
+    return 0;
+}
 
 void InfoDoPrint(Obj cls, Obj lvl, Obj args)
 {
@@ -53,6 +73,9 @@ void InfoDoPrint(Obj cls, Obj lvl, Obj args)
 
 Obj InfoCheckLevel(Obj selectors, Obj level)
 {
+    if (STATE(ShowUsedInfoClassesActive)) {
+        CALL_2ARGS(ShowUsedInfoClassesHandler, selectors, level);
+    }
     // Fast-path the most common failing case.
     // The fast-path only deals with the case where all arguments are of the
     // correct type, and were False is returned.
@@ -77,17 +100,32 @@ Obj InfoCheckLevel(Obj selectors, Obj level)
 *F * * * * * * * * * * * * * initialize module * * * * * * * * * * * * * * *
 */
 
+/****************************************************************************
+**
+*V  GVarFuncs . . . . . . . . . . . . . . . . . . list of functions to export
+*/
+static StructGVarFunc GVarFuncs[] = {
+    GVAR_FUNC(ShowUsedInfoClasses, 1, "choice"), { 0, 0, 0, 0, 0 }
+};
+
 
 /****************************************************************************
 **
 *F  InitKernel( <module> )  . . . . . . . . initialise kernel data structures
 */
 static Int InitKernel(StructInitInfo * module)
 {
+    /* init filters and functions                                          */
+    InitHdlrFuncsFromTable(GVarFuncs);
+
     /* The work of handling Info messages is delegated to the GAP level */
     ImportFuncFromLibrary("InfoDecision", &InfoDecision);
     ImportFuncFromLibrary("DefaultInfoHandler", &DefaultInfoHandler);
     ImportFuncFromLibrary("IsInfoClassListRep", &IsInfoClassListRep);
+    ImportFuncFromLibrary("RESET_SHOW_USED_INFO_CLASSES",
+                          &ResetShowUsedInfoClassesHandler);
+    ImportFuncFromLibrary("SHOW_USED_INFO_CLASSES",
+                          &ShowUsedInfoClassesHandler);
 
     /* return success                                                      */
     return 0;
@@ -100,6 +138,9 @@ static Int InitKernel(StructInitInfo * module)
 */
 static Int InitLibrary(StructInitInfo * module)
 {
+
+    InitGVarFuncsFromTable(GVarFuncs);
+
     ExportAsConstantGVar(INFODATA_CURRENTLEVEL);
     ExportAsConstantGVar(INFODATA_CLASSNAME);
     ExportAsConstantGVar(INFODATA_HANDLER);

tst/testinstall/info.tst

@@ -53,6 +53,20 @@ gap> Info(InfoTest1 + InfoTest2, 0);
 Error, level 0 Info messages are not allowed
 gap> Info(InfoTest1 + InfoTest2, "apple");
 Error, usage : Info(<selectors>, <level>, ...)
+gap> ShowUsedInfoClasses(true);
+gap> Info(InfoTest2, 2, "apple");
+#I Would print info with SetInfoLevel(InfoTest2,2)
+#I Would print info with SetInfoLevel(InfoGlobal,3)
+#I  apple
+gap> Info(InfoTest1 + InfoTest2, 2, "apple");
+#I Would print info with SetInfoLevel(InfoTest1,2)
+#I  apple
+gap> Info(InfoTest1 + InfoTest2, 2, "apple");
+#I  apple
+gap> Info(InfoTest1 + InfoTest2, 3, "apple");
+#I Would print info with SetInfoLevel(InfoTest1,3)
+#I Would print info with SetInfoLevel(InfoTest2,3)
+gap> ShowUsedInfoClasses(false);
 gap> str := "";;
 gap> str2 := "";;
 gap> SetDefaultInfoOutput(OutputTextString(str, false));