modula2: iso library SysClock.mod and wrapclock.cc fixes.

This patch corrects the C equivalent of m2 LONGINT parameters
in wrapclock.cc and corrects the SysClock.mod module.
wrapclock.cc uses a typedef long long int longint_t to match
m2 LONGINT (rather than unsigned long).  These fixes
prevent calls to SysClock hanging spinning on an (incorrect)
large day count from the epoch.

gcc/m2/ChangeLog:

	* gm2-compiler/M2Quads.mod (EndBuildFor): Improve
	block comments.
	* gm2-libs-iso/SysClock.mod (ExtractDate): Replace
	testDays with yearOfDays.  New local variable monthOfDays.

libgm2/ChangeLog:

	* libm2iso/wrapclock.cc (longint_t): New declaration.
	(GetTimespec): Replace types for sec and nano with
	longint_t.
	(SetTimespec): Replace types for sec and nano with
	longint_t.

Signed-off-by: Gaius Mulley <gaiusmod2@gmail.com>

2 files changed, 15 insertions, 11 deletions

diff --git a/gcc/m2/gm2-compiler/M2Quads.mod b/gcc/m2/gm2-compiler/M2Quads.mod
index 95ca15a..f3a5c05 100644
--- a/gcc/m2/gm2-compiler/M2Quads.mod
+++ b/gcc/m2/gm2-compiler/M2Quads.mod
@@ -4625,7 +4625,7 @@ BEGIN
       BuildRange (InitForLoopEndRangeCheck (tsym, BySym)) ;  (* --fixme-- pass endpostok.  *)
       IncQuad := NextQuad ;
       (* we have explicitly checked using the above and also
-         this addition can legally overflow if a cardinal type
+         this addition can legitimately overflow if a cardinal type
          is counting down.  The above test will generate a more
          precise error message, so we suppress overflow detection
          here.  *)
@@ -4636,7 +4636,7 @@ BEGIN
       BuildRange (InitForLoopEndRangeCheck (IdSym, BySym)) ;
       IncQuad := NextQuad ;
       (* we have explicitly checked using the above and also
-         this addition can legally overflow if a cardinal type
+         this addition can legitimately overflow if a cardinal type
          is counting down.  The above test will generate a more
          precise error message, so we suppress overflow detection
          here.  *)
@@ -5548,7 +5548,7 @@ END IsReallyPointer ;
 
 
 (*
-   LegalUnboundedParam - returns TRUE if the parameter, Actual, can legally be
+   LegalUnboundedParam - returns TRUE if the parameter, Actual, can legitimately be
                          passed to ProcSym, i, the, Formal, parameter.
 *)
 
diff --git a/gcc/m2/gm2-libs-iso/SysClock.mod b/gcc/m2/gm2-libs-iso/SysClock.mod
index 56d5503..5f2c377 100644
--- a/gcc/m2/gm2-libs-iso/SysClock.mod
+++ b/gcc/m2/gm2-libs-iso/SysClock.mod
@@ -137,7 +137,8 @@ END daysInYear ;
 
 
 (*
-   ExtractDate - extracts the year, month, day from days.
+   ExtractDate - extracts the year, month, day from secs.  days is the
+                 total days since 1970.
 *)
 
 PROCEDURE ExtractDate (days: LONGCARD;
@@ -145,28 +146,29 @@ PROCEDURE ExtractDate (days: LONGCARD;
 VAR
    testMonth,
    testYear : CARDINAL ;
-   testDays : LONGCARD ;
+   monthOfDays,
+   yearOfDays : LONGCARD ;
 BEGIN
    testYear := 1970 ;
    LOOP
-      testDays := daysInYear (31, 12, testYear) ;
-      IF days < testDays
+      yearOfDays := daysInYear (31, 12, testYear) ;
+      IF days < yearOfDays
       THEN
          year := testYear ;
          testMonth := 1 ;
          LOOP
-            testDays := daysInMonth (year, testMonth) ;
-            IF days < testDays
+            monthOfDays := daysInMonth (year, testMonth) ;
+            IF days < monthOfDays
             THEN
                day := VAL (Day, days) + MIN (Day) ;
                month := VAL (Month, testMonth) ;
                RETURN
             END ;
-            DEC (days, testDays) ;
+            DEC (days, monthOfDays) ;
             INC (testMonth)
          END
       ELSE
-         DEC (days, testDays) ;
+         DEC (days, yearOfDays) ;
          INC (testYear)
       END
    END
@@ -218,6 +220,8 @@ BEGIN
                printf ("getclock = %ld\n", sec)
             END ;
             WITH userData DO
+               (* Here we keep dividing sec by max seconds, minutes, hours
+                  to convert sec into total days since epoch.  *)
                second := VAL (Sec, DivMod (sec, MAX (Sec) + 1)) ;
                minute := VAL (Min, DivMod (sec, MAX (Min) + 1)) ;
                hour := VAL (Hour, DivMod (sec, MAX (Hour) + 1)) ;