PR modula2/114418 missing import of TSIZE from system causes ICE

This patch detects whether the symbol func is NulSym before generating
an error and if so just uses the token location and fixed string to
generate an error message.

gcc/m2/ChangeLog:

	PR modula2/114418
	* gm2-compiler/PCSymBuild.mod (PushConstFunctionType): Check
	func against NulSym and issue an error.

gcc/testsuite/ChangeLog:

	PR modula2/114418
	* gm2/pim/fail/missingtsize.mod: New test.
	* gm2/pim/fail/missingtsize2.mod: New test.

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

3 files changed, 53 insertions, 11 deletions

diff --git a/gcc/m2/gm2-compiler/PCSymBuild.mod b/gcc/m2/gm2-compiler/PCSymBuild.mod
index e216540..9a6e8c0 100644
--- a/gcc/m2/gm2-compiler/PCSymBuild.mod
+++ b/gcc/m2/gm2-compiler/PCSymBuild.mod
@@ -1413,6 +1413,38 @@ END buildConstFunction ;
 
 
 (*
+   ErrorConstFunction - generate an error message at functok using func in the
+                        error message providing it is not NulSym.
+*)
+
+PROCEDURE ErrorConstFunction (func: CARDINAL; functok: CARDINAL) ;
+BEGIN
+   IF func = NulSym
+   THEN
+      IF Iso
+      THEN
+         ErrorFormat0 (NewError (functok),
+                       'the only functions permissible in a constant expression are: CAP, CHR, CMPLX, FLOAT, HIGH, IM, LENGTH, MAX, MIN, ODD, ORD, RE, SIZE, TSIZE, TRUNC, VAL and gcc builtins')
+      ELSE
+         ErrorFormat0 (NewError (functok),
+                       'the only functions permissible in a constant expression are: CAP, CHR, FLOAT, HIGH, MAX, MIN, ODD, ORD, SIZE, TSIZE, TRUNC, VAL and gcc builtins')
+      END
+   ELSE
+      IF Iso
+      THEN
+         MetaErrorT1 (functok,
+                      'the only functions permissible in a constant expression are: CAP, CHR, CMPLX, FLOAT, HIGH, IM, LENGTH, MAX, MIN, ODD, ORD, RE, SIZE, TSIZE, TRUNC, VAL and gcc builtins, but not {%1Ead}',
+                      func)
+      ELSE
+         MetaErrorT1 (functok,
+                      'the only functions permissible in a constant expression are: CAP, CHR, FLOAT, HIGH, MAX, MIN, ODD, ORD, SIZE, TSIZE, TRUNC, VAL and gcc builtins, but not {%1Ead}',
+                      func)
+      END
+   END
+END ErrorConstFunction ;
+
+
+(*
    PushConstFunctionType -
 *)
 
@@ -1426,7 +1458,10 @@ BEGIN
    PopTtok (func, functok) ;
    IF inDesignator
    THEN
-      IF (func#Convert) AND
+      IF func = NulSym
+      THEN
+         ErrorConstFunction (func, functok)
+      ELSIF (func#Convert) AND
          (IsPseudoBaseFunction(func) OR
           IsPseudoSystemFunctionConstExpression(func) OR
           (IsProcedure(func) AND IsProcedureBuiltin(func)))
@@ -1442,16 +1477,7 @@ BEGIN
             WriteFormat0('a constant type conversion can only have one argument')
          END
       ELSE
-         IF Iso
-         THEN
-            MetaErrorT1 (functok,
-                         'the only functions permissible in a constant expression are: CAP, CHR, CMPLX, FLOAT, HIGH, IM, LENGTH, MAX, MIN, ODD, ORD, RE, SIZE, TSIZE, TRUNC, VAL and gcc builtins, but not {%1Ead}',
-                        func)
-         ELSE
-            MetaErrorT1 (functok,
-                         'the only functions permissible in a constant expression are: CAP, CHR, FLOAT, HIGH, MAX, MIN, ODD, ORD, SIZE, TSIZE, TRUNC, VAL and gcc builtins, but not {%1Ead}',
-                        func)
-         END
+         ErrorConstFunction (func, functok)
       END
    END ;
    PushTtok (func, functok)
diff --git a/gcc/testsuite/gm2/pim/fail/missingtsize.mod b/gcc/testsuite/gm2/pim/fail/missingtsize.mod
new file mode 100644
index 0000000..23ec055
--- /dev/null
+++ b/gcc/testsuite/gm2/pim/fail/missingtsize.mod
@@ -0,0 +1,8 @@
+MODULE missingtsize ;
+
+CONST
+   NoOfBytes = TSIZE (CARDINAL) ;
+
+BEGIN
+
+END missingtsize.
diff --git a/gcc/testsuite/gm2/pim/fail/missingtsize2.mod b/gcc/testsuite/gm2/pim/fail/missingtsize2.mod
new file mode 100644
index 0000000..8e85944
--- /dev/null
+++ b/gcc/testsuite/gm2/pim/fail/missingtsize2.mod
@@ -0,0 +1,8 @@
+MODULE missingtsize2 ;
+
+CONST
+   NoOfBytes = TSIZE (CARDINAL) * 4 ;
+
+BEGIN
+
+END missingtsize2.
\ No newline at end of file