From: Gaius Mulley <gaiusmod2@gmail.com>
Date: Sun, 2 Mar 2025 19:04:37 +0000 (+0000)
Subject: PR modula2/119088 ICE when for loop accesses an unknown variable as the iterator
X-Git-Tag: basepoints/gcc-16~1767
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=585aa4065f1028c2fbfab55462e5e5e6b3c208c4;p=thirdparty%2Fgcc.git

PR modula2/119088 ICE when for loop accesses an unknown variable as the iterator

This patch fixes an ICE which occurs when a FOR statement attempts to
use an undeclared variable as its iterator.

gcc/m2/ChangeLog:

	PR modula2/119088
	* gm2-compiler/M2SymInit.mod (ConfigSymInit): Reimplement to
	defensively check for NulSym type.

gcc/testsuite/ChangeLog:

	PR modula2/119088
	* gm2/pim/fail/tinyfor4.mod: New test.

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

diff --git a/gcc/m2/gm2-compiler/M2SymInit.mod b/gcc/m2/gm2-compiler/M2SymInit.mod
index ffe1f9b8da3..6c8912f2c4c 100644
--- a/gcc/m2/gm2-compiler/M2SymInit.mod
+++ b/gcc/m2/gm2-compiler/M2SymInit.mod
@@ -202,16 +202,23 @@ BEGIN
       desc^.sym := sym ;
       desc^.type := GetSType (sym) ;
       desc^.initialized := FALSE ;
-      IF IsRecord (desc^.type)
+      (* An unknown symbol will have no type.  *)
+      IF desc^.type = NulSym
       THEN
-         desc^.kind := record ;
-         desc^.rec.fieldDesc := Indexing.InitIndex (1) ;
-         PopulateFields (desc, desc^.type)
-      ELSE
          desc^.kind := scalar ;
-         IF IsArray (desc^.type)
+         desc^.initialized := TRUE   (* For now we don't attempt to handle array types.  *)
+      ELSE
+         IF IsRecord (desc^.type)
          THEN
-            desc^.initialized := TRUE   (* For now we don't attempt to handle array types.  *)
+            desc^.kind := record ;
+            desc^.rec.fieldDesc := Indexing.InitIndex (1) ;
+            PopulateFields (desc, desc^.type)
+         ELSE
+            desc^.kind := scalar ;
+            IF IsArray (desc^.type)
+            THEN
+               desc^.initialized := TRUE   (* For now we don't attempt to handle array types.  *)
+            END
          END
       END
    END
diff --git a/gcc/testsuite/gm2/pim/fail/tinyfor4.mod b/gcc/testsuite/gm2/pim/fail/tinyfor4.mod
new file mode 100644
index 00000000000..155b72565da
--- /dev/null
+++ b/gcc/testsuite/gm2/pim/fail/tinyfor4.mod
@@ -0,0 +1,7 @@
+MODULE tinyfor4 ;  
+
+VAR
+  v: INTEGER;
+BEGIN
+   FOR i := 0 TO v DO END
+END tinyfor4.