backend: fix ICE segfault on empty static loops

tommyscholly · tommyscholly · commit 31f2dbaee265 · 2025-05-07T23:39:47.000-04:00
gcc/rust/ChangeLog:

	* backend/rust-constexpr.cc (eval_constant_expression): Check if t is a NULL_TREE

Signed-off-by: Tom Schollenberger &lt;tss2344@g.rit.edu&gt;
diff --git a/gcc/rust/backend/rust-constexpr.cc b/gcc/rust/backend/rust-constexpr.cc
@@ -1901,7 +1901,11 @@ eval_constant_expression (const constexpr_ctx *ctx, tree t, bool lval,
 
   location_t loc = EXPR_LOCATION (t);
 
-  if (CONSTANT_CLASS_P (t))
+  if (t == NULL_TREE)
+    {
+      return t;
+    }
+  else if (CONSTANT_CLASS_P (t))
     {
       if (TREE_OVERFLOW (t))
 	{

Original file line number	Diff line number	Diff line change
`@@ -1901,7 +1901,11 @@ eval_constant_expression (const constexpr_ctx *ctx, tree t, bool lval,`
`1901`	`1901`
`1902`	`1902`	`location_t loc = EXPR_LOCATION (t);`
`1903`	`1903`
`1904`		`- if (CONSTANT_CLASS_P (t))`
	`1904`	`+ if (t == NULL_TREE)`
	`1905`	`+ {`
	`1906`	`+ return t;`
	`1907`	`+ }`
	`1908`	`+ else if (CONSTANT_CLASS_P (t))`
`1905`	`1909`	`{`
`1906`	`1910`	`if (TREE_OVERFLOW (t))`
`1907`	`1911`	`{`