[PATCH] c/100522 - avoid invalid GIMPLE in GIMPLE parsing

[Richard Biener]

This plugs a few easy holes avoiding ICEs down the route.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

2021-05-18  Richard Biener  <rguent...@suse.de>

        PR c/100522
gcc/c/
        * gimple-parser.c (c_parser_gimple_postfix_expression_after_primary):
        Diagnose calls to non-functions.
        (c_parser_gimple_statement): Diagnose unexpected assignment RHS.

gcc/testsuite/
        * gcc.dg/gimplefe-error-10.c: New testcase.
---
 gcc/c/gimple-parser.c                    | 11 +++++++++++
 gcc/testsuite/gcc.dg/gimplefe-error-10.c |  8 ++++++++
 2 files changed, 19 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/gimplefe-error-10.c

diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
index 398e21631d9..dfacf23c40a 100644
--- a/gcc/c/gimple-parser.c
+++ b/gcc/c/gimple-parser.c
@@ -877,6 +877,11 @@ c_parser_gimple_statement (gimple_parser &parser, 
gimple_seq *seq)
          rhs.value = build3_loc (loc, COND_EXPR, TREE_TYPE (trueval.value),
                                  rhs.value, trueval.value, falseval.value);
        }
+      if (get_gimple_rhs_class (TREE_CODE (rhs.value)) == GIMPLE_INVALID_RHS)
+       {
+         c_parser_error (parser, "unexpected RHS for assignment");
+         return;
+       }
       assign = gimple_build_assign (lhs.value, rhs.value);
       gimple_seq_add_stmt_without_update (seq, assign);
       gimple_set_location (assign, loc);
@@ -1754,6 +1759,12 @@ c_parser_gimple_postfix_expression_after_primary 
(gimple_parser &parser,
              c_parser_gimple_expr_list (parser, &exprlist);
            c_parser_skip_until_found (parser, CPP_CLOSE_PAREN,
                                       "expected %<)%>");
+           if (!FUNC_OR_METHOD_TYPE_P (TREE_TYPE (expr.value)))
+             {
+               c_parser_error (parser, "invalid call to non-function");
+               expr.set_error ();
+               break;
+             }
            expr.value = build_call_array_loc
                (expr_loc, TREE_TYPE (TREE_TYPE (expr.value)),
                 expr.value, exprlist.length (), exprlist.address ());
diff --git a/gcc/testsuite/gcc.dg/gimplefe-error-10.c 
b/gcc/testsuite/gcc.dg/gimplefe-error-10.c
new file mode 100644
index 00000000000..13d86ac5d1d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gimplefe-error-10.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-fgimple" } */
+
+__GIMPLE
+void foo() {
+  int t1;
+  t1_1 = t1_1(); /* { dg-error "invalid call" } */
+}
-- 
2.26.2