[gcc r13-3522] c++: Fix excess precision related ICE on invalid binop [PR107382, PR107383]

[gcc r13-3522] c++: Fix excess precision related ICE on invalid binop [PR107382, PR107383]

[Jakub Jelinek]

https://gcc.gnu.org/g:bfb7994a9fb0b10767d12b8d670c081014ad8b01

commit r13-3522-gbfb7994a9fb0b10767d12b8d670c081014ad8b01
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Oct 27 10:24:45 2022 +0200

    c++: Fix excess precision related ICE on invalid binop [PR107382, PR107383]
    
    The following tests ICE in the gcc_assert (common); in cp_build_binary_op.
    I've missed that while for * common is set always, while for +, - and /
    it is in some cases not.
    If it is not, then
      if (!result_type
          && arithmetic_types_p
          && (shorten || common || short_compare))
    condition is false, then the following
      if (may_need_excess_precision
          && (orig_type0 != type0 || orig_type1 != type1)
          && build_type == NULL_TREE)
    would fail the assertion there and if there wouldn't be excess precision,
      if (code == SPACESHIP_EXPR)
    would be false (for SPACESHIP_EXPR we always have build_type set like for
    other comparisons) and then trigger
      if (!result_type)
        {
          if (complain & tf_error)
            {
              binary_op_rich_location richloc (location,
                                               orig_op0, orig_op1, true);
              error_at (&richloc,
                        "invalid operands of types %qT and %qT to binary %qO",
                        TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
            }
          return error_mark_node;
        }
    So, if result_type is NULL, we don't really need to compute
    semantic_result_type because nothing will use it anyway and can get
    fall through into the error/return error_mark_node; case.
    
    2022-10-27  Jakub Jelinek  <jakub@redhat.com>
    
            PR c++/107382
            PR c++/107383
            * typeck.cc (cp_build_binary_op): Don't compute semantic_result_type
            if result_type is NULL.
    
            * g++.dg/diagnostic/bad-binary-ops2.C: New test.

Diff:
---
 gcc/cp/typeck.cc                                  |  3 ++-
 gcc/testsuite/g++.dg/diagnostic/bad-binary-ops2.C | 26 +++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 4605f734e2d..2e0fd8fbf17 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -6179,7 +6179,8 @@ cp_build_binary_op (const op_location_t &location,
     }
   if (may_need_excess_precision
       && (orig_type0 != type0 || orig_type1 != type1)
-      && build_type == NULL_TREE)
+      && build_type == NULL_TREE
+      && result_type)
     {
       gcc_assert (common);
       semantic_result_type = cp_common_type (orig_type0, orig_type1);
diff --git a/gcc/testsuite/g++.dg/diagnostic/bad-binary-ops2.C b/gcc/testsuite/g++.dg/diagnostic/bad-binary-ops2.C
new file mode 100644
index 00000000000..627e8a573f1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/diagnostic/bad-binary-ops2.C
@@ -0,0 +1,26 @@
+// PR c++/107382
+// PR c++/107383
+// { dg-do compile }
+// { dg-options "-O2 -fexcess-precision=standard" }
+
+void
+foo ()
+{
+  float t[2] = { 1, 2 };
+  int const *s = 0;
+  t[1] / s;	// { dg-error "invalid operands of types 'float' and 'const int\\\*' to binary 'operator/'" }
+}
+
+void
+bar ()
+{
+  float t[2] = { 1, 2 };
+  int const *s[2] = { 0, 0 };
+  t[1] / s[0];	// { dg-error "invalid operands of types 'float' and 'const int\\\*' to binary 'operator/'" }
+}
+
+void
+baz (float a, int* b)
+{
+  a -= b;	// { dg-error "invalid operands of types 'float' and 'int\\\*' to binary 'operator-'" }
+}