[PATCH] c: Fix warning after an error on a return statment [PR60440]

[Andrew Pinski]

Like r5-6912-g3dbb84276aca10 but this is for the C front-end.
Basically we have an error on a return statement, we just return
error_mark_node and then the warning happens as there is no return
statement. Anyways instead mark the current function for supression
of the warning instead.

        PR c/60440

gcc/c/ChangeLog:

        * c-typeck.cc (c_finish_return): Mark the current function
        for supression of the -Wreturn-type if there was an error
        on the return statement.

gcc/testsuite/ChangeLog:

        * gcc.dg/Wreturn-mismatch-2.c: Change dg-warning
        for the last -Wreturn-type to dg-bogus.
        * gcc.dg/pr60440-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
 gcc/c/c-typeck.cc                         |  7 ++++++-
 gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c |  2 +-
 gcc/testsuite/gcc.dg/pr60440-1.c          | 10 ++++++++++
 3 files changed, 17 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr60440-1.c

diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc
index 691b583db3f..a13989a6607 100644
--- a/gcc/c/c-typeck.cc
+++ b/gcc/c/c-typeck.cc
@@ -12765,7 +12765,12 @@ c_finish_return (location_t loc, tree retval, tree 
origtype, bool musttail_p)
 
       current_function_returns_value = 1;
       if (t == error_mark_node)
-       return NULL_TREE;
+       {
+         /* Suppress -Wreturn-type for this function.  */
+         if (warn_return_type)
+           suppress_warning (current_function_decl, OPT_Wreturn_type);
+         return NULL_TREE;
+       }
 
       save = in_late_binary_op;
       if (C_BOOLEAN_TYPE_P (TREE_TYPE (res))
diff --git a/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c 
b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
index 08811024b7e..52852261a0d 100644
--- a/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
+++ b/gcc/testsuite/gcc.dg/Wreturn-mismatch-2.c
@@ -37,5 +37,5 @@ int
 f7 (void)
 {
   return f1 (); /* { dg-error "void value not ignored as it ought to be" } */
-} /* { dg-warning "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
+} /* { dg-bogus "control reaches end of non-void\[^\n\r\]*-Wreturn-type" } */
 
diff --git a/gcc/testsuite/gcc.dg/pr60440-1.c b/gcc/testsuite/gcc.dg/pr60440-1.c
new file mode 100644
index 00000000000..cd179cf1c52
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr60440-1.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Wreturn-type" } */
+
+/* PR c/60440 */
+/* Don't warn for a missing return when there was an error
+   on the return stamtent. */
+
+int f(int a) {
+  return a + b; /* { dg-error "undeclared" } */
+} /* { dg-bogus "control reaches end of non-void function" } */
-- 
2.34.1