diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc
index c58ff4ab2488c0f37daf4b3521e243bd157b29f8..a84b35ea23e79e4b7321f47f515264ce3dde9d02 100644
--- a/gcc/c/c-decl.cc
+++ b/gcc/c/c-decl.cc
@@ -8480,8 +8480,8 @@ grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
or definition of the function. In the case where the tag was
first declared within the parameter list, a warning has
already been given. If a parameter has void type, then
- however the function cannot be defined or called, so
- warn. */
+ this has already received an error (constraint violation in C2Y,
+ previously implicitly undefined behavior). */
for (parm = arg_info->parms, typelt = arg_types, parmno = 1;
parm;
@@ -8508,17 +8508,6 @@ grokparms (struct c_arg_info *arg_info, bool funcdef_flag)
TREE_TYPE (parm) = error_mark_node;
arg_types = NULL_TREE;
}
- else if (VOID_TYPE_P (type))
- {
- if (DECL_NAME (parm))
- warning_at (input_location, 0,
- "parameter %u (%q+D) has void type",
- parmno, parm);
- else
- warning_at (DECL_SOURCE_LOCATION (parm), 0,
- "parameter %u has void type",
- parmno);
- }
}
if (DECL_NAME (parm) && TREE_USED (parm))
@@ -8627,12 +8616,14 @@ get_parm_info (bool ellipsis, tree expr)
if (TREE_ASM_WRITTEN (decl))
error_at (b->locus,
"parameter %q+D has just a forward declaration", decl);
- /* Check for (..., void, ...) and issue an error. */
- else if (VOID_TYPE_P (type) && !DECL_NAME (decl))
+ /* Check for (..., void, ...) and named void parameters and issue an
+ error. */
+ else if (VOID_TYPE_P (type))
{
if (!gave_void_only_once_err)
{
- error_at (b->locus, "%<void%> must be the only parameter");
+ error_at (b->locus,
+ "%<void%> must be the only parameter and unnamed");
gave_void_only_once_err = true;
}
}
diff --git a/gcc/testsuite/gcc.dg/c2y-void-parm-1.c b/gcc/testsuite/gcc.dg/c2y-void-parm-1.c
new file mode 100644
index 0000000000000000000000000000000000000000..aff757ee21c43d64484b5bbaa07d8f84772c7519
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/c2y-void-parm-1.c
@@ -0,0 +1,152 @@
+/* Test errors for void parameters (constraint violation in C2Y, previously
+ implicit undefined behavior; bug 114816). */
+/* { dg-do compile } */
+/* { dg-options "-std=c2y -pedantic-errors" } */
+
+typedef void Void;
+typedef const void CVoid;
+typedef volatile void VVoid;
+
+/* Valid cases. */
+void f1 (void);
+void f2 (Void);
+void df1 (void) {}
+void df2 (Void) {}
+
+/* All other variants are invalid. */
+
+void g1 (const void); /* { dg-error "void" } */
+void g2 (CVoid); /* { dg-error "void" } */
+void g3 (volatile void); /* { dg-error "void" } */
+void g4 (VVoid); /* { dg-error "void" } */
+void g5 (register void); /* { dg-error "void" } */
+void g6 (register Void); /* { dg-error "void" } */
+
+void h1 (void x); /* { dg-error "void" } */
+void h2 (Void x); /* { dg-error "void" } */
+void h3 (const void x); /* { dg-error "void" } */
+void h4 (CVoid x); /* { dg-error "void" } */
+void h5 (volatile void x); /* { dg-error "void" } */
+void h6 (VVoid x); /* { dg-error "void" } */
+void h7 (register void x); /* { dg-error "void" } */
+void h8 (register Void x); /* { dg-error "void" } */
+
+void i1 (void, ...); /* { dg-error "void" } */
+void i2 (Void, ...); /* { dg-error "void" } */
+void i3 (const void, ...); /* { dg-error "void" } */
+void i4 (CVoid, ...); /* { dg-error "void" } */
+void i5 (volatile void, ...); /* { dg-error "void" } */
+void i6 (VVoid, ...); /* { dg-error "void" } */
+void i7 (register void, ...); /* { dg-error "void" } */
+void i8 (register Void, ...); /* { dg-error "void" } */
+
+void j1 (void x, ...); /* { dg-error "void" } */
+void j2 (Void x, ...); /* { dg-error "void" } */
+void j3 (const void x, ...); /* { dg-error "void" } */
+void j4 (CVoid x, ...); /* { dg-error "void" } */
+void j5 (volatile void x, ...); /* { dg-error "void" } */
+void j6 (VVoid x, ...); /* { dg-error "void" } */
+void j7 (register void x, ...); /* { dg-error "void" } */
+void j8 (register Void x, ...); /* { dg-error "void" } */
+
+void k1 (int i, void); /* { dg-error "void" } */
+void k2 (int i, Void); /* { dg-error "void" } */
+void k3 (int i, const void); /* { dg-error "void" } */
+void k4 (int i, CVoid); /* { dg-error "void" } */
+void k5 (int i, volatile void); /* { dg-error "void" } */
+void k6 (int i, VVoid); /* { dg-error "void" } */
+void k7 (int i, register void); /* { dg-error "void" } */
+void k8 (int i, register Void); /* { dg-error "void" } */
+void k9 (int i, void x); /* { dg-error "void" } */
+void k10 (int i, Void x); /* { dg-error "void" } */
+void k11 (int i, const void x); /* { dg-error "void" } */
+void k12 (int i, CVoid x); /* { dg-error "void" } */
+void k13 (int i, volatile void x); /* { dg-error "void" } */
+void k14 (int i, VVoid x); /* { dg-error "void" } */
+void k15 (int i, register void x); /* { dg-error "void" } */
+void k16 (int i, register Void x); /* { dg-error "void" } */
+
+void l1 (void, int i); /* { dg-error "void" } */
+void l2 (Void, int i); /* { dg-error "void" } */
+void l3 (const void, int i); /* { dg-error "void" } */
+void l4 (CVoid, int i); /* { dg-error "void" } */
+void l5 (volatile void, int i); /* { dg-error "void" } */
+void l6 (VVoid, int i); /* { dg-error "void" } */
+void l7 (register void, int i); /* { dg-error "void" } */
+void l8 (register Void, int i); /* { dg-error "void" } */
+void l9 (void x, int i); /* { dg-error "void" } */
+void l10 (Void x, int i); /* { dg-error "void" } */
+void l11 (const void x, int i); /* { dg-error "void" } */
+void l12 (CVoid x, int i); /* { dg-error "void" } */
+void l13 (volatile void x, int i); /* { dg-error "void" } */
+void l14 (VVoid x, int i); /* { dg-error "void" } */
+void l15 (register void x, int i); /* { dg-error "void" } */
+void l16 (register Void x, int i); /* { dg-error "void" } */
+
+void dg1 (const void) {} /* { dg-error "void|incomplete" } */
+void dg2 (CVoid) {} /* { dg-error "void|incomplete" } */
+void dg3 (volatile void) {} /* { dg-error "void|incomplete" } */
+void dg4 (VVoid) {} /* { dg-error "void|incomplete" } */
+void dg5 (register void) {} /* { dg-error "void|incomplete" } */
+void dg6 (register Void) {} /* { dg-error "void|incomplete" } */
+
+void dh1 (void x) {} /* { dg-error "void|incomplete" } */
+void dh2 (Void x) {} /* { dg-error "void|incomplete" } */
+void dh3 (const void x) {} /* { dg-error "void|incomplete" } */
+void dh4 (CVoid x) {} /* { dg-error "void|incomplete" } */
+void dh5 (volatile void x) {} /* { dg-error "void|incomplete" } */
+void dh6 (VVoid x) {} /* { dg-error "void|incomplete" } */
+void dh7 (register void x) {} /* { dg-error "void|incomplete" } */
+void dh8 (register Void x) {} /* { dg-error "void|incomplete" } */
+
+void di1 (void, ...) {} /* { dg-error "void|incomplete" } */
+void di2 (Void, ...) {} /* { dg-error "void|incomplete" } */
+void di3 (const void, ...) {} /* { dg-error "void|incomplete" } */
+void di4 (CVoid, ...) {} /* { dg-error "void|incomplete" } */
+void di5 (volatile void, ...) {} /* { dg-error "void|incomplete" } */
+void di6 (VVoid, ...) {} /* { dg-error "void|incomplete" } */
+void di7 (register void, ...) {} /* { dg-error "void|incomplete" } */
+void di8 (register Void, ...) {} /* { dg-error "void|incomplete" } */
+
+void dj1 (void x, ...) {} /* { dg-error "void|incomplete" } */
+void dj2 (Void x, ...) {} /* { dg-error "void|incomplete" } */
+void dj3 (const void x, ...) {} /* { dg-error "void|incomplete" } */
+void dj4 (CVoid x, ...) {} /* { dg-error "void|incomplete" } */
+void dj5 (volatile void x, ...) {} /* { dg-error "void|incomplete" } */
+void dj6 (VVoid x, ...) {} /* { dg-error "void|incomplete" } */
+void dj7 (register void x, ...) {} /* { dg-error "void|incomplete" } */
+void dj8 (register Void x, ...) {} /* { dg-error "void|incomplete" } */
+
+void dk1 (int i, void) {} /* { dg-error "void|incomplete" } */
+void dk2 (int i, Void) {} /* { dg-error "void|incomplete" } */
+void dk3 (int i, const void) {} /* { dg-error "void|incomplete" } */
+void dk4 (int i, CVoid) {} /* { dg-error "void|incomplete" } */
+void dk5 (int i, volatile void) {} /* { dg-error "void|incomplete" } */
+void dk6 (int i, VVoid) {} /* { dg-error "void|incomplete" } */
+void dk7 (int i, register void) {} /* { dg-error "void|incomplete" } */
+void dk8 (int i, register Void) {} /* { dg-error "void|incomplete" } */
+void dk9 (int i, void x) {} /* { dg-error "void|incomplete" } */
+void dk10 (int i, Void x) {} /* { dg-error "void|incomplete" } */
+void dk11 (int i, const void x) {} /* { dg-error "void|incomplete" } */
+void dk12 (int i, CVoid x) {} /* { dg-error "void|incomplete" } */
+void dk13 (int i, volatile void x) {} /* { dg-error "void|incomplete" } */
+void dk14 (int i, VVoid x) {} /* { dg-error "void|incomplete" } */
+void dk15 (int i, register void x) {} /* { dg-error "void|incomplete" } */
+void dk16 (int i, register Void x) {} /* { dg-error "void|incomplete" } */
+
+void dl1 (void, int i) {} /* { dg-error "void|incomplete" } */
+void dl2 (Void, int i) {} /* { dg-error "void|incomplete" } */
+void dl3 (const void, int i) {} /* { dg-error "void|incomplete" } */
+void dl4 (CVoid, int i) {} /* { dg-error "void|incomplete" } */
+void dl5 (volatile void, int i) {} /* { dg-error "void|incomplete" } */
+void dl6 (VVoid, int i) {} /* { dg-error "void|incomplete" } */
+void dl7 (register void, int i) {} /* { dg-error "void|incomplete" } */
+void dl8 (register Void, int i) {} /* { dg-error "void|incomplete" } */
+void dl9 (void x, int i) {} /* { dg-error "void|incomplete" } */
+void dl10 (Void x, int i) {} /* { dg-error "void|incomplete" } */
+void dl11 (const void x, int i) {} /* { dg-error "void|incomplete" } */
+void dl12 (CVoid x, int i) {} /* { dg-error "void|incomplete" } */
+void dl13 (volatile void x, int i) {} /* { dg-error "void|incomplete" } */
+void dl14 (VVoid x, int i) {} /* { dg-error "void|incomplete" } */
+void dl15 (register void x, int i) {} /* { dg-error "void|incomplete" } */
+void dl16 (register Void x, int i) {} /* { dg-error "void|incomplete" } */
diff --git a/gcc/testsuite/gcc.dg/noncompile/920616-2.c b/gcc/testsuite/gcc.dg/noncompile/920616-2.c
index e43d00981f40adf1bcfa377f9f6d15337181c55c..a31a38e2925023ca26853bc1c69891d245fd6702 100644
--- a/gcc/testsuite/gcc.dg/noncompile/920616-2.c
+++ b/gcc/testsuite/gcc.dg/noncompile/920616-2.c
@@ -1 +1 @@
-void f(void a,...){} /* { dg-error "has incomplete type" } */
+void f(void a,...){} /* { dg-error "void|has incomplete type" } */
diff --git a/gcc/testsuite/gcc.dg/noncompile/921116-1.c b/gcc/testsuite/gcc.dg/noncompile/921116-1.c
index 890bbb63404d6b9622fbf7cb113373dd25bcf54f..3c07450cd4cfcac6b66166f3aaae3edab1c323ce 100644
--- a/gcc/testsuite/gcc.dg/noncompile/921116-1.c
+++ b/gcc/testsuite/gcc.dg/noncompile/921116-1.c
@@ -1 +1 @@
-void a (void x) {} /* { dg-error "has incomplete type" } */
+void a (void x) {} /* { dg-error "void|has incomplete type" } */
diff --git a/gcc/testsuite/gcc.dg/parm-incomplete-1.c b/gcc/testsuite/gcc.dg/parm-incomplete-1.c
index 0c0ae85d86fa3e4fdf953b21ad8e50e6d9a5f392..e4122f07c69c0789384311efd9f2ec3f50248797 100644
--- a/gcc/testsuite/gcc.dg/parm-incomplete-1.c
+++ b/gcc/testsuite/gcc.dg/parm-incomplete-1.c
@@ -22,6 +22,6 @@ union u;
void v(union u x) { } /* { dg-error "parameter 1 \\('x'\\) has incomplete type" } */
-void p(void x); /* { dg-warning "parameter 1 \\('x'\\) has void type" } */
+void p(void x); /* { dg-error "'void' must be the only parameter and unnamed" } */
-void q(const void x); /* { dg-warning "parameter 1 \\('x'\\) has void type" } */
+void q(const void x); /* { dg-error "'void' must be the only parameter and unnamed" } */