Tested x86_64-pc-linux-gnu, OK for trunk?
-- 8< --
-Waddress-of-packed-member, in addition to the documented warning about
taking the address of a packed member, also warns about casting from
a pointer to a TYPE_PACKED type to a pointer to a type with greater
alignment.
This wrongly warns if the source is a pointer to enum when -fshort-enums
is on, since that is also represented by TYPE_PACKED.
And there's already -Wcast-align to catch casting from pointer to less
aligned type (packed or otherwise) to pointer to more aligned type; even
apart from the enum problem, this seems like a somewhat arbitrary subset of
that warning. Though that isn't currently on by default.
So, this patch removes the undocumented type-based warning from
-Waddress-of-packed-member. Some of the tests where the warning is
desirable I changed to use -Wcast-align=strict instead. The ones that
require -Wno-incompatible-pointer-types, I just removed.
gcc/c-family/ChangeLog:
* c-warn.cc (check_address_or_pointer_of_packed_member):
Remove warning based on TYPE_PACKED.
gcc/testsuite/ChangeLog:
* c-c++-common/Waddress-of-packed-member-1.c: Don't expect
a warning on the cast cases.
* c-c++-common/pr51628-35.c: Use -Wcast-align=strict.
* g++.dg/warn/Waddress-of-packed-member3.C: Likewise.
* gcc.dg/pr88928.c: Likewise.
* gcc.dg/pr51628-20.c: Removed.
* gcc.dg/pr51628-21.c: Removed.
* gcc.dg/pr51628-25.c: Removed.
---
gcc/c-family/c-warn.cc | 58 +------------------
.../Waddress-of-packed-member-1.c | 12 ++--
gcc/testsuite/c-c++-common/pr51628-35.c | 6 +-
.../g++.dg/warn/Waddress-of-packed-member3.C | 8 +--
gcc/testsuite/gcc.dg/pr51628-20.c | 11 ----
gcc/testsuite/gcc.dg/pr51628-21.c | 11 ----
gcc/testsuite/gcc.dg/pr51628-25.c | 9 ---
gcc/testsuite/gcc.dg/pr88928.c | 6 +-
8 files changed, 19 insertions(+), 102 deletions(-)
delete mode 100644 gcc/testsuite/gcc.dg/pr51628-20.c
delete mode 100644 gcc/testsuite/gcc.dg/pr51628-21.c
delete mode 100644 gcc/testsuite/gcc.dg/pr51628-25.c
diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc
index d2938b91043..2a399ba6d14 100644
--- a/gcc/c-family/c-warn.cc
+++ b/gcc/c-family/c-warn.cc
@@ -2991,10 +2991,9 @@ check_alignment_of_packed_member (tree type, tree field,
bool rvalue)
return NULL_TREE;
}
-/* Return struct or union type if the right hand value, RHS:
- 1. Is a pointer value which isn't aligned to a pointer type TYPE.
- 2. Is an address which takes the unaligned address of packed member
- of struct or union when assigning to TYPE.
+/* Return struct or union type if the right hand value, RHS
+ is an address which takes the unaligned address of packed member
+ of struct or union when assigning to TYPE.
Otherwise, return NULL_TREE. */
static tree
@@ -3021,57 +3020,6 @@ check_address_or_pointer_of_packed_member (tree type,
tree rhs)
type = TREE_TYPE (type);
- if (TREE_CODE (rhs) == PARM_DECL
- || VAR_P (rhs)
- || TREE_CODE (rhs) == CALL_EXPR)
- {
- tree rhstype = TREE_TYPE (rhs);
- if (TREE_CODE (rhs) == CALL_EXPR)
- {
- rhs = CALL_EXPR_FN (rhs); /* Pointer expression. */
- if (rhs == NULL_TREE)
- return NULL_TREE;
- rhs = TREE_TYPE (rhs); /* Pointer type. */
- /* We could be called while processing a template and RHS could be
- a functor. In that case it's a class, not a pointer. */
- if (!rhs || !POINTER_TYPE_P (rhs))
- return NULL_TREE;
- rhs = TREE_TYPE (rhs); /* Function type. */
- rhstype = TREE_TYPE (rhs);
- if (!rhstype || !POINTER_TYPE_P (rhstype))
- return NULL_TREE;
- rvalue = true;
- }
- if (rvalue && POINTER_TYPE_P (rhstype))
- rhstype = TREE_TYPE (rhstype);
- while (TREE_CODE (rhstype) == ARRAY_TYPE)
- rhstype = TREE_TYPE (rhstype);
- if (TYPE_PACKED (rhstype))
- {
- unsigned int type_align = min_align_of_type (type);
- unsigned int rhs_align = min_align_of_type (rhstype);
- if (rhs_align < type_align)
- {
- auto_diagnostic_group d;
- location_t location = EXPR_LOC_OR_LOC (rhs, input_location);
- if (warning_at (location, OPT_Waddress_of_packed_member,
- "converting a packed %qT pointer (alignment %d) "
- "to a %qT pointer (alignment %d) may result in "
- "an unaligned pointer value",
- rhstype, rhs_align, type, type_align))
- {
- tree decl = TYPE_STUB_DECL (rhstype);
- if (decl)
- inform (DECL_SOURCE_LOCATION (decl), "defined here");
- decl = TYPE_STUB_DECL (type);
- if (decl)
- inform (DECL_SOURCE_LOCATION (decl), "defined here");
- }
- }
- }
- return NULL_TREE;
- }
-
tree context = NULL_TREE;
/* Check alignment of the object. */
diff --git a/gcc/testsuite/c-c++-common/Waddress-of-packed-member-1.c
b/gcc/testsuite/c-c++-common/Waddress-of-packed-member-1.c
index 95a376664da..0f5188df70a 100644
--- a/gcc/testsuite/c-c++-common/Waddress-of-packed-member-1.c
+++ b/gcc/testsuite/c-c++-common/Waddress-of-packed-member-1.c
@@ -52,12 +52,12 @@ void foo (void)
f0 = *&__real__ t0.f; /* { dg-bogus "may result in an unaligned
pointer value" } */
f0 = *&__imag__ t0.f; /* { dg-bogus "may result in an unaligned
pointer value" } */
i1 = (&t0.c, (int*) 0); /* { dg-bogus "may result in an unaligned
pointer value" } */
- t2 = (struct t**) t10; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
- t2 = (struct t**) t100; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
- t2 = (struct t**) t1; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
- t2 = (struct t**) bar(); /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
- t2 = (struct t**) baz(); /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
- t2 = (struct t**) bazz(); /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
+ t2 = (struct t**) t10; /* { dg-bogus "may result in an unaligned
pointer value" } */
+ t2 = (struct t**) t100; /* { dg-bogus "may result in an unaligned
pointer value" } */
+ t2 = (struct t**) t1; /* { dg-bogus "may result in an unaligned
pointer value" } */
+ t2 = (struct t**) bar(); /* { dg-bogus "may result in an unaligned
pointer value" } */
+ t2 = (struct t**) baz(); /* { dg-bogus "may result in an unaligned
pointer value" } */
+ t2 = (struct t**) bazz(); /* { dg-bogus "may result in an unaligned
pointer value" } */
i1 = &t0.b; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
i1 = &t1->b; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
i1 = &t10[0].b; /* { dg-warning "may result in an unaligned
pointer value" "" { target { ! default_packed } } } */
diff --git a/gcc/testsuite/c-c++-common/pr51628-35.c
b/gcc/testsuite/c-c++-common/pr51628-35.c
index fa37d99beb7..a88c19ea0df 100644
--- a/gcc/testsuite/c-c++-common/pr51628-35.c
+++ b/gcc/testsuite/c-c++-common/pr51628-35.c
@@ -1,6 +1,6 @@
/* PR c/51628. */
/* { dg-do compile } */
-/* { dg-options "-O" } */
+/* { dg-options "-O -Wcast-align=strict" } */
struct B { int i; };
struct C { struct B b; } __attribute__ ((packed));
@@ -12,12 +12,12 @@ long *
foo1 (void)
{
return (long *) p;
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
+/* { dg-warning "increases required alignment" "" { target { ! default_packed
} } .-1 } */
}
long *
foo2 (void)
{
return (long *) bar ();
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
+/* { dg-warning "increases required alignment" "" { target { ! default_packed
} } .-1 } */
}
diff --git a/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C
b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C
index aeffb969c01..28dd05d366c 100644
--- a/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C
+++ b/gcc/testsuite/g++.dg/warn/Waddress-of-packed-member3.C
@@ -1,5 +1,5 @@
// { dg-do compile { target { ! default_packed } } }
-// Test that -Waddress-of-packed-member works with member functions.
+// { dg-additional-options -Wcast-align=strict }
struct S {
char c;
@@ -16,8 +16,8 @@ S**
f ()
{
S **s;
- s = reinterpret_cast<S**>(foo ()); // { dg-warning "converting a packed" }
- s = reinterpret_cast<S**>(x.memfn ()); // { dg-warning "converting a packed"
}
- s = reinterpret_cast<S**>(X::smemfn ()); // { dg-warning "converting a
packed" }
+ s = reinterpret_cast<S**>(foo ()); // { dg-warning "increases required
alignment" }
+ s = reinterpret_cast<S**>(x.memfn ()); // { dg-warning "increases required
alignment" }
+ s = reinterpret_cast<S**>(X::smemfn ()); // { dg-warning "increases required
alignment" }
return s;
}
diff --git a/gcc/testsuite/gcc.dg/pr51628-20.c
b/gcc/testsuite/gcc.dg/pr51628-20.c
deleted file mode 100644
index 2249d85098b..00000000000
--- a/gcc/testsuite/gcc.dg/pr51628-20.c
+++ /dev/null
@@ -1,11 +0,0 @@
-/* PR c/51628. */
-/* { dg-do compile } */
-/* { dg-options "-O -Wno-incompatible-pointer-types" } */
-
-struct B { int i; };
-struct C { struct B b; } __attribute__ ((packed));
-
-extern struct C *p;
-
-long* g8 (void) { return p; }
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-21.c
b/gcc/testsuite/gcc.dg/pr51628-21.c
deleted file mode 100644
index f1adbe64002..00000000000
--- a/gcc/testsuite/gcc.dg/pr51628-21.c
+++ /dev/null
@@ -1,11 +0,0 @@
-/* PR c/51628. */
-/* { dg-do compile } */
-/* { dg-options "-O -Wno-incompatible-pointer-types" } */
-
-struct B { int i; };
-struct C { struct B b; } __attribute__ ((packed));
-
-extern struct C p[];
-
-long* g8 (void) { return p; }
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr51628-25.c
b/gcc/testsuite/gcc.dg/pr51628-25.c
deleted file mode 100644
index f00d9b1bcac..00000000000
--- a/gcc/testsuite/gcc.dg/pr51628-25.c
+++ /dev/null
@@ -1,9 +0,0 @@
-/* PR c/51628. */
-/* { dg-do compile } */
-/* { dg-options "-O -Wno-incompatible-pointer-types" } */
-
-struct B { int i; };
-struct C { struct B b; } __attribute__ ((packed));
-
-long* g8 (struct C *p) { return p; }
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
diff --git a/gcc/testsuite/gcc.dg/pr88928.c b/gcc/testsuite/gcc.dg/pr88928.c
index 0b6c1d70f05..1d176d6d51d 100644
--- a/gcc/testsuite/gcc.dg/pr88928.c
+++ b/gcc/testsuite/gcc.dg/pr88928.c
@@ -1,6 +1,6 @@
-/* { dg-do compile } */
-/* { dg-options "-Wno-pedantic -Waddress-of-packed-member" } */
+/* { dg-do compile { target { ! default_packed } } } */
+/* { dg-options "-Wno-pedantic -Waddress-of-packed-member -Wcast-align=strict"
} */
struct a { } __attribute__((__packed__));
void c (struct a **);
void d (const struct a *b) { c ((struct a **) b); }
-/* { dg-warning "may result in an unaligned pointer value" "" { target { !
default_packed } } .-1 } */
+/* { dg-warning "increases required alignment" "" { target *-*-* } .-1 } */
base-commit: 65bd6de0de57abc86931a5e0b9a8d453ad530004
--
2.39.3
