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| author | Vit Kabele <vit.kabele@sysgo.com> | 2022-07-09 13:06:43 -0400 |
|---|---|---|
| committer | Jeff Law <jeffreyalaw@gmail.com> | 2022-07-09 13:06:43 -0400 |
| commit | 7a16d39903ed1bf159f7933a19ccae62155b371b (patch) | |
| tree | b62ff16b5eeb075a8cc7f130c9f63d2b618853f9 /gcc | |
| parent | d9fa599dc7584d89e758a09a3d68982f12d8751c (diff) | |
| download | gcc-7a16d39903ed1bf159f7933a19ccae62155b371b.zip gcc-7a16d39903ed1bf159f7933a19ccae62155b371b.tar.gz gcc-7a16d39903ed1bf159f7933a19ccae62155b371b.tar.bz2 | |
[PATCH v3] c: Extend the -Wpadded message with actual padding size
gcc/ChangeLog:
* stor-layout.cc (finalize_record_size): Extend warning message.
gcc/testsuite/ChangeLog:
* c-c++-common/Wpadded.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/stor-layout.cc | 7 | ||||
| -rw-r--r-- | gcc/testsuite/c-c++-common/Wpadded.c | 14 |
2 files changed, 20 insertions, 1 deletions
diff --git a/gcc/stor-layout.cc b/gcc/stor-layout.cc index 765f22f6..88923c4 100644 --- a/gcc/stor-layout.cc +++ b/gcc/stor-layout.cc @@ -1781,7 +1781,12 @@ finalize_record_size (record_layout_info rli) && simple_cst_equal (unpadded_size, TYPE_SIZE (rli->t)) == 0 && input_location != BUILTINS_LOCATION && !TYPE_ARTIFICIAL (rli->t)) - warning (OPT_Wpadded, "padding struct size to alignment boundary"); + { + tree pad_size + = size_binop (MINUS_EXPR, TYPE_SIZE_UNIT (rli->t), unpadded_size_unit); + warning (OPT_Wpadded, + "padding struct size to alignment boundary with %E bytes", pad_size); + } if (warn_packed && TREE_CODE (rli->t) == RECORD_TYPE && TYPE_PACKED (rli->t) && ! rli->packed_maybe_necessary diff --git a/gcc/testsuite/c-c++-common/Wpadded.c b/gcc/testsuite/c-c++-common/Wpadded.c new file mode 100644 index 0000000..c5be468 --- /dev/null +++ b/gcc/testsuite/c-c++-common/Wpadded.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ +/* { dg-options "-Wpadded" } */ + +/* + * The struct is on single line, because C++ compiler emits the -Wpadded + * warning at the first line of the struct definition, while the C compiler at + * the last line. This way the test passes on both. + * + * Attribute aligned is needed for the test to pass on targets where + * the default behaviour is to pack the struct and also on targets that align + * 4 byte fields to 2 byte boundary. + */ +struct S { __UINT32_TYPE__ i; char c; } __attribute__((aligned(4))); /* { dg-warning "padding struct size to alignment boundary with 3 bytes" } */ + |