mirror of
https://github.com/llvm/llvm-project.git
synced 2025-04-26 00:36:06 +00:00
43feb3eeb1
The `-Wpadded` diagnostics are usually very noisy and generally not helpful. However, reporting padding that was introduced in bit-fields is rather helpful. For example, yesterday in SerenityOS's discord we had very unpleasant experience of debugging Windows portability issue, and its root cause was that under `x86_64-pc-windows-msvc` a padding was introduced for one of the bit-fields. So, this PR separates bit-field-related padding diagnostics into a new `-Wpadded-bitfield`. The diagnostic group is also enabled by `-Wpadded` for compatibility reasons.
42 lines
900 B
C++
42 lines
900 B
C++
// RUN: %clang_cc1 -triple=x86_64-none-none -Wpadded-bitfield -verify=expected %s -emit-llvm-only
|
|
|
|
struct S1 {
|
|
unsigned a : 1;
|
|
unsigned long long : 0; // expected-warning {{padding struct 'S1' with 63 bits to align anonymous bit-field}}
|
|
};
|
|
|
|
struct S2 {
|
|
unsigned a : 1;
|
|
unsigned long long b : 64; // expected-warning {{padding struct 'S2' with 63 bits to align 'b'}}
|
|
};
|
|
|
|
struct S3 {
|
|
char a : 1;
|
|
short b : 16; // expected-warning {{padding struct 'S3' with 15 bits to align 'b'}}
|
|
};
|
|
|
|
struct [[gnu::packed]] S4 {
|
|
char a : 1;
|
|
short b : 16;
|
|
};
|
|
|
|
struct S5 {
|
|
unsigned a : 1;
|
|
unsigned long long b : 63;
|
|
};
|
|
|
|
struct S6 {
|
|
unsigned a : 1;
|
|
unsigned long long b;
|
|
};
|
|
|
|
struct S7 {
|
|
int word;
|
|
struct {
|
|
int filler __attribute__ ((aligned (8)));
|
|
};
|
|
};
|
|
|
|
// The warnings are emitted when the layout of the structs is computed, so we have to use them.
|
|
void f(S1, S2, S3, S4, S5, S6, S7){}
|