Printing the raw symbol is useful in inline asm (e.g. getting the C++
mangled name, referencing a symbol in a custom way while ensuring it is
not optimized out even if internal). Similar constraints are available
in other targets (e.g. "S" for aarch64/riscv, "Cs" for m68k).
```
namespace ns { extern int var, a[4]; }
void foo() {
asm(".pushsection .xxx,\"aw\"; .dc.a %p0; .popsection" :: "Ws"(&ns::var));
asm(".reloc ., BFD_RELOC_NONE, %p0" :: "Ws"(&ns::a[3]));
}
```
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105576
Summary:
An inline asm call may result in an immediate input value after inlining.
Therefore, don't emit a diagnostic here if the input isn't an immediate.
Reviewers: joerg, eli.friedman, rsmith
Subscribers: asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, s.egerton, krytarowski, mgorny, riccibruno, eraman, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60943
llvm-svn: 368104
Apparently GCC allows this, and there's code relying on it (see bug).
The idea is to allow expression that would have been allowed if they
were cast to int. So I based the code on how such a cast would be done
(the CK_PointerToIntegral case in IntExprEvaluator::VisitCastExpr()).
Differential Revision: https://reviews.llvm.org/D58821
llvm-svn: 355491
The current constraint logic is both too lax and too strict. It fails
for input outside the [INT_MIN..INT_MAX] range, but it also implicitly
accepts 0 as value when it should not. Adjust logic to handle both
correctly.
Differential Revision: https://reviews.llvm.org/D58649
llvm-svn: 354937
Add additional constraint checking for target specific behaviour for inline
assembly constraints. We would previously silently let all arguments through
for these constraints. In cases where the constraints were violated, we could
end up failing to select instructions and triggering assertions or worse,
silently ignoring instructions.
llvm-svn: 225244
