https://bugs.llvm.org/show_bug.cgi?id=39899
Bug ID: 39899
Summary: Clang/LLVM Produces a constant description of a global
constant, even when that constant has storage
Product: clang
Version: trunk
Hardware: PC
OS: Linux
Status: NEW
Severity: enhancement
Priority: P
Component: LLVM Codegen
Assignee: unassignedclangb...@nondot.org
Reporter: dblai...@gmail.com
CC: apra...@apple.com, echri...@gmail.com,
jdevliegh...@apple.com, llvm-bugs@lists.llvm.org,
neeil...@live.com, paul.robin...@am.sony.com,
richard-l...@metafoo.co.uk
Given this:
static const int x = 3;
const int *y() {
return &x;
}
int z() {
return 1;
}
Clang produces IR with a variable description like this:
@_ZL1x = internal constant i32 3, align 4, !dbg !0
!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
Which seems all right and good.
but if you change the "return 1" to "return x", you get IR like this:
@_ZL1x = internal constant i32 3, align 4, !dbg !0
!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression(DW_OP_constu,
3, DW_OP_stack_value))
It's weird that the !dbg is even attached to the global anymore, since it
doesn't use its address in the location expression at all.
But also, it's a regression to describe something with a constant when it does
have storage - it means you can't, say evaluate "&i" in a debugger, or pass the
address of the global to a function that wants an address, etc.
According to some rough debugging with godbolt, this regression first appeared
in the 4.0 release.
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
