On RISC-V, clang emits empty name symbols used for label differences. (In GCC the symbols are typically `.L0`)
After D95916, the empty name symbols can show up in llvm-symbolizer's symbolization output.
They have no names and thus not useful. Set `SF_FormatSpecific` so that llvm-symbolizer will ignore them.
`SF_FormatSpecific` is also used in LTO but that case should not matter.
Corresponding addr2line problem: https://sourceware.org/bugzilla/show_bug.cgi?id=27585
Reviewed By: luismarques
Differential Revision: https://reviews.llvm.org/D98669
}
if (ESym->getType() == ELF::STT_FUNC && (ESym->st_value & 1) == 1)
Result |= SymbolRef::SF_Thumb;
+ } else if (EF.getHeader().e_machine == ELF::EM_RISCV) {
+ if (Expected<StringRef> NameOrErr = getSymbolName(Sym)) {
+ // Mark empty name symbols used for label differences.
+ if (NameOrErr->empty())
+ Result |= SymbolRef::SF_FormatSpecific;
+ } else {
+ // TODO: Actually report errors helpfully.
+ consumeError(NameOrErr.takeError());
+ }
}
if (ESym->st_shndx == ELF::SHN_UNDEF)
--- /dev/null
+# REQUIRES: riscv-registered-target
+## Ignore empty name symbols.
+
+# RUN: llvm-mc -filetype=obj -triple=riscv64 %s -o %t
+# RUN: llvm-readelf -s %t | FileCheck %s --check-prefix=SYM
+
+# SYM: 0000000000000004 0 NOTYPE LOCAL DEFAULT [[#]] {{$}}
+# SYM: 0000000000000000 0 NOTYPE GLOBAL DEFAULT [[#]] foo
+
+## Make sure we test at an address larger than or equal to an empty name symbol.
+# RUN: llvm-symbolizer --obj=%t 0 4 | FileCheck %s
+
+# CHECK: foo
+# CHECK-NEXT: ??:0:0
+# CHECK-EMPTY:
+# CHECK-NEXT: foo
+# CHECK-NEXT: ??:0:0
+
+.globl foo
+foo:
+ nop
+ .file 1 "/tmp" "a.s"
+ .loc 1 1 0
+ nop
+
+.section .debug_line,"",@progbits