diff options
| author | Nathan Chancellor <nathan@kernel.org> | 2023-12-05 16:53:52 -0700 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-17 18:08:28 -0800 |
| commit | a4426641f00cd2c293c91e881ab31faaf76b20fb (patch) | |
| tree | b9be92ca1998bd9e31df0898ce676b97a3e31cfa /lib | |
| parent | ae84ff9a14a5a8d36a329a30626800155782e617 (diff) | |
lib/Kconfig.debug: Update AS_HAS_NON_CONST_LEB128 comment and name
Fangrui noted that the comment around CONFIG_AS_HAS_NON_CONST_LEB128
could be made more accurate because explicit .sleb128 directives are not
emitted, only .uleb128 directives are. Rename the symbol to
CONFIG_AS_HAS_NON_CONST_ULEB128 as a result.
Further clarifications include replacing "symbol deltas" with the more
accurate "label differences", noting that this issue has been resolved
in newer binutils (2.41+), and it only occurs when a port uses RISC-V
style linker relaxation.
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-3-aedf00a382ac@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a0ebce05a368..76c2cc697573 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -231,9 +231,10 @@ config DEBUG_INFO in the "Debug information" choice below, indicating that debug information will be generated for build targets. -# Clang is known to generate .{s,u}leb128 with symbol deltas with DWARF5, which -# some targets may not support: https://sourceware.org/bugzilla/show_bug.cgi?id=27215 -config AS_HAS_NON_CONST_LEB128 +# Clang generates .uleb128 with label differences for DWARF v5, a feature that +# older binutils ports do not support when utilizing RISC-V style linker +# relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215 +config AS_HAS_NON_CONST_ULEB128 def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:) choice @@ -258,7 +259,7 @@ config DEBUG_INFO_NONE config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT bool "Rely on the toolchain's implicit default DWARF version" select DEBUG_INFO - depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) + depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128) help The implicit default version of DWARF debug info produced by a toolchain changes over time. @@ -283,7 +284,7 @@ config DEBUG_INFO_DWARF5 bool "Generate DWARF Version 5 debuginfo" select DEBUG_INFO depends on !ARCH_HAS_BROKEN_DWARF5 - depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_LEB128) + depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128) help Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc 5.0+ accepts the -gdwarf-5 flag but only had partial support for some |