diff options
Diffstat (limited to 'gcc/config/bpf/bpf.cc')
| -rw-r--r-- | gcc/config/bpf/bpf.cc | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc index 1d0abd7..437bd65 100644 --- a/gcc/config/bpf/bpf.cc +++ b/gcc/config/bpf/bpf.cc @@ -154,6 +154,10 @@ static const struct attribute_spec bpf_attribute_table[] = { "preserve_access_index", 0, -1, false, true, false, true, bpf_handle_preserve_access_index_attribute, NULL }, + /* Support for `naked' function attribute. */ + { "naked", 0, 1, false, false, false, false, + bpf_handle_fndecl_attribute, NULL }, + /* The last attribute spec is set to be NULL. */ { NULL, 0, 0, false, false, false, false, NULL, NULL } }; @@ -335,6 +339,21 @@ bpf_function_value_regno_p (const unsigned int regno) #undef TARGET_FUNCTION_VALUE_REGNO_P #define TARGET_FUNCTION_VALUE_REGNO_P bpf_function_value_regno_p + +/* Determine whether to warn about lack of return statement in a + function. */ + +static bool +bpf_warn_func_return (tree decl) +{ + /* Naked functions are implemented entirely in assembly, including + the return instructions. */ + return lookup_attribute ("naked", DECL_ATTRIBUTES (decl)) == NULL_TREE; +} + +#undef TARGET_WARN_FUNC_RETURN +#define TARGET_WARN_FUNC_RETURN bpf_warn_func_return + /* Compute the size of the function's stack frame, including the local area and the register-save area. */ @@ -388,6 +407,9 @@ bpf_expand_prologue (void) dynamically. This should have been checked already and an error emitted. */ gcc_assert (!cfun->calls_alloca); + + /* If we ever need to have a proper prologue here, please mind the + `naked' function attribute. */ } /* Expand to the instructions in a function epilogue. This function @@ -399,6 +421,9 @@ bpf_expand_epilogue (void) /* See note in bpf_expand_prologue for an explanation on why we are not restoring callee-saved registers in BPF. */ + /* If we ever need to do anything else than just generating a return + instruction here, please mind the `naked' function attribute. */ + emit_jump_insn (gen_exit ()); } |