bc: in non-interactive config, let compiler know that error funcs do not return

function                                             old     new   delta
bc_num_s                                             235     239      +4
bc_lex_next                                           92      91      -1
dc_parse_register                                     53      51      -2
dc_parse_parse                                        46      44      -2
bc_vm_run                                            624     622      -2
bc_program_assignStr                                 146     144      -2
bc_parse_else                                        135     133      -2
bc_parse_body                                        116     114      -2
bc_num_a                                             445     443      -2
bc_func_insert                                        97      95      -2
bc_program_pushVar                                   203     200      -3
bc_parse_text                                        133     130      -3
bc_error_bad_character                                17      14      -3
bc_error                                              14      11      -3
bc_program_printStream                               157     153      -4
bc_program_prep                                       91      87      -4
bc_program_copyToVar                                 311     307      -4
bc_num_ulong                                          95      90      -5
bc_num_p                                             445     440      -5
bc_program_print                                     711     704      -7
bc_parse_endBody                                     365     358      -7
bc_num_r                                             237     230      -7
bc_num_d                                             550     543      -7
dc_lex_token                                         682     674      -8
bc_program_pushArray                                 147     139      -8
bc_program_assign                                    485     475     -10
bc_program_read                                      333     322     -11
bc_lex_token                                        1278    1266     -12
bc_parse_stmt                                       1780    1767     -13
bc_program_modexp                                    723     707     -16
dc_parse_expr                                        762     744     -18
bc_program_execStr                                   496     478     -18
bc_program_call                                      347     329     -18
bc_vm_file                                           219     197     -22
bc_program_binOpPrep                                 311     289     -22
bc_parse_name                                        539     513     -26
bc_parse_parse                                       451     423     -28
bc_program_num                                       912     880     -32
bc_read_line                                         172     139     -33
bc_program_exec                                     4048    4010     -38
bc_parse_auto                                        313     275     -38
bc_parse_expr_empty_ok                              2095    2036     -59
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/41 up/down: 4/-509)          Total: -505 bytes
   text	   data	    bss	    dec	    hex	filename
 983707	    485	   7296	 991488	  f2100	busybox_old
 983202	    485	   7296	 990983	  f1f07	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 39 insertions, 26 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 26ab94cbd..aa478e461 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -976,7 +976,20 @@ static void bc_verror_msg(const char *fmt, va_list p)
         }
 }
 
-static NOINLINE int bc_error_fmt(const char *fmt, ...)
+#if ENABLE_FEATURE_BC_SIGNALS
+# define ERRORFUNC       /*nothing*/
+# define ERROR_RETURN(a) a
+#else
+# if ENABLE_FEATURE_CLEAN_UP
+#  define ERRORFUNC       /*nothing*/
+#  define ERROR_RETURN(a) a
+# else
+#  define ERRORFUNC       NORETURN
+#  define ERROR_RETURN(a) /*nothing*/
+# endif
+#endif
+
+static NOINLINE ERRORFUNC int bc_error_fmt(const char *fmt, ...)
 {
         va_list p;
 
@@ -986,7 +999,7 @@ static NOINLINE int bc_error_fmt(const char *fmt, ...)
 
         if (!ENABLE_FEATURE_CLEAN_UP && !G_ttyin)
                 exit(1);
-        return BC_STATUS_FAILURE;
+        ERROR_RETURN(return BC_STATUS_FAILURE;)
 }
 
 #if ENABLE_BC
@@ -1016,52 +1029,52 @@ static NOINLINE int bc_posix_error_fmt(const char *fmt, ...)
 // function must not have caller-cleaned parameters on stack.
 // Unfortunately, vararg function API does exactly that on most arches.
 // Thus, use these shims for the cases when we have no vararg PARAMS:
-static int bc_error(const char *msg)
+static ERRORFUNC int bc_error(const char *msg)
 {
-        return bc_error_fmt("%s", msg);
+        ERROR_RETURN(return) bc_error_fmt("%s", msg);
 }
-#if ENABLE_BC
-static int bc_POSIX_requires(const char *msg)
+static ERRORFUNC int bc_error_bad_character(char c)
 {
-        return bc_posix_error_fmt("POSIX requires %s", msg);
+        ERROR_RETURN(return) bc_error_fmt("bad character '%c'", c);
 }
-static int bc_POSIX_does_not_allow(const char *msg)
+static ERRORFUNC int bc_error_bad_expression(void)
 {
-        return bc_posix_error_fmt("%s%s", "POSIX does not allow ", msg);
+        ERROR_RETURN(return) bc_error("bad expression");
 }
-static int bc_POSIX_does_not_allow_bool_ops_this_is_bad(const char *msg)
+static ERRORFUNC int bc_error_bad_token(void)
 {
-        return bc_posix_error_fmt("%s%s %s", "POSIX does not allow ", "boolean operators; the following is bad:", msg);
+        ERROR_RETURN(return) bc_error("bad token");
 }
-static int bc_POSIX_does_not_allow_empty_X_expression_in_for(const char *msg)
+static ERRORFUNC int bc_error_stack_has_too_few_elements(void)
 {
-        return bc_posix_error_fmt("%san empty %s expression in a for loop", "POSIX does not allow ", msg);
+        ERROR_RETURN(return) bc_error("stack has too few elements");
 }
-#endif
-static int bc_error_bad_character(char c)
+static ERRORFUNC int bc_error_variable_is_wrong_type(void)
 {
-        return bc_error_fmt("bad character '%c'", c);
+        ERROR_RETURN(return) bc_error("variable is wrong type");
 }
-static int bc_error_bad_expression(void)
+static ERRORFUNC int bc_error_nested_read_call(void)
 {
-        return bc_error("bad expression");
+        ERROR_RETURN(return) bc_error("read() call inside of a read() call");
 }
-static int bc_error_bad_token(void)
+#if ENABLE_BC
+static int bc_POSIX_requires(const char *msg)
 {
-        return bc_error("bad token");
+        return bc_posix_error_fmt("POSIX requires %s", msg);
 }
-static int bc_error_stack_has_too_few_elements(void)
+static int bc_POSIX_does_not_allow(const char *msg)
 {
-        return bc_error("stack has too few elements");
+        return bc_posix_error_fmt("%s%s", "POSIX does not allow ", msg);
 }
-static int bc_error_variable_is_wrong_type(void)
+static int bc_POSIX_does_not_allow_bool_ops_this_is_bad(const char *msg)
 {
-        return bc_error("variable is wrong type");
+        return bc_posix_error_fmt("%s%s %s", "POSIX does not allow ", "boolean operators; the following is bad:", msg);
 }
-static int bc_error_nested_read_call(void)
+static int bc_POSIX_does_not_allow_empty_X_expression_in_for(const char *msg)
 {
-        return bc_error("read() call inside of a read() call");
+        return bc_posix_error_fmt("%san empty %s expression in a for loop", "POSIX does not allow ", msg);
 }
+#endif
 
 static void bc_vec_grow(BcVec *v, size_t n)
 {