bc: remove BC_STATUS_EOF (again), the condition is detectable as len==0

function                                             old     new   delta
bc_read_line                                         147     129     -18
bc_vm_run                                            618     591     -27
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-45)             Total: -45 bytes
   text	   data	    bss	    dec	    hex	filename
 980802	    485	   7296	 988583	  f15a7	busybox_old
 980757	    485	   7296	 988538	  f157a	busybox_unstripped

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

1 files changed, 9 insertions, 19 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 9cc29f0ea..9809fa72f 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -187,7 +187,6 @@ typedef enum BcStatus {
         BC_STATUS_SUCCESS = 0,
         BC_STATUS_FAILURE = 1,
         BC_STATUS_PARSE_EMPTY_EXP = 2, // bc_parse_expr_empty_ok() uses this
-        BC_STATUS_EOF = 3, // bc_vm_stdin() uses this
 } BcStatus;
 
 #define BC_VEC_INVALID_IDX ((size_t) -1)
@@ -1364,15 +1363,10 @@ static int push_input_byte(BcVec *vec, char c)
         return 0;
 }
 
-// This is not a "z" function:
-// can return success (0) or BC_STATUS_EOF.
-// Exits with error message if read error is detected.
-static BcStatus bc_read_line(BcVec *vec)
+static void bc_read_line(BcVec *vec)
 {
-        BcStatus s;
         bool bad_chars;
 
-        s = BC_STATUS_SUCCESS;
         do {
                 int c;
 
@@ -1397,7 +1391,6 @@ static BcStatus bc_read_line(BcVec *vec)
                         if (n <= 0) { // read errors or EOF, or ^D, or ^C
                                 if (n == 0) // ^C
                                         goto intr;
-                                s = BC_STATUS_EOF;
                                 break;
                         }
                         i = 0;
@@ -1425,9 +1418,6 @@ static BcStatus bc_read_line(BcVec *vec)
                                 if (c == EOF) {
                                         if (ferror(stdin))
                                                 quit(); // this emits error message
-                                        // If we had some input before EOF, do not report EOF yet:
-                                        if (vec->len == 0)
-                                                s = BC_STATUS_EOF;
                                         // Note: EOF does not append '\n', therefore:
                                         // printf 'print 123\n' | bc - works
                                         // printf 'print 123' | bc   - fails (syntax error)
@@ -1439,8 +1429,6 @@ static BcStatus bc_read_line(BcVec *vec)
         } while (bad_chars);
 
         bc_vec_pushZeroByte(vec);
-
-        return s;
 }
 
 static char* bc_read_file(const char *path)
@@ -5416,8 +5404,7 @@ static BC_STATUS zbc_program_read(void)
         G.prog.file = NULL;
         G.in_read = 1;
 
-        s = bc_read_line(&buf);
-        //if (s) goto io_err; - wrong, nonzero return means EOF, not error
+        bc_read_line(&buf);
 
         common_parse_init(&parse, BC_PROG_READ);
         bc_lex_file(&parse.l);
@@ -7091,13 +7078,18 @@ static BcStatus bc_vm_stdin(void)
         // with a backslash to the parser. The reason for that is because the parser
         // treats a backslash+newline combo as whitespace, per the bc spec. In that
         // case, and for strings and comments, the parser will expect more stuff.
+        s = BC_STATUS_SUCCESS;
         comment = false;
         str = 0;
-        while ((s = bc_read_line(&buf)) == BC_STATUS_SUCCESS) {
+        for (;;) {
                 size_t len;
-                char *string = buf.v;
+                char *string;
 
+                bc_read_line(&buf);
                 len = buf.len - 1;
+                if (len == 0) // "" buf means EOF
+                        break;
+                string = buf.v;
                 if (len == 1) {
                         if (str && buf.v[0] == G.send)
                                 str -= 1;
@@ -7146,8 +7138,6 @@ static BcStatus bc_vm_stdin(void)
 
                 bc_vec_pop_all(&buffer);
         }
-        if (s == BC_STATUS_EOF) // input EOF (^D) is not an error
-                s = BC_STATUS_SUCCESS;
 
         if (str) {
                 s = bc_error("string end could not be found");