bc: eliminate BC_STATUS_INPUT_EOF

function                                             old     new   delta
fflush_and_check                                       -      36     +36
bc_num_a                                             445     456     +11
bc_num_ulong                                          85      95     +10
bc_vm_run                                           1978    1984      +6
bc_num_s                                             246     252      +6
bc_err_msgs                                          192     188      -4
quit                                                  38      32      -6
bc_vm_process                                        139     132      -7
bc_program_reset                                     172     159     -13
bc_parse_create                                      192     175     -17
bc_read_line                                         349     311     -38
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/6 up/down: 69/-85)            Total: -16 bytes
   text	   data	    bss	    dec	    hex	filename
 987844	    485	   7296	 995625	  f3129	busybox_old
 987828	    485	   7296	 995609	  f3119	busybox_unstripped

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

diff --git a/miscutils/bc.c b/miscutils/bc.c
index c3d118417a30630f731b291dc905a74b9188995a..c819decffe70a67d274fa7d152a48ad913ab34f9 100644 (file)
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -171,7 +171,7 @@ typedef enum BcStatus {
        BC_STATUS_SUCCESS,
 
 //     BC_STATUS_ALLOC_ERR,
-       BC_STATUS_INPUT_EOF,
+//     BC_STATUS_INPUT_EOF,
        BC_STATUS_BIN_FILE,
 //     BC_STATUS_PATH_IS_DIR,
 
@@ -240,7 +240,7 @@ typedef enum BcStatus {
 static const char *const bc_err_msgs[] = {
        NULL,
 //     "memory allocation error",
-       "I/O error",
+//     "I/O error",
        "file is not text:",
 //     "path is a directory:",
 
@@ -875,6 +875,7 @@ struct globals {
 
        smallint tty;
        smallint ttyin;
+       smallint eof;
 } FIX_ALIASING;
 #define G (*ptr_to_globals)
 #define INIT_G() do { \
@@ -1121,11 +1122,20 @@ static const char bc_lib[] = {
 };
 #endif // ENABLE_BC
 
+static void fflush_and_check(void)
+{
+       fflush_all();
+       if (ferror(stdout) || ferror(stderr))
+               bb_perror_msg_and_die("output error");
+}
+
 static void quit(void) NORETURN;
 static void quit(void)
 {
-       fflush_all();
-       exit(ferror(stdout) || ferror(stderr));
+       if (ferror(stdin))
+               bb_perror_msg_and_die("input error");
+       fflush_and_check();
+       exit(0);
 }
 
 static void bc_vec_grow(BcVec *v, size_t n)
@@ -1284,7 +1294,7 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
 
        bc_vec_npop(vec, vec->len);
 
-       fflush(stdout);
+       fflush_and_check();
 #if ENABLE_FEATURE_BC_SIGNALS
        if (bb_got_signal) { // ^C was pressed
  intr:
@@ -1297,15 +1307,12 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
 #endif
        if (G.ttyin && !G_posix)
                fputs(prompt, stderr);
-       fflush(stderr);
+       fflush_and_check();
 
 #if ENABLE_FEATURE_BC_SIGNALS
        errno = 0;
 #endif
        do {
-               if (ferror(stdout) || ferror(stderr))
-                       bb_perror_msg_and_die("output error");
-
                i = fgetc(stdin);
 
                if (i == EOF) {
@@ -1318,8 +1325,12 @@ static BcStatus bc_read_line(BcVec *vec, const char *prompt)
                        }
 #endif
                        if (ferror(stdin))
-                               bb_perror_msg_and_die("input error");
-                       return BC_STATUS_INPUT_EOF;
+                               quit(); // this emits error message
+                       G.eof = 1;
+                       // Note: EOF does not append '\n', therefore:
+                       // printf 'print 123\n' | bc - works
+                       // printf 'print 123' | bc   - fails (syntax error)
+                       break;
                }
 
                c = (signed char) i;
@@ -3627,7 +3638,7 @@ static void bc_parse_create(BcParse *p, size_t func,
        bc_vec_init(&p->ops, sizeof(BcLexType), NULL);
 
        p->parse = parse;
-       p->auto_part = (p->nbraces = 0);
+       // p->auto_part = p->nbraces = 0; - already is
        bc_parse_updateFunc(p, func);
 }
 
@@ -6473,9 +6484,9 @@ static BcStatus bc_program_reset(BcStatus s)
        if (!s || s == BC_STATUS_EXEC_SIGNAL) {
                if (!G.ttyin)
                        quit();
-               fflush(stdout);
+               fflush_and_check(); // make sure buffered stdout is printed
                fputs(bc_program_ready_msg, stderr);
-               fflush(stderr);
+               fflush_and_check();
                s = BC_STATUS_SUCCESS;
        }
 
@@ -6910,7 +6921,7 @@ static BcStatus bc_vm_process(const char *text)
 
        if (BC_PARSE_CAN_EXEC(&G.prs)) {
                s = bc_program_exec();
-               fflush(stdout);
+               fflush_and_check();
                if (s)
                        s = bc_vm_error(bc_program_reset(s), G.prs.l.f, 0);
        }
@@ -6961,7 +6972,7 @@ 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.
-       while ((s = bc_read_line(&buf, ">>> ")) == BC_STATUS_SUCCESS) {
+       while (!G.eof && (s = bc_read_line(&buf, ">>> ")) == BC_STATUS_SUCCESS) {
 
                char *string = buf.v;
 
@@ -7012,11 +7023,6 @@ static BcStatus bc_vm_stdin(void)
 
        if (s == BC_STATUS_BIN_FILE) s = bc_vm_error(s, G.prs.l.f, 0);
 
-       // INPUT_EOF will always happen when stdin is
-       // closed. It's not a problem in that case.
-       if (s == BC_STATUS_INPUT_EOF)
-               s = BC_STATUS_SUCCESS;
-
        if (str)
                s = bc_vm_error(BC_STATUS_LEX_NO_STRING_END, G.prs.l.f,
                                G.prs.l.line);