From 1be73dd9ad6d2cf6747934374c1d58bd9bc211b4 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 26 Sep 2021 13:25:49 +0200 Subject: shell: fix parsing of $(( (v)++ + NUM )) function old new delta evaluate_string 988 1011 +23 Signed-off-by: Denys Vlasenko --- shell/ash_test/ash-arith/arith-postinc.right | 3 ++ shell/ash_test/ash-arith/arith-postinc.tests | 4 ++ shell/hush_test/hush-arith/arith-postinc.right | 3 ++ shell/hush_test/hush-arith/arith-postinc.tests | 4 ++ shell/math.c | 52 +++++++++++++++----------- 5 files changed, 44 insertions(+), 22 deletions(-) diff --git a/shell/ash_test/ash-arith/arith-postinc.right b/shell/ash_test/ash-arith/arith-postinc.right index c95ce02bf..5cd4ba6b4 100644 --- a/shell/ash_test/ash-arith/arith-postinc.right +++ b/shell/ash_test/ash-arith/arith-postinc.right @@ -2,4 +2,7 @@ 1 1 1 1 1 1 +6 6 +7 7 +7 7 Ok:0 diff --git a/shell/ash_test/ash-arith/arith-postinc.tests b/shell/ash_test/ash-arith/arith-postinc.tests index 3fd9bfed5..f2ae778df 100755 --- a/shell/ash_test/ash-arith/arith-postinc.tests +++ b/shell/ash_test/ash-arith/arith-postinc.tests @@ -2,4 +2,8 @@ echo 1 $((0++1)) echo 1 $((0--1)) x=-1; echo 1 $((0-$x)) x=+1; echo 1 $((0+$x)) +a=3 +echo 6 $((a+++3)) # a++ + 3 +echo 7 $(((a)+++3)) # a + + + 3 +echo 7 $(((a)+++3)) # a + + + 3 echo Ok:$? diff --git a/shell/hush_test/hush-arith/arith-postinc.right b/shell/hush_test/hush-arith/arith-postinc.right index c95ce02bf..5cd4ba6b4 100644 --- a/shell/hush_test/hush-arith/arith-postinc.right +++ b/shell/hush_test/hush-arith/arith-postinc.right @@ -2,4 +2,7 @@ 1 1 1 1 1 1 +6 6 +7 7 +7 7 Ok:0 diff --git a/shell/hush_test/hush-arith/arith-postinc.tests b/shell/hush_test/hush-arith/arith-postinc.tests index 3fd9bfed5..f2ae778df 100755 --- a/shell/hush_test/hush-arith/arith-postinc.tests +++ b/shell/hush_test/hush-arith/arith-postinc.tests @@ -2,4 +2,8 @@ echo 1 $((0++1)) echo 1 $((0--1)) x=-1; echo 1 $((0-$x)) x=+1; echo 1 $((0+$x)) +a=3 +echo 6 $((a+++3)) # a++ + 3 +echo 7 $(((a)+++3)) # a + + + 3 +echo 7 $(((a)+++3)) # a + + + 3 echo Ok:$? diff --git a/shell/math.c b/shell/math.c index 049d5703b..76d22c9bd 100644 --- a/shell/math.c +++ b/shell/math.c @@ -116,10 +116,6 @@ #include "libbb.h" #include "math.h" -#define lookupvar (math_state->lookupvar) -#define setvar (math_state->setvar ) -//#define endofname (math_state->endofname) - typedef unsigned char operator; /* An operator's token id is a bit of a bitfield. The lower 5 bits are the @@ -258,7 +254,7 @@ static const char* arith_lookup_val(arith_state_t *math_state, var_or_num_t *t) { if (t->var) { - const char *p = lookupvar(t->var); + const char *p = math_state->lookupvar(t->var); if (p) { remembered_name *cur; remembered_name cur_save; @@ -445,16 +441,15 @@ arith_apply(arith_state_t *math_state, operator op, var_or_num_t *numstack, var_ if (top_of_stack->var == NULL) { /* Hmm, 1=2 ? */ -//TODO: actually, bash allows ++7 but for some reason it evals to 7, not 8 goto err; } /* Save to shell variable */ sprintf(buf, ARITH_FMT, rez); - setvar(top_of_stack->var, buf); + math_state->setvar(top_of_stack->var, buf); /* After saving, make previous value for v++ or v-- */ if (op == TOK_POST_INC) rez--; - else if (op == TOK_POST_DEC) + if (op == TOK_POST_DEC) rez++; } @@ -607,11 +602,9 @@ evaluate_string(arith_state_t *math_state, const char *expr) const char *p; operator op; operator prec; - char arithval; expr = skip_whitespace(expr); - arithval = *expr; - if (arithval == '\0') { + if (*expr == '\0') { if (expr == start_expr) { /* Null expression */ numstack->val = 0; @@ -628,6 +621,7 @@ evaluate_string(arith_state_t *math_state, const char *expr) * append a closing right paren * and let the loop process it */ expr = ptr_to_rparen; +//bb_error_msg("expr=')'"); continue; } /* At this point, we're done with the expression */ @@ -635,19 +629,16 @@ evaluate_string(arith_state_t *math_state, const char *expr) /* ...but if there isn't, it's bad */ goto err; } - if (numstack->var) { - /* expression is $((var)) only, lookup now */ - errmsg = arith_lookup_val(math_state, numstack); - } goto ret; } p = endofname(expr); if (p != expr) { /* Name */ - size_t var_name_size = (p-expr) + 1; /* +1 for NUL */ + size_t var_name_size = (p - expr) + 1; /* +1 for NUL */ numstackptr->var = alloca(var_name_size); safe_strncpy(numstackptr->var, expr, var_name_size); +//bb_error_msg("var:'%s'", numstackptr->var); expr = p; num: numstackptr->second_val_present = 0; @@ -656,11 +647,12 @@ evaluate_string(arith_state_t *math_state, const char *expr) continue; } - if (isdigit(arithval)) { + if (isdigit(*expr)) { /* Number */ numstackptr->var = NULL; errno = 0; numstackptr->val = strto_arith_t(expr, (char**) &expr); +//bb_error_msg("val:%lld", numstackptr->val); if (errno) numstackptr->val = 0; /* bash compat */ goto num; @@ -671,10 +663,10 @@ evaluate_string(arith_state_t *math_state, const char *expr) /* Special case: XYZ--, XYZ++, --XYZ, ++XYZ are recognized * only if XYZ is a variable name, not a number or EXPR. IOW: * "a+++v" is a++ + v. + * "(a)+++7" is ( a ) + + + 7. * "7+++v" is 7 + ++v, not 7++ + v. * "--7" is - - 7, not --7. - * "++++a" is + + ++a, not ++ ++ a. - * (we still mishandle "(a)+++7", should be treated as (a) + + + 7, but we do increment a) + * "++++a" is + + ++a, not ++ ++a. */ if ((expr[0] == '+' || expr[0] == '-') && (expr[1] == expr[0]) @@ -756,26 +748,40 @@ evaluate_string(arith_state_t *math_state, const char *expr) * "applied" in this way. */ prec = PREC(op); +//bb_error_msg("prec:%02x", prec); if ((prec > 0 && prec < UNARYPREC) || prec == SPEC_PREC) { /* not left paren or unary */ if (lasttok != TOK_NUM) { /* binary op must be preceded by a num */ goto err; } + /* The algorithm employed here is simple: while we don't + * hit an open paren nor the bottom of the stack, pop + * tokens and apply them */ while (stackptr != stack) { operator prev_op = *--stackptr; if (op == TOK_RPAREN) { - /* The algorithm employed here is simple: while we don't - * hit an open paren nor the bottom of the stack, pop - * tokens and apply them */ +//bb_error_msg("op == TOK_RPAREN"); if (prev_op == TOK_LPAREN) { +//bb_error_msg("prev_op == TOK_LPAREN"); +//bb_error_msg(" %p %p numstackptr[-1].var:'%s'", numstack, numstackptr-1, numstackptr[-1].var); + if (numstackptr[-1].var) { + /* Expression is (var), lookup now */ + errmsg = arith_lookup_val(math_state, &numstackptr[-1]); + if (errmsg) + goto err_with_custom_msg; + /* Erase var name: (var) is just a number, for example, (var) = 1 is not valid */ + numstackptr[-1].var = NULL; + } /* Any operator directly after a * close paren should consider itself binary */ lasttok = TOK_NUM; goto next; } +//bb_error_msg("prev_op != TOK_LPAREN"); } else { operator prev_prec = PREC(prev_op); +//bb_error_msg("op != TOK_RPAREN"); fix_assignment_prec(prec); fix_assignment_prec(prev_prec); if (prev_prec < prec @@ -785,6 +791,7 @@ evaluate_string(arith_state_t *math_state, const char *expr) break; } } +//bb_error_msg("arith_apply(prev_op:%02x)", prev_op); errmsg = arith_apply(math_state, prev_op, numstack, &numstackptr); if (errmsg) goto err_with_custom_msg; @@ -794,6 +801,7 @@ evaluate_string(arith_state_t *math_state, const char *expr) } /* Push this operator to the stack and remember it */ +//bb_error_msg("push op:%02x", op); *stackptr++ = lasttok = op; next: ; } /* while (1) */ -- cgit v1.2.3