expression nodes now can have a flag EX_ERROR

diff --git a/lang/cem/cemcom/arith.c b/lang/cem/cemcom/arith.c
index 29755d4..629fbac 100644 (file)
--- a/lang/cem/cemcom/arith.c
+++ b/lang/cem/cemcom/arith.c
@@ -110,12 +110,10 @@ ch76pointer(expp, oper, tp)
        )               /* ch 7.7 */
                ch7cast(expp, CAST, tp);
        else    {
-               if ((*expp)->ex_type != error_type)
-                       expr_error(*expp, "%s on %s and pointer",
+               expr_error(*expp, "%s on %s and pointer",
                                symbol2str(oper),
                                symbol2str((*expp)->ex_type->tp_fund)
                        );
-               (*expp)->ex_type = error_type;
                ch7cast(expp, oper, tp);
        }
 }
@@ -177,8 +175,11 @@ erroneous2int(expp)
        /*      the (erroneous) expression *expp is replaced by an
                int expression
        */
+       int flags = (*expp)->ex_flags;
+       
        free_expression(*expp);
        *expp = intexpr((arith)0, INT);
+       (*expp)->ex_flags = (flags | EX_ERROR);
 }
 
 struct expr *
@@ -291,8 +292,7 @@ opnd2integral(expp, oper)
        register int fund = (*expp)->ex_type->tp_fund;
 
        if (fund != INT && fund != LONG)        {
-               if (fund != ERRONEOUS)
-                       expr_error(*expp, "%s operand to %s",
+               expr_error(*expp, "%s operand to %s",
                                symbol2str(fund), symbol2str(oper));
                erroneous2int(expp);
                /* fund = INT; */

diff --git a/lang/cem/cemcom/ch7.c b/lang/cem/cemcom/ch7.c
index 9812e8f..0f39bcf 100644 (file)
--- a/lang/cem/cemcom/ch7.c
+++ b/lang/cem/cemcom/ch7.c
@@ -61,7 +61,6 @@ ch7sel(expp, oper, idf)
                /* filter out illegal expressions "non_lvalue.sel" */
                if (!(*expp)->ex_lvalue) {
                        expr_error(*expp, "dot requires lvalue");
-                       (*expp)->ex_type = error_type;
                        return;
                }
        }
@@ -102,6 +101,8 @@ ch7sel(expp, oper, idf)
                        */
                        (*expp)->VL_VALUE += sd->sd_offset;
                        (*expp)->ex_type = sd->sd_type;
+                       if ((*expp)->ex_type == error_type)
+                               (*expp)->ex_flags |= EX_ERROR;
                }
                else
                if ((*expp)->ex_class == Oper)  {
@@ -110,16 +111,20 @@ ch7sel(expp, oper, idf)
                        if (op->op_oper == '.' || op->op_oper == ARROW) {
                                op->op_right->VL_VALUE += sd->sd_offset;
                                (*expp)->ex_type = sd->sd_type;
+                               if ((*expp)->ex_type == error_type)
+                                       (*expp)->ex_flags |= EX_ERROR;
                        }
                        else
                                *expp = new_oper(sd->sd_type, *expp, '.',
                                                intexpr(sd->sd_offset, INT));
                }
        }
-       else /* oper == ARROW */
+       else    {
+               /* oper == ARROW */
                *expp = new_oper(sd->sd_type,
                        *expp, oper, intexpr(sd->sd_offset, INT));
-       (*expp)->ex_lvalue = sd->sd_type->tp_fund != ARRAY;
+       }
+       (*expp)->ex_lvalue = (sd->sd_type->tp_fund != ARRAY);
 }
 
 ch7incr(expp, oper)
@@ -152,8 +157,7 @@ ch7incr(expp, oper)
                addend = (arith)1;
 #endif NOBITFIELD
        else    {
-               if ((*expp)->ex_type != error_type)
-                       expr_error(*expp, "%s on %s",
+               expr_error(*expp, "%s on %s",
                                symbol2str(oper),
                                symbol2str((*expp)->ex_type->tp_fund)
                        );
@@ -280,18 +284,22 @@ ch7cast(expp, oper, tp)
                        (*expp)->ex_type = tp;
        }
        else
+       if (oldtp->tp_fund == ERRONEOUS)        {
+               /* we just won't look */
+               (*expp)->ex_type = tp;          /* brute force */
+       }
+       else
        if (oldtp->tp_size == tp->tp_size && oper == CAST)      {
                expr_warning(*expp, "dubious conversion based on equal size");
                (*expp)->ex_type = tp;          /* brute force */
        }
-       else
-       {
+       else    {
                if (oldtp->tp_fund != ERRONEOUS && tp->tp_fund != ERRONEOUS)
                        expr_error(*expp, "cannot convert %s to %s",
                                symbol2str(oldtp->tp_fund),
                                symbol2str(tp->tp_fund)
                        );
-               (*expp)->ex_type = tp;
+               (*expp)->ex_type = tp;          /* brute force */
        }
 }
 

diff --git a/lang/cem/cemcom/ch7bin.c b/lang/cem/cemcom/ch7bin.c
index 12d9267..217eecb 100644 (file)
--- a/lang/cem/cemcom/ch7bin.c
+++ b/lang/cem/cemcom/ch7bin.c
@@ -64,9 +64,8 @@ ch7bin(expp, oper, expr)
                        ch7mon('*', expp);
                }
                if ((*expp)->ex_type->tp_fund != FUNCTION)      {
-                       if ((*expp)->ex_type != error_type)
-                               expr_error(*expp, "call of non-function (%s)",
-                                       symbol2str((*expp)->ex_type->tp_fund));
+                       expr_error(*expp, "call of non-function (%s)",
+                               symbol2str((*expp)->ex_type->tp_fund));
                        /* leave the expression; it may still serve */
                        free_expression(expr);  /* there go the parameters */
                }
@@ -202,7 +201,6 @@ ch7bin(expp, oper, expr)
                )       {
                        if ((*expp)->ex_type != expr->ex_type)  {
                                expr_error(*expp, "illegal balance");
-                               (*expp)->ex_type = error_type;
                        }
                }
                else    {

diff --git a/lang/cem/cemcom/ch7mon.c b/lang/cem/cemcom/ch7mon.c
index 5c14419..f18969f 100644 (file)
--- a/lang/cem/cemcom/ch7mon.c
+++ b/lang/cem/cemcom/ch7mon.c
@@ -28,11 +28,9 @@ ch7mon(oper, expp)
                if ((*expp)->ex_type->tp_fund == ARRAY)
                        array2pointer(expp);
                if ((*expp)->ex_type->tp_fund != POINTER)       {
-                       if ((*expp)->ex_type != error_type)
-                               expr_error(*expp,
-                                       "* applied to non-pointer (%s)",
-                                       symbol2str((*expp)->ex_type->tp_fund));
-                       (*expp)->ex_type = error_type;
+                       expr_error(*expp,
+                               "* applied to non-pointer (%s)",
+                               symbol2str((*expp)->ex_type->tp_fund));
                }
                else {
                        expr = *expp;
@@ -59,13 +57,11 @@ ch7mon(oper, expp)
 #ifndef NOBITFIELD
                if ((*expp)->ex_type->tp_fund == FIELD) {
                        expr_error(*expp, "& applied to field variable");
-                       (*expp)->ex_type = error_type;
                }
                else
 #endif NOBITFIELD
                if (!(*expp)->ex_lvalue)        {
                        expr_error(*expp, "& applied to non-lvalue");
-                       (*expp)->ex_type = error_type;
                }
                else {
                        /* assume that enums are already filtered out   */
@@ -79,7 +75,6 @@ ch7mon(oper, expp)
                                if (def->df_sc == REGISTER) {
                                        expr_error(*expp,
                                        "& on register variable not allowed");
-                                       (*expp)->ex_type = error_type;
                                        break;  /* break case '&' */
                                }
                                def->df_register = REG_NONE;

diff --git a/lang/cem/cemcom/dumpidf.c b/lang/cem/cemcom/dumpidf.c
index 867b731..1c20e88 100644 (file)
--- a/lang/cem/cemcom/dumpidf.c
+++ b/lang/cem/cemcom/dumpidf.c
@@ -318,11 +318,11 @@ p1_expr(lvl, expr)
                printf("NILEXPR\n");
                return;
        }
-       printf("expr: L=%u, T=%s, %cV, F=%02o, D=%d, %s: ",
+       printf("expr: L=%u, T=%s, %cV, F=%03o, D=%d, %s: ",
                expr->ex_line,
                type2str(expr->ex_type),
                expr->ex_lvalue ? 'l' : 'r',
-               expr->ex_flags,
+               expr->ex_flags & 0xFF,
                expr->ex_depth,
                expr->ex_class == Value ? "Value" :
                expr->ex_class == String ? "String" :

diff --git a/lang/cem/cemcom/error.c b/lang/cem/cemcom/error.c
index 7b1629e..0917808 100644 (file)
--- a/lang/cem/cemcom/error.c
+++ b/lang/cem/cemcom/error.c
@@ -56,7 +56,10 @@ expr_error(expr, fmt, args)
        struct expr *expr;
        char *fmt;
 {
+       if (expr->ex_flags & EX_ERROR)
+               return;                 /* to prevent proliferation */
        _error(ERROR, expr, fmt, &args);
+       expr->ex_flags |= EX_ERROR;
 }
 
 /*VARARGS1*/
@@ -71,6 +74,8 @@ expr_warning(expr, fmt, args)
        struct expr *expr;
        char *fmt;
 {
+       if (expr->ex_flags & EX_ERROR)
+               return;                 /* to prevent proliferation */
        _error(WARNING, expr, fmt, &args);
 }
 

diff --git a/lang/cem/cemcom/expr.c b/lang/cem/cemcom/expr.c
index f343c6a..ba07d30 100644 (file)
--- a/lang/cem/cemcom/expr.c
+++ b/lang/cem/cemcom/expr.c
@@ -169,12 +169,13 @@ idf2expr(expr)
        }
        /* now def != 0 */
        if (def->df_type->tp_fund == LABEL) {
-               error("illegal use of label %s", idf->id_text);
-               expr->ex_type = error_type;
+               expr_error(expr, "illegal use of label %s", idf->id_text);
        }
        else {
                def->df_used = 1;
                expr->ex_type = def->df_type;
+               if (expr->ex_type == error_type)
+                       expr->ex_flags |= EX_ERROR;
        }
        expr->ex_lvalue =
                (       def->df_type->tp_fund == FUNCTION ||
@@ -381,7 +382,6 @@ chk_cst_expr(expp)
        
        if (err) {
                erroneous2int(expp);
-               (*expp)->ex_type = error_type;
        }
 }
 

diff --git a/lang/cem/cemcom/expr.str b/lang/cem/cemcom/expr.str
index 5809dcc..2531672 100644 (file)
--- a/lang/cem/cemcom/expr.str
+++ b/lang/cem/cemcom/expr.str
@@ -68,11 +68,12 @@ struct expr {
 /*     some bits for the ex_flag field, to keep track of various
        interesting properties of an expression.
 */
-#define        EX_SIZEOF       001             /* contains sizeof operator */
-#define        EX_CAST         002             /* contains cast */
-#define        EX_LOGICAL      004             /* contains logical operator */
-#define        EX_COMMA        010             /* contains expression comma */
-#define        EX_PARENS       020             /* the top level is parenthesized */
+#define        EX_SIZEOF       0001            /* contains sizeof operator */
+#define        EX_CAST         0002            /* contains cast */
+#define        EX_LOGICAL      0004            /* contains logical operator */
+#define        EX_COMMA        0010            /* contains expression comma */
+#define        EX_PARENS       0020            /* the top level is parenthesized */
+#define        EX_ERROR        0200            /* the expression is wrong */
 
 #define        NILEXPR         ((struct expr *)0)
 

diff --git a/lang/cem/cemcom/ival.c b/lang/cem/cemcom/ival.c
index cbc7fb0..8e921e9 100644 (file)
--- a/lang/cem/cemcom/ival.c
+++ b/lang/cem/cemcom/ival.c
@@ -668,8 +668,7 @@ con_int(expr)
 illegal_init_cst(expr)
        struct expr *expr;
 {
-       if (expr->ex_type->tp_fund != ERRONEOUS)
-               expr_error(expr, "illegal initialisation constant");
+       expr_error(expr, "illegal initialisation constant");
 }
 
 too_many_initialisers(expr)

diff --git a/lang/cem/cemcom/program.g b/lang/cem/cemcom/program.g
index 5817aa0..36da56e 100644 (file)
--- a/lang/cem/cemcom/program.g
+++ b/lang/cem/cemcom/program.g
@@ -71,7 +71,8 @@ control_if_expression
                {
 #ifndef NOPP
                        if (expr->ex_flags & EX_SIZEOF)
-                               error("sizeof not allowed in preprocessor");
+                               expr_error(expr,
+                                       "sizeof not allowed in preprocessor");
                        ifval = expr->VL_VALUE;
                        free_expression(expr);
 #endif NOPP

diff --git a/lang/cem/cemcom/switch.c b/lang/cem/cemcom/switch.c
index 7965c70..28db313 100644 (file)
--- a/lang/cem/cemcom/switch.c
+++ b/lang/cem/cemcom/switch.c
@@ -129,6 +129,11 @@ code_case(expr)
                return;
        }
        
+       if (expr->ex_flags & EX_ERROR)  {
+               /* is probably 0 anyway */
+               return;
+       }
+       
        expr->ex_type = sh->sh_type;
        cut_size(expr);