Fix several issues with evaluation of the ++ and -- operators.

These would generally not work correctly on bit-fields, or on floating-point values that were in a structure or were accessed via a pointer.

The below program is an example that would demonstrate problems:

#include <stdio.h>

int main(void) {
        struct {
                signed int i:7;
                unsigned long int j:6;
                _Bool b:1;
                double d;
        } s = {-10, -20, 0, 5.0};

        double d = 70.0, *dp = &d;

        printf("%i\n", (int)s.i++);
        printf("%i\n", (int)s.i--);
        printf("%i\n", (int)++s.i);
        printf("%i\n", (int)--s.i);
        printf("%i\n", (int)s.i);

        printf("%i\n", (int)s.j++);
        printf("%i\n", (int)s.j--);
        printf("%i\n", (int)++s.j);
        printf("%i\n", (int)--s.j);
        printf("%i\n", (int)s.j);

        printf("%i\n", s.b++);
        printf("%i\n", s.b--);
        printf("%i\n", ++s.b);
        printf("%i\n", --s.b);
        printf("%i\n", s.b);

        printf("%f\n", s.d++);
        printf("%f\n", s.d--);
        printf("%f\n", ++s.d);
        printf("%f\n", --s.d);
        printf("%f\n", s.d);

        printf("%f\n", (*dp)++);
        printf("%f\n", (*dp)--);
        printf("%f\n", ++*dp);
        printf("%f\n", --*dp);
        printf("%f\n", *dp);
}
This commit is contained in:
Stephen Heumann 2021-01-26 12:31:54 -06:00
parent acab97ae08
commit f2a66a524a

View File

@ -2368,10 +2368,11 @@ var
begin {DoIncDec}
L_Value(tree);
with tree^.id^ do
if (tree^.token.kind = ident)
and ((iType^.kind in [scalarType,pointerType])
or ((iType^.kind = arrayType) and (storage = parameter))) then begin
if (tree^.token.kind = ident)
and ((tree^.id^.iType^.kind in [scalarType,pointerType])
or ((tree^.id^.iType^.kind = arrayType) and (tree^.id^.storage = parameter)))
then
with tree^.id^ do begin
{check for ++ or -- of a constant}
if iType^.isConstant then
@ -2459,62 +2460,64 @@ var
otherwise: ;
end; {case}
expressionType := itype;
end {if}
else begin
end {with}
else begin
{do an indirect ++ or --}
LoadAddress(tree); {get the address to save to}
if expressionType^.kind = arrayType then
expressionType := expressionType^.aType
else if expressionType^.kind = pointerType then
expressionType := expressionType^.pType;
if expressionType^.kind = scalarType then
if expressionType^.baseType in [cgByte,cgUByte,cgWord,cgUWord] then
tp := expressionType^.baseType
else
tp := UsualUnaryConversions
{do an indirect ++ or --}
LoadAddress(tree); {get the address to save to}
if expressionType^.kind = arrayType then
expressionType := expressionType^.aType
else if expressionType^.kind = pointerType then
expressionType := expressionType^.pType;
if expressionType^.kind = scalarType then
if expressionType^.baseType in
[cgByte,cgUByte,cgWord,cgUWord,cgReal,cgDouble,cgComp,cgExtended] then
tp := expressionType^.baseType
else
tp := UsualUnaryConversions;
if (tp in [cgByte,cgUByte,cgWord,cgUword])
and (expressionType^.cType <> ctBool) then
Gen0t(pc_i, tp) {do indirect inc/dec}
else begin
t1 := GetTemp(cgLongSize);
Gen2t(pc_str, t1, 0, cgULong);
Gen2t(pc_lod, t1, 0, cgULong);
Gen2t(pc_lod, t1, 0, cgULong);
FreeTemp(t1, cgLongSize);
Gen1t(pc_ind, 0, tp); {load the value}
if pc_l in [pc_lli,pc_lld] then
if expressionType^.cType = ctBool then begin
t1 := GetTemp(cgWordSize);
Gen2t(pc_cop, t1, 0, cgWord);
end; {if}
IncOrDec(pc_l in [pc_lli,pc_lil]); {do the ++ or --}
if isBitField then {copy the value}
if bitDisp+bitSize > 16 then begin
Gen2t(pc_cbf, bitDisp, bitSize, cgLong);
Gen0t(pc_bno, cgLong);
end {if}
else begin
Gen2t(pc_cbf, bitDisp, bitSize, cgWord);
Gen0t(pc_bno, cgWord);
end {else}
else begin
Gen0t(pc_cpi, tp);
Gen0t(pc_bno, tp);
end; {else}
if pc_l in [pc_lli,pc_lld] then {correct the value for postfix ops}
if expressionType^.cType = ctBool then begin
Gen0t(pc_pop, cgWord);
Gen2t(pc_lod, t1, 0, cgWord);
Gen0t(pc_bno, cgWord);
FreeTemp(t1, cgWordSize);
end {if}
else
IncOrDec(pc_l = pc_lld);
end; {else}
tp := UsualUnaryConversions
else
tp := UsualUnaryConversions;
if (tp in [cgByte,cgUByte,cgWord,cgUword])
and (expressionType^.cType <> ctBool)
and not isBitField then
Gen0t(pc_i, tp) {do indirect inc/dec}
else begin
t1 := GetTemp(cgLongSize);
Gen2t(pc_str, t1, 0, cgULong);
Gen2t(pc_lod, t1, 0, cgULong);
Gen2t(pc_lod, t1, 0, cgULong);
FreeTemp(t1, cgLongSize);
{load the value}
if isBitField then begin
if unsigned then
Gen2t(pc_lbu, bitDisp, bitSize, tp)
else
Gen2t(pc_lbf, bitDisp, bitSize, tp);
end {if}
else
Gen1t(pc_ind, 0, tp);
if pc_l in [pc_lli,pc_lld] then
if expressionType^.cType = ctBool then begin
t1 := GetTemp(cgWordSize);
Gen2t(pc_cop, t1, 0, cgWord);
end; {if}
IncOrDec(pc_l in [pc_lli,pc_lil]); {do the ++ or --}
if isBitField then {copy the value}
Gen2t(pc_cbf, bitDisp, bitSize, tp)
else
Gen0t(pc_cpi, tp);
Gen0t(pc_bno, tp);
if pc_l in [pc_lli,pc_lld] then {correct the value for postfix ops}
if expressionType^.cType = ctBool then begin
Gen0t(pc_pop, cgWord);
Gen2t(pc_lod, t1, 0, cgWord);
Gen0t(pc_bno, cgWord);
FreeTemp(t1, cgWordSize);
end {if}
else
IncOrDec(pc_l = pc_lld);
end; {else}
end; {else}
1:
end; {DoIncDec}