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Commit 5fd66ae0 authored by Jack Palevich's avatar Jack Palevich
Browse files

Improve address operator (unary &). 

Until now the address operator only worked with simple variables.
Now it works with arbitrary expressions (that are lvalues or function
names). So for example this now works:

struct S { int a[10]};

int f(struct S* p) {
    return &p->a[3];
}
parent 91acb148

libacc/acc.cpp

+13 −5
Original line number Diff line number Diff line
@@ -4450,10 +4450,8 @@ class Compiler : public ErrorSink { 
                unary();

                doPointer();

            } else if (t == '&') {

                VariableInfo* pVI = VI(tok);

                pGen->leaR0((int) pVI->pAddress, createPtrType(pVI->pType),

                        ET_RVALUE);

                next();

                unary();

                doAddressOf();

            } else if (t == EOF ) {

                error("Unexpected EOF.");

            } else if (t == ';') {
@@ -4656,6 +4654,16 @@ class Compiler : public ErrorSink { 
        }

    }



    void doAddressOf() {

        Type* pR0 = pGen->getR0Type();

        bool isFuncPtr = pR0->tag == TY_POINTER && pR0->pHead->tag == TY_FUNC;

        if ((! isFuncPtr) && pGen->getR0ExpressionType() != ET_LVALUE) {

            error("Expected an lvalue");

        }

        Type* pR0Type = pGen->getR0Type();

        pGen->setR0ExpressionType(ET_RVALUE);

    }



    /* Recursive descent parser for binary operations.

     */

    void binaryOp(int level) {
@@ -5293,7 +5301,7 @@ class Compiler : public ErrorSink { 


    void checkLVal() {

        if (pGen->getR0ExpressionType() != ET_LVALUE) {

            error("Expected an lval");

            error("Expected an lvalue");

        }

    }

libacc/tests/data/addressOf.c

0 → 100644
+31 −0
Original line number Diff line number Diff line 
void testStruct() {

    struct str {

        float x;

        float y;

    };



    struct str base;

    int index = 0;



    base.x = 10.0;

    struct str *s = &base;



    float *v = &(*s).x;

    float *v2 = &s[index].x;

    printf("testStruct: %g %g %g\n",base.x, *v, *v2);

}



void testArray() {

    int a[2];

    a[0] = 1;

    a[1] = 2;

    int* p = &a[0];

    int* p2 = a;

    printf("testArray: %d %d %d\n", a[0], *p, *p2);

}



int main() {

    testStruct();

    testArray();

    return 0;

}

libacc/tests/test.py

+7 −0
Original line number Diff line number Diff line
@@ -469,6 +469,13 @@ testCopying: 37 == 37 
testUnion: 1 == 0x3f800000

testArgs: (6, 8, 10, 12)

result: 6

""","""""")



    def testAddressOf(self):

        self.compileCheck(["-R", "data/addressOf.c"], """Executing compiled code:

testStruct: 10 10 10

testArray: 1 1 1

result: 0

""","""""")



def main():