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Commit f1f39cca authored by Jack Palevich's avatar Jack Palevich
Browse files

Make sure we don't overflow various internal compiler buffers. 

We may replace some of these tables with dynamically growing data
structures, but in the meantime we will not trash memory.
parent ac0e95eb

libacc/acc.cpp

+26 −8
Original line number Diff line number Diff line
@@ -1083,7 +1083,7 @@ class Compiler : public ErrorSink { 
    int dch;    // Macro state: Saves old value of ch during a macro playback.

    char* last_id;

    void* pSymbolBase;

    void* pGlobalBase;

    char* pGlobalBase;

    char* pVarsBase; // Value of variables



    InputStream* file;
@@ -1154,6 +1154,9 @@ class Compiler : public ErrorSink { 
    static const char operatorLevel[];



    void pdef(int t) {

        if (dstk - sym_stk >= ALLOC_SIZE) {

            error("Symbol table exhausted");

        }

        *dstk++ = t;

    }
@@ -1219,6 +1222,9 @@ class Compiler : public ErrorSink { 
                tokc = strtol(last_id, 0, 0);

                tok = TOK_NUM;

            } else {

                if (dstk - sym_stk + 1 > ALLOC_SIZE) {

                    error("symbol stack overflow");

                }

                * dstk = TAG_TOK; /* no need to mark end of string (we

                 suppose data is initialized to zero by calloc) */

                tok = (intptr_t) (strstr(sym_stk, (last_id - 1))
@@ -1226,6 +1232,9 @@ class Compiler : public ErrorSink { 
                * dstk = 0; /* mark real end of ident for dlsym() */

                tok = tok * 8 + TOK_IDENT;

                if (tok > TOK_DEFINE) {

                    if (tok + 8 > ALLOC_SIZE) {

                        error("Variable Table overflow.");

                    }

                    tok = (intptr_t) (pVarsBase + tok);

                    /*        printf("tok=%s %x\n", last_id, tok); */

                    /* define handling */
@@ -1350,11 +1359,12 @@ class Compiler : public ErrorSink { 
            pGen->li((int) glo);

            while (ch != '\"') {

                getq();

                *glo++ = ch;

                *allocGlobalSpace(1) = ch;

                inp();

            }

            *glo = 0;

            glo = (char*) (((intptr_t) glo + 4) & -4); /* align heap */

            /* align heap */

            allocGlobalSpace((char*) (((intptr_t) glo + 4) & -4) - glo);

            inp();

            next();

        } else {
@@ -1584,8 +1594,7 @@ class Compiler : public ErrorSink { 
                        loc = loc + 4;

                        *(int *) tok = -loc;

                    } else {

                        *(int* *) tok = (int*) glo;

                        glo = glo + 4;

                        *(int* *) tok = (int*) allocGlobalSpace(4);

                    }

                    next();

                    if (tok == ',')
@@ -1621,13 +1630,22 @@ class Compiler : public ErrorSink { 
        }

    }



    char* allocGlobalSpace(int bytes) {

        if (glo - pGlobalBase + bytes > ALLOC_SIZE) {

            error("Global space exhausted");

        }

        char* result = glo;

        glo += bytes;

        return result;

    }



    void cleanup() {

        if (sym_stk != 0) {

            free(sym_stk);

            sym_stk = 0;

        }

        if (pGlobalBase != 0) {

            free((void*) pGlobalBase);

            free(pGlobalBase);

            pGlobalBase = 0;

        }

        if (pVarsBase != 0) {
@@ -1730,8 +1748,8 @@ public: 
            dstk = strcpy(sym_stk,

                    " int if else while break return for define main ")

                    + TOK_STR_SIZE;

            pGlobalBase = calloc(1, ALLOC_SIZE);

            glo = (char*) pGlobalBase;

            pGlobalBase = (char*) calloc(1, ALLOC_SIZE);

            glo = pGlobalBase;

            pVarsBase = (char*) calloc(1, ALLOC_SIZE);

            inp();

            next();