-static void CascadeSwitch (ExprDesc* Expr)
-/* Handle a switch statement for chars with a cmp cascade for the selector */
-{
- unsigned ExitLab; /* Exit label */
- unsigned NextLab; /* Next case label */
- unsigned CodeLab; /* Label that starts the actual selector code */
- int HaveBreak; /* Remember if we exited with break */
- int HaveDefault; /* Remember if we had a default label */
- int lcount; /* Label count */
- unsigned Flags; /* Code generator flags */
- ExprDesc lval; /* Case label expression */
- long Val; /* Case label value */
-
-
- /* Get the unqualified type of the switch expression */
- type ExprType = UnqualifiedType (Expr->Type[0]);
-
- /* Create a loop so we may break out, init labels */
- ExitLab = GetLocalLabel ();
- AddLoop (oursp, 0, ExitLab, 0, 0);
-
- /* Setup some variables needed in the loop below */
- Flags = TypeOf (Expr->Type) | CF_CONST | CF_FORCECHAR;
- CodeLab = NextLab = 0;
- HaveBreak = 1;
- HaveDefault = 0;
-
- /* Parse the labels */
- lcount = 0;
- while (CurTok.Tok != TOK_RCURLY) {
-
- if (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) {
-
- /* If the code for the previous selector did not end with a
- * break statement, we must jump over the next selector test.
- */
- if (!HaveBreak) {
- /* Define a label for the code */
- if (CodeLab == 0) {
- CodeLab = GetLocalLabel ();
- }
- g_jump (CodeLab);
- }
-
- /* If we have a cascade label, emit it */
- if (NextLab) {
- g_defcodelabel (NextLab);
- NextLab = 0;
- }
-
- while (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) {
-
- /* Parse the selector */
- if (CurTok.Tok == TOK_CASE) {
-
- /* Count labels */
- ++lcount;
-
- /* Skip the "case" token */
- NextToken ();
-
- /* Read the selector expression */
- constexpr (&lval);
- if (!IsClassInt (lval.Type)) {
- Error ("Switch quantity not an integer");
- }
-
- /* Check the range of the expression */
- Val = lval.ConstVal;
- switch (ExprType) {
-
- case T_SCHAR:
- /* Signed char */
- if (Val < -128 || Val > 127) {
- Error ("Range error");
- }
- break;
-
- case T_UCHAR:
- if (Val < 0 || Val > 255) {
- Error ("Range error");
- }
- break;
-
- case T_INT:
- if (Val < -32768 || Val > 32767) {
- Error ("Range error");
- }
- break;
-
- case T_UINT:
- if (Val < 0 || Val > 65535) {
- Error ("Range error");
- }
- break;
-
- default:
- Internal ("Invalid type: %04X", ExprType);
- }
-
- /* Emit a compare */
- g_cmp (Flags, Val);
-
- /* If another case follows after the colon (which is
- * currently pending and cannot be skipped since otherwise
- * the debug infos will get wrong), we will jump to the
- * code if the condition is true.
- */
- if (NextTok.Tok == TOK_CASE) {
- /* Create a code label if needed */
- if (CodeLab == 0) {
- CodeLab = GetLocalLabel ();
- }
- g_falsejump (CF_NONE, CodeLab);
- } else if (NextTok.Tok != TOK_DEFAULT) {
- /* No case follows, jump to next selector */
- if (NextLab == 0) {
- NextLab = GetLocalLabel ();
- }
- g_truejump (CF_NONE, NextLab);
- }
-
- /* Skip the colon */
- ConsumeColon ();
-
- } else {
-
- /* Default case */
- NextToken ();
-
- /* Handle the pathologic case: DEFAULT followed by CASE */
- if (NextTok.Tok == TOK_CASE) {
- if (CodeLab == 0) {
- CodeLab = GetLocalLabel ();
- }
- g_jump (CodeLab);
- }
-
- /* Skip the colon */
- ConsumeColon ();
-
- /* Remember that we had a default label */
- HaveDefault = 1;
- }
-
- }
-
- }
-
- /* Emit a code label if we have one */
- if (CodeLab) {
- g_defcodelabel (CodeLab);
- CodeLab = 0;
- }
-
- /* Parse statements */
- if (CurTok.Tok != TOK_RCURLY) {
- HaveBreak = Statement (0);
- }
- }
-
- /* Check if we have any labels */
- if (lcount == 0 && !HaveDefault) {
- Warning ("No case labels");
- }
-
- /* Define the exit label and, if there's a next label left, create this
- * one, too.
- */
- if (NextLab) {
- g_defcodelabel (NextLab);
- }
- g_defcodelabel (ExitLab);
-
- /* Eat the closing curly brace */
- NextToken ();
-
- /* End the loop */
- DelLoop ();
-}
-
-
-
-static void TableSwitch (ExprDesc* Expr)
-/* Handle a switch statement via table based selector */
-{
- /* Entry for one case in a switch statement */
- typedef struct {
- long Value; /* selector value */
- unsigned Label; /* label for this selector */
- } SwitchEntry;
-
- unsigned DefaultLabel; /* Label for default case */
- unsigned ExitLabel; /* exit label */
- int lcase; /* label for compares */
- int HaveBreak; /* Last statement has a break */
- unsigned Flags; /* Code generator flags */
- ExprDesc lval; /* Case label expression */
- unsigned I;
- SwitchEntry* P;
- Collection SwitchTab;
-
- /* Initialize the collection for the switch entries */
- InitCollection (&SwitchTab);
-
- /* Create a look so we may break out, init labels */
- HaveBreak = 0; /* Keep gcc silent */
- DefaultLabel = 0; /* No default case until now */
- ExitLabel = GetLocalLabel (); /* get exit */
- AddLoop (oursp, 0, ExitLabel, 0, 0);
-
- /* Jump behind the code for the CASE labels */
- g_jump (lcase = GetLocalLabel ());
- while (CurTok.Tok != TOK_RCURLY) {
- if (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) {
- do {
- if (CurTok.Tok == TOK_CASE) {
- NextToken ();
- constexpr (&lval);
- if (!IsClassInt (lval.Type)) {
- Error ("Switch quantity not an integer");
- }
- P = xmalloc (sizeof (SwitchEntry));
- P->Value = lval.ConstVal;
- P->Label = GetLocalLabel ();
- CollAppend (&SwitchTab, P);
- g_defcodelabel (P->Label);
- } else if (DefaultLabel == 0) {
- NextToken ();
- DefaultLabel = GetLocalLabel ();
- g_defcodelabel (DefaultLabel);
- } else {
- /* We already had a default label */
- Error ("Multiple default labels in one switch");
- /* Try to recover */
- NextToken ();
- }
- ConsumeColon ();
- } while (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT);
- HaveBreak = 0;
- }
- if (CurTok.Tok != TOK_RCURLY) {
- HaveBreak = Statement (0);
- }
- }
-
- /* Check if we have any labels */
- if (CollCount(&SwitchTab) == 0 && DefaultLabel == 0) {
- Warning ("No case labels");
- }
-
- /* Eat the closing curly brace */
- NextToken ();
-
- /* If the last statement doesn't have a break or return, add one */
- if (!HaveBreak) {
- g_jump (ExitLabel);
- }
-
- /* Actual selector code goes here */
- g_defcodelabel (lcase);
-
- /* Create the call to the switch subroutine */
- Flags = TypeOf (Expr->Type);
- g_switch (Flags);
-
- /* First entry is negative of label count */
- g_defdata (CF_INT | CF_CONST, -((int)CollCount(&SwitchTab))-1, 0);
-
- /* Create the case selector table */
- for (I = 0; I < CollCount (&SwitchTab); ++I) {
- P = CollAt (&SwitchTab, I);
- g_case (Flags, P->Label, P->Value); /* Create one label */
- }
-
- if (DefaultLabel != 0) {
- g_jump (DefaultLabel);
- }
- g_defcodelabel (ExitLabel);
- DelLoop ();
-
- /* Free the allocated space for the labels */
- for (I = 0; I < CollCount (&SwitchTab); ++I) {
- xfree (CollAt (&SwitchTab, I));
- }
-
- /* Free the collection itself */
- DoneCollection (&SwitchTab);
-}
-
-
-
-static void SwitchStatement (void)
-/* Handle a 'switch' statement */
-{
- ExprDesc Expr; /* Switch statement expression */
-
- /* Eat the "switch" */
- NextToken ();
-
- /* Read the switch expression */
- ConsumeLParen ();
- intexpr (&Expr);
- ConsumeRParen ();
-
- /* result of expr is in P */
- ConsumeLCurly ();
-
- /* Now decide which sort of switch we will create: */
- if (IsTypeChar (Expr.Type) || (CodeSizeFactor >= 200 && IsClassInt (Expr.Type))) {
- CascadeSwitch (&Expr);
- } else {
- TableSwitch (&Expr);
- }
-}
-
-
-