/*****************************************************************************/
/* */
-/* swstmt.c */
+/* swstmt.c */
/* */
-/* Parse the switch statement */
+/* Parse the switch statement */
/* */
/* */
/* */
-/* (C) 1998-2006 Ullrich von Bassewitz */
-/* Römerstraße 52 */
+/* (C) 1998-2008 Ullrich von Bassewitz */
+/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/*****************************************************************************/
-/* Code */
+/* Data */
+/*****************************************************************************/
+
+
+
+typedef struct SwitchCtrl SwitchCtrl;
+struct SwitchCtrl {
+ Collection* Nodes; /* CaseNode tree */
+ TypeCode ExprType; /* Basic switch expression type */
+ unsigned Depth; /* Number of bytes the selector type has */
+ unsigned DefaultLabel; /* Label for the default branch */
+
+
+
+};
+
+/* Pointer to current switch control struct */
+static SwitchCtrl* Switch = 0;
+
+
+
+/*****************************************************************************/
+/* Code */
/*****************************************************************************/
void SwitchStatement (void)
/* Handle a switch statement for chars with a cmp cascade for the selector */
{
- Collection* Nodes; /* CaseNode tree */
- ExprDesc SwitchExpr; /* Switch statement expression */
- ExprDesc CaseExpr; /* Case label expression */
- TypeCode SwitchExprType; /* Basic switch expression type */
- CodeMark CaseCodeStart; /* Start of code marker */
- CodeMark SwitchCodeStart; /* Start of switch code */
- CodeMark SwitchCodeEnd; /* End of switch code */
- unsigned Depth; /* Number of bytes the selector type has */
- unsigned ExitLabel; /* Exit label */
- unsigned CaseLabel; /* Label for case */
- unsigned DefaultLabel; /* Label for the default branch */
- unsigned SwitchCodeLabel; /* Label for the switch code */
- long Val; /* Case label value */
- int HaveBreak = 0; /* True if the last statement had a break */
+ ExprDesc SwitchExpr; /* Switch statement expression */
+ CodeMark CaseCodeStart; /* Start of code marker */
+ CodeMark SwitchCodeStart;/* Start of switch code */
+ CodeMark SwitchCodeEnd; /* End of switch code */
+ unsigned ExitLabel; /* Exit label */
+ unsigned SwitchCodeLabel;/* Label for the switch code */
+ int HaveBreak = 0; /* True if the last statement had a break */
+ int RCurlyBrace; /* True if last token is right curly brace */
+ SwitchCtrl* OldSwitch; /* Pointer to old switch control data */
+ SwitchCtrl SwitchData; /* New switch data */
/* Eat the "switch" token */
Expression0 (&SwitchExpr);
if (!IsClassInt (SwitchExpr.Type)) {
Error ("Switch quantity is not an integer");
- /* To avoid any compiler errors, make the expression a valid int */
- ED_MakeConstAbsInt (&SwitchExpr, 1);
+ /* To avoid any compiler errors, make the expression a valid int */
+ ED_MakeConstAbsInt (&SwitchExpr, 1);
}
ConsumeRParen ();
*/
GetCodePos (&CaseCodeStart);
- /* Opening curly brace */
- ConsumeLCurly ();
-
- /* Get the unqualified type of the switch expression */
- SwitchExprType = UnqualifiedType (SwitchExpr.Type[0].C);
-
- /* Get the number of bytes the selector type has */
- Depth = SizeOf (SwitchExpr.Type);
- CHECK (Depth == SIZEOF_CHAR || Depth == SIZEOF_INT || Depth == SIZEOF_LONG);
+ /* Setup the control structure, save the old and activate the new one */
+ SwitchData.Nodes = NewCollection ();
+ SwitchData.ExprType = UnqualifiedType (SwitchExpr.Type[0].C);
+ SwitchData.Depth = SizeOf (SwitchExpr.Type);
+ SwitchData.DefaultLabel = 0;
+ OldSwitch = Switch;
+ Switch = &SwitchData;
/* Get the exit label for the switch statement */
ExitLabel = GetLocalLabel ();
/* Create a loop so we may use break. */
AddLoop (ExitLabel, 0);
- /* Create the collection for the case node tree */
- Nodes = NewCollection ();
+ /* Make sure a curly brace follows */
+ if (CurTok.Tok != TOK_LCURLY) {
+ Error ("`{' expected");
+ }
- /* Clear the label for the default branch */
- DefaultLabel = 0;
+ /* Parse the following statement, which will actually be a compound
+ * statement because of the curly brace at the current input position
+ */
+ HaveBreak = Statement (&RCurlyBrace);
- /* Parse the labels */
- while (CurTok.Tok != TOK_RCURLY) {
+ /* Check if we had any labels */
+ if (CollCount (SwitchData.Nodes) == 0 && SwitchData.DefaultLabel == 0) {
+ Warning ("No case labels");
+ }
- while (CurTok.Tok == TOK_CASE || CurTok.Tok == TOK_DEFAULT) {
+ /* If the last statement did not have a break, we may have an open
+ * label (maybe from an if or similar). Emitting code and then moving
+ * this code to the top will also move the label to the top which is
+ * wrong. So if the last statement did not have a break (which would
+ * carry the label), add a jump to the exit. If it is useless, the
+ * optimizer will remove it later.
+ */
+ if (!HaveBreak) {
+ g_jump (ExitLabel);
+ }
- /* Parse the selector */
- if (CurTok.Tok == TOK_CASE) {
+ /* Remember the current position */
+ GetCodePos (&SwitchCodeStart);
- /* Skip the "case" token */
- NextToken ();
+ /* Output the switch code label */
+ g_defcodelabel (SwitchCodeLabel);
- /* Read the selector expression */
- ConstAbsIntExpr (hie1, &CaseExpr);
+ /* Generate code */
+ if (SwitchData.DefaultLabel == 0) {
+ /* No default label, use switch exit */
+ SwitchData.DefaultLabel = ExitLabel;
+ }
+ g_switch (SwitchData.Nodes, SwitchData.DefaultLabel, SwitchData.Depth);
- /* Check the range of the expression */
- Val = CaseExpr.IVal;
- switch (SwitchExprType) {
+ /* Move the code to the front */
+ GetCodePos (&SwitchCodeEnd);
+ MoveCode (&SwitchCodeStart, &SwitchCodeEnd, &CaseCodeStart);
- case T_SCHAR:
- /* Signed char */
- if (Val < -128 || Val > 127) {
- Error ("Range error");
- }
- break;
+ /* Define the exit label */
+ g_defcodelabel (ExitLabel);
- case T_UCHAR:
- if (Val < 0 || Val > 255) {
- Error ("Range error");
- }
- break;
+ /* Exit the loop */
+ DelLoop ();
- case T_SHORT:
- case T_INT:
- if (Val < -32768 || Val > 32767) {
- Error ("Range error");
- }
- break;
+ /* Switch back to the enclosing switch statement if any */
+ Switch = OldSwitch;
- case T_USHORT:
- case T_UINT:
- if (Val < 0 || Val > 65535) {
- Error ("Range error");
- }
- break;
+ /* Free the case value tree */
+ FreeCaseNodeColl (SwitchData.Nodes);
- case T_LONG:
- case T_ULONG:
- break;
+ /* If the case statement was (correctly) terminated by a closing curly
+ * brace, skip it now.
+ */
+ if (RCurlyBrace) {
+ NextToken ();
+ }
+}
- default:
- Internal ("Invalid type: %06lX", SwitchExprType);
- }
- /* Insert the case selector into the selector table */
- CaseLabel = InsertCaseValue (Nodes, Val, Depth);
- /* Define this label */
- g_defcodelabel (CaseLabel);
+void CaseLabel (void)
+/* Handle a case sabel */
+{
+ ExprDesc CaseExpr; /* Case label expression */
+ long Val; /* Case label value */
+ unsigned CodeLabel; /* Code label for this case */
- /* Skip the colon */
- ConsumeColon ();
- } else {
+ /* Skip the "case" token */
+ NextToken ();
- /* Default case */
- NextToken ();
+ /* Read the selector expression */
+ ConstAbsIntExpr (hie1, &CaseExpr);
+ Val = CaseExpr.IVal;
- /* Check if we do already have a default branch */
- if (DefaultLabel == 0) {
+ /* Now check if we're inside a switch statement */
+ if (Switch != 0) {
- /* Generate and emit the default label */
- DefaultLabel = GetLocalLabel ();
- g_defcodelabel (DefaultLabel);
+ /* Check the range of the expression */
+ switch (Switch->ExprType) {
- } else {
- /* We had the default label already */
- Error ("Duplicate `default' case");
- }
+ case T_SCHAR:
+ /* Signed char */
+ if (Val < -128 || Val > 127) {
+ Error ("Range error");
+ }
+ break;
- /* Skip the colon */
- ConsumeColon ();
+ case T_UCHAR:
+ if (Val < 0 || Val > 255) {
+ Error ("Range error");
+ }
+ break;
- }
+ case T_SHORT:
+ case T_INT:
+ if (Val < -32768 || Val > 32767) {
+ Error ("Range error");
+ }
+ break;
- }
+ case T_USHORT:
+ case T_UINT:
+ if (Val < 0 || Val > 65535) {
+ Error ("Range error");
+ }
+ break;
- /* Parse statements */
- if (CurTok.Tok != TOK_RCURLY) {
- HaveBreak = Statement (0);
- }
- }
+ case T_LONG:
+ case T_ULONG:
+ break;
- /* Check if we had any labels */
- if (CollCount (Nodes) == 0 && DefaultLabel == 0) {
+ default:
+ Internal ("Invalid type: %06lX", Switch->ExprType);
+ }
- Warning ("No case labels");
+ /* Insert the case selector into the selector table */
+ CodeLabel = InsertCaseValue (Switch->Nodes, Val, Switch->Depth);
- }
+ /* Define this label */
+ g_defcodelabel (CodeLabel);
- /* If the last statement did not have a break, we may have an open
- * label (maybe from an if or similar). Emitting code and then moving
- * this code to the top will also move the label to the top which is
- * wrong. So if the last statement did not have a break (which would
- * carry the label), add a jump to the exit. If it is useless, the
- * optimizer will remove it later.
- */
- if (!HaveBreak) {
- g_jump (ExitLabel);
- }
+ } else {
- /* Remember the current position */
- GetCodePos (&SwitchCodeStart);
+ /* case keyword outside a switch statement */
+ Error ("Case label not within a switch statement");
- /* Output the switch code label */
- g_defcodelabel (SwitchCodeLabel);
+ }
- /* Generate code */
- g_switch (Nodes, DefaultLabel? DefaultLabel : ExitLabel, Depth);
+ /* Skip the colon */
+ ConsumeColon ();
+}
- /* Move the code to the front */
- GetCodePos (&SwitchCodeEnd);
- MoveCode (&SwitchCodeStart, &SwitchCodeEnd, &CaseCodeStart);
- /* Define the exit label */
- g_defcodelabel (ExitLabel);
- /* Eat the closing curly brace */
+void DefaultLabel (void)
+/* Handle a default label */
+{
+ /* Default case */
NextToken ();
- /* Free the case value tree */
- FreeCaseNodeColl (Nodes);
+ /* Now check if we're inside a switch statement */
+ if (Switch != 0) {
- /* End the loop */
- DelLoop ();
+ /* Check if we do already have a default branch */
+ if (Switch->DefaultLabel == 0) {
+
+ /* Generate and emit the default label */
+ Switch->DefaultLabel = GetLocalLabel ();
+ g_defcodelabel (Switch->DefaultLabel);
+
+ } else {
+ /* We had the default label already */
+ Error ("Multiple default labels in one switch");
+ }
+
+ } else {
+
+ /* case keyword outside a switch statement */
+ Error ("`default' label not within a switch statement");
+
+ }
+
+ /* Skip the colon */
+ ConsumeColon ();
}
projects / cc65 / blobdiff