Allow omission of braces on multiple-statement switch cases.

include/Defs.h

@@ -287,6 +287,9 @@ struct FileData {
     // The column that was last marked as "valid", the start of the error block if something goes wrong.
     long CurrentSafeColumn;
 
+    // Whether or not we are currently parsing a switch statement - changes the behavior of compound statements!
+    bool SwitchStatement;
+
     // The symbol currently being lexed - TokenTypes index and integer value.
     struct Token CurrentSymbol;
     // The function currently being parsed - null if in global scope or if finished.

src/Parser.c

@@ -39,10 +39,13 @@ static int OperatorPrecedence(int Token) {
     int Prec = Precedence[Token];
 
     if (Prec == 0 || Token >= PPMM_PLUS) {
-        if (Token == TY_IDENTIFIER)
-            DieMessage("Attempting to determine operator precedence of identifier", CurrentIdentifier);
+        if (Token == TY_IDENTIFIER) {
+            ErrorReport("Attempting to determine operator precedence of identifier %s\n", CurrentIdentifier);
+            exit(1);
+        }
 
-        DieMessage("Attempting to determine operator precedence of an EOF or INT literal", TokenNames[Token]);
+        ErrorReport("Attempting to determine operator precedence of an EOF or INT literal: %s\n", TokenNames[Token]);
+        exit(1);
     }
 
     return Prec;
@@ -259,9 +262,8 @@ struct ASTNode* ParsePrimary(void) {
             return Node;
     }
 
-
     Tokenise();
-
+    Safe();
     return Node;
 }
 
@@ -286,7 +288,7 @@ struct ASTNode* ParsePrecedenceASTNode(int PreviousTokenPrecedence) {
     // int LeftType, RightType;
     int NodeType, OpType;
 
-    fflush(stdout);
+    Safe();
     LeftNode = PrefixStatement();
 
     NodeType = CurrentFile->CurrentSymbol.type;
@@ -296,14 +298,19 @@ struct ASTNode* ParsePrecedenceASTNode(int PreviousTokenPrecedence) {
         return LeftNode;
     }
 
+    Safe();
+
     while ((OperatorPrecedence(NodeType) > PreviousTokenPrecedence) ||
            (IsRightExpr(OpType) && OperatorPrecedence(OpType) == PreviousTokenPrecedence)) {
         Tokenise();
         if (CurrentFile->CurrentSymbol.type == LI_RPARE)
             break;
 
+        Safe();
+
         RightNode = ParsePrecedenceASTNode(Precedence[NodeType]);
 
+        Safe();
         /**
          * While parsing this node, we may need to widen some types.
          * This requires a few functions and checks.
@@ -483,7 +490,9 @@ struct ASTNode* ParseStatement(void) {
     printf("\t\tBranch leads to here, type %s/%d\r\n", TokenNames[CurrentFile->CurrentSymbol.type], CurrentFile->CurrentSymbol.type);
     switch (CurrentFile->CurrentSymbol.type) {
         case LI_LBRAC:
+            Tokenise();
             Node = ParseCompound();
+            VerifyToken(LI_RBRAC, "}");
             return Node;
         case TY_CHAR:
         case TY_LONG:
@@ -541,10 +550,6 @@ struct ASTNode* ParseStatement(void) {
 struct ASTNode* ParseCompound() {
     struct ASTNode* Left = NULL, * Tree;
 
-    // Compound statements are defined by comprising
-    //  multiple statements inside { a bracket block }
-    VerifyToken(LI_LBRAC, "{");
-
     while (1) {
         printf("\tNew branch in compound\n");
 
@@ -563,7 +568,11 @@ struct ASTNode* ParseCompound() {
         }
 
         if (CurrentFile->CurrentSymbol.type == LI_RBRAC) {
-            VerifyToken(LI_RBRAC, "}");
+            fflush(stdout);
+            return Left;
+        }
+
+        if (CurrentFile->SwitchStatement && (CurrentFile->CurrentSymbol.type == KW_CASE || CurrentFile->CurrentSymbol.type == KW_DEFAULT)) {
             return Left;
         }
     }
@@ -592,7 +601,6 @@ void ParseGlobals() {
     printf("Parsing global definitions\r\n");
 
     while (1) {
-
         // We loop early if there's a struct, and since a struct may be the last
         // thing in a file, we need to check for eof before anything else
         if (CurrentFile->CurrentSymbol.type == LI_EOF)

src/Statements.c

@@ -292,7 +292,9 @@ struct ASTNode* ParseFunction(int Type) {
     CurrentFile->FunctionEntry = OldFunction;
 
     CurrentFile->CurrentLoopDepth = 0;
+    VerifyToken(LI_LBRAC, "{");
     Tree = ParseCompound();
+    VerifyToken(LI_RBRAC, "}");
 
     if (Type != RET_VOID) {
         // Functions with one statement have no composite node, so we have to check
@@ -550,6 +552,7 @@ struct ASTNode* SwitchStatement() {
     int ASTOp, casevalue;
 
     printf("\tParsing switch statement\n");
+    CurrentFile->SwitchStatement = true;
 
     // Skip switch(
     Tokenise();
@@ -615,7 +618,7 @@ struct ASTNode* SwitchStatement() {
                 VerifyToken(LI_COLON, ":");
                 Safe();
 
-                left = ParseStatement();
+                left = ParseCompound();
                 OptionallyConsume(LI_SEMIC);
                 cases++;
                 Safe();
@@ -641,6 +644,7 @@ struct ASTNode* SwitchStatement() {
     // Consume the right brace immediately
     VerifyToken(LI_RBRAC, "}");
 
+    CurrentFile->SwitchStatement = false;
     return root;
 }
 
@@ -668,8 +672,8 @@ struct ASTNode* SwitchStatement() {
  * @return the AST of this statement
  */
 struct ASTNode* BreakStatement() {
-    if (CurrentFile->CurrentLoopDepth == 0) 
-        Die("Unable to break without a loop");
+    if (CurrentFile->CurrentLoopDepth == 0 && !CurrentFile->SwitchStatement)
+        Die("Unable to break without a loop or switch statement");
     
     Tokenise();
 

tests/switch.er

@@ -11,9 +11,9 @@ int :: main() {
              case 1: {
                 y = 5;
                 break; }
-             case 2: {
+             case 2:
                 y = 7;
-                break; }
+                break;
              case 3:
                 y = 9;
              default: