C style character translation in ca65

libsrc/common/fgets.s

@@ -90,22 +90,7 @@ read_loop:
         bne     :+
         inc     ptr4+1
 
-        ; The next code line:
+:       cmp     #'\n'    ; #'\n' should get translated properly
-        ;
-        ;     .byte $c9, "\n"
-        ;
-        ; corresponds to a CMP #imm with the target-specific newline value as its operand.
-        ; This works because (with the 'string_escapes' feature enabled), the "\n" string
-        ; assembles to the target-specific value for the newline character.
-        ;
-        ; It would be better if we could just write:
-        ;
-        ;     cmp #'\n'
-        ;
-        ; Unfortunately, ca65 doesn't currently handle escape characters in character
-        ; constants. In the longer term, fixing that would be the preferred solution.
-
-:       .byte   $c9, "\n"       ; cmp #'\n'
         beq     done
         bne     read_loop
 

src/ca65/scanner.c

@@ -46,6 +46,7 @@
 #include "check.h"
 #include "filestat.h"
 #include "fname.h"
+#include "tgttrans.h"
 #include "xmalloc.h"
 
 /* ca65 */
@@ -788,14 +789,33 @@ static void ReadIdent (void)
 static void ReadStringConst (int StringTerm)
 /* Read a string constant into SVal. */
 {
+    int NeedNext;
+
     /* Skip the leading string terminator */
     NextChar ();
 
     /* Read the string */
     while (1) {
+        int Cooked = 1;
+        NeedNext = 1;
+
+        if (StringTerm == 0 && SB_GetLen(&CurTok.SVal) == 1) {
+            if (C == '\'') {
+                break;
+            }
+            else if (MissingCharTerm) {
+               NeedNext = 0;
+               break;
+            }
+            else {
+                Error ("Illegal character constant");
+            }
+        }
+
         if (C == StringTerm) {
             break;
         }
+
         if (C == '\n' || C == EOF) {
             Error ("Newline in string constant");
             break;
@@ -808,20 +828,74 @@ static void ReadStringConst (int StringTerm)
                 case EOF:
                     Error ("Unterminated escape sequence in string constant");
                     break;
-                case '\\':
+                case '?':
-                case '\'':
+                    C = '\?';
-                case '"':
                     break;
-                case 't':
+                case 'a':
-                    C = '\x09';
+                    C = '\a';
+                    break;
+                case 'b':
+                    C = '\b';
+                    break;
+                case 'e':
+                    C = '\x1B'; /* see comments in cc65/scanner.c */
+                    break;
+                case 'f':
+                    C = '\f';
                     break;
                 case 'r':
-                    C = '\x0D';
+                    C = '\r';
                     break;
                 case 'n':
-                    C = '\x0A';
+                    C = '\n';
                     break;
+                case 't':
+                    C = '\t';
+                    break;
+                case 'v':
+                    C = '\v';
+                    break;
+                case '\\':
+                    C = '\\'; /* unnecessary but more readable */
+                    break;
+                case '\'':
+                    C = '\''; /* unnecessary but more readable */
+                    if (StringTerm == 0) {
+                        /* special case used by character constants
+                        ** when LooseStringTerm not set.  this will
+                        ** cause '\' to be a valid character constant
+                        */
+                        C = '\\';
+                        NeedNext = 0;
+                    }
+                    break;
+                case '\"':
+                    C = '\"'; /* unnecessary but more readable */
+                    break;
+                case '0':
+                case '1':
+                case '2':
+                case '3':
+                case '4':
+                case '5':
+                case '6':
+                case '7':
+                    { /* brace needed for scoping */
+                        int Count = 1;
+                        int Final = DigitVal(C);
+                        Cooked = 0;
+                        NextChar ();
+                        while (IsODigit (C) && Count++ < 3) {
+                           Final = (Final << 3) | DigitVal(C);
+                           NextChar();
+                        }
+                        if (C >= 256)
+                            Error ("Octal character constant out of range");
+                    }
+                    break;
+                case 'X':
                 case 'x':
+                    Cooked = 0;
                     NextChar ();
                     if (IsXDigit (C)) {
                         char high_nibble = DigitVal (C) << 4;
@@ -839,14 +913,19 @@ static void ReadStringConst (int StringTerm)
         }
 
         /* Append the char to the string */
-        SB_AppendChar (&CurTok.SVal, C);
+        SB_AppendCharCooked (&CurTok.SVal, C, Cooked);
 
+        if (NeedNext) {
             /* Skip the character */
             NextChar ();
+            NeedNext = 1;
+        }
     }
 
+    if (NeedNext) {
         /* Skip the trailing terminator */
         NextChar ();
+    }
 
     /* Terminate the string */
     SB_Terminate (&CurTok.SVal);
@@ -1465,12 +1544,13 @@ CharAgain:
             return;
 
         case '\'':
+            if (LooseStringTerm) {
                 /* Hack: If we allow ' as terminating character for strings, read
                 ** the following stuff as a string, and check for a one character
                 ** string later.
                 */
-            if (LooseStringTerm) {
                 ReadStringConst ('\'');
+                TgtTranslateStrBuf(&CurTok.SVal);
                 if (SB_GetLen (&CurTok.SVal) == 1) {
                     CurTok.IVal = SB_AtUnchecked (&CurTok.SVal, 0);
                     CurTok.Tok = TOK_CHARCON;
@@ -1478,22 +1558,17 @@ CharAgain:
                     CurTok.Tok = TOK_STRCON;
                 }
             } else {
-                /* Always a character constant */
+                /* Always a character constant
-                NextChar ();
+                ** Hack: Pass 0 to ReadStringConst for special handling.
-                if (C == EOF || IsControl (C)) {
+                */
+                ReadStringConst(0);
+                TgtTranslateStrBuf(&CurTok.SVal);
+                if (SB_GetLen(&CurTok.SVal) != 1) {
                     Error ("Illegal character constant");
                     goto CharAgain;
                 }
-                CurTok.IVal = C;
+                CurTok.IVal = SB_AtUnchecked (&CurTok.SVal, 0);
                 CurTok.Tok = TOK_CHARCON;
-                NextChar ();
-                if (C != '\'') {
-                    if (!MissingCharTerm) {
-                        Error ("Illegal character constant");
-                    }
-                } else {
-                    NextChar ();
-                }
             }
             return;