From fec7b57ec20325996f177e0442275be365d24734 Mon Sep 17 00:00:00 2001
From: Stephen Heumann <stephenheumann@gmail.com>
Date: Tue, 22 Feb 2022 18:48:34 -0600
Subject: [PATCH] Generate a string representation of tokens merged with ##.

This is necessary for correct behavior if such tokens are subsequently stringized with #. Previously, only the first half of the token would be produced.

Here is an example demonstrating the issue:

#define mkstr(a) # a
#define in_between(a) mkstr(a)
#define joinstr(a,b) in_between(a ## b)
#include <stdio.h>
int main(void) {
        puts(joinstr(123,456));
        puts(joinstr(abc,def));
        puts(joinstr(dou,ble));
        puts(joinstr(+,=));
        puts(joinstr(:,>));
}
---
 Scanner.pas | 37 +++++++++++++++++++++++++++++++++++++
 cc.notes    |  2 ++
 2 files changed, 39 insertions(+)

diff --git a/Scanner.pas b/Scanner.pas
index 01ea4e5..9bea469 100644
--- a/Scanner.pas
+++ b/Scanner.pas
@@ -4742,6 +4742,42 @@ var
    end; {CharConstant}
 
 
+   procedure ConcatenateTokenString(tPtr: tokenListRecordPtr);
+   
+   { Concatenate the strings for the current token and the one  }
+   { represented by tPtr, and update tokenStart/tokenEnd to     }
+   { point to the new string.                                   }
+   
+   var
+      len: longint;                     {length of new token string}
+      srcPtr, destPtr: ptr;             {pointers for data copying}
+   
+   begin {ConcatenateTokenString}
+   len := ord4(tokenEnd)-ord4(tokenStart)
+      +ord4(tPtr^.tokenEnd)-ord4(tPtr^.tokenStart)+1;
+   if len <= maxint then begin
+      destPtr := GMalloc(ord(len));
+      srcPtr := tokenStart;
+      tokenStart := destPtr;
+      while srcPtr <> tokenEnd do begin
+         destPtr^ := srcPtr^;
+         destPtr := ptr(ord4(destPtr)+1);
+         srcPtr := ptr(ord4(srcPtr)+1);
+         end; {while}
+      srcPtr := tPtr^.tokenStart;
+      while srcPtr <> tPtr^.tokenEnd do begin
+         destPtr^ := srcPtr^;
+         destPtr := ptr(ord4(destPtr)+1);
+         srcPtr := ptr(ord4(srcPtr)+1);
+         end; {while}
+      destPtr^ := tPtr^.tokenEnd^;
+      tokenEnd := destPtr;
+      end {if}
+   else
+      Error(90);
+   end; {ConcatenateTokenString}
+
+
 begin {NextToken}
 if ifList = nil then			{do pending EndInclude calls}
    while includeCount <> 0 do begin
@@ -4807,6 +4843,7 @@ if tokenList <> nil then begin          {get a token put back by a macro}
             tPtr := tokenList;
             tToken := token;
             Merge(tToken, tPtr^.token);
+            ConcatenateTokenString(tPtr);
             tokenList := tPtr^.next;
             token := tToken;
             tokenExpandEnabled := true;
diff --git a/cc.notes b/cc.notes
index a08a6b6..40ddf44 100644
--- a/cc.notes
+++ b/cc.notes
@@ -1784,6 +1784,8 @@ int foo(int[42]);
 
 182. #pragma path directives were not saved in .sym files.  This could cause ORCA/C not to search the proper paths for include files that were not represented in the .sym file (e.g. because they were included after a function).
 
+183. The # preprocessor operator would not work correctly on tokens that had been produced by the ## preprocessor operator.
+
 -- Bugs from C 2.1.0 that have been fixed -----------------------------------
 
 1.  In some situations, fread() reread the first 1K or so of the file.