Re: [Tinycc-devel] Dollar Sign in Identifiers Extension

[Ramsay Jones]

On 13/04/15 16:01, Daniel Holden wrote:
> Hi,
> 
> I've attached a new patch which tests for dollars in identifiers in C.
> 
> I've added a new parsing flag `PARSE_FLAG_ASM` to block the use of dollar  
> identifiers when parsing asm. This could probably be combined with the 
> `PARSE_FLAG_ASM_COMMENTS` flag.
> 
> Currently the flag only blocks identifiers in asm _starting_ with a dollar. I 
> think this is the only syntactically valid place in which dollars occurring 
> could conflict with gas asm, but they might appear inside identifiers if the 
> programmer is either referencing a symbol with a dollar in _or_ if they've 
> made a syntax error. I'll look into it more and do some more testing.
> 
> I'm on 64 bit and I have to hack the makefiles to run the assembly tests 
> because they are written in 32-bit x86. Does anyone have a 32-bit machine 
> they are testing tcc on?
> 

Your patch does not apply to the mob branch:

  $ git apply ../dollars-in-identifiers.patch
  ../dollars-in-identifiers.patch:36: trailing whitespace.
    
  ../dollars-in-identifiers.patch:40: trailing whitespace.
          || (parse_flags & PARSE_FLAG_ASM)) goto parse_simple;       
  ../dollars-in-identifiers.patch:41: trailing whitespace.
    
  ../dollars-in-identifiers.patch:135: trailing whitespace.
   
  ../dollars-in-identifiers.patch:138: trailing whitespace.
   
  error: patch failed: tcc.h:528
  error: tcc.h: patch does not apply
  error: patch failed: libtcc.c:1423
  error: libtcc.c: patch does not apply
  error: patch failed: tccpp.c:2178
  error: tccpp.c: patch does not apply
  error: patch failed: ./tests/tests2/Makefile:67
  error: ./tests/tests2/Makefile: patch does not apply
  $ 

... but I'm guessing you already know that!

Applying your patch instead to the master branch:

  $ git apply ../dollars-in-identifiers.patch
  ../dollars-in-identifiers.patch:36: trailing whitespace.
    
  ../dollars-in-identifiers.patch:40: trailing whitespace.
          || (parse_flags & PARSE_FLAG_ASM)) goto parse_simple;       
  ../dollars-in-identifiers.patch:41: trailing whitespace.
    
  ../dollars-in-identifiers.patch:135: trailing whitespace.
   
  ../dollars-in-identifiers.patch:138: trailing whitespace.
   
  warning: squelched 3 whitespace errors
  warning: 8 lines add whitespace errors.
  $ 

... shows that you are introducing some whitespace errors
(although the number of lines doesn't seem to tally!).

After 'git apply'-ing your patch and staging ('git add'-ing)
your changes (including the new files), then:

  $ git diff --cached --check
  tccpp.c:2181: trailing whitespace.
  +    
  tccpp.c:2185: trailing whitespace.
  +        || (parse_flags & PARSE_FLAG_ASM)) goto parse_simple;       
  tccpp.c:2186: trailing whitespace.
  +    
  tests/tests2/56_dollars.c:20: trailing whitespace.
  +   
  tests/tests2/56_dollars.c:23: trailing whitespace.
  +   
  tests/tests2/56_dollars.c:24: trailing whitespace.
  +   int $ = 10; 
  tests/tests2/56_dollars.c:30: trailing whitespace.
  +   
  tests/tests2/56_dollars.c:42: new blank line at EOF.
  $ 

(you can't see the red highlight on the trailing whitespace in
an email, of course! ;)

Note: so far this is on an 64-bit system, I was going to try on
a 32-bit system later.

After running:

  $ make clean
  ...
  $ ./configure
  ...
  $ make
  ...
  $ make test
  ...
  Test: 56_dollars...
  56_dollars.c:14: error: '$' undeclared
  make[2]: *** [56_dollars.test] Error 1
  make[2]: Leaving directory `/home/ramsay/tinycc/tests/tests2'
  make[1]: *** [moretests] Error 2
  make[1]: Leaving directory `/home/ramsay/tinycc/tests'
  make: *** [test] Error 2
  $ 

So, I'm obviously doing something wrong, sorry! :(

I suspect it's not worth trying on 32-bit, if I can't get it
to work on a 64-bit system.

ATB,
Ramsay Jones