[antlr-interest] C example error

[Brian Catlin]

I tried to build the PolyDiff example from Examples-v3, using
ANTLR-3.1-2009-06-28 and libantlr3c-3.2 in Visual Studio 2008.  The output
from the build:

 

1>------ Rebuild All started: Project: polydiff, Configuration: Debug Win32
------

1>Deleting intermediate and output files for project 'polydiff',
configuration 'Debug|Win32'

1>Translating to parser/lexer combination

1>Translating to parser/lexer combination

1>Translating to parser/lexer combination

1>Translating to parser/lexer combination

1>.\PolyDifferentiator.g(0,0) : warning 138 : grammar PolyDifferentiator: no
start rule (no rule can obviously be followed by EOF)

1>Compiling...

1>Simplifier.c

1>PolyPrinter.c

1>PolyParser.c

1>PolyLexer.c

1>PolyDifferentiator.c

1>main.c

1>Generating Code...

1>Compiling manifest to resources...

1>Microsoft (R) Windows (R) Resource Compiler Version 6.1.7600.16385

1>Copyright (C) Microsoft Corporation.  All rights reserved.

1>Linking...

1>LINK : C:\MIMOS\ANTLR\examples-v3\C\Debug\polydiff.exe not found or not
built by the last incremental link; performing full link

1>   Creating library C:\MIMOS\ANTLR\examples-v3\C\Debug\polydiff.lib and
object C:\MIMOS\ANTLR\examples-v3\C\Debug\polydiff.exp

1>Embedding manifest...

1>Microsoft (R) Windows (R) Resource Compiler Version 6.1.7600.16385

1>Copyright (C) Microsoft Corporation.  All rights reserved.

1>Build log was saved at
"file://c:\MIMOS\ANTLR\examples-v3\C\polydiff\Debug\BuildLog.htm
<file:///c:\MIMOS\ANTLR\examples-v3\C\polydiff\Debug\BuildLog.htm> "

1>polydiff - 0 error(s), 1 warning(s)

========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

 

As you can see, there is a warning generating PolyDifferentiator.g

 

When I run the resulting program, I get an access violation in addChild
(antlr3basetree.c) at the ->, because child has not been initialized

 

void      

addChild (pANTLR3_BASE_TREE tree, pANTLR3_BASE_TREE child)

{

      ANTLR3_UINT32   n;

      ANTLR3_UINT32   i;

 

      if    (child == NULL)

      {

            return;

      }

 

->  if    (child->isNilNode(child) == ANTLR3_TRUE)

      {

            if  (child->children != NULL && child->children ==
tree->children)