compilation error with postgres 9.3 on ubuntu

I start on studying database development with postgres recently, and I’m sure I need to start from compilation of the source code, but a compilation problem comes to me.
The one I coped with is shared below, and I would like to show my linux environment first:

Compilation Env:

Ubuntu 13.10  
Linux rugal-TM8473 3.11.0-15-generic #23-Ubuntu SMP Mon Dec 9 18:17:04 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux  
gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9)  
bison (GNU Bison) 2.7.12-4996  

Error Stack:

make -C preproc all
make[4]: Entering directory `/home/rugal/workspace/postgresql/src/interfaces/ecpg/preproc'
gcc -O2 -Wall -Wmissing-prototypes -Wpointer-arith -Wdeclaration-after-statement -Wendif-labels -Wmissing-format-attribute -Wformat-security -fno-strict-aliasing -fwrapv -fexcess-precision=standard -pthread  -D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS -DECPG_COMPILE -I../include -I../../../../src/interfaces/ecpg/include -I. -I. -DMAJOR_VERSION=4 -DMINOR_VERSION=10 -DPATCHLEVEL=0 -I../../../../src/include -D_GNU_SOURCE   -c -o preproc.o preproc.c -MMD -MP -MF .deps/preproc.Po
In file included from preproc.y:15004:0:
pgc.l: In function ‘base_yylex’:
pgc.l:403:24: error: ‘ET_FATAL’ undeclared (first use in this function)
       BEGIN(state_before);
                        ^
pgc.l:403:24: note: each undeclared identifier is reported only once for each function it appears in
In file included from preproc.y:15004:0:
pgc.l: In function ‘parse_include’:
pgc.l:1366:28: error: ‘ET_FATAL’ undeclared (first use in this function)
    if (!yyin)
                            ^
make[4]: *** [preproc.o] Error 1

This problem keep bothering even after I used
make distclean
./configure --enable-depend && make

At first, I found some solution mentioned about the bison parser generator, so I regenerator some syntax file.
bison -d -o preproc.c preproc.y
But this continue bothering me. I feel helpless…

Night after that, I find a other method to cope with it:

--- a/src/interfaces/ecpg/preproc/type.h
+++ b/src/interfaces/ecpg/preproc/type.h
@@ -186,7 +186,7 @@ struct assignment
 
 enum errortype


 {
-   ET_WARNING, ET_ERROR, ET_FATAL


+   ET_WARNING, ET_ERROR
 };

After adding this enum, ET_FATAL, compilation become successful!
But there still has a strange warning:

preproc.y: In function ‘vmmerror’:
preproc.y:76:2: warning: enumeration value ‘ET_FATAL’ not handled in switch [-Wswitch]
  switch(type)
  ^

Which indicating the enum I just added is already retired. What can I do next?

So I sent my first mail to psql-hackers mail group, and I got replied:

You have to rebuild the auto-generated pgc.c, preproc.c and preproc.y or simplyremove them to force a rebuild.

This directed me. I deleted pgc.c preproc.c preproc.h preproc.y, which I used to treat as important, but turn out to be generated files.
And this time, I could make successfully!

I have learned it is the reason that the first time I make, those .y files are generated automatically, but they would not deleted by make distclean, which result in the above error.
Also I got to know, make maintainer-clean can clean all unnecessary file, hackers will use this to clean all no-needed files when they coding.
I have learnt more from this, compilation principle is so important that it was a great pity for my school do not have this class!

Let’s start developing PostgreSQL