Use awk to parse source code - shell

Question

I'm looking to create documentation from source code that I have. I've been looking around and something like awk seems like it will work, but I've had no luck so far. The information is split in two files, file1.c and file2.c.
Note: I've set up an automatic build environment for the program. This detects changes in the source and builds it. I would like to generate a text file containing a list of any variables which have been modified since the last successful build. The script I'm looking for would be a post-build step, and would run after compilation
In file1.c I have a list of function calls (all the same function) that have a string name to identify them such as:
newFunction("THIS_IS_THE_STRING_I_WANT", otherVariables, 0, &iAlsoNeedThis);
newFunction("I_WANT_THIS_STRING_TOO", otherVariable, 0, &iAnotherOneINeed);
etc...
The fourth parameter in the function call contains the value of the string name in file2. For example:
iAlsoNeedThis = 25;
iAnotherOneINeed = 42;
etc...
I'm looking to output the list to a txt file in the following format:
THIS_IS_THE_STRING_I_WANT = 25
I_WANT_THIS_STRING_TOO = 42
Is there any way of do this?
Thanks

Answer 1

Here is a start:
NR==FNR { # Only true when we are reading the first file
split($1,s,"\"") # Get the string in quotes from the first field
gsub(/[^a-zA-Z]/,"",$4) # Remove the none alpha chars from the forth field
m[$4]=s[2] # Create array
next
}
$1 in m { # Match feild four from file1 with field one file2
sub(/;/,"") # Get rid of the ;
print m[$1],$2,$3 # Print output
}
Saving this script.awk and running it with your example produces:
$ awk -f script.awk file1 file2
THIS_IS_THE_STRING_I_WANT = 25
I_WANT_THIS_STRING_TOO = 42
Edit:
The modifications you require affects the first line of the script:
NR==FNR && $3=="0," && /start here/,/end here/ {

Answer 2

You can do it in the shell like so.
#!/bin/sh
eval $(sed 's/[^a-zA-Z0-9=]//g' file2)
while read -r line; do
case $line in
(newFunction*)
set -- $line
string=${1#*\"}
string=${string%%\"*}
while test $# -gt 1; do shift; done
x=${1#&}
x=${x%);}
eval x=\$$x
printf '%s = %s\n' $string $x
esac
done < file1.c
Assumptions: newFunction is at the start of the line. Nothing follows the );. Whitespace exactly as in your samples. Output
THIS_IS_THE_STRING_I_WANT = 25
I_WANT_THIS_STRING_TOO = 42

Answer 3

You can execute file file2.c so variables will be defined in bash. Then, you will just have to print $iAlsoNeedThis to get value from iAlsoNeedThis = 25;
It can be done with . file2.c.
Then, what you can do is:
while read line;
do
name=$(echo $line | cut -d"\"" -f2);
value=$(echo $line | cut -d"&" -f2 | cut -d")" -f1);
echo $name = ${!value};
done < file1.c
to get the THIS_IS_THE_STRING_I_WANT, I_WANT_THIS_STRING_TOO text.