[maven] disable JAVA_HOME during capture

Summary:
The maven script now checks for a java command in `JAVA_HOME`

```
if [ -z "$JAVA_HOME" ] ; then
  JAVACMD=`which java`
else
  JAVACMD="$JAVA_HOME/bin/java"
fi
```
when running under infer (where we specify infer as a compiler) and a valid `JAVA_HOME`, this check fails with
```
The JAVA_HOME environment variable is not defined correctly
This environment variable is needed to run this program
NB: JAVA_HOME should point to a JDK not a JRE
```
We unset `JAVA_HOME` when running under infer, bypassing this check (it still requires a java executable in the path).

Reviewed By: geralt-encore

Differential Revision:
D68148333

Privacy Context Container: L1208441

fbshipit-source-id: 1d6bf0994f58f9c225f2a889c8145754eb6f6ea8

infer/src/base/Config.ml

@@ -398,7 +398,7 @@ let infer_inside_maven_env_var = "INFER_INSIDE_MAVEN"
 
 let maven = CLOpt.is_env_var_set infer_inside_maven_env_var
 
-let env_inside_maven = `Extend [(infer_inside_maven_env_var, "1")]
+let maven_env = `Extend [(infer_inside_maven_env_var, "1"); ("JAVA_HOME", "")]
 
 let infer_is_javac = maven
 

infer/src/base/Config.mli

@@ -39,7 +39,8 @@ val build_system_of_exe_name : string -> build_system
 
 val string_of_build_system : build_system -> string
 
-val env_inside_maven : Unix.env
+val maven_env : Unix.env
+(** tell Infer it's running inside maven and disable JAVA_HOME *)
 
 (** {2 Constant configuration values} *)
 

infer/src/integration/Maven.ml

@@ -174,4 +174,4 @@ let capture ~prog ~args =
     "Running maven capture:@\n%s %s@." prog
     (String.concat ~sep:" " (List.map ~f:(Printf.sprintf "'%s'") capture_args)) ;
   (* let children infer processes know that they are spawned by Maven *)
-  Process.create_process_and_wait ~prog ~args:capture_args ~env:Config.env_inside_maven ()
+  Process.create_process_and_wait ~prog ~args:capture_args ~env:Config.maven_env ()