use gunzip instead of assuming gtar

Author: kroening

COMPILING.md

@@ -88,11 +88,8 @@ We assume that you have a Debian/Ubuntu or Red Hat-like distribution.
    ```
 3. Get MiniSat2 by entering
    ```
-   cd cbmc-git
-   wget http://ftp.debian.org/debian/pool/main/m/minisat2/minisat2_2.2.1.orig.tar.gz
-   gtar xfz minisat_2.2.1.orig.tar.gz
-   mv minisat2-2.2.1 minisat-2.2.1
-   (cd minisat-2.2.1; patch -p1 < ../scripts/minisat-2.2.1-patch)
+   cd cbmc-git/src
+   gmake minisat2-download DOWNLOADER=wget
    ```
 4. Type
    ```

src/Makefile

@@ -91,20 +91,22 @@ DOWNLOADER = lwp-download
 minisat2-download:
 	@echo "Downloading Minisat 2.2.1"
 	@$(DOWNLOADER) http://ftp.debian.org/debian/pool/main/m/minisat2/minisat2_2.2.1.orig.tar.gz
-	@tar xfz minisat2_2.2.1.orig.tar.gz
+	@gunzip minisat2_2.2.1.orig.tar.gz
+	@tar xf minisat2_2.2.1.orig.tar
 	@rm -Rf ../minisat-2.2.1
 	@mv minisat2-2.2.1 ../minisat-2.2.1
 	@(cd ../minisat-2.2.1; patch -p1 < ../scripts/minisat-2.2.1-patch)
-	@rm minisat2_2.2.1.orig.tar.gz
+	@rm minisat2_2.2.1.orig.tar
 
 glucose-download:
 	@echo "Downloading glucose-syrup"
 	@$(DOWNLOADER) http://www.labri.fr/perso/lsimon/downloads/softwares/glucose-syrup.tgz
-	@tar xfz glucose-syrup.tgz
+	@gunzip glucose-syrup.tgz
+	@tar xf glucose-syrup.tar
 	@rm -Rf ../glucose-syrup
 	@mv glucose-syrup ../
 	@(cd ../glucose-syrup; patch -p1 < ../scripts/glucose-syrup-patch)
-	@rm glucose-syrup.tgz
+	@rm glucose-syrup.tar
 
 ipasir-download:
 	# get the 2016 version of the ipasir package, which contains a few solvers