Merge pull request #2398 from ipfs/check-go-version

Check go version

Makefile

@@ -19,6 +19,9 @@ godep:
 
 toolkit_upgrade: gx_upgrade gxgo_upgrade
 
+go_check:
+	@bin/check_go_version "1.5.2"
+
 gx_upgrade:
 	go get -u github.com/whyrusleeping/gx
 
@@ -29,7 +32,7 @@ gx_check:
 	@bin/check_gx_program "gx" "0.3" 'Upgrade or install gx using your package manager or run `make gx_upgrade`'
 	@bin/check_gx_program "gx-go" "0.2" 'Upgrade or install gx-go using your package manager or run `make gxgo_upgrade`'
 
-deps: gx_check
+deps: go_check gx_check
 	gx --verbose install --global
 
 # saves/vendors third-party dependencies to Godeps/_workspace
@@ -53,7 +56,8 @@ clean:
 uninstall:
 	cd cmd/ipfs && go clean -i -ldflags=$(ldflags)
 
-PHONY += all help godep toolkit_upgrade gx_upgrade gxgo_upgrade gx_check deps vendor install build nofuse clean uninstall
+PHONY += all help godep toolkit_upgrade gx_upgrade gxgo_upgrade gx_check
+PHONY += go_check deps vendor install build nofuse clean uninstall
 
 ##############################################################
 # tests targets

bin/check_go_version

@@ -0,0 +1,86 @@
+#!/bin/sh
+#
+# Check that the go version is at least equal to a minimum version
+# number.
+#
+# Call it for example like this:
+#
+#   $ check_go_version "1.5.2"
+#
+
+USAGE="$0 GO_MIN_VERSION"
+
+die() {
+    printf >&2 "fatal: %s\n" "$@"
+    exit 1
+}
+
+# Get arguments
+
+test "$#" -eq "1" || die "This program must be passed exactly 1 arguments" "Usage: $USAGE"
+
+GO_MIN_VERSION="$1"
+
+UPGRADE_MSG="Please take a look at https://golang.org/doc/install to install or upgrade go."
+
+die_upgrade() {
+    printf >&2 "fatal: %s\n" "$@"
+    printf >&2 "=> %s\n" "$UPGRADE_MSG"
+    exit 1
+}
+
+major_number() {
+    vers="$1"
+
+    # Hack around 'expr' exiting with code 1 when it outputs 0
+    case "$vers" in
+        0) echo "0" ;;
+        0.*) echo "0" ;;
+        *) expr "$vers" : "\([^.]*\).*" || return 1
+    esac
+}
+
+check_at_least_version() {
+    MIN_VERS="$1"
+    CUR_VERS="$2"
+    PROG_NAME="$3"
+
+    # Get major, minor and fix numbers for each version
+    MIN_MAJ=$(major_number "$MIN_VERS") || die "No major version number in '$MIN_VERS' for '$PROG_NAME'"
+    CUR_MAJ=$(major_number "$CUR_VERS") || die "No major version number in '$CUR_VERS' for '$PROG_NAME'"
+
+    if MIN_MIN=$(expr "$MIN_VERS" : "[^.]*\.\([^.]*\).*"); then
+        MIN_FIX=$(expr "$MIN_VERS" : "[^.]*\.[^.]*\.\([^.]*\).*") || MIN_FIX="0"
+    else
+        MIN_MIN="0"
+        MIN_FIX="0"
+    fi
+    if CUR_MIN=$(expr "$CUR_VERS" : "[^.]*\.\([^.]*\).*"); then
+        CUR_FIX=$(expr "$CUR_VERS" : "[^.]*\.[^.]*\.\([^.]*\).*") || CUR_FIX="0"
+    else
+        CUR_MIN="0"
+        CUR_FIX="0"
+    fi
+
+    # Compare versions
+    VERS_LEAST="$PROG_NAME version '$CUR_VERS' should be at least '$MIN_VERS'"
+    test "$CUR_MAJ" -gt $(expr "$MIN_MAJ" - 1) || die_upgrade "$VERS_LEAST"
+    test "$CUR_MAJ" -gt "$MIN_MAJ" || {
+        test "$CUR_MIN" -gt $(expr "$MIN_MIN" - 1) || die_upgrade "$VERS_LEAST"
+        test "$CUR_MIN" -gt "$MIN_MIN" || {
+            test "$CUR_FIX" -ge "$MIN_FIX" || die_upgrade "$VERS_LEAST"
+        }
+    }
+}
+
+# Check that the go binary exist and is in the path
+
+type go >/dev/null 2>&1 || die_upgrade "go is not installed or not in the PATH!"
+
+# Check the go binary version
+
+VERS_STR=$(go version 2>&1) || die "'go version' failed with output: $VERS_STR"
+
+GO_CUR_VERSION=$(expr "$VERS_STR" : ".*go version go\([^ ]*\) .*") || die "Invalid 'go version' output: $VERS_STR"
+
+check_at_least_version "$GO_MIN_VERSION" "$GO_CUR_VERSION" "go"