gnu: Refer to 'gcc' instead of 'gcc-4.9'.

* gnu/packages/commencement.scm (gcc-boot0, cross-gcc-wrapper,
  libstdc++, gcc-final): Refer to GCC instead of GCC-4.9.
* gnu/packages/cross-base.scm (%xgcc): New variable.
  (cross-gcc-arguments, cross-gcc): Refer to %XGCC instead of GCC-4.9.
* gnu/packages/llvm.scm (clang-from-llvm): Refer to GCC instead of GCC-4.9.
* gnu/packages/make-bootstrap.scm (package-with-relocatable-glibc,
  %gcc-static, %gcc-stripped): Likewise.

gnu/packages/commencement.scm

@@ -167,7 +167,7 @@
 
 (define gcc-boot0
   (package-with-bootstrap-guile
-   (package (inherit gcc-4.9)
+   (package (inherit gcc)
      (name "gcc-cross-boot0")
      (arguments
       `(#:guile ,%bootstrap-guile
@@ -177,7 +177,7 @@
                    (ice-9 regex)
                    (srfi srfi-1)
                    (srfi srfi-26))
-        ,@(substitute-keyword-arguments (package-arguments gcc-4.9)
+        ,@(substitute-keyword-arguments (package-arguments gcc)
             ((#:configure-flags flags)
              `(append (list ,(string-append "--target=" (boot-triplet))
 
@@ -240,7 +240,7 @@
                     (with-directory-excursion
                         (string-append out "/lib/gcc/"
                                        ,(boot-triplet)
-                                       "/" ,(package-version gcc-4.9))
+                                       "/" ,(package-version gcc))
                       (symlink "libgcc.a" "libgcc_eh.a"))))
                 ,phases))))))
 
@@ -256,7 +256,7 @@
 
      ;; No need for Texinfo at this stage.
      (native-inputs (alist-delete "texinfo"
-                                  (package-native-inputs gcc-4.9))))))
+                                  (package-native-inputs gcc))))))
 
 (define perl-boot0
   (package-with-bootstrap-guile
@@ -352,7 +352,7 @@
 (define (cross-gcc-wrapper gcc binutils glibc bash)
   "Return a wrapper for the pseudo-cross toolchain GCC/BINUTILS/GLIBC
 that makes it available under the native tool names."
-  (package (inherit gcc-4.9)
+  (package (inherit gcc)
     (name (string-append (package-name gcc) "-wrapped"))
     (source #f)
     (build-system trivial-build-system)
@@ -520,7 +520,7 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
   ;; (remember that GCC-BOOT0 cannot build libstdc++.)
   ;; TODO: Write in terms of 'make-libstdc++'.
   (package-with-bootstrap-guile
-   (package (inherit gcc-4.9)
+   (package (inherit gcc)
      (name "libstdc++")
      (arguments
       `(#:guile ,%bootstrap-guile
@@ -539,7 +539,7 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
                                             (assoc-ref %outputs "out")
                                             "/include"
                                             ;; "/include/c++/"
-                                            ;; ,(package-version gcc-4.9)
+                                            ;; ,(package-version gcc)
                                             ))))
      (outputs '("out"))
      (inputs %boot2-inputs)
@@ -573,7 +573,7 @@ exec ~a/bin/~a-~a -B~a/lib -Wl,-dynamic-linker -Wl,~a/~a \"$@\"~%"
        ;; doesn't honor $LIBRARY_PATH, which breaks `gnu-build-system'.)
        ,@(substitute-keyword-arguments (package-arguments gcc-boot0)
            ((#:configure-flags boot-flags)
-            (let loop ((args (package-arguments gcc-4.9)))
+            (let loop ((args (package-arguments gcc)))
               (match args
                 ((#:configure-flags normal-flags _ ...)
                  normal-flags)

gnu/packages/cross-base.scm

@@ -36,6 +36,11 @@
             cross-libc
             cross-gcc))
 
+(define %xgcc
+  ;; GCC package used as the basis for cross-compilation.  It doesn't have to
+  ;; be 'gcc' and can be a specific variant such as 'gcc-4.8'.
+  gcc)
+
 (define (cross p target)
   (package (inherit p)
     (name (string-append (package-name p) "-cross-" target))
@@ -90,7 +95,7 @@ may be either a libc package or #f.)"
     ;; <http://lists.fedoraproject.org/pipermail/arm/2010-August/000663.html>
     ;; for instance.
     (let ((args `(#:strip-binaries? #f
-                  ,@(package-arguments gcc-4.9))))
+                  ,@(package-arguments %xgcc))))
      (substitute-keyword-arguments args
        ((#:configure-flags flags)
         `(append (list ,(string-append "--target=" target)
@@ -199,14 +204,14 @@ may be either a libc package or #f.)"
   "Return a cross-compiler for TARGET, where TARGET is a GNU triplet.  Use
 XBINUTILS as the associated cross-Binutils.  If LIBC is false, then build a
 GCC that does not target a libc; otherwise, target that libc."
-  (package (inherit gcc-4.9)
+  (package (inherit %xgcc)
     (name (string-append "gcc-cross-"
                          (if libc "" "sans-libc-")
                          target))
-    (source (origin (inherit (package-source gcc-4.9))
+    (source (origin (inherit (package-source %xgcc))
               (patches
                (append
-                (origin-patches (package-source gcc-4.9))
+                (origin-patches (package-source %xgcc))
                 (cons (search-patch "gcc-cross-environment-variables.patch")
                       (cross-gcc-patches target))))))
 
@@ -236,7 +241,7 @@ GCC that does not target a libc; otherwise, target that libc."
        ("libc-native" ,@(assoc-ref %final-inputs "libc"))
 
        ;; Remaining inputs.
-       ,@(let ((inputs (append (package-inputs gcc-4.9)
+       ,@(let ((inputs (append (package-inputs %xgcc)
                                (alist-delete "libc" %final-inputs))))
            (if libc
                `(("libc" ,libc)

gnu/packages/llvm.scm

@@ -96,7 +96,7 @@ tools as well as libraries with equivalent functionality.")
     (native-inputs (package-native-inputs llvm))
     (inputs
      `(("libxml2" ,libxml2)
-       ("gcc-lib" ,gcc-4.9 "lib")
+       ("gcc-lib" ,gcc "lib")
        ,@(package-inputs llvm)))
     (propagated-inputs
      `(("llvm" ,llvm)))

gnu/packages/make-bootstrap.scm

@@ -103,11 +103,11 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
             ("cross-binutils" ,(cross-binutils target))
             ,@%final-inputs))
         `(("libc" ,(glibc-for-bootstrap))
-          ("gcc" ,(package (inherit gcc-4.9)
+          ("gcc" ,(package (inherit gcc)
                     (outputs '("out")) ; all in one so libgcc_s is easily found
                     (inputs
                      `(("libc",(glibc-for-bootstrap))
-                       ,@(package-inputs gcc-4.9)))))
+                       ,@(package-inputs gcc)))))
           ,@(fold alist-delete %final-inputs '("libc" "gcc")))))
 
   (package-with-explicit-inputs p inputs
@@ -389,7 +389,7 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
 (define %gcc-static
   ;; A statically-linked GCC, with stripped-down functionality.
   (package-with-relocatable-glibc
-   (package (inherit gcc-4.9)
+   (package (inherit gcc)
      (name "gcc-static")
      (outputs '("out"))                           ; all in one
      (arguments
@@ -398,7 +398,7 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
                    (srfi srfi-1)
                    (srfi srfi-26)
                    (ice-9 regex))
-        ,@(substitute-keyword-arguments (package-arguments gcc-4.9)
+        ,@(substitute-keyword-arguments (package-arguments gcc)
             ((#:guile _) #f)
             ((#:implicit-inputs? _) #t)
             ((#:configure-flags flags)
@@ -453,12 +453,12 @@ for `sh' in $PATH, and without nscd, and with static NSS modules."
             ("gmp-native" ,gmp)
             ("mpfr-native" ,mpfr)
             ("mpc-native" ,mpc)
-            ,@(package-native-inputs gcc-4.9))
-          (package-native-inputs gcc-4.9))))))
+            ,@(package-native-inputs gcc))
+          (package-native-inputs gcc))))))
 
 (define %gcc-stripped
   ;; The subset of GCC files needed for bootstrap.
-  (package (inherit gcc-4.9)
+  (package (inherit gcc)
     (name "gcc-stripped")
     (build-system trivial-build-system)
     (source #f)