gnu: Remove more GCC < 7 workarounds.

* gnu/packages/abiword.scm (abiword)[arguments]: Do not pass "-std=c++11" to
the GCC command line.
* gnu/packages/aidc.scm (zbar)[arguments]: Likewise.
* gnu/packages/android.scm (android-libbase, android-libcutils,
android-libziparchive, fastboot)[arguments]: Likewise.
* gnu/packages/audio.scm (azr3, guitarix, suil)[arguments]: Likewise.
* gnu/packages/bioinformatics.scm (bless)[arguments]: Likewise.
* gnu/packages/bittorrent.scm (libtorrent-rasterbar)[arguments]: Likewise.
* gnu/packages/code.scm (rtags)[arguments]: Likewise.
* gnu/packages/coq.scm (coq-gappa)[arguments]: Likewise.
* gnu/packages/emulators.scm (dolphin-emu)[arguments]: Likewise.
* gnu/packages/engineering.scm (xyce-serial, xyce-parallel)[arguments]: Likewise.
* gnu/packages/gnupg.scm (pinentry-qt)[arguments]: Likewise.
* gnu/packages/gobby.scm (libnet6, obby)[arguments]: Likewise.
* gnu/packages/graph.scm (python-faiss)[arguments]: Likewise.
* gnu/packages/graphics.scm (povray)[arguments]: Likewise.
* gnu/packages/image-processing.scm (opencv, itk-snap)[arguments]: Likewise.
* gnu/packages/image.scm (freeimage)[arguments]: Likewise.
* gnu/packages/kodi.scm (crossguid)[arguments]: Likewise.
* gnu/packages/music.scm (amsynth, qmidiarp, qmidiroute, seq24)[arguments]: Likewise.
* gnu/packages/pdf.scm (python-poppler-qt5)[arguments]: Likewise.
* gnu/packages/sagemath.scm (lcalc)[arguments]: Likewise.
* gnu/packages/video.scm (vlc, mlt, v4l-utils)[arguments]: Likewise.

gnu/packages/abiword.scm

@@ -83,7 +83,7 @@ (define-public abiword
         ;; the tests to pass.
         #:tests? #f
         #:make-flags
-        (list "CXXFLAGS=-std=c++11" "gtk_update_icon_cache=true")))
+        (list "gtk_update_icon_cache=true")))
     (inputs
       `(("boost" ,boost)
         ("enchant" ,enchant)

gnu/packages/aidc.scm

@@ -130,8 +130,7 @@ (define-public zbar
                                "--with-python=auto"
                                (string-append "--with-dbusconfdir="
                                               (assoc-ref %outputs "out")
-                                              "/etc")
-                               "CXXFLAGS=-std=c++11")))
+                                              "/etc"))))
     (native-inputs
      `(("glib" ,glib "bin")
        ("pkg-config" ,pkg-config)))

gnu/packages/android.scm

@@ -217,7 +217,6 @@ (define android-libbase
     (build-system android-ndk-build-system)
     (arguments
      `(#:tests? #f ; Test failure: logging.UNIMPLEMENTED
-       #:make-flags '("CXXFLAGS=-std=gnu++11")
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'enter-source
@@ -257,7 +256,7 @@ (define android-libcutils
                    "CC = gcc\n"
 
                    "CFLAGS += -fPIC\n"
-                   "CXXFLAGS += -std=gnu++11 -fPIC\n"
+                   "CXXFLAGS += -fPIC\n"
                    "CPPFLAGS += -Iinclude -I../include\n"
                    "LDFLAGS += -shared -Wl,-soname,$(NAME).so.0\n"
 
@@ -312,7 +311,7 @@ (define-public android-libziparchive
     (build-system android-ndk-build-system)
     (arguments
      `(#:make-flags '("CFLAGS=-Wno-error"
-                      "CXXFLAGS=-fpermissive -Wno-error -std=gnu++11")
+                      "CXXFLAGS=-fpermissive -Wno-error")
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'enter-source
@@ -631,8 +630,7 @@ (define-public fastboot
     (source (android-platform-system-core version))
     (build-system android-ndk-build-system)
     (arguments
-     `(#:make-flags (list "CXXFLAGS=-std=gnu++11")
-       #:phases
+     `(#:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'enter-source
            (lambda _

gnu/packages/audio.scm

@@ -521,8 +521,6 @@ (define-public azr3
      `(#:tests? #f ; no check target
        #:make-flags
        (list "LV2PEG=ttl2c"
-             "CXXFLAGS=-std=gnu++11"
-             "CFLAGS=-std=gnu++11"
              (string-append "prefix=" %output)
              (string-append "pkgdatadir=" %output "/share/azr3-jack"))
        #:phases
@@ -1328,8 +1326,7 @@ (define-public guitarix
        #:configure-flags
        (list
         ;; Add the output lib directory to the RUNPATH.
-        (string-append "--ldflags=-Wl,-rpath=" %output "/lib")
-        "--cxxflags=-std=c++11")
+        (string-append "--ldflags=-Wl,-rpath=" %output "/lib"))
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'fix-boost-includes
@@ -2427,9 +2424,7 @@ (define-public suil
                 "0ay7hl6nr6ip1nn9k2m8ri3b52b6sx9mhixmcy4fy3kr2a88ksd1"))))
     (build-system waf-build-system)
     (arguments
-     `(#:tests? #f                      ; no check target
-       #:configure-flags
-       '("CXXFLAGS=-std=gnu++11")))
+     `(#:tests? #f))                    ;no check target
     (inputs
      `(("lv2" ,lv2)
        ("gtk+" ,gtk+-2)

gnu/packages/bioinformatics.scm

@@ -1443,8 +1443,7 @@ (define-public bless
                                            "-lboost_system"
                                            "-lboost_iostreams"
                                            "-lz"
-                                           "-fopenmp"
-                                           "-std=c++11"))))
+                                           "-fopenmp"))))
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'do-not-build-bundled-pigz

gnu/packages/bittorrent.scm

@@ -400,18 +400,7 @@ (define-public libtorrent-rasterbar
              "--enable-tests")
        #:make-flags (list
                      (string-append "LDFLAGS=-Wl,-rpath="
-                                    (assoc-ref %outputs "out") "/lib"))
-       #:phases (modify-phases %standard-phases
-           (add-after 'unpack 'compile-python-c++11
-             (lambda _
-               ;; Make sure the Python bindings are compiled in C++ mode to
-               ;; avoid undefined references as mentioned in
-               ;; <https://github.com/qbittorrent/qBittorrent/issues/638>.
-               ;; XXX: This can be removed for 1.2+.
-               (substitute* "bindings/python/setup.py"
-                 (("\\+ target_specific\\(\\)\\,")
-                  "+ target_specific() + ['-std=c++11'],"))
-               #t)))))
+                                    (assoc-ref %outputs "out") "/lib"))))
     (inputs `(("boost" ,boost)
               ("openssl" ,openssl)))
     (native-inputs `(("python" ,python-2)

gnu/packages/code.scm

@@ -431,7 +431,6 @@ (define-public rtags
      '(#:build-type "RelWithDebInfo"
        #:configure-flags
        '("-DRTAGS_NO_ELISP_FILES=1"
-         "-DCMAKE_CXX_FLAGS=-std=c++11"
          "-DBUILD_TESTING=FALSE")
        #:tests? #f))
     (native-inputs

gnu/packages/coq.scm

@@ -256,8 +256,7 @@ (define-public coq-gappa
     (arguments
      `(#:configure-flags
        (list (string-append "--libdir=" (assoc-ref %outputs "out")
-                            "/lib/coq/user-contrib/Gappa")
-             "CXXFLAGS=-std=c++11")
+                            "/lib/coq/user-contrib/Gappa"))
        #:phases
        (modify-phases %standard-phases
          (add-before 'configure 'fix-remake

gnu/packages/emulators.scm

@@ -161,7 +161,7 @@ (define-public dolphin-emu
                       (string-append (assoc-ref inputs "vulkan-loader")
                                      "/lib/libvulkan.so")))
                  (chdir "docs")
-                 (invoke "bash" "-c" "g++ -O2 -std=c++11 $(freetype-config \
+                 (invoke "bash" "-c" "g++ -O2 $(freetype-config \
 --cflags --libs) gc-font-tool.cpp -o gc-font-tool")
                  (invoke "./gc-font-tool" "a" fontfile "font_western.bin")
                  (invoke "./gc-font-tool" "s" fontfile "font_japanese.bin")

gnu/packages/engineering.scm

@@ -1546,7 +1546,7 @@ (define-public xyce-serial
      `(#:tests? #f
        #:configure-flags
        (list
-        "CXXFLAGS=-O3 -std=c++11"
+        "CXXFLAGS=-O3"
         (string-append "ARCHDIR="
                        (assoc-ref %build-inputs "trilinos")))))
     (native-inputs
@@ -1586,7 +1586,7 @@ (define-public xyce-parallel
     (arguments
      `(,@(substitute-keyword-arguments (package-arguments xyce-serial)
            ((#:configure-flags flags)
-            `(list "CXXFLAGS=-O3 -std=c++11"
+            `(list "CXXFLAGS=-O3"
                    "CXX=mpiCC"
                    "CC=mpicc"
                    "F77=mpif77"

gnu/packages/gnupg.scm

@@ -866,8 +866,6 @@ (define-public pinentry-qt
     (inputs
      `(("qtbase" ,qtbase)
        ,@(package-inputs pinentry-tty)))
-    (arguments
-     `(#:configure-flags '("CXXFLAGS=-std=gnu++11")))
   (description
    "Pinentry provides a console and a Qt GUI that allows users to enter a
 passphrase when @code{gpg} is run and needs it.")))

gnu/packages/gobby.scm

@@ -47,9 +47,7 @@ (define-public libnet6
     (native-inputs
      `(("pkg-config" ,pkg-config)))
     (arguments
-     `(#:configure-flags
-       '("CXXFLAGS=-std=c++11")         ; required by libsigc++
-       #:phases
+     `(#:phases
        (modify-phases %standard-phases
          (add-before 'configure 'update-gnutls-api
            (lambda _
@@ -88,9 +86,6 @@ (define-public obby
      `(("libsigc++" ,libsigc++)
        ("gnutls" ,gnutls)
        ("libnet6" ,libnet6)))
-    (arguments
-     ;; Required by libsigc++.
-     `(#:configure-flags '("CXXFLAGS=-std=c++11")))
     (home-page "https://gobby.github.io/")
     (synopsis "Library for building collaborative editors")
     (description

gnu/packages/graph.scm

@@ -389,7 +389,7 @@ (define-public python-faiss
 PYTHONCFLAGS =-I~a/include/python~am/ -I~a/lib/python~a/site-packages/numpy/core/include
 LIBS = -lpython~am -lfaiss
 SHAREDFLAGS = -shared -fopenmp
-CXXFLAGS = -fpermissive -std=c++11 -fopenmp -fPIC
+CXXFLAGS = -fpermissive -fopenmp -fPIC
 CPUFLAGS = ~{~a ~}~%"
                            (assoc-ref inputs "python*") python-version
                            (assoc-ref inputs "python-numpy") python-version

gnu/packages/graphics.scm

@@ -673,7 +673,6 @@ (define-public povray
        (list "COMPILED_BY=Guix"
              (string-append "--with-boost-libdir="
                             (assoc-ref %build-inputs "boost") "/lib")
-             "CXXFLAGS=-std=c++11"
              "--disable-optimiz-arch")
        #:phases
        (modify-phases %standard-phases

gnu/packages/image-processing.scm

@@ -269,10 +269,6 @@ (define-public opencv
              "-DWITH_CAROTENE=OFF" ; only visible on arm/aarch64
              "-DENABLE_PRECOMPILED_HEADERS=OFF"
 
-             ;; FIXME: OpenEXR requires C++11 or later.  Remove this when
-             ;; the default compiler is GCC 7.
-             "-DCMAKE_CXX_FLAGS=-std=gnu++11"
-
              ;; CPU-Features:
              ;; See cmake/OpenCVCompilerOptimizations.cmake
              ;; (CPU_ALL_OPTIMIZATIONS) for a list of all optimizations
@@ -729,8 +725,7 @@ (define-public itk-snap
              "-DSNAP_VERSION_GIT_BRANCH=release"
              "-DSNAP_VERSION_GIT_TIMESTAMP=0"
              "-DSNAP_PACKAGE_QT_PLUGINS=OFF"
-             "-DCMAKE_POSITION_INDEPENDENT_CODE=ON"
-             "-DCMAKE_CXX_FLAGS=-std=gnu++11 -fpermissive")
+             "-DCMAKE_POSITION_INDEPENDENT_CODE=ON")
        #:phases
        (modify-phases %standard-phases
          ;; During the installation phase all libraries provided by all

gnu/packages/image.scm

@@ -973,11 +973,7 @@ (define-public freeimage
             ;; We need '-fpermissive' for Source/FreeImage.h.
             ;; libjxr doesn't have a pkg-config file.
             (string-append "CFLAGS+=-O2 -fPIC -fvisibility=hidden -fpermissive "
-                           "-I" (assoc-ref %build-inputs "libjxr") "/include/jxrlib "
-
-                           ;; FIXME: OpenEXR 2.4.0 requires C++11 or later.
-                           ;; Remove when the default compiler is > GCC 5.
-                           "-std=gnu++11"))
+                           "-I" (assoc-ref %build-inputs "libjxr") "/include/jxrlib"))
       #:tests? #f)) ; no check target
    (native-inputs
     `(("pkg-config" ,pkg-config)

gnu/packages/kodi.scm

@@ -104,14 +104,12 @@ (define-public crossguid
            (replace 'build
              (lambda _
                (invoke "g++" "-c" "guid.cpp" "-o" "guid.o"
-                       "-std=c++11" "-DGUID_LIBUUID")
+                        "-DGUID_LIBUUID")
                (invoke "ar" "rvs" "libcrossguid.a" "guid.o")))
            (replace 'check
              (lambda _
-               (invoke "g++" "-c" "test.cpp" "-o" "test.o"
-                       "-std=c++11")
-               (invoke "g++" "-c" "testmain.cpp" "-o" "testmain.o"
-                       "-std=c++11")
+               (invoke "g++" "-c" "test.cpp" "-o" "test.o")
+               (invoke "g++" "-c" "testmain.cpp" "-o" "testmain.o")
                (invoke "g++" "test.o" "guid.o" "testmain.o"
                        "-o" "test" "-luuid")
                (invoke (string-append (getcwd) "/test"))))

gnu/packages/music.scm

@@ -1514,14 +1514,6 @@ (define-public amsynth
         (base32
          "1882pfcmf3rqg3vd4qflzkppcv158d748i603spqjbxqi8z7x7w0"))))
     (build-system gnu-build-system)
-    (arguments
-     `(#:phases
-       (modify-phases %standard-phases
-         (add-before 'configure 'set-flags
-           (lambda _
-             ;; Compile with C++11, required by gtkmm.
-             (setenv "CXXFLAGS" "-std=c++11")
-             #t)))))
     (inputs
      `(("alsa-lib" ,alsa-lib)
        ("jack" ,jack-1)
@@ -3569,8 +3561,7 @@ (define-public qmidiarp
     (build-system gnu-build-system)
     (arguments
      `(#:configure-flags
-       (list "--enable-qt5"
-             "CXXFLAGS=-std=gnu++11")))
+       (list "--enable-qt5")))
     (inputs
      `(("qtbase" ,qtbase)
        ("alsa-lib" ,alsa-lib)
@@ -3601,8 +3592,7 @@ (define-public qmidiroute
     (build-system gnu-build-system)
     (arguments
      `(#:configure-flags
-       (list "--enable-qt5"
-             "CXXFLAGS=-std=gnu++11")))
+       (list "--enable-qt5")))
     (inputs
      `(("qtbase" ,qtbase)
        ("alsa-lib" ,alsa-lib)))
@@ -3631,9 +3621,6 @@ (define-public seq24
                 "12dphdhnvfk1k0vmagi1v2lhyxjyj1j3cz6ksjw0ydcvid1x8ap2"))
               (patches (search-patches "seq24-rename-mutex.patch"))))
     (build-system gnu-build-system)
-    (arguments
-     `(#:configure-flags
-       (list "CXXFLAGS=-std=gnu++11")))
     (inputs
      `(("gtkmm" ,gtkmm-2)
        ("alsa-lib" ,alsa-lib)

gnu/packages/pdf.scm

@@ -200,10 +200,7 @@ (define-public python-poppler-qt5
              (substitute* "setup.py"
                ;; This check always fails, so disable it.
                (("if not check_qtxml\\(\\)")
-                "if True")
-               ;; Enable C++11, which is needed because of Qt5.
-               (("\\*\\*ext_args" line)
-                (string-append "extra_compile_args=['-std=gnu++11'], " line)))
+                "if True"))
              ;; We need to pass an extra flag here.  This cannot be in
              ;; configure-flags because it should not be passed for the
              ;; installation phase.

gnu/packages/sagemath.scm

@@ -404,11 +404,7 @@ (define-public lcalc
                   (string-append "INSTALL_DIR=" out))
                  ;; Sage renames the include directory, so we do it also.
                  (("include/Lfunction")
-                  "include/libLfunction")
-                 ;; Add --std=c++11 to be compatible with the "auto" keyword
-                 ;; introduced by lcalc-using-namespace-std.patch.
-                 (("^#EXTRA= -pg")
-                  "EXTRA=--std=c++11")))
+                  "include/libLfunction")))
              #t))
          (add-before 'install 'make-output-dirs
            (lambda* (#:key outputs #:allow-other-keys)

gnu/packages/video.scm

@@ -1180,8 +1180,7 @@ (define-public vlc
        ("xcb-util-keysyms" ,xcb-util-keysyms)))
     (arguments
      `(#:configure-flags
-       `("CXXFLAGS=-std=gnu++11"
-         "BUILDCC=gcc"
+       `("BUILDCC=gcc"
          ,(string-append "LDFLAGS=-Wl,-rpath -Wl,"
                          (assoc-ref %build-inputs "ffmpeg")
                          "/lib"))                 ;needed for the tests
@@ -2219,7 +2218,7 @@ (define-public mlt
     (build-system gnu-build-system)
     (arguments
      `(#:tests? #f                      ; no tests
-       #:make-flags '("CC=gcc" "CXX=g++ -std=gnu++11")
+       #:make-flags '("CC=gcc" "CXX=g++")
        #:configure-flags
        (list "--enable-gpl3"
              "--enable-gpl")
@@ -2278,8 +2277,7 @@ (define-public v4l-utils
      '(#:configure-flags
        (list (string-append "--with-udevdir="
                             (assoc-ref %outputs "out")
-                            "/lib/udev")
-             "CXXFLAGS=-std=gnu++11")))
+                            "/lib/udev"))))
     (native-inputs
      `(("perl" ,perl)
        ("pkg-config" ,pkg-config)))