* Fix weird behaviour with "gcc -v" due to linker flags being appended

to the gcc invocation.

  If we pass a flag like -Wl, then gcc will call the linker unless it
  can figure out that it has to do something else (e.g., because of a
  "-c" flag).  So if no non-flag arguments are given, don't pass any
  linker flags.  This catches cases like "gcc" (should just print
  "gcc: no input files") and "gcc -v" (should print the version).

svn path=/nixpkgs/trunk/; revision=8644

pkgs/build-support/gcc-wrapper-new/add-flags

@@ -0,0 +1,24 @@
+# `-B@out@/bin' forces gcc to use ld-wrapper.sh when calling ld.
+export NIX_CFLAGS_COMPILE="-B@out@/bin/ $NIX_CFLAGS_COMPILE"
+
+if test -e @out@/nix-support/libc-cflags; then
+    export NIX_CFLAGS_COMPILE="$(cat @out@/nix-support/libc-cflags) $NIX_CFLAGS_COMPILE"
+fi
+
+if test -e @out@/nix-support/libc-ldflags; then
+    export NIX_LDFLAGS="$(cat @out@/nix-support/libc-ldflags) $NIX_LDFLAGS"
+fi
+
+if test -e @out@/nix-support/gcc-cflags; then
+    export NIX_CFLAGS_COMPILE="$(cat @out@/nix-support/gcc-cflags) $NIX_CFLAGS_COMPILE"
+fi
+
+if test -e @out@/nix-support/gcc-ldflags; then
+    export NIX_LDFLAGS="$(cat @out@/nix-support/gcc-ldflags) $NIX_LDFLAGS"
+fi
+
+if test -e @out@/nix-support/libc-ldflags-before; then
+    export NIX_LDFLAGS_BEFORE="$(cat @out@/nix-support/libc-ldflags-before) $NIX_LDFLAGS_BEFORE"
+fi
+
+export NIX_GCC_WRAPPER_FLAGS_SET=1

pkgs/build-support/gcc-wrapper-new/builder.sh

@@ -0,0 +1,110 @@
+source $stdenv/setup
+
+
+ensureDir $out/bin
+ensureDir $out/nix-support
+
+
+if test -z "$nativeLibc"; then
+    dynamicLinker="$libc/lib/$dynamicLinker"
+    echo $dynamicLinker > $out/nix-support/dynamic-linker
+
+    # The "-B$libc/lib/" flag is a quick hack to force gcc to link
+    # against the crt1.o from our own glibc, rather than the one in
+    # /usr/lib.  (This is only an issue when using an `impure'
+    # compiler/linker, i.e., one that searches /usr/lib and so on.)
+    echo "-B$libc/lib/ -isystem $libc/include" > $out/nix-support/libc-cflags
+    
+    echo "-L$libc/lib" > $out/nix-support/libc-ldflags
+
+    # The dynamic linker is passed in `ldflagsBefore' to allow
+    # explicit overrides of the dynamic linker by callers to gcc/ld
+    # (the *last* value counts, so ours should come first).
+    echo "-dynamic-linker $dynamicLinker" > $out/nix-support/libc-ldflags-before
+fi
+
+if test -n "$nativeTools"; then
+    gccPath="$nativePrefix/bin"
+    ldPath="$nativePrefix/bin"
+else
+    if test -e "$gcc/lib64"; then
+        gccLDFlags="$gccLDFlags -L$gcc/lib64"
+    fi
+    gccLDFlags="$gccLDFlags -L$gcc/lib"
+    echo "$gccLDFlags" > $out/nix-support/gcc-ldflags
+
+    # GCC shows $gcc/lib in `gcc -print-search-dirs', but not
+    # $gcc/lib64 (even though it does actually search there...)..
+    # This confuses libtool.  So add it to the compiler tool search
+    # path explicitly.
+    if test -e "$gcc/lib64"; then
+        gccCFlags="$gccCFlags -B$gcc/lib64"
+    fi
+    echo "$gccCFlags" > $out/nix-support/gcc-cflags
+    
+    gccPath="$gcc/bin"
+    ldPath="$binutils/bin"
+fi
+
+
+doSubstitute() {
+    local src=$1
+    local dst=$2
+    substitute "$src" "$dst" \
+        --subst-var "out" \
+        --subst-var "shell" \
+        --subst-var "gcc" \
+        --subst-var "gccProg" \
+        --subst-var "binutils" \
+        --subst-var "libc" \
+        --subst-var-by "ld" "$ldPath/ld"
+}
+
+
+# Make wrapper scripts around gcc, g++, and g77.  Also make symlinks
+# cc, c++, and f77.
+mkGccWrapper() {
+    local dst=$1
+    local src=$2
+
+    if ! test -f "$src"; then
+        echo "$src does not exist (skipping)"
+        return
+    fi
+
+    gccProg="$src"
+    doSubstitute "$gccWrapper" "$dst"
+    chmod +x "$dst"
+}
+
+mkGccWrapper $out/bin/gcc $gccPath/gcc
+ln -s gcc $out/bin/cc
+
+mkGccWrapper $out/bin/g++ $gccPath/g++
+ln -s g++ $out/bin/c++
+
+mkGccWrapper $out/bin/g77 $gccPath/g77
+ln -s g77 $out/bin/f77
+
+
+# Create a symlink to as (the assembler).  This is useful when a
+# gcc-wrapper is installed in a user environment, as it ensures that
+# the right assembler is called.
+ln -s $ldPath/as $out/bin/as
+
+
+# Make a wrapper around the linker.
+doSubstitute "$ldWrapper" "$out/bin/ld"
+chmod +x "$out/bin/ld"
+
+
+# Emit a setup hook.  Also store the path to the original GCC and
+# Glibc.
+test -n "$gcc" && echo $gcc > $out/nix-support/orig-gcc
+test -n "$libc" && echo $libc > $out/nix-support/orig-libc
+
+doSubstitute "$addFlags" "$out/nix-support/add-flags.sh"
+
+doSubstitute "$setupHook" "$out/nix-support/setup-hook"
+
+cp -p $utils $out/nix-support/utils.sh

pkgs/build-support/gcc-wrapper-new/default.nix

@@ -0,0 +1,41 @@
+# The Nix `gcc' stdenv.mkDerivation is not directly usable, since it doesn't
+# know where the C library and standard header files are.  Therefore
+# the compiler produced by that package cannot be installed directly
+# in a user environment and used from the command line.  This
+# stdenv.mkDerivation provides a wrapper that sets up the right environment
+# variables so that the compiler and the linker just "work".
+
+{ name ? "", stdenv, nativeTools, nativeLibc, nativePrefix ? ""
+, gcc ? null, libc ? null, binutils ? null, shell ? ""
+}:
+
+assert nativeTools -> nativePrefix != "";
+assert !nativeTools -> gcc != null && binutils != null;
+assert !nativeLibc -> libc != null;
+
+stdenv.mkDerivation {
+  builder = ./builder.sh;
+  setupHook = ./setup-hook.sh;
+  gccWrapper = ./gcc-wrapper.sh;
+  ldWrapper = ./ld-wrapper.sh;
+  utils = ./utils.sh;
+  addFlags = ./add-flags;
+  inherit nativeTools nativeLibc nativePrefix gcc libc binutils;
+  name = if name == "" then gcc.name else name;
+  langC = if nativeTools then true else gcc.langC;
+  langCC = if nativeTools then true else gcc.langCC;
+  langF77 = if nativeTools then false else gcc.langF77;
+  shell = if shell == "" then stdenv.shell else shell;
+  meta = if gcc != null && (gcc ? meta) then gcc.meta else
+    { description = "System C compiler wrapper";
+    };
+
+  # The dynamic linker has different names on different Linux platforms.
+  dynamicLinker =
+    if !nativeLibc then
+      (if stdenv.system == "i686-linux" then "ld-linux.so.2" else
+       if stdenv.system == "x86_64-linux" then "ld-linux-x86-64.so.2" else
+       if stdenv.system == "powerpc-linux" then "ld.so.1" else
+       abort "don't know the name of the dynamic linker for this platform")
+    else "";
+}

pkgs/build-support/gcc-wrapper-new/gcc-wrapper.sh

@@ -0,0 +1,144 @@
+#! @shell@ -e
+
+if test -n "$NIX_GCC_WRAPPER_START_HOOK"; then
+    source "$NIX_GCC_WRAPPER_START_HOOK"
+fi
+
+if test -z "$NIX_GCC_WRAPPER_FLAGS_SET"; then
+    source @out@/nix-support/add-flags.sh
+fi
+
+source @out@/nix-support/utils.sh
+
+
+# Figure out if linker flags should be passed.  GCC prints annoying
+# warnings when they are not needed.
+dontLink=0
+getVersion=0
+nonFlagArgs=0
+
+for i in "$@"; do
+    if test "$i" = "-c"; then
+        dontLink=1
+    elif test "$i" = "-S"; then
+        dontLink=1
+    elif test "$i" = "-E"; then
+        dontLink=1
+    elif test "$i" = "-E"; then
+        dontLink=1
+    elif test "$i" = "-M"; then
+        dontLink=1
+    elif test "$i" = "-MM"; then
+        dontLink=1
+    elif test "${i:0:1}" != "-"; then
+        nonFlagArgs=1
+    fi
+done
+
+# If we pass a flag like -Wl, then gcc will call the linker unless it
+# can figure out that it has to do something else (e.g., because of a
+# "-c" flag).  So if no non-flag arguments are given, don't pass any
+# linker flags.  This catches cases like "gcc" (should just print
+# "gcc: no input files") and "gcc -v" (should print the version).
+if test "$nonFlagArgs" = "0"; then
+    dontLink=1
+fi
+
+
+# Optionally filter out paths not refering to the store.
+params=("$@")
+if test "$NIX_ENFORCE_PURITY" = "1" -a -n "$NIX_STORE"; then
+    rest=()
+    n=0
+    while test $n -lt ${#params[*]}; do
+        p=${params[n]}
+        p2=${params[$((n+1))]}
+        if test "${p:0:3}" = "-L/" && badPath "${p:2}"; then
+            skip $p
+        elif test "$p" = "-L" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "${p:0:3}" = "-I/" && badPath "${p:2}"; then
+            skip $p
+        elif test "$p" = "-I" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "$p" = "-isystem" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        else
+            rest=("${rest[@]}" "$p")
+        fi
+        n=$((n + 1))
+    done
+    params=("${rest[@]}")
+fi
+
+
+# Add the flags for the C compiler proper.
+extraAfter=($NIX_CFLAGS_COMPILE)
+extraBefore=()
+
+if test "$dontLink" != "1"; then
+
+    # Add the flags that should only be passed to the compiler when
+    # linking.
+    extraAfter=(${extraAfter[@]} $NIX_CFLAGS_LINK)
+
+    # Add the flags that should be passed to the linker (and prevent
+    # `ld-wrapper' from adding NIX_LDFLAGS again).
+    for i in $NIX_LDFLAGS_BEFORE; do
+        extraBefore=(${extraBefore[@]} "-Wl,$i")
+    done
+    for i in $NIX_LDFLAGS; do
+	if test "${i:0:3}" = "-L/"; then
+	    extraAfter=(${extraAfter[@]} "$i")
+	else
+	    extraAfter=(${extraAfter[@]} "-Wl,$i")
+	fi
+    done
+    export NIX_LDFLAGS_SET=1
+
+    if test "$NIX_STRIP_DEBUG" = "1"; then
+        # Add executable-stripping flags.
+        extraAfter=(${extraAfter[@]} $NIX_CFLAGS_STRIP)
+    fi
+fi
+
+# As a very special hack, if the arguments are just `-v', then don't
+# add anything.  This is to prevent `gcc -v' (which normally prints
+# out the version number and returns exit code 0) from printing out
+# `No input files specified' and returning exit code 1.
+if test "$*" = "-v"; then
+    extraAfter=()
+    extraBefore=()
+fi    
+
+# Optionally print debug info.
+if test "$NIX_DEBUG" = "1"; then
+  echo "original flags to @gccProg@:" >&2
+  for i in "${params[@]}"; do
+      echo "  $i" >&2
+  done
+  echo "extraBefore flags to @gccProg@:" >&2
+  for i in ${extraBefore[@]}; do
+      echo "  $i" >&2
+  done
+  echo "extraAfter flags to @gccProg@:" >&2
+  for i in ${extraAfter[@]}; do
+      echo "  $i" >&2
+  done
+fi
+
+if test -n "$NIX_GCC_WRAPPER_EXEC_HOOK"; then
+    source "$NIX_GCC_WRAPPER_EXEC_HOOK"
+fi
+
+
+# Call the real `gcc'.  Filter out warnings from stderr about unused
+# `-B' flags, since they confuse some programs.  Deep bash magic to
+# apply grep to stderr (by swapping stdin/stderr twice).
+if test -z "$NIX_GCC_NEEDS_GREP"; then
+    @gccProg@ ${extraBefore[@]} "${params[@]}" ${extraAfter[@]}
+else
+    (@gccProg@ ${extraBefore[@]} "${params[@]}" ${extraAfter[@]} 3>&2 2>&1 1>&3- \
+        | (grep -v 'file path prefix' || true); exit ${PIPESTATUS[0]}) 3>&2 2>&1 1>&3-
+    exit $?
+fi    

pkgs/build-support/gcc-wrapper-new/ld-wrapper.sh

@@ -0,0 +1,145 @@
+#! @shell@ -e
+
+if test -n "$NIX_LD_WRAPPER_START_HOOK"; then
+    source "$NIX_LD_WRAPPER_START_HOOK"
+fi
+
+if test -z "$NIX_GCC_WRAPPER_FLAGS_SET"; then
+    source @out@/nix-support/add-flags.sh
+fi
+
+source @out@/nix-support/utils.sh
+
+
+# Optionally filter out paths not refering to the store.
+params=("$@")
+if test "$NIX_ENFORCE_PURITY" = "1" -a -n "$NIX_STORE" \
+        -a \( -z "$NIX_IGNORE_LD_THROUGH_GCC" -o -z "$NIX_LDFLAGS_SET" \); then
+    rest=()
+    n=0
+    while test $n -lt ${#params[*]}; do
+        p=${params[n]}
+        p2=${params[$((n+1))]}
+        if test "${p:0:3}" = "-L/" && badPath "${p:2}"; then
+            skip $p
+        elif test "$p" = "-L" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "$p" = "-rpath" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "$p" = "-dynamic-linker" && badPath "$p2"; then
+            n=$((n + 1)); skip $p2
+        elif test "${p:0:1}" = "/" && badPath "$p"; then
+            # We cannot skip this; barf.
+            echo "impure path \`$p' used in link" >&2
+            exit 1
+        else
+            rest=("${rest[@]}" "$p")
+        fi
+        n=$((n + 1))
+    done
+    params=("${rest[@]}")
+fi
+
+
+extra=()
+extraBefore=()
+
+if test -z "$NIX_LDFLAGS_SET"; then
+    extra=(${extra[@]} $NIX_LDFLAGS)
+    extraBefore=(${extraBefore[@]} $NIX_LDFLAGS_BEFORE)
+fi
+
+
+# Add all used dynamic libraries to the rpath.
+if test "$NIX_DONT_SET_RPATH" != "1"; then
+
+    # First, find all -L... switches.
+    allParams=("${params[@]}" ${extra[@]})
+    libPath=""
+    addToLibPath() {
+        local path="$1"
+        if test "${path:0:1}" != "/"; then return 0; fi
+        case "$path" in
+            *..*|*./*|*/.*|*//*)
+                local path2
+                if path2=$(readlink -f "$path"); then
+                    path="$path2"
+                fi
+                ;;
+        esac
+        case $libPath in
+            *\ $path\ *) return 0 ;;
+        esac
+        libPath="$libPath $path "
+    }
+    n=0
+    while test $n -lt ${#allParams[*]}; do
+        p=${allParams[n]}
+        p2=${allParams[$((n+1))]}
+        if test "${p:0:3}" = "-L/"; then
+            addToLibPath ${p:2}
+        elif test "$p" = "-L"; then
+            addToLibPath ${p2}
+            n=$((n + 1))
+        fi
+        n=$((n + 1))
+    done
+
+    # Second, for each -l... switch, find the directory containing the
+    # library and add it to the rpath.
+    rpath=""
+    addToRPath() {
+        # If the path is not in the store, don't add it to the rpath.
+        # This typically happens for libraries in /tmp that are later
+        # copied to $out/lib.  If not, we're screwed.
+        if test "${1:0:${#NIX_STORE}}" != "$NIX_STORE"; then return 0; fi
+        case $rpath in
+            *\ $1\ *) return 0 ;;
+        esac
+        rpath="$rpath $1 "
+    }
+    findLib() {
+        for i in $libPath; do
+            if test -f $i/lib$1.so; then
+                addToRPath $i
+            fi
+        done
+    }
+    n=0
+    while test $n -lt ${#allParams[*]}; do
+        p=${allParams[n]}
+        p2=${allParams[$((n+1))]}
+        if test "${p:0:2}" = "-l"; then
+            findLib ${p:2}
+        elif test "$p" = "-l"; then
+            # I haven't seen `-l foo', but you never know...
+            findLib ${p2}
+            n=$((n + 1))
+        fi
+        n=$((n + 1))
+    done
+
+    # Finally, add `-rpath' switches.
+    for i in $rpath; do
+        extra=(${extra[@]} -rpath $i)
+    done
+fi
+
+
+# Optionally print debug info.
+if test "$NIX_DEBUG" = "1"; then
+  echo "original flags to @ld@:" >&2
+  for i in "${params[@]}"; do
+      echo "  $i" >&2
+  done
+  echo "extra flags to @ld@:" >&2
+  for i in ${extra[@]}; do
+      echo "  $i" >&2
+  done
+fi
+
+if test -n "$NIX_LD_WRAPPER_EXEC_HOOK"; then
+    source "$NIX_LD_WRAPPER_EXEC_HOOK"
+fi
+
+exec @ld@ ${extraBefore[@]} "${params[@]}" ${extra[@]}

pkgs/build-support/gcc-wrapper-new/setup-hook.sh

@@ -0,0 +1,29 @@
+addCVars () {
+    if test -d $1/include; then
+        export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -I$1/include"
+    fi
+
+    if test -d $1/lib64; then
+        export NIX_LDFLAGS="$NIX_LDFLAGS -L$1/lib64"
+    fi
+
+    if test -d $1/lib; then
+        export NIX_LDFLAGS="$NIX_LDFLAGS -L$1/lib"
+    fi
+}
+
+envHooks=(${envHooks[@]} addCVars)
+
+# Note: these come *after* $out in the PATH (see setup.sh).
+
+if test -n "@gcc@"; then
+    PATH=$PATH:@gcc@/bin
+fi
+
+if test -n "@binutils@"; then
+    PATH=$PATH:@binutils@/bin
+fi
+
+if test -n "@libc@"; then
+    PATH=$PATH:@libc@/bin
+fi

pkgs/build-support/gcc-wrapper-new/utils.sh

@@ -0,0 +1,23 @@
+skip () {
+    if test "$NIX_DEBUG" = "1"; then
+        echo "skipping impure path $1" >&2
+    fi
+}
+
+
+# Checks whether a path is impure.  E.g., `/lib/foo.so' is impure, but
+# `/nix/store/.../lib/foo.so' isn't.
+badPath() {
+    local p=$1
+    
+    # Relative paths are okay (since they're presumably relative to
+    # the temporary build directory).
+    if test "${p:0:1}" != "/"; then return 1; fi
+    
+    # Otherwise, the path should refer to the store or some temporary
+    # directory (including the build directory).
+    test \
+        "${p:0:${#NIX_STORE}}" != "$NIX_STORE" -a \
+        "${p:0:4}" != "/tmp" -a \
+        "${p:0:${#NIX_BUILD_TOP}}" != "$NIX_BUILD_TOP"
+}

pkgs/top-level/all-packages.nix

@@ -669,10 +669,14 @@ rec {
     profiledCompiler = true;
   });
 
-  gcc41 = useFromStdenv (stdenv ? gcc) stdenv.gcc (wrapGCC (import ../development/compilers/gcc-4.1 {
+  gcc41 = lowPrio (useFromStdenv (stdenv ? gcc) stdenv.gcc (wrapGCC (import ../development/compilers/gcc-4.1 {
     inherit fetchurl stdenv noSysDirs;
     profiledCompiler = false;
-  }));
+  })));
+
+  # !!! GCC with the new wrapper.  Should be removed eventually (and
+  # then the lowPrio on gcc41 should go, of course).
+  gccNew = wrapGCCNew (gcc.gcc);
 
   gccApple = wrapGCC (import ../development/compilers/gcc-apple {
     inherit fetchurl stdenv noSysDirs;
@@ -842,6 +846,14 @@ rec {
     inherit stdenv binutils;
   };
 
+  wrapGCCNew = baseGCC: import ../build-support/gcc-wrapper-new {
+    nativeTools = false;
+    nativeLibc = false;
+    gcc = baseGCC;
+    libc = glibc;
+    inherit stdenv binutils;
+  };
+
 
   ### DEVELOPMENT / INTERPRETERS