Merge branch 'bergkvist/make-c-wrapper' into make-c-wrapper

doc/stdenv/stdenv.chapter.md

@@ -796,7 +796,7 @@ A setup-hook very similar to `makeWrapper`, only it creates a tiny _compiled_ wr
 
 Compiled wrappers generated by `makeBinaryWrapper` can be inspected with `less <path-to-wrapper>` - by scrolling past the binary data you should be able to see the C code that generated the executable and there see the environment variables that were injected into the wrapper.
 
-Similarly to `wrapProgram`, the `makeBinaryWrapper` setup-hook provides a `wrapProgramBinary` with similar command line arguments.
+Similarly to `wrapProgram`, the `makeBinaryWrapper` setup-hook provides a `binaryWrapProgram` with similar command line arguments.
 
 ### `substitute` \<infile\> \<outfile\> \<subs\> {#fun-substitute}
 
@@ -875,7 +875,7 @@ Convenience function for `makeWrapper` that replaces `<\executable\>` with a wra
 
 If you will apply it multiple times, it will overwrite the wrapper file and you will end up with double wrapping, which should be avoided.
 
-### `wrapProgramBinary` \<executable\> \<makeBinaryWrapperArgs\> {#fun-wrapProgramBinary}
+### `binaryWrapProgram` \<executable\> \<makeBinaryWrapperArgs\> {#fun-binaryWrapProgram}
 
 Convenience function for `makeBinaryWrapper` that replaces `<\executable\>` with a wrapper that executes the original program. It takes all the same arguments as `makeBinaryWrapper`, except for `--argv0`.
 

pkgs/build-support/setup-hooks/make-binary-wrapper.sh

@@ -51,14 +51,14 @@ wrapProgram() {
     makeWrapper "$hidden" "$prog" --inherit-argv0 "${@:2}"
 }
 
-# Generate source code for the wrapper in such a way that the wrapper source code
+# Generate source code for the wrapper in such a way that the wrapper inputs
 # will still be readable even after compilation
 # makeDocumentedCWrapper EXECUTABLE ARGS
 # ARGS: same as makeWrapper
 makeDocumentedCWrapper() {
     local src docs
     src=$(makeCWrapper "$@")
-    docs=$(documentationString "$src")
+    docs=$(docstring "$@")
     printf '%s\n\n' "$src"
     printf '%s\n' "$docs"
 }
@@ -66,7 +66,7 @@ makeDocumentedCWrapper() {
 # makeCWrapper EXECUTABLE ARGS
 # ARGS: same as makeWrapper
 makeCWrapper() {
-    local argv0 inherit_argv0 n params cmd main flagsBefore flags executable params length
+    local argv0 inherit_argv0 n params cmd main flagsBefore flags executable length
     local uses_prefix uses_suffix uses_assert uses_assert_success uses_stdio uses_asprintf
     executable=$(escapeStringLiteral "$1")
     params=("$@")
@@ -150,8 +150,8 @@ makeCWrapper() {
     done
     # shellcheck disable=SC2086
     [ -z "$flagsBefore" ] || main="$main"${main:+$'\n'}$(addFlags $flagsBefore)$'\n'$'\n'
-    [ -z "$inherit_argv0" ] && main="$main    argv[0] = \"${argv0:-${executable}}\";"$'\n'
+    [ -z "$inherit_argv0" ] && main="${main}argv[0] = \"${argv0:-${executable}}\";"$'\n'
-    main="$main    return execv(\"${executable}\", argv);"$'\n'
+    main="${main}return execv(\"${executable}\", argv);"$'\n'
 
     [ -z "$uses_asprintf" ] || printf '%s\n' "#define _GNU_SOURCE         /* See feature_test_macros(7) */"
     printf '%s\n' "#include <unistd.h>"
@@ -162,8 +162,8 @@ makeCWrapper() {
     [ -z "$uses_prefix" ] || printf '\n%s\n' "$(setEnvPrefixFn)"
     [ -z "$uses_suffix" ] || printf '\n%s\n' "$(setEnvSuffixFn)"
     printf '\n%s' "int main(int argc, char **argv) {"
-    printf '\n%s' "$main"
+    printf '\n%s' "$(indent4 "$main")"
-    printf '%s\n' "}"
+    printf '\n%s\n' "}"
 }
 
 addFlags() {
@@ -238,14 +238,6 @@ unsetEnv() {
     assertValidEnvName "$1"
 }
 
-# Put the entire source code into const char* SOURCE_CODE to make it readable after compilation.
-# documentationString SOURCE_CODE
-documentationString() {
-    local docs
-    docs=$(escapeStringLiteral $'\n----------\n// This binary wrapper was compiled from the following generated C-code:\n'"$1"$'\n----------\n')
-    printf '%s' "const char * SOURCE_CODE = \"$docs\";"
-}
-
 # Makes it safe to insert STRING within quotes in a C String Literal.
 # escapeStringLiteral STRING
 escapeStringLiteral() {
@@ -257,6 +249,12 @@ escapeStringLiteral() {
     printf '%s' "$result"
 }
 
+# Indents every non-empty line by 4 spaces. To avoid trailing whitespace, we don't indent empty lines
+# indent4 TEXT_BLOCK
+indent4() {
+    printf '%s' "$1" | awk '{ if ($0 != "") { print "    "$0 } else { print $0 }}'
+}
+
 assertValidEnvName() {
     case "$1" in
         *=*) printf '\n%s\n' "#error Illegal environment variable name \`$1\` (cannot contain \`=\`)";;
@@ -295,3 +293,84 @@ void set_env_suffix(char *env, char *sep, char *suffix) {
 }
 "
 }
+
+# Embed a C string which shows up as readable text in the compiled binary wrapper
+# documentationString ARGS
+docstring() {
+    printf '%s' "const char * DOCSTRING = \"$(escapeStringLiteral "
+
+
+# ------------------------------------------------------------------------------------
+# The C-code for this binary wrapper has been generated using the following command:
+
+
+makeCWrapper $(formatArgs "$@")
+
+
+# (Use \`nix-shell -p makeBinaryWrapper\` to get access to makeCWrapper in your shell)
+# ------------------------------------------------------------------------------------
+
+
+")\";"
+}
+
+# formatArgs EXECUTABLE ARGS
+formatArgs() {
+    printf '%s' "$1"
+    shift
+    while [ $# -gt 0 ]; do
+        case "$1" in
+            --set)
+                formatArgsLine 2 "$@"
+                shift 2
+            ;;
+            --set-default)
+                formatArgsLine 2 "$@"
+                shift 2
+            ;;
+            --unset)
+                formatArgsLine 1 "$@"
+                shift 1
+            ;;
+            --prefix)
+                formatArgsLine 3 "$@"
+                shift 3
+            ;;
+            --suffix)
+                formatArgsLine 3 "$@"
+                shift 3
+            ;;
+            --chdir)
+                formatArgsLine 1 "$@"
+                shift 1
+            ;;
+            --add-flags)
+                formatArgsLine 1 "$@"
+                shift 1
+            ;;
+            --argv0)
+                formatArgsLine 1 "$@"
+                shift 1
+            ;;
+            --inherit-argv0)
+                formatArgsLine 0 "$@"
+            ;;
+        esac
+        shift
+    done
+    printf '%s\n' ""
+}
+
+# formatArgsLine ARG_COUNT ARGS
+formatArgsLine() {
+    local ARG_COUNT LENGTH
+    ARG_COUNT=$1
+    LENGTH=$#
+    shift
+    printf '%s' $' \\\n    '"$1"
+    shift
+    while [ "$ARG_COUNT" -gt $((LENGTH - $# - 2)) ]; do
+        printf ' %s' "${1@Q}"
+        shift
+    done
+}