Revert "Merge pull request #28029 from cstrahan/hardening-fix"

This reverts commit 0dbc0067604eb9629d1458fcf2b226a88e728f14, reversing
changes made to cb7f7742652acdf3086b3d132163b5ea2c2328eb.

Should go into staging.

4 files changed, 59 insertions, 68 deletions

diff --git a/pkgs/build-support/cc-wrapper/add-flags.sh b/pkgs/build-support/cc-wrapper/add-flags.sh
index e384d30ecbb6..604aaf6b6cf0 100644
--- a/pkgs/build-support/cc-wrapper/add-flags.sh
+++ b/pkgs/build-support/cc-wrapper/add-flags.sh
@@ -30,10 +30,10 @@ fi
 # We need to mangle names for hygiene, but also take parameters/overrides
 # from the environment.
 for var in "${var_templates_list[@]}"; do
-    mangleVarList "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarList "$var" "${role_infixes[@]}"
 done
 for var in "${var_templates_bool[@]}"; do
-    mangleVarBool "$var" ${role_infixes[@]+"${role_infixes[@]}"}
+    mangleVarBool "$var" "${role_infixes[@]}"
 done
 
 # `-B@out@/bin' forces cc to use ld-wrapper.sh when calling ld.
diff --git a/pkgs/build-support/cc-wrapper/add-hardening.sh b/pkgs/build-support/cc-wrapper/add-hardening.sh
index 026e48671447..a35ff3cb4260 100644
--- a/pkgs/build-support/cc-wrapper/add-hardening.sh
+++ b/pkgs/build-support/cc-wrapper/add-hardening.sh
@@ -1,72 +1,67 @@
-declare -a hardeningCFlags=()
-
-declare -A hardeningEnableMap=()
+hardeningFlags=(fortify stackprotector pic strictoverflow format relro bindnow)
+# Intentionally word-split in case 'hardeningEnable' is defined in
+# Nix. Also, our bootstrap tools version of bash is old enough that
+# undefined arrays trip `set -u`.
+if [[ -v hardeningEnable[@] ]]; then
+  hardeningFlags+=(${hardeningEnable[@]})
+fi
+hardeningCFlags=()
 
-# Intentionally word-split in case 'NIX_HARDENING_ENABLE' is defined in Nix. The
-# array expansion also prevents undefined variables from causing trouble with
-# `set -u`.
-for flag in ${NIX_@infixSalt@_HARDENING_ENABLE-}; do
-  hardeningEnableMap["$flag"]=1
-done
+declare -A hardeningDisableMap
 
-# Remove unsupported flags.
-for flag in @hardening_unsupported_flags@; do
-  unset -v hardeningEnableMap["$flag"]
+# Intentionally word-split in case 'hardeningDisable' is defined in Nix.
+for flag in ${hardeningDisable[@]:-IGNORED_KEY} @hardening_unsupported_flags@
+do
+  hardeningDisableMap[$flag]=1
 done
 
 if (( "${NIX_DEBUG:-0}" >= 1 )); then
-  declare -a allHardeningFlags=(fortify stackprotector pie pic strictoverflow format)
-  declare -A hardeningDisableMap=()
-
-  # Determine which flags were effectively disabled so we can report below.
-  for flag in "${allHardeningFlags[@]}"; do
-    if [[ -z "${hardeningEnableMap[$flag]-}" ]]; then
-      hardeningDisableMap["$flag"]=1
-    fi
-  done
-
   printf 'HARDENING: disabled flags:' >&2
   (( "${#hardeningDisableMap[@]}" )) && printf ' %q' "${!hardeningDisableMap[@]}" >&2
   echo >&2
+fi
 
-  if (( "${#hardeningEnableMap[@]}" )); then
+if [[ -z "${hardeningDisableMap[all]:-}" ]]; then
+  if (( "${NIX_DEBUG:-0}" >= 1 )); then
     echo 'HARDENING: Is active (not completely disabled with "all" flag)' >&2;
   fi
+  for flag in "${hardeningFlags[@]}"
+  do
+    if [[ -z "${hardeningDisableMap[$flag]:-}" ]]; then
+      case $flag in
+        fortify)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling fortify >&2; fi
+          hardeningCFlags+=('-O2' '-D_FORTIFY_SOURCE=2')
+          ;;
+        stackprotector)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling stackprotector >&2; fi
+          hardeningCFlags+=('-fstack-protector-strong' '--param' 'ssp-buffer-size=4')
+          ;;
+        pie)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling CFlags -fPIE >&2; fi
+          hardeningCFlags+=('-fPIE')
+          if [[ ! ("$*" =~ " -shared " || "$*" =~ " -static ") ]]; then
+            if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling LDFlags -pie >&2; fi
+            hardeningCFlags+=('-pie')
+          fi
+          ;;
+        pic)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling pic >&2; fi
+          hardeningCFlags+=('-fPIC')
+          ;;
+        strictoverflow)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling strictoverflow >&2; fi
+          hardeningCFlags+=('-fno-strict-overflow')
+          ;;
+        format)
+          if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling format >&2; fi
+          hardeningCFlags+=('-Wformat' '-Wformat-security' '-Werror=format-security')
+          ;;
+        *)
+          # Ignore unsupported. Checked in Nix that at least *some*
+          # tool supports each flag.
+          ;;
+      esac
+    fi
+  done
 fi
-
-for flag in "${!hardeningEnableMap[@]}"; do
-  case $flag in
-    fortify)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling fortify >&2; fi
-      hardeningCFlags+=('-O2' '-D_FORTIFY_SOURCE=2')
-      ;;
-    stackprotector)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling stackprotector >&2; fi
-      hardeningCFlags+=('-fstack-protector-strong' '--param' 'ssp-buffer-size=4')
-      ;;
-    pie)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling CFlags -fPIE >&2; fi
-      hardeningCFlags+=('-fPIE')
-      if [[ ! ("$*" =~ " -shared " || "$*" =~ " -static ") ]]; then
-        if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling LDFlags -pie >&2; fi
-        hardeningCFlags+=('-pie')
-      fi
-      ;;
-    pic)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling pic >&2; fi
-      hardeningCFlags+=('-fPIC')
-      ;;
-    strictoverflow)
-       if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling strictoverflow >&2; fi
-      hardeningCFlags+=('-fno-strict-overflow')
-      ;;
-    format)
-      if (( "${NIX_DEBUG:-0}" >= 1 )); then echo HARDENING: enabling format >&2; fi
-      hardeningCFlags+=('-Wformat' '-Wformat-security' '-Werror=format-security')
-      ;;
-    *)
-      # Ignore unsupported. Checked in Nix that at least *some*
-      # tool supports each flag.
-      ;;
-  esac
-done
diff --git a/pkgs/build-support/cc-wrapper/cc-wrapper.sh b/pkgs/build-support/cc-wrapper/cc-wrapper.sh
index 8a3cfb694b4f..c2e6c1406358 100644
--- a/pkgs/build-support/cc-wrapper/cc-wrapper.sh
+++ b/pkgs/build-support/cc-wrapper/cc-wrapper.sh
@@ -134,8 +134,8 @@ fi
 source @out@/nix-support/add-hardening.sh
 
 # Add the flags for the C compiler proper.
-extraAfter=($NIX_@infixSalt@_CFLAGS_COMPILE)
-extraBefore=(${hardeningCFlags[@]+"${hardeningCFlags[@]}"})
+extraAfter=($NIX_@infixSalt@_CFLAGS_COMPILE "${hardeningCFlags[@]}")
+extraBefore=()
 
 if [ "$dontLink" != 1 ]; then
 
diff --git a/pkgs/build-support/cc-wrapper/setup-hook.sh b/pkgs/build-support/cc-wrapper/setup-hook.sh
index 15b84dca2794..29a7306b9b7e 100644
--- a/pkgs/build-support/cc-wrapper/setup-hook.sh
+++ b/pkgs/build-support/cc-wrapper/setup-hook.sh
@@ -147,10 +147,6 @@ export ${role_pre}CXX=@named_cxx@
 export CC${role_post}=@named_cc@
 export CXX${role_post}=@named_cxx@
 
-# If unset, assume the default hardening flags.
-: ${NIX_HARDENING_ENABLE="fortify stackprotector pic strictoverflow format relro bindnow"}
-export NIX_HARDENING_ENABLE
-
 # No local scope in sourced file
 unset -v role_pre role_post
 set +u