From ec2d611c267b47b412eea0fd21dbc54d23dff095 Mon Sep 17 00:00:00 2001
From: Matthias Maennich <maennich@google.com>
Date: Mon, 7 Dec 2020 21:35:08 +0000
Subject: [PATCH] hermetic build: hermetic host tools

Use the glibc prebuilt sysroot as sysroot for all host tools. In order
to use that, also add the prebuilt kernel tools (include, lib64) to
satisfy dependencies like openssl (via boringssl).

Bug: 135570712
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I20bc005488b166b8363c17af9a602c66f7db6298
---
 _setup_env.sh       | 12 ++++++++++++
 build-tools/sysroot |  1 +
 hermetic/Dockerfile |  2 --
 3 files changed, 13 insertions(+), 2 deletions(-)
 create mode 120000 build-tools/sysroot

diff --git a/_setup_env.sh b/_setup_env.sh
index 2a61312..b1a0f66 100644
--- a/_setup_env.sh
+++ b/_setup_env.sh
@@ -108,6 +108,18 @@ if [ -n "${HERMETIC_TOOLCHAIN}" ]; then
   # (e.g. debug info)
   export KCPPFLAGS="-ffile-prefix-map=${ROOT_DIR}/="
 
+  # set the common sysroot
+  sysroot_flags+="--sysroot=${ROOT_DIR}/build/build-tools/sysroot "
+
+  # add openssl (via boringssl) and other prebuilts into the lookup path
+  cflags+="-I${ROOT_DIR}/prebuilts/kernel-build-tools/linux-x86/include "
+
+  # add openssl and further prebuilt libraries into the lookup path
+  ldflags+="-Wl,-rpath,${ROOT_DIR}/prebuilts/kernel-build-tools/linux-x86/lib64 "
+  ldflags+="-L ${ROOT_DIR}/prebuilts/kernel-build-tools/linux-x86/lib64 "
+
+  export HOSTCFLAGS="$sysroot_flags $cflags"
+  export HOSTLDFLAGS="$sysroot_flags $ldflags"
 fi
 
 for PREBUILT_BIN in "${PREBUILTS_PATHS[@]}"; do
diff --git a/build-tools/sysroot b/build-tools/sysroot
new file mode 120000
index 0000000..d0298f1
--- /dev/null
+++ b/build-tools/sysroot
@@ -0,0 +1 @@
+../../prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.17-4.8/sysroot
\ No newline at end of file
diff --git a/hermetic/Dockerfile b/hermetic/Dockerfile
index 502e6b6..70aa2f2 100644
--- a/hermetic/Dockerfile
+++ b/hermetic/Dockerfile
@@ -5,8 +5,6 @@ RUN apt-get -y update                            \
 # Those are likely essential
     git                                          \
 # To be removed
-    libc6-dev                                    \
-    libssl-dev                                   \
     rsync                                        \
 && apt-get clean                                 \
 && rm -rf /var/lib/apt/lists/*