Compiler-quietening

[users/jgh/exim.git] / src / scripts / reversion

diff --git a/src/scripts/reversion b/src/scripts/reversion
index c4618868ec52e4026c6c21422d8968a9752d7696..00fc028b57df1432170740e4c59a3c17744bf887 100755 (executable)
--- a/src/scripts/reversion
+++ b/src/scripts/reversion
@@ -1,4 +1,9 @@
 #!/bin/sh
+# Copyright (c) The Exim Maintainers 2017
+
+set -e
+LC_ALL=C
+export LC_ALL
 
 # Update Exim's version header file.
 
@@ -32,13 +37,18 @@ fi
 
 # If this tree is a git working directory, use that to get version information.
 
-if [ -d ../../.git ] || [ "$1" = "release" ]
+if [ -d ../../.git ] || [ -f ../../.git ] || [ "$1" = "release" ]
 then
        # Modify the output of git describe into separate parts for
        # the name "exim" and the release and variant versions.
        # Put a dot in the version number and remove a spurious g.
-       set $(git describe --dirty=-XX --match 'exim-4*' |
-               sed 's|-| |;s|_|.|;s|[-_]| _|;s|-g|-|')
+       if [ "$2" ]
+       then
+           description=$(git describe "$2")
+       else
+           description=$(git describe --dirty=-XX --match 'exim-4*')
+       fi
+       set $(echo "$description" | sed 's|-| |;s|_|.|;s|[-_]| _|;s|-g|-|')
        # Only update if we need to
        if [ "$2 $3" != "$EXIM_RELEASE_VERSION $EXIM_VARIANT_VERSION" ]
        then
@@ -61,10 +71,41 @@ EXIM_COMPILE_NUMBER=$(expr "${EXIM_COMPILE_NUMBER:-0}" + 1)
 
 echo "$EXIM_COMPILE_NUMBER" >cnumber.h
 
+# Reproducible builds, accept a build timestamp override from environ per
+# <https://reproducible-builds.org/specs/source-date-epoch/>.
+# We require a fairly modern date(1) command here, which is not portable
+# to some of the systems Exim is built on.  That's okay, because the scenarios
+# are:
+#  1) Local postmaster building, not using $SOURCE_DATE_EPOCH, doesn't matter
+#  2) Packaging folks who don't care about reproducible builds
+#  3) Packaging folks who care but are using systems where date Just Works
+#  3) Packaging folks who care and can put a modern date(1) in $PATH
+#  4) Packaging folks who care and can supply us with a clean patch to support
+#     their requirements
+#  5) Packaging folks who care but won't do any work to support their strange
+#     old systems and want us to do the work for them.  We don't care either,
+#     they're SOL and have to live without reproducible builds.
+#
+exim_build_date_override=''
+if [ ".${SOURCE_DATE_EPOCH:-}" != "." ]; then
+  fmt='+%d-%b-%Y %H:%M:%S'
+  # Non-reproducible, we use __DATE__ and __TIME__ in C, which respect timezone
+  # (think localtime, not gmtime); for reproduction between systems, UTC makes
+  # more sense and the examples available use UTC without explicitly mandating
+  # it.  I think that we can switch behavior and use UTC for reproducible
+  # builds without it causing any problems: nothing really cares about timezone.
+  # GNU date: "date -d @TS"
+  # BSD date: "date -r TS"
+  exim_build_date_override="$(date -u -d "@${SOURCE_DATE_EPOCH}" "$fmt" 2>/dev/null || date -u -r "${SOURCE_DATE_EPOCH}" "$fmt" 2>/dev/null)"
+fi
+
 ( echo '# automatically generated file - see ../scripts/reversion'
   echo EXIM_RELEASE_VERSION='"'"$EXIM_RELEASE_VERSION"'"'
   echo EXIM_VARIANT_VERSION='"'"$EXIM_VARIANT_VERSION"'"'
   echo EXIM_COMPILE_NUMBER='"'"$EXIM_COMPILE_NUMBER"'"'
+  if [ ".${exim_build_date_override:-}" != "." ]; then
+    echo EXIM_BUILD_DATE_OVERRIDE='"'"${exim_build_date_override}"'"'
+  fi
 ) >version.sh
 
 if [ ! -f version.h ]
@@ -73,6 +114,9 @@ then
   echo '#define EXIM_RELEASE_VERSION "'"$EXIM_RELEASE_VERSION"'"'
   echo '#define EXIM_VARIANT_VERSION "'"$EXIM_VARIANT_VERSION"'"'
   echo '#define EXIM_VERSION_STR EXIM_RELEASE_VERSION EXIM_VARIANT_VERSION'
+  if [ ".${exim_build_date_override:-}" != "." ]; then
+    echo '#define EXIM_BUILD_DATE_OVERRIDE "'"${exim_build_date_override}"'"'
+  fi
 ) >version.h
 fi