configure: do_compiler: Dump some extra info under bash

This makes it much easier to find a particular thing in config.log.

We have to use the ${BASH_LINENO[*]} syntax which is a syntax error in
other shells, so test what shell we are running and use eval.

The extra output is only printed if configure is run with bash.  On
systems where /bin/sh is not bash, it is necessary to say bash
./configure to get the extra debug info in the log.

Suggested-by: Eric Blake <[email protected]>
Signed-off-by: Ian Jackson <[email protected]>
CC: Kent R. Spillner <[email protected]>
CC: Janosch Frank <[email protected]>
CC: Thomas Huth <[email protected]>
CC: Peter Maydell <[email protected]>
CC: Paolo Bonzini <[email protected]>
Tested-by: Thomas Huth <[email protected]>

diff --git a/configure b/configure
index aa35aef14b8338358fbb8571a3fab83d4995e6da..f9ba9eaae7edbe5439a5fb3ec07eef8ced105679 100755 (executable)
--- a/configure
+++ b/configure
@@ -60,6 +60,11 @@ do_compiler() {
     # is compiler binary to execute.
     local compiler="$1"
     shift
+    if test -n "$BASH_VERSION"; then eval '
+        echo >>config.log "
+funcs: ${FUNCNAME[*]}
+lines: ${BASH_LINENO[*]}"
+    '; fi
     echo $compiler "$@" >> config.log
     $compiler "$@" >> config.log 2>&1 || return $?
     # Test passed. If this is an --enable-werror build, rerun