configure: do_compiler: Dump some extra info under bash

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

The information may be lacking in other shells, resulting in harmless
empty output.  (This is why we don't use the proper ${FUNCNAME[*]}
array syntax - other shells will choke on that.)

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.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Kent R. Spillner <kspillner@acm.org>
CC: Janosch Frank <frankja@linux.vnet.ibm.com>
CC: Thomas Huth <thuth@redhat.com>
CC: Peter Maydell <peter.maydell@linaro.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
---
v6: Fix commit message wording.
v4: No longer tag this patch RFC.

diff --git a/configure b/configure
index 0a8059f59a4ba606af351e64aeff263eb2c9e881..841c146df1ffdd95f10055d300d840d18cc26d48 100755 (executable)
--- a/configure
+++ b/configure
@@ -60,6 +60,10 @@ do_compiler() {
     # is compiler binary to execute.
     local compiler="$1"
     shift
+    echo >>config.log "
+funcs: ${FUNCNAME}
+lines: ${BASH_LINENO}
+files: ${BASH_SOURCE}"
     echo $compiler "$@" >> config.log
     $compiler "$@" >> config.log 2>&1 || return $?
     # Test passed. If this is an --enable-werror build, rerun