configure.ac: Fix CFLAGS settings.

Don't override/overwrite CFLAGS in configure.ac, but rather amend it
with (currently) "-Wall -Wextra".

This properly allows users/packagers to do things like:

 ./configure (this will default to using "-g -O2" additionally)

 CFLAGS="-g -O2" ./configure (same as above)

 CFLAGS="" ./configure (no additional flags)

 CFLAGS="-g -O0" ./configure (disable optimization, e.g. for valgrind use)

 etc. etc.

diff --git a/configure.ac b/configure.ac
index ea04095808f5639b2576def2107f24f85a017ed5..a0c93efbae8799dc8e5810566d4e45ad44aa115c 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -38,7 +38,8 @@ AH_TOP([#ifndef SIGROK_CLI_CONFIG_H
 #define SIGROK_CLI_CONFIG_H    /* To stop multiple inclusions. */])
 AH_BOTTOM([#endif /* SIGROK_CLI_CONFIG_H */])
 
-CFLAGS="-g -Wall -Wextra"
+# Enable more compiler warnings via -Wall and -Wextra.
+CFLAGS="$CFLAGS -Wall -Wextra"
 
 # Checks for programs.
 AC_PROG_CC