From c646686fc0abdcd955dcb9479059c715b8115874 Mon Sep 17 00:00:00 2001
From: "Wladimir J. van der Laan" <laanwj@gmail.com>
Date: Mon, 14 May 2018 15:27:46 +0200
Subject: [PATCH] Merge #13005: Make --enable-debug to pick better options

9e49db2 Make --enable-debug to pick better options (Evan Klitzke)

Pull request description:

  Cherry-picked (and rebased) 94189645e67f364c4445d62e2b00c282d885cbbf from the "up for grabs" PR: "[build] Make --enable-debug pick better options" (#12695).

  See previous review in #12695.

Tree-SHA512: a93cdadcf13e2ef8519acb1ce4f41ce95057a388347bb0a86a5c164dc7d0b0d14d4bb2a466082d5a100b8d50de65c605c40abaed555e8ea77c99e28800a34439
---
 configure.ac    | 30 ++++++++++++++++++++----------
 src/Makefile.am |  4 ++--
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 6a775214aa..f8368abfab 100644
--- a/configure.ac
+++ b/configure.ac
@@ -281,14 +281,22 @@ AC_LANG_PUSH([C++])
 AX_CHECK_COMPILE_FLAG([-Werror],[CXXFLAG_WERROR="-Werror"],[CXXFLAG_WERROR=""])
 
 if test "x$enable_debug" = xyes; then
-    CPPFLAGS="$CPPFLAGS -DDEBUG"
-    if test "x$GCC" = xyes; then
-        CFLAGS="$CFLAGS -g3 -O0"
-    fi
+  # Prefer -Og, fall back to -O0 if that is unavailable.
+  AX_CHECK_COMPILE_FLAG(
+    [-Og],
+    [[DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -Og"]],
+    [AX_CHECK_COMPILE_FLAG([-O0],[[DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -O0"]],,[[$CXXFLAG_WERROR]])],
+    [[$CXXFLAG_WERROR]])
 
-    if test "x$GXX" = xyes; then
-        CXXFLAGS="$CXXFLAGS -g3 -O0"
-    fi
+  # Prefer -g3, fall back to -g if that is unavailable.
+  AX_CHECK_COMPILE_FLAG(
+    [-g3],
+    [[DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -g3"]],
+    [AX_CHECK_COMPILE_FLAG([-g],[[DEBUG_CXXFLAGS="$DEBUG_CXXFLAGS -g"]],,[[$CXXFLAG_WERROR]])],
+    [[$CXXFLAG_WERROR]])
+
+  AX_CHECK_PREPROC_FLAG([-DDEBUG],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG"]],,[[$CXXFLAG_WERROR]])
+  AX_CHECK_PREPROC_FLAG([-DDEBUG_LOCKORDER],[[DEBUG_CPPFLAGS="$DEBUG_CPPFLAGS -DDEBUG_LOCKORDER"]],,[[$CXXFLAG_WERROR]])
 else
     # We always enable at at least -g1 debug info to support proper stacktraces in crash infos
     # Stacktraces will be suboptimal due to optimization, but better than nothing. Also, -fno-omit-frame-pointer
@@ -1450,6 +1458,8 @@ AC_SUBST(BITCOIN_CLI_NAME)
 AC_SUBST(BITCOIN_TX_NAME)
 
 AC_SUBST(RELDFLAGS)
+AC_SUBST(DEBUG_CPPFLAGS)
+AC_SUBST(DEBUG_CXXFLAGS)
 AC_SUBST(ERROR_CXXFLAGS)
 AC_SUBST(GPROF_CXXFLAGS)
 AC_SUBST(GPROF_LDFLAGS)
@@ -1564,9 +1574,9 @@ echo "  build os            = $BUILD_OS"
 echo
 echo "  CC                  = $CC"
 echo "  CFLAGS              = $CFLAGS"
-echo "  CPPFLAGS            = $CPPFLAGS"
+echo "  CPPFLAGS            = $DEBUG_CPPFLAGS $HARDENED_CPPFLAGS $CPPFLAGS"
 echo "  CXX                 = $CXX"
-echo "  CXXFLAGS            = $CXXFLAGS"
-echo "  LDFLAGS             = $LDFLAGS"
+echo "  CXXFLAGS            = $DEBUG_CXXFLAGS $HARDENED_CXXFLAGS $ERROR_CXXFLAGS $GPROF_CXXFLAGS $CXXFLAGS"
+echo "  LDFLAGS             = $PTHREAD_CFLAGS $HARDENED_LDFLAGS $GPROF_LDFLAGS $LDFLAGS"
 echo "  ARFLAGS             = $ARFLAGS"
 echo
diff --git a/src/Makefile.am b/src/Makefile.am
index c85d1b5c2b..945988e959 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -6,8 +6,8 @@
 DIST_SUBDIRS = secp256k1 univalue
 
 AM_LDFLAGS = $(PTHREAD_CFLAGS) $(LIBTOOL_LDFLAGS) $(HARDENED_LDFLAGS) $(GPROF_LDFLAGS) $(SANITIZER_LDFLAGS)
-AM_CXXFLAGS = $(HARDENED_CXXFLAGS) $(ERROR_CXXFLAGS) $(GPROF_CXXFLAGS) $(SANITIZER_CXXFLAGS)
-AM_CPPFLAGS = $(HARDENED_CPPFLAGS)
+AM_CXXFLAGS = $(DEBUG_CXXFLAGS) $(HARDENED_CXXFLAGS) $(ERROR_CXXFLAGS) $(GPROF_CXXFLAGS) $(SANITIZER_CXXFLAGS)
+AM_CPPFLAGS = $(DEBUG_CPPFLAGS) $(HARDENED_CPPFLAGS)
 AM_LIBTOOLFLAGS = --preserve-dup-deps
 EXTRA_LIBRARIES =