Reinstate DEBUG_PESSIMIZE (by Christian Ionescu-Idbohrn)

2 files changed, 21 insertions, 15 deletions

diff --git a/Config.in b/Config.in
index 3b374967b..0a7edf84c 100644
--- a/Config.in
+++ b/Config.in
@@ -396,6 +396,17 @@ config DEBUG
 
           Most people should answer N.
 
+config DEBUG_PESSIMIZE
+        bool "Disable compiler optimizations."
+        default n
+        depends on DEBUG
+        help
+          The compiler's optimization of source code can eliminate and reorder
+          code, resulting in an executable that's hard to understand when
+          stepping through it with a debugger.  This switches it off, resulting
+          in a much bigger executable that more closely matches the source
+          code.
+
 config WERROR
         bool "Abort compilation on any warning"
         default n
@@ -404,18 +415,6 @@ config WERROR
 
           Most people should answer N.
 
-# Seems to be unused
-#config DEBUG_PESSIMIZE
-#       bool "Disable compiler optimizations."
-#       default n
-#       depends on DEBUG
-#       help
-#         The compiler's optimization of source code can eliminate and reorder
-#         code, resulting in an executable that's hard to understand when
-#         stepping through it with a debugger.  This switches it off, resulting
-#         in a much bigger executable that more closely matches the source
-#         code.
-
 choice
         prompt "Additional debugging library"
         default NO_DEBUG_LIB
diff --git a/Makefile.flags b/Makefile.flags
index e9405476b..0ffc05c35 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -35,7 +35,7 @@ endif
 # gcc 3.x emits bogus "old style proto" warning on find.c:alloc_action()
 CFLAGS += $(call cc-ifversion, -ge, 0400, -Wold-style-definition)
 
-CFLAGS += $(call cc-option,-Os -fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,)
+CFLAGS += $(call cc-option,-fno-builtin-strlen -finline-limit=0 -fomit-frame-pointer -ffunction-sections -fdata-sections,)
 # -fno-guess-branch-probability: prohibit pseudo-random guessing
 # of branch probabilities (hopefully makes bloatcheck more stable):
 CFLAGS += $(call cc-option,-fno-guess-branch-probability,)
@@ -46,8 +46,15 @@ CFLAGS += $(call cc-option,-falign-functions=1 -falign-jumps=1 -falign-labels=1
 # be fixed..
 #CFLAGS+=$(call cc-option,-Wconversion,)
 
-ifeq ($(CONFIG_DEBUG),y)
-CFLAGS += $(call cc-option,-g)
+ifneq ($(CONFIG_DEBUG),y)
+CFLAGS += $(call cc-option,-Os,)
+else
+CFLAGS += $(call cc-option,-g,)
+ifeq ($(CONFIG_DEBUG_PESSIMIZE),y)
+CFLAGS += $(call cc-option,-O0,)
+else
+CFLAGS += $(call cc-option,-Os,)
+endif
 endif
 
 # If arch/$(ARCH)/Makefile did not override it (with, say, -fPIC)...