Update Makefile and compiler checks so that users don't inadvertently

change mandatory compiler flags.

src/Makefile

@@ -1,19 +1,18 @@
 #
-# UPX Makefile - needs GNU make 3.81 or better
+# UPX Makefile - needs GNU make
 #
 # Copyright (C) 1996-2020 Markus Franz Xaver Johannes Oberhumer
 #
 
+MAKEFLAGS += -rR
+.SUFFIXES:
+export SHELL = /bin/sh
+
 # build configuration options for this Makefile
 BUILD_TYPE_DEBUG    ?= 0
 BUILD_TYPE_SANITIZE ?= 0
 BUILD_USE_DEPEND    ?= 1
 
-MAKEFLAGS += -r
-.SUFFIXES:
-export SHELL = /bin/sh
-override ee = $($1) $(EXTRA_$1) $(upx_$1) $(upx_EXTRA_$1) $($(basename $(notdir $@)).$1)
-
 ifndef srcdir
   srcdir := $(dir $(lastword $(MAKEFILE_LIST)))
   srcdir := $(shell echo '$(srcdir)' | sed 's,/*$$,,' || echo 'ERROR')
@@ -34,6 +33,14 @@ exeext ?= .out
 libext ?= .a
 objext ?= .o
 
+# flags composition
+override all_flags = $(mf.$1) $($1) $(EXTRA_$1) $(upx_$1) $(upx_EXTRA_$1) $($(basename $(notdir $@)).$1)
+ALL_CPPFLAGS = $(strip $(call all_flags,CPPFLAGS))
+ALL_CXXFLAGS = $(strip $(call all_flags,CXXFLAGS))
+ALL_LDFLAGS  = $(strip $(call all_flags,LDFLAGS))
+ALL_LDADD    = $(strip $(call all_flags,LDADD))
+ALL_LIBS     = $(strip $(call all_flags,LIBS))
+
 upx_SOURCES := $(sort $(wildcard $(srcdir)/*.cpp))
 upx_OBJECTS := $(notdir $(upx_SOURCES:.cpp=$(objext)))
 
@@ -54,30 +61,32 @@ LIBS += -lucl -lz
 # LZMA from https://github.com/upx/upx-lzma-sdk
 include $(top_srcdir)/src/stub/src/c/Makevars.lzma
 
-CPPFLAGS += $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)
+# optional flags
-CXXFLAGS += -std=c++14
 ifeq ($(BUILD_TYPE_DEBUG),1)
   CXXFLAGS_OPTIMIZE ?= -O0 -g
 else
   CXXFLAGS_OPTIMIZE ?= -O2
 endif
-CXXFLAGS += $(CXXFLAGS_OPTIMIZE)
-# protect against security threats caused by misguided C++ compiler "optimizations"
-ifeq ($(findstring clang,$(CXX)),)
-CXXFLAGS += -fno-delete-null-pointer-checks
-endif
-CXXFLAGS += -fno-strict-aliasing -fwrapv
-CXXFLAGS += -funsigned-char
-CXXFLAGS += -Wall -W -Wcast-align -Wcast-qual -Wmissing-declarations -Wpointer-arith -Wshadow -Wsign-compare -Wvla -Wwrite-strings
-CXXFLAGS_WERROR ?= -Werror
-CXXFLAGS += $(CXXFLAGS_WERROR)
-
 ifeq ($(BUILD_TYPE_SANITIZE),1)
   CXXFLAGS_SANITIZE ?= -fsanitize=address,undefined -fno-omit-frame-pointer -DACC_CFG_NO_UNALIGNED
-CXXFLAGS += $(CXXFLAGS_SANITIZE)
+else
-# these are the only 2 objects that are actually speed-sensitive
+  CXXFLAGS_SANITIZE ?= -fstack-protector-all
-compress_lzma$(objext) filteri$(objext) : override CXXFLAGS_SANITIZE =
 endif
+ifeq ($(findstring clang,$(CXX)),)
+  CXXFLAGS_NO_DELETE_NULL_POINTER_CHECKS ?= -fno-delete-null-pointer-checks
+endif
+CXXFLAGS_WERROR ?= -Werror
+
+# Mandatory Flags - DO NOT CHANGE!
+mf.CPPFLAGS += $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES)
+mf.CXXFLAGS += $(CXXFLAGS_OPTIMIZE)
+# protect against security threats caused by misguided C++ compiler "optimizations"
+mf.CXXFLAGS += $(CXXFLAGS_NO_DELETE_NULL_POINTER_CHECKS)
+mf.CXXFLAGS += -fno-strict-aliasing -fno-strict-overflow
+mf.CXXFLAGS += -funsigned-char
+mf.CXXFLAGS += $(CXXFLAGS_SANITIZE)
+mf.CXXFLAGS += -Wall -W -Wcast-align -Wcast-qual -Wmissing-declarations -Wpointer-arith -Wshadow -Wvla -Wwrite-strings
+mf.CXXFLAGS += $(CXXFLAGS_WERROR)
 
 # rules
 all: upx$(exeext) | ./.depend
@@ -85,20 +94,30 @@ all: upx$(exeext) | ./.depend
 
 upx$(exeext): $(upx_OBJECTS) $(upx_DEPENDENCIES)
 	$($(notdir $@).PRE_LINK_STEP)
-	$(strip $(CXXLD) $(call ee,CXXFLAGS) $(call ee,LDFLAGS) -o $@ $(upx_OBJECTS) $(call ee,LDADD) $(call ee,LIBS))
+	$(strip $(CXXLD) $(ALL_CXXFLAGS) $(ALL_LDFLAGS) -o $@ $(upx_OBJECTS) $(ALL_LDADD) $(ALL_LIBS))
 	$($(notdir $@).POST_LINK_STEP)
 	$(CHECK_WHITESPACE)
 
 %.o : %.cpp | ./.depend
-	$(strip $(CXX) $(call ee,CPPFLAGS) $(call ee,CXXFLAGS) -o $@ -c $<)
+	$(strip $(CXX) $(ALL_CPPFLAGS) $(ALL_CXXFLAGS) -o $@ -c $<)
 %.cpp.ii : %.cpp
-	$(strip $(CXX) $(call ee,CPPFLAGS) $(call ee,CXXFLAGS) -o $@ -E $<)
+	$(strip $(CXX) $(ALL_CPPFLAGS) $(ALL_CXXFLAGS) -o $@ -E $<)
+
+# object overrides
+compress_lzma$(objext) : INCLUDES += -I$(UPX_LZMADIR)
+# these are the only 2 objects that are actually speed-sensitive
+compress_lzma$(objext) : override CXXFLAGS_SANITIZE =
+filteri$(objext)       : override CXXFLAGS_SANITIZE =
+# disable some warnings
+compress_lzma$(objext) : upx_CXXFLAGS += -Wno-shadow
+p_mach$(objext)        : upx_CXXFLAGS += -Wno-cast-align
 
 ifeq ($(BUILD_USE_DEPEND),1)
 ./.depend: $(sort $(wildcard $(srcdir)/*.cpp $(srcdir)/*.h)) $(MAKEFILE_LIST)
 	@rm -f $@
 	@echo "Updating $@"
-	@$(strip $(CXX) $(call ee,CPPFLAGS) $(call ee,CXXFLAGS) -MM) $(filter %.cpp,$^) > $@
+	@$(strip $(CXX) $(ALL_CPPFLAGS) $(ALL_CXXFLAGS) -MM) $(filter %.cpp,$^) > $@
+./.depend : INCLUDES += -I$(UPX_LZMADIR)
 else
 ./.depend:
 .PHONY: ./.depend
@@ -117,11 +136,6 @@ endif
 mostlyclean clean distclean maintainer-clean:
 	rm -f *.d *.ii *.map *.o *.obj *.res ./.depend upx.exe upx.out upx.ttp upx$(exeext)
 
-./.depend compress_lzma$(objext) : INCLUDES += -I$(UPX_LZMADIR)
-
-compress_lzma$(objext) : CXXFLAGS += -Wno-shadow
-p_mach$(objext)        : CXXFLAGS += -Wno-cast-align
-
 .PHONY: all mostlyclean clean distclean maintainer-clean
 
 ifeq ($(MAKECMDGOALS),mostlyclean)

src/conf.h

@@ -65,6 +65,8 @@
 #  error "UINT_MAX"
 #endif
 ACC_COMPILE_TIME_ASSERT_HEADER(sizeof(int) == 4)
+ACC_COMPILE_TIME_ASSERT_HEADER(sizeof(long long) == 8)
+// check sane compiler mandatory flags
 ACC_COMPILE_TIME_ASSERT_HEADER(-1 == ~0) // two's complement - see http://wg21.link/P0907R4
 ACC_COMPILE_TIME_ASSERT_HEADER(0u-1 == ~0u) // two's complement - see http://wg21.link/P0907R4
 ACC_COMPILE_TIME_ASSERT_HEADER((1u << 31) << 1 == 0)
@@ -179,7 +181,7 @@ typedef unsigned char   upx_byte;
 // see C 11 standard, Annex K
 typedef size_t upx_rsize_t;
 #define UPX_RSIZE_MAX       UPX_RSIZE_MAX_MEM
-#define UPX_RSIZE_MAX_MEM   (768 * 1024 * 1024)   // DO NOT CHANGE
+#define UPX_RSIZE_MAX_MEM   (768 * 1024 * 1024)   // DO NOT CHANGE !!!
 #define UPX_RSIZE_MAX_STR   (1024 * 1024)
 
 
@@ -671,6 +673,7 @@ void e_exit(int ec) __attribute__((__noreturn__));
 #else
 void e_exit(int ec);
 #endif
+void upx_compiler_sanity_check(void);
 
 
 // msg.cpp

src/main.cpp

@@ -1289,12 +1289,22 @@ static bool test(void)
     return true;
 }};
 
+template <class A, class B> struct TestNoStrictAliasingStruct {
+    __acc_static_noinline bool test(A *a, B *b) { *a = 0; *b = (B)((B)0-1); return *a != 0; }
+};
+template <class A, class B> static inline bool testNoStrictAliasing(A *a, B *b) {
+    return TestNoStrictAliasingStruct<A,B>::test(a, b);
+}
+template <class T> struct TestIntegerWrap {
+    static inline bool inc(T x) { return x + 1 > x; }
+    static inline bool dec(T x) { return x - 1 < x; }
+};
 
 #define ACC_WANT_ACC_CHK_CH 1
 #undef ACCCHK_ASSERT
 #include "miniacc.h"
 
-__acc_static_noinline void upx_sanity_check(void)
+void upx_compiler_sanity_check(void)
 {
 #define ACC_WANT_ACC_CHK_CH 1
 #undef ACCCHK_ASSERT
@@ -1340,6 +1350,7 @@ __acc_static_noinline void upx_sanity_check(void)
         else { assert(revlen == 12 || revlen == 13); }
         if (revlen == 6 || revlen == 13) { assert(gitrev[revlen-1] == '+'); }
     }
+    assert(UPX_RSIZE_MAX_MEM == 805306368);
 
 #if 1
     assert(TestBELE<LE16>::test());
@@ -1396,6 +1407,18 @@ __acc_static_noinline void upx_sanity_check(void)
     assert(get_be64_signed(d) == UPX_INT64_C(9186918263483431288));
     }
 #endif
+
+    union { short v_short; int v_int; long v_long; } u;
+    assert(testNoStrictAliasing(&u.v_short, &u.v_long));
+
+    assert( TestIntegerWrap<int>::inc(0));
+    assert(!TestIntegerWrap<int>::inc(INT_MAX));
+    assert( TestIntegerWrap<int>::dec(0));
+    assert(!TestIntegerWrap<int>::dec(INT_MIN));
+    assert( TestIntegerWrap<unsigned>::inc(0));
+    assert(!TestIntegerWrap<unsigned>::inc(UINT_MAX));
+    assert( TestIntegerWrap<unsigned>::dec(1));
+    assert(!TestIntegerWrap<unsigned>::dec(0));
 }
 
 
@@ -1427,7 +1450,7 @@ int __acc_cdecl_main main(int argc, char *argv[])
 #endif
     acc_wildargv(&argc, &argv);
 
-    upx_sanity_check();
+    upx_compiler_sanity_check();
     opt->reset();
 
     if (!argv[0] || !argv[0][0])

src/work.cpp

@@ -255,6 +255,7 @@ static void unlink_ofile(char *oname) {
 }
 
 void do_files(int i, int argc, char *argv[]) {
+    upx_compiler_sanity_check();
     if (opt->verbose >= 1) {
         show_head();
         UiPacker::uiHeader();