Always pass -fno-strict-aliasing during compilation (#714)

The ksh93 codebase is incompatible with strict aliasing, yet currently the default flags enable -fstrict-aliasing via the -Os optimization flag. Additionally, manually passing a higher level optimization flag via CCFLAGS (e.g. -O3) will result in strict aliasing becoming inadvertently enabled unless -fno-strict-aliasing is explicitly passed to disable it (cf. the Fedora and OpenSUSE build scripts for ksh[*]). This commit implements a probe that will detect the existence of -fno-strict-aliasing and use it via ${mam_cc_FLAGS}, bypassing CCFLAGS. [*]: https://src.fedoraproject.org/rpms/ksh/blob/rawhide/f/ksh.spec#_49 https://build.opensuse.org/package/view_file/shells/ksh/ksh.spec?expand=1
ksh93 · Mar 23, 2024 · 27ece9f · 27ece9f
1 parent 5e3a169
commit 27ece9f
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Showing 7 changed files with 24 additions and 7 deletions.
diff --git a/src/cmd/INIT/make.probe b/src/cmd/INIT/make.probe
@@ -3,7 +3,7 @@
 # Glenn Fowler
 # AT&T Research
 #
-# @(#)make.probe (ksh 93u+m) 2024-03-20
+# @(#)make.probe (ksh 93u+m) 2024-03-23
 #
 # C probe for make
 #
@@ -37,6 +37,7 @@ probe_nmflags="'' -p -B"
 probe_optimize="-Os -O"
 probe_pic="-Kpic -KPIC -fpic -fPIC -pic -PIC +z +Z"
 probe_no_protect="'-fno-stack-protector -fno-stack-protector-all' -GS-"
+probe_no_strict_aliasing="-fno-strict-aliasing"
 probe_readonly="-R -Krodata -xMerge -Wa,-r"
 probe_shared="'' -G -b -c -shared -Wl,dll"
 probe_shared_name="-Wl,-soname= -h"
@@ -149,6 +150,7 @@ makeoptions=
 nmedit=
 nmflags=
 no_protect=
+no_strict_aliasing=
 optimize=
 prefix_archive=lib
 prefix_dynamic=
@@ -1455,6 +1457,19 @@ then	e=`wc -c < e`
 		esac
 	done
 
+	eval set x $probe_no_strict_aliasing
+	while	:
+	do	shift
+		case $# in
+		0)	break ;;
+		esac
+		rm -f warn.$obj
+		$cc $1 -c warn.$src 2>e && test -f warn.$obj || continue
+		case $(wc -c < e) in
+		$e)	no_strict_aliasing=$1; break ;;
+		esac
+	done
+
 	case $version_string in
 	$probe_gcc_version)	probe_optimize="$probe_gcc_optimize $probe_optimize" ;;
 	esac
@@ -1979,6 +1994,7 @@ CC_NM=$nm
 CC_NMEDIT=$nmedit
 CC_NMFLAGS=$nmflags
 CC_NOPROTECT=$no_protect
+CC_NOSTRICTALIASING=$no_strict_aliasing
 CC_OPTIMIZE=$optimize
 CC_READONLY=$readonly
 CC_REPOSITORY=$repository
@@ -2086,6 +2102,7 @@ esac
 echo CC.NMEDIT ="$CC_NMEDIT"
 echo CC.NMFLAGS = $CC_NMFLAGS
 echo CC.NOPROTECT = $CC_NOPROTECT
+echo CC.NOSTRICTALIASING = $CC_NOSTRICTALIASING
 echo CC.OPTIMIZE = $CC_OPTIMIZE
 echo CC.PICBIG = $CC_PICBIG
 echo CC.PICSMALL = $CC_PICSMALL

diff --git a/src/cmd/builtin/Mamfile b/src/cmd/builtin/Mamfile
@@ -8,7 +8,7 @@ setv MAMAKE_STRICT 3
 setv INSTALLROOT ../../..
 setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
 setv CC cc
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING}
 setv CCFLAGS
 setv CCLDFLAGS ${-strip-symbols?1?${mam_cc_LD_STRIP}??}
 setv IFFEFLAGS

diff --git a/src/cmd/ksh93/Mamfile b/src/cmd/ksh93/Mamfile
@@ -8,7 +8,7 @@ setv INSTALLROOT ../../..
 setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
 setv CC cc
 setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING}
 setv CCFLAGS
 setv CCLDFLAGS ${-strip-symbols?1?${mam_cc_LD_STRIP}??}
 setv IFFEFLAGS

diff --git a/src/lib/libast/Mamfile b/src/lib/libast/Mamfile
@@ -8,7 +8,7 @@ setv INSTALLROOT ../../..
 setv PACKAGEROOT ../../../../..
 setv CC cc
 setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} -D_BLD_ast ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} -D_BLD_ast ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING}
 setv CCFLAGS
 setv CCLDFLAGS ${-strip-symbols?1?${mam_cc_LD_STRIP}??}
 setv IFFEFLAGS

diff --git a/src/lib/libcmd/Mamfile b/src/lib/libcmd/Mamfile
@@ -8,7 +8,7 @@ setv INSTALLROOT ../../..
 setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
 setv CC cc
 setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} -DERROR_CATALOG=\""libcmd"\" -DHOSTTYPE=\""${mam_cc_HOSTTYPE}"\" -D_BLD_cmd
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING} -DERROR_CATALOG=\""libcmd"\" -DHOSTTYPE=\""${mam_cc_HOSTTYPE}"\" -D_BLD_cmd
 setv CCFLAGS
 setv IFFEFLAGS
 setv LDFLAGS

diff --git a/src/lib/libdll/Mamfile b/src/lib/libdll/Mamfile
@@ -8,7 +8,7 @@ setv INSTALLROOT ../../..
 setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
 setv CC cc
 setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_DLL} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING}
 setv CCFLAGS
 setv IFFEFLAGS
 setv LDFLAGS

diff --git a/src/lib/libsum/Mamfile b/src/lib/libsum/Mamfile
@@ -8,7 +8,7 @@ setv INSTALLROOT ../../..
 setv PACKAGE_ast_INCLUDE ${INSTALLROOT}/include/ast
 setv CC cc
 setv AR ${mam_cc_AR} ${mam_cc_AR_ARFLAGS}
-setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_PIC} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?}
+setv mam_cc_FLAGS ${mam_cc_TARGET} ${mam_cc_PIC} ${-debug-symbols?1?${mam_cc_DEBUG} -D_BLD_DEBUG?${mam_cc_OPTIMIZE}?} ${mam_cc_NOSTRICTALIASING}
 setv CCFLAGS
 setv IFFEFLAGS
 setv LDFLAGS