Link DLLs with -static-libgcc on mingw-w64 i686

This has become necessary with version 8.0.0 of the mingw-w64 runtime
which causes libgcc_s_sjlj-1.dll to be linked with all DLLs, It does
not appear to be doing this for executables, which means that
executables using C++ should still be able to operate as before (in
particular, ocaml-mccs).

8 files changed, 30 insertions, 9 deletions

diff --git a/Changes b/Changes
index 3e76eee7ff..0248d3d998 100644
--- a/Changes
+++ b/Changes
@@ -453,6 +453,11 @@ OCaml 4.12.0
 - #10008: Improve error message for aliases to the current compilation unit.
   (Leo White, review by Gabriel Scherer)
 
+- #10046: Link all DLLs with -static-libgcc on mingw32 to prevent dependency
+  on libgcc_s_sjlj-1.dll with mingw-w64 runtime 8.0.0 (previously this was
+  only needed for dllunix.dll).
+  (David Allsopp, report by Andreas Hauptmann, review by ???)
+
 ### Internal/compiler-libs changes:
 
 - #8987: Make some locations more accurate
diff --git a/Makefile.build_config.in b/Makefile.build_config.in
index fa6b2b71e3..49a3f14c0c 100644
--- a/Makefile.build_config.in
+++ b/Makefile.build_config.in
@@ -27,3 +27,7 @@ INSTALL_PROG ?= @INSTALL_PROGRAM@
 # The command to generate C dependency information
 DEP_CC=@DEP_CC@ -MM
 COMPUTE_DEPS=@compute_deps@
+
+# This is munged into utils/config.ml, not overridable by other parts of
+# the build system.
+OC_DLL_LDFLAGS=@oc_dll_ldflags@
diff --git a/configure b/configure
index e47435a011..16536c5b1a 100755
--- a/configure
+++ b/configure
@@ -803,6 +803,7 @@ ocamlc_cppflags
 ocamlc_cflags
 nativecclibs
 bytecclibs
+oc_dll_ldflags
 oc_ldflags
 oc_cppflags
 oc_cflags
@@ -2780,6 +2781,7 @@ internal_cppflags=""
 ocamlc_cflags=""
 ocamlc_cppflags=""
 oc_ldflags=""
+oc_dll_ldflags=""
 with_sharedlibs=true
 ostype="Unix"
 iflexdir=""
@@ -2886,6 +2888,7 @@ VERSION=4.13.0+dev0-2020-10-19
 
 
 
+
  # TODO: rename this variable
 
 
@@ -12783,7 +12786,7 @@ fi
     if $with_sharedlibs; then :
   case $host in #(
   i686-*-*) :
-    flexdll_chain="mingw" ;; #(
+    flexdll_chain="mingw"; oc_dll_ldflags="-static-libgcc" ;; #(
   x86_64-*-*) :
     flexdll_chain="mingw64" ;; #(
   *) :
@@ -13629,6 +13632,11 @@ if test x"$enable_shared" != "xno"; then :
   *-*-mingw32) :
     mksharedlib='$(FLEXLINK)'
       mkmaindll='$(FLEXLINK) -maindll'
+      if test -n "$oc_dll_ldflags"; then :
+
+        mksharedlib="$mksharedlib -link \"$oc_dll_ldflags\""
+        mkmaindll="$mkmaindll -link \"$oc_dll_ldflags\""
+fi
       shared_libraries_supported=$with_sharedlibs ;; #(
   *-pc-windows) :
     mksharedlib='$(FLEXLINK)'
diff --git a/configure.ac b/configure.ac
index c1e52891e3..f1c90241a1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -52,6 +52,7 @@ internal_cppflags=""
 ocamlc_cflags=""
 ocamlc_cppflags=""
 oc_ldflags=""
+oc_dll_ldflags=""
 with_sharedlibs=true
 ostype="Unix"
 iflexdir=""
@@ -108,6 +109,7 @@ AC_SUBST([toolchain])
 AC_SUBST([oc_cflags])
 AC_SUBST([oc_cppflags])
 AC_SUBST([oc_ldflags])
+AC_SUBST([oc_dll_ldflags])
 AC_SUBST([bytecclibs])
 AC_SUBST([nativecclibs])
 AC_SUBST([ocamlc_cflags])
@@ -679,7 +681,7 @@ AS_CASE([$CC,$host],
   [*,*-*-mingw32],
     [AS_IF([$with_sharedlibs],
       [AS_CASE([$host],
-        [i686-*-*], [flexdll_chain="mingw"],
+        [i686-*-*], [flexdll_chain="mingw"; oc_dll_ldflags="-static-libgcc"],
         [x86_64-*-*], [flexdll_chain="mingw64"])
       flexlink="flexlink -chain $flexdll_chain -merge-manifest -stack 16777216"
       flexdir=`$flexlink -where | tr -d '\015'`
@@ -822,6 +824,9 @@ AS_IF([test x"$enable_shared" != "xno"],
     [*-*-mingw32],
       [mksharedlib='$(FLEXLINK)'
       mkmaindll='$(FLEXLINK) -maindll'
+      AS_IF([test -n "$oc_dll_ldflags"],[
+        mksharedlib="$mksharedlib -link \"$oc_dll_ldflags\""
+        mkmaindll="$mkmaindll -link \"$oc_dll_ldflags\""])
       shared_libraries_supported=$with_sharedlibs],
     [*-pc-windows],
       [mksharedlib='$(FLEXLINK)'
diff --git a/otherlibs/win32unix/Makefile b/otherlibs/win32unix/Makefile
index 0d6fafea34..149b8e9382 100644
--- a/otherlibs/win32unix/Makefile
+++ b/otherlibs/win32unix/Makefile
@@ -54,11 +54,7 @@ unixLabels.cmi: \
 
 include ../Makefile.otherlibs.common
 
-ifeq "$(SYSTEM)" "mingw"
-LDOPTS=-ldopt "-link -static-libgcc" $(addprefix -ldopt ,$(WIN32_LIBS))
-else
 LDOPTS=$(addprefix -ldopt ,$(WIN32_LIBS))
-endif
 
 clean::
 	rm -f $(UNIX_FILES) $(UNIX_CAML_FILES)
diff --git a/testsuite/Makefile b/testsuite/Makefile
index 6ca578464b..d7fc326ea3 100644
--- a/testsuite/Makefile
+++ b/testsuite/Makefile
@@ -58,8 +58,9 @@ else
   ifeq "$(FLEXLINK_ENV)" ""
     ocamltest := MKDLL="$(MKDLL)" SORT=$(SORT) MAKE=$(MAKE) $(ocamltest_program)
   else
+    FLEXLINK_DLL_LDFLAGS=$(if $(OC_DLL_LDFLAGS), -link "$(OC_DLL_LDFLAGS)")
     MKDLL=$(WINTOPDIR)/boot/ocamlrun $(WINTOPDIR)/flexdll/flexlink.exe \
-                                     $(FLEXLINK_FLAGS)
+                                     $(FLEXLINK_FLAGS) $(FLEXLINK_DLL_LDFLAGS)
 
     ocamltest := $(FLEXLINK_ENV) MKDLL="$(MKDLL)" SORT=$(SORT) MAKE=$(MAKE) \
                                  $(ocamltest_program)
diff --git a/utils/Makefile b/utils/Makefile
index 871fc2fe59..11e2cebe2e 100644
--- a/utils/Makefile
+++ b/utils/Makefile
@@ -39,6 +39,7 @@ SUBST_QUOTE2=\
 SUBST_QUOTE=$(call SUBST_QUOTE2,$1,$($1))
 
 FLEXLINK_LDFLAGS=$(if $(OC_LDFLAGS), -link "$(OC_LDFLAGS)")
+FLEXLINK_DLL_LDFLAGS=$(if $(OC_DLL_LDFLAGS), -link "$(OC_DLL_LDFLAGS)")
 
 config.ml: config.mlp $(ROOTDIR)/Makefile.config Makefile
 	sed $(call SUBST,AFL_INSTRUMENT) \
@@ -64,6 +65,7 @@ config.ml: config.mlp $(ROOTDIR)/Makefile.config Makefile
 	    $(call SUBST_STRING,MKDLL) \
 	    $(call SUBST_STRING,MKEXE) \
 	    $(call SUBST_STRING,FLEXLINK_LDFLAGS) \
+	    $(call SUBST_STRING,FLEXLINK_DLL_LDFLAGS) \
 	    $(call SUBST_STRING,MKMAINDLL) \
 	    $(call SUBST,MODEL) \
 	    $(call SUBST_STRING,NATIVECCLIBS) \
diff --git a/utils/config.mlp b/utils/config.mlp
index 10df2bdbe7..5bfa30d694 100644
--- a/utils/config.mlp
+++ b/utils/config.mlp
@@ -65,9 +65,9 @@ let mkdll, mkexe, mkmaindll =
           let c = flexlink.[i] in
           if c = '/' then '\\' else c in
         (String.init (String.length flexlink) f) ^ " %%FLEXLINK_FLAGS%%" in
-      flexlink,
+      flexlink ^ "%%FLEXLINK_DLL_LDFLAGS%%",
       flexlink ^ " -exe%%FLEXLINK_LDFLAGS%%",
-      flexlink ^ " -maindll"
+      flexlink ^ " -maindll%%FLEXLINK_DLL_LDFLAGS%%"
     with Not_found ->
       "%%MKDLL%%", "%%MKEXE%%", "%%MKMAINDLL%%"
   else