Hello! I would like to propose a new parameter for gcc: -mcrtdll= to
allow specifying against which Windows C Runtime library should be
binary linked. On Windows there are more crt libraries and currently gcc
links to libmsvcrt.a which is in most cases symlink to libmsvcrt-os.a
(but can be changed, e.g. during mingw-w64 building). mingw-w64 project
already builds import .a library for every crt dll library (from the old
crtdll.dll up to the new ucrtbase.dll), so it is ready for usage. Simple
patch for gcc which implements -mcrtdll parameter is below. Note that on
internet are other very similar patches for -mcrtdll= parameters and
some are parts of custom mingw32 / mingw-w64 gcc builds. What do you
think? Could gcc have "official" support for -mcrtdll= parameter?
--- gcc/config/i386/cygming.opt 2022-02-06 21:00:05.377656896 +0100
+++ gcc/config/i386/cygming.opt 2022-02-06 21:04:06.690995944 +0100
@@ -22,6 +22,10 @@ mconsole
Target RejectNegative
Create console application.
+mcrtdll=
+Target RejectNegative Joined
+Link with specified C RunTime DLL library.
+
mdll
Target RejectNegative
Generate code for a DLL.
--- gcc/config/i386/mingw32.h 2022-01-16 17:28:31.157999097 +0100
+++ gcc/config/i386/mingw32.h 2022-01-16 17:36:03.552856726 +0100
@@ -95,7 +95,20 @@ along with GCC; see the file COPYING3.
#undef CPP_SPEC
#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{mthreads:-D_MT} " \
"%{" SPEC_PTHREAD1 ":-D_REENTRANT} " \
- "%{" SPEC_PTHREAD2 ": } "
+ "%{" SPEC_PTHREAD2 ": } " \
+ "%{mcrtdll=crtdll*:-U__MSVCRT__ -D__CRTDLL__} " \
+ "%{mcrtdll=msvcrt10*:-D__MSVCRT_VERSION__=0x100} " \
+ "%{mcrtdll=msvcrt20*:-D__MSVCRT_VERSION__=0x200} " \
+ "%{mcrtdll=msvcrt40*:-D__MSVCRT_VERSION__=0x400} " \
+ "%{mcrtdll=msvcrt-os*:-D__MSVCRT_VERSION__=0x700} " \
+ "%{mcrtdll=msvcr70*:-D__MSVCRT_VERSION__=0x700} " \
+ "%{mcrtdll=msvcr71*:-D__MSVCRT_VERSION__=0x701} " \
+ "%{mcrtdll=msvcr80*:-D__MSVCRT_VERSION__=0x800} " \
+ "%{mcrtdll=msvcr90*:-D__MSVCRT_VERSION__=0x900} " \
+ "%{mcrtdll=msvcr100*:-D__MSVCRT_VERSION__=0xA00} " \
+ "%{mcrtdll=msvcr110*:-D__MSVCRT_VERSION__=0xB00} " \
+ "%{mcrtdll=msvcr120*:-D__MSVCRT_VERSION__=0xC00} " \
+ "%{mcrtdll=ucrt*:-D_UCRT} "
/* For Windows applications, include more libraries, but always include
kernel32. */
@@ -185,11 +198,16 @@ along with GCC; see the file COPYING3.
#define REAL_LIBGCC_SPEC \
"%{mthreads:-lmingwthrd} -lmingw32 \
" SHARED_LIBGCC_SPEC " \
- -lmoldname -lmingwex -lmsvcrt -lkernel32"
+ -lmoldname -lmingwex %{!mcrtdll=*:-lmsvcrt} %{mcrtdll=*:-l%*} -lkernel32"
#undef STARTFILE_SPEC
-#define STARTFILE_SPEC "%{shared|mdll:dllcrt2%O%s} \
- %{!shared:%{!mdll:crt2%O%s}} %{pg:gcrt2%O%s} \
+#define STARTFILE_SPEC " \
+ %{shared|mdll:%{mcrtdll=crtdll*:dllcrt1%O%s}} \
+ %{shared|mdll:%{!mcrtdll=crtdll*:dllcrt2%O%s}} \
+ %{!shared:%{!mdll:%{mcrtdll=crtdll*:crt1%O%s}}} \
+ %{!shared:%{!mdll:%{!mcrtdll=crtdll*:crt2%O%s}}} \
+ %{pg:%{mcrtdll=crtdll*:gcrt1%O%s}} \
+ %{pg:%{!mcrtdll=crtdll*:gcrt2%O%s}} \
crtbegin.o%s \
%{fvtable-verify=none:%s; \
fvtable-verify=preinit:vtv_start.o%s; \
