--- a/build/moz.configure/rust.configure
+++ b/build/moz.configure/rust.configure
@@ -102,39 +102,42 @@ set_config('MOZ_RUST', rust_compiler)
 @template
 def rust_triple_alias(host_or_target):
     """Template defining the alias used for rustc's --target flag.
     `host_or_target` is either `host` or `target` (the @depends functions
     from init.configure).
     """
     assert host_or_target in (host, target)
 
-    @depends(rustc, host_or_target, when=rust_compiler)
+    @depends(rustc, host_or_target, building_with_gcc, when=rust_compiler)
     @imports('os')
     @imports('subprocess')
     @imports(_from='mozbuild.configure.util', _import='LineIO')
     @imports(_from='mozbuild.shellutil', _import='quote')
     @imports(_from='tempfile', _import='mkstemp')
     @imports(_from='textwrap', _import='dedent')
-    def rust_target(rustc, host_or_target):
+    def rust_target(rustc, host_or_target, building_with_gcc):
         # Rust's --target options are similar to, but not exactly the same
         # as, the autoconf-derived targets we use.  An example would be that
         # Rust uses distinct target triples for targetting the GNU C++ ABI
         # and the MSVC C++ ABI on Win32, whereas autoconf has a single
         # triple and relies on the user to ensure that everything is
         # compiled for the appropriate ABI.  We need to perform appropriate
         # munging to get the correct option to rustc.
         #
         # The canonical list of targets supported can be derived from:
         #
         # https://github.com/rust-lang/rust/blob/master/src/librustc_back/target/mod.rs
 
         # Avoid having to write out os+kernel for all the platforms where
         # they don't differ.
         os_or_kernel = host_or_target.kernel if host_or_target.kernel == 'Linux' and host_or_target.os != 'Android' else host_or_target.os
+        # If we are targetting Windows but the compiler is gcc, we need to
+        # use a different rustc target
+        os_or_kernel = 'WINNT-MINGW' if building_with_gcc and host_or_target.kernel == 'WINNT' else os_or_kernel
         rustc_target = {
             # DragonFly
             ('x86_64', 'DragonFly'): 'x86_64-unknown-dragonfly',
             # FreeBSD
             ('aarch64', 'FreeBSD'): 'aarch64-unknown-freebsd',
             ('x86', 'FreeBSD'): 'i686-unknown-freebsd',
             ('x86_64', 'FreeBSD'): 'x86_64-unknown-freebsd',
             # NetBSD
@@ -158,20 +161,20 @@ def rust_triple_alias(host_or_target):
             ('arm', 'iOS'): 'armv7s-apple-ios',
             ('x86', 'iOS'): 'i386-apple-ios',
             ('x86_64', 'iOS'): 'x86_64-apple-ios',
             # Android
             ('aarch64', 'Android'): 'aarch64-linux-android',
             ('arm', 'Android'): 'armv7-linux-androideabi',
             ('x86', 'Android'): 'i686-linux-android',
             # Windows
-            # XXX better detection of CXX needed here, to figure out whether
-            # we need i686-pc-windows-gnu instead, since mingw32 builds work.
             ('x86', 'WINNT'): 'i686-pc-windows-msvc',
             ('x86_64', 'WINNT'): 'x86_64-pc-windows-msvc',
+            ('x86', 'WINNT-MINGW'): 'i686-pc-windows-gnu',
+            ('x86_64', 'WINNT-MINGW'): 'x86_64-pc-windows-gnu',
         }.get((host_or_target.cpu, os_or_kernel), None)
 
         if rustc_target is None:
             die("Don't know how to translate {} for rustc".format(host_or_target.alias))
 
         # Check to see whether our rustc has a reasonably functional stdlib
         # for our chosen target.
         target_arg = '--target=' + rustc_target

--- a/config/expandlibs_config.py
+++ b/config/expandlibs_config.py
@@ -12,16 +12,18 @@ def normalize_suffix(suffix):
         value = '.' + value
     return value
 
 # Variables from the build system
 AR = substs['AR']
 AR_EXTRACT = substs['AR_EXTRACT'].replace('$(AR)', AR)
 DLL_PREFIX = substs['DLL_PREFIX']
 LIB_PREFIX = substs['LIB_PREFIX']
+RUST_LIB_PREFIX = substs['RUST_LIB_PREFIX']
 OBJ_SUFFIX = normalize_suffix(substs['OBJ_SUFFIX'])
 LIB_SUFFIX = normalize_suffix(substs['LIB_SUFFIX'])
+RUST_LIB_SUFFIX = normalize_suffix(substs['RUST_LIB_SUFFIX'])
 DLL_SUFFIX = normalize_suffix(substs['DLL_SUFFIX'])
 IMPORT_LIB_SUFFIX = normalize_suffix(substs['IMPORT_LIB_SUFFIX'])
 LIBS_DESC_SUFFIX = normalize_suffix(substs['LIBS_DESC_SUFFIX'])
 EXPAND_LIBS_LIST_STYLE = substs['EXPAND_LIBS_LIST_STYLE']
 EXPAND_LIBS_ORDER_STYLE = substs['EXPAND_LIBS_ORDER_STYLE']
 LD_PRINT_ICF_SECTIONS = substs['LD_PRINT_ICF_SECTIONS']

--- a/config/makefiles/debugmake.mk
+++ b/config/makefiles/debugmake.mk
@@ -89,16 +89,17 @@ showbuild:
 		OS_LIBS \
 		EXTRA_LIBS \
 		BIN_FLAGS \
 		INCLUDES \
 		DEFINES \
 		ACDEFINES \
 		BIN_SUFFIX \
 		LIB_SUFFIX \
+		RUST_LIB_SUFFIX \
 		DLL_SUFFIX \
 		IMPORT_LIB_SUFFIX \
 		INSTALL \
 		VPATH \
 	)
 
 showhost:
 	$(call print_vars,\

--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -403,19 +403,21 @@ dnl ====================================
 dnl set the defaults first
 dnl ========================================================
 AS_BIN=$AS
 AR_EXTRACT='$(AR) x'
 AS='$(CC)'
 AS_DASH_C_FLAG='-c'
 DLL_PREFIX=lib
 LIB_PREFIX=lib
+RUST_LIB_PREFIX=lib
 DLL_SUFFIX=.so
 OBJ_SUFFIX=o
 LIB_SUFFIX=a
+RUST_LIB_SUFFIX=a
 IMPORT_LIB_SUFFIX=
 DIRENT_INO=d_ino
 MOZ_USER_DIR=".mozilla"
 
 MOZ_FIX_LINK_PATHS="-Wl,-rpath-link,${DIST}/bin -Wl,-rpath-link,${prefix}/lib"
 
 dnl Configure platform-specific CPU architecture compiler options.
 dnl ==============================================================
@@ -668,18 +670,20 @@ case "$target" in
         AR='lib'
         AR_FLAGS='-NOLOGO -OUT:$@'
         AR_EXTRACT=
         RANLIB='echo not_ranlib'
         STRIP='echo not_strip'
         PKG_SKIP_STRIP=1
         OBJ_SUFFIX=obj
         LIB_SUFFIX=lib
+        RUST_LIB_SUFFIX=lib
         DLL_PREFIX=
         LIB_PREFIX=
+        RUST_LIB_PREFIX=
         IMPORT_LIB_SUFFIX=lib
         MKSHLIB='$(LINK) -NOLOGO -DLL -OUT:$@ -PDB:$(LINK_PDBFILE) $(DSO_LDOPTS)'
         MKCSHLIB='$(LINK) -NOLOGO -DLL -OUT:$@ -PDB:$(LINK_PDBFILE) $(DSO_LDOPTS)'
         WIN32_SUBSYSTEM_VERSION=6.01
         WIN32_CONSOLE_EXE_LDFLAGS=-SUBSYSTEM:CONSOLE,$WIN32_SUBSYSTEM_VERSION
         WIN32_GUI_EXE_LDFLAGS=-SUBSYSTEM:WINDOWS,$WIN32_SUBSYSTEM_VERSION
         DSO_LDOPTS=-SUBSYSTEM:WINDOWS,$WIN32_SUBSYSTEM_VERSION
         _USE_CPP_INCLUDE_FLAG=1
@@ -2090,20 +2094,22 @@ AC_SUBST(TARGET_XPCOM_ABI)
 
 AC_SUBST(WRAP_LDFLAGS)
 AC_SUBST(MKSHLIB)
 AC_SUBST(MKCSHLIB)
 AC_SUBST(DSO_CFLAGS)
 AC_SUBST(DSO_PIC_CFLAGS)
 AC_SUBST(DSO_LDOPTS)
 AC_SUBST(LIB_PREFIX)
+AC_SUBST(RUST_LIB_PREFIX)
 AC_SUBST(DLL_PREFIX)
 AC_SUBST(DLL_SUFFIX)
 AC_DEFINE_UNQUOTED(MOZ_DLL_SUFFIX, "$DLL_SUFFIX")
 AC_SUBST(LIB_SUFFIX)
+AC_SUBST(RUST_LIB_SUFFIX)
 AC_SUBST(OBJ_SUFFIX)
 AC_SUBST(BIN_SUFFIX)
 AC_SUBST(IMPORT_LIB_SUFFIX)
 AC_SUBST(USE_N32)
 AC_SUBST(CC_VERSION)
 AC_SUBST(MOZ_LINKER)
 AC_SUBST(WIN32_CONSOLE_EXE_LDFLAGS)
 AC_SUBST(WIN32_GUI_EXE_LDFLAGS)

--- a/old-configure.in
+++ b/old-configure.in
@@ -501,19 +501,21 @@ dnl ====================================
 dnl set the defaults first
 dnl ========================================================
 AS_BIN=$AS
 AR_EXTRACT='$(AR) x'
 AS='$(CC)'
 AS_DASH_C_FLAG='-c'
 DLL_PREFIX=lib
 LIB_PREFIX=lib
+RUST_LIB_PREFIX=lib
 DLL_SUFFIX=.so
 OBJ_SUFFIX=o
 LIB_SUFFIX=a
+RUST_LIB_SUFFIX=a
 IMPORT_LIB_SUFFIX=
 DIRENT_INO=d_ino
 MOZ_USER_DIR=".mozilla"
 
 MOZ_FIX_LINK_PATHS="-Wl,-rpath-link,${DIST}/bin -Wl,-rpath-link,${prefix}/lib"
 
 MOZ_FS_LAYOUT=unix
 
@@ -921,16 +923,18 @@ case "$target" in
         NSPR_LDFLAGS="$NSPR_LDFLAGS -static-libgcc"
         # Use temp file for windres (bug 213281)
         RCFLAGS='-O coff --use-temp-file'
         # mingw doesn't require kernel32, user32, and advapi32 explicitly
         LIBS="$LIBS -luuid -lgdi32 -lwinmm -lwsock32 -luserenv -lsecur32"
         MOZ_FIX_LINK_PATHS=
         DLL_PREFIX=
         IMPORT_LIB_SUFFIX=a
+        RUST_LIB_PREFIX=
+        RUST_LIB_SUFFIX=lib
 
         WIN32_CONSOLE_EXE_LDFLAGS=-mconsole
         WIN32_GUI_EXE_LDFLAGS=-mwindows
 
         # GCC/binutils can't link to a function if we try to include dllexport function
         # in the same library as dllimport caller. To work around it, we build NSPR
         # and NSS with -mnop-fun-dllimport flag. The drawback of this solution is that
         # function thunks need to be generated for cross-DLL calls.
@@ -943,18 +947,20 @@ case "$target" in
         AR='lib'
         AR_FLAGS='-NOLOGO -OUT:$@'
         AR_EXTRACT=
         RANLIB='echo not_ranlib'
         STRIP='echo not_strip'
         PKG_SKIP_STRIP=1
         OBJ_SUFFIX=obj
         LIB_SUFFIX=lib
+        RUST_LIB_SUFFIX=lib
         DLL_PREFIX=
         LIB_PREFIX=
+        RUST_LIB_PREFIX=
         IMPORT_LIB_SUFFIX=lib
         MKSHLIB='$(LINK) -NOLOGO -DLL -OUT:$@ -PDB:$(LINK_PDBFILE) $(DSO_LDOPTS)'
         MKCSHLIB='$(LINK) -NOLOGO -DLL -OUT:$@ -PDB:$(LINK_PDBFILE) $(DSO_LDOPTS)'
         WIN32_SUBSYSTEM_VERSION=6.01
         WIN32_CONSOLE_EXE_LDFLAGS=-SUBSYSTEM:CONSOLE,$WIN32_SUBSYSTEM_VERSION
         WIN32_GUI_EXE_LDFLAGS=-SUBSYSTEM:WINDOWS,$WIN32_SUBSYSTEM_VERSION
         DSO_LDOPTS=-SUBSYSTEM:WINDOWS,$WIN32_SUBSYSTEM_VERSION
         _USE_CPP_INCLUDE_FLAG=1
@@ -5317,20 +5323,22 @@ AC_SUBST(GCC_USE_GNU_LD)
 
 AC_SUBST(WRAP_LDFLAGS)
 AC_SUBST(MKSHLIB)
 AC_SUBST(MKCSHLIB)
 AC_SUBST(DSO_CFLAGS)
 AC_SUBST(DSO_PIC_CFLAGS)
 AC_SUBST(DSO_LDOPTS)
 AC_SUBST(LIB_PREFIX)
+AC_SUBST(RUST_LIB_PREFIX)
 AC_SUBST(DLL_PREFIX)
 AC_SUBST(DLL_SUFFIX)
 AC_DEFINE_UNQUOTED(MOZ_DLL_SUFFIX, "$DLL_SUFFIX")
 AC_SUBST(LIB_SUFFIX)
+AC_SUBST(RUST_LIB_SUFFIX)
 AC_SUBST(OBJ_SUFFIX)
 AC_SUBST(BIN_SUFFIX)
 AC_SUBST(IMPORT_LIB_SUFFIX)
 AC_SUBST(USE_N32)
 AC_SUBST(CC_VERSION)
 AC_SUBST(NS_ENABLE_TSF)
 AC_SUBST(WIN32_CONSOLE_EXE_LDFLAGS)
 AC_SUBST(WIN32_GUI_EXE_LDFLAGS)

--- a/python/mozbuild/mozbuild/backend/configenvironment.py
+++ b/python/mozbuild/mozbuild/backend/configenvironment.py
@@ -120,18 +120,21 @@ class ConfigEnvironment(object):
         self.source = source
         self.defines = ReadOnlyDict(defines or {})
         self.non_global_defines = non_global_defines or []
         self.substs = dict(substs or {})
         self.topsrcdir = mozpath.abspath(topsrcdir)
         self.topobjdir = mozpath.abspath(topobjdir)
         self.mozconfig = mozpath.abspath(mozconfig) if mozconfig else None
         self.lib_prefix = self.substs.get('LIB_PREFIX', '')
+        self.rust_lib_prefix = self.substs.get('RUST_LIB_PREFIX', '')
         if 'LIB_SUFFIX' in self.substs:
             self.lib_suffix = '.%s' % self.substs['LIB_SUFFIX']
+        if 'RUST_LIB_SUFFIX' in self.substs:
+            self.rust_lib_suffix = '.%s' % self.substs['RUST_LIB_SUFFIX']
         self.dll_prefix = self.substs.get('DLL_PREFIX', '')
         self.dll_suffix = self.substs.get('DLL_SUFFIX', '')
         if self.substs.get('IMPORT_LIB_SUFFIX'):
             self.import_prefix = self.lib_prefix
             self.import_suffix = '.%s' % self.substs['IMPORT_LIB_SUFFIX']
         else:
             self.import_prefix = self.dll_prefix
             self.import_suffix = self.dll_suffix

--- a/python/mozbuild/mozbuild/frontend/data.py
+++ b/python/mozbuild/mozbuild/frontend/data.py
@@ -534,19 +534,19 @@ class RustLibrary(StaticLibrary):
         StaticLibrary.__init__(self, context, basename, **args)
         self.cargo_file = cargo_file
         self.crate_type = crate_type
         # We need to adjust our naming here because cargo replaces '-' in
         # package names defined in Cargo.toml with underscores in actual
         # filenames. But we need to keep the basename consistent because
         # many other things in the build system depend on that.
         assert self.crate_type == 'staticlib'
-        self.lib_name = '%s%s%s' % (context.config.lib_prefix,
+        self.lib_name = '%s%s%s' % (context.config.rust_lib_prefix,
                                      basename.replace('-', '_'),
-                                     context.config.lib_suffix)
+                                     context.config.rust_lib_suffix)
         self.dependencies = dependencies
         build_dir = mozpath.join(target_dir,
                                  cargo_output_directory(context, self.TARGET_SUBST_VAR))
         self.import_name = mozpath.join(build_dir, self.lib_name)
         self.deps_path = mozpath.join(build_dir, 'deps')
         self.features = features
         self.target_dir = target_dir
 

--- a/python/mozbuild/mozbuild/test/backend/common.py
+++ b/python/mozbuild/mozbuild/test/backend/common.py
@@ -43,60 +43,70 @@ CONFIGS = defaultdict(lambda: {
             'MOZ_WIDGET_TOOLKIT': 'android',
         },
     },
     'binary-components': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'LIB_PREFIX': 'lib',
+            'RUST_LIB_PREFIX': 'lib',
             'LIB_SUFFIX': 'a',
+            'RUST_LIB_SUFFIX': 'a',
             'COMPILE_ENVIRONMENT': '1',
         },
     },
     'rust-library': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'COMPILE_ENVIRONMENT': '1',
             'RUST_TARGET': 'x86_64-unknown-linux-gnu',
             'LIB_PREFIX': 'lib',
+            'RUST_LIB_PREFIX': 'lib',
             'LIB_SUFFIX': 'a',
+            'RUST_LIB_SUFFIX': 'a',
         },
     },
     'host-rust-library': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'COMPILE_ENVIRONMENT': '1',
             'RUST_HOST_TARGET': 'x86_64-unknown-linux-gnu',
             'RUST_TARGET': 'armv7-linux-androideabi',
             'LIB_PREFIX': 'lib',
+            'RUST_LIB_PREFIX': 'lib',
             'LIB_SUFFIX': 'a',
+            'RUST_LIB_SUFFIX': 'a',
         },
     },
     'host-rust-library-features': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'COMPILE_ENVIRONMENT': '1',
             'RUST_HOST_TARGET': 'x86_64-unknown-linux-gnu',
             'RUST_TARGET': 'armv7-linux-androideabi',
             'LIB_PREFIX': 'lib',
+            'RUST_LIB_PREFIX': 'lib',
             'LIB_SUFFIX': 'a',
+            'RUST_LIB_SUFFIX': 'a',
         },
     },
     'rust-library-features': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'COMPILE_ENVIRONMENT': '1',
             'RUST_TARGET': 'x86_64-unknown-linux-gnu',
             'LIB_PREFIX': 'lib',
+            'RUST_LIB_PREFIX': 'lib',
             'LIB_SUFFIX': 'a',
+            'RUST_LIB_SUFFIX': 'a',
         },
     },
     'rust-programs': {
         'defines': {},
         'non_global_defines': [],
         'substs': {
             'COMPILE_ENVIRONMENT': '1',
             'RUST_TARGET': 'i686-pc-windows-msvc',

--- a/python/mozbuild/mozbuild/test/common.py
+++ b/python/mozbuild/mozbuild/test/common.py
@@ -37,14 +37,16 @@ class MockConfig(object):
 
         self.substs_unicode = ReadOnlyDict({k.decode('utf-8'): v.decode('utf-8',
             'replace') for k, v in self.substs.items()})
 
         self.defines = self.substs
 
         self.external_source_dir = None
         self.lib_prefix = 'lib'
+        self.rust_lib_prefix = 'lib'
         self.lib_suffix = '.a'
+        self.rust_lib_suffix = '.a'
         self.import_prefix = 'lib'
         self.import_suffix = '.so'
         self.dll_prefix = 'lib'
         self.dll_suffix = '.so'
         self.error_is_fatal = error_is_fatal