Add base variables for windows clang

This just copies most of what exists for clang on Linux, but doesn't
actually turn on clang support.

Bug: 69933068
Test: m nothing; compare ninja files
Change-Id: I2cf203026e7ced32004a91d7f3baf4a6415085eb

2 files changed, 65 insertions, 8 deletions

diff --git a/cc/config/clang.go b/cc/config/clang.go
index 2ef153be..302c68ee 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -77,6 +77,9 @@ var ClangUnknownCflags = sorted([]string{
 	"-fno-inline-functions-called-once",
 	"-mfpmath=sse",
 	"-mbionic",
+
+	// windows
+	"--enable-stdcall-fixup",
 })
 
 var ClangLibToolingUnknownCflags = []string{
diff --git a/cc/config/x86_windows_host.go b/cc/config/x86_windows_host.go
index c9bafe61..016e7112 100644
--- a/cc/config/x86_windows_host.go
+++ b/cc/config/x86_windows_host.go
@@ -41,15 +41,30 @@ var (
 
 		"--sysroot ${WindowsGccRoot}/${WindowsGccTriple}",
 	}
+	windowsClangCflags = append(ClangFilterUnknownCflags(windowsCflags), []string{}...)
 
 	windowsIncludeFlags = []string{
 		"-isystem ${WindowsGccRoot}/${WindowsGccTriple}/include",
 		"-isystem ${WindowsGccRoot}/lib/gcc/${WindowsGccTriple}/4.8.3/include",
 	}
 
+	windowsClangCppflags = []string{
+		"-isystem ${WindowsGccRoot}/${WindowsGccTriple}/include/c++/4.8.3",
+		"-isystem ${WindowsGccRoot}/${WindowsGccTriple}/include/c++/4.8.3/backward",
+	}
+
+	windowsX86ClangCppflags = []string{
+		"-isystem ${WindowsGccRoot}/${WindowsGccTriple}/include/c++/4.8.3/${WindowsGccTriple}/32",
+	}
+
+	windowsX8664ClangCppflags = []string{
+		"-isystem ${WindowsGccRoot}/${WindowsGccTriple}/include/c++/4.8.3/${WindowsGccTriple}",
+	}
+
 	windowsLdflags = []string{
 		"--enable-stdcall-fixup",
 	}
+	windowsClangLdflags = append(ClangFilterUnknownCflags(windowsLdflags), []string{}...)
 
 	windowsX86Cflags = []string{
 		"-m32",
@@ -64,11 +79,21 @@ var (
 		"-Wl,--large-address-aware",
 		"-L${WindowsGccRoot}/${WindowsGccTriple}/lib32",
 	}
+	windowsX86ClangLdflags = append(ClangFilterUnknownCflags(windowsX86Ldflags), []string{
+		"-B${WindowsGccRoot}/lib/gcc/${WindowsGccTriple}/4.8.3/32",
+		"-L${WindowsGccRoot}/lib/gcc/${WindowsGccTriple}/4.8.3/32",
+		"-B${WindowsGccRoot}/${WindowsGccTriple}/lib32",
+	}...)
 
 	windowsX8664Ldflags = []string{
 		"-m64",
 		"-L${WindowsGccRoot}/${WindowsGccTriple}/lib64",
 	}
+	windowsX8664ClangLdflags = append(ClangFilterUnknownCflags(windowsX8664Ldflags), []string{
+		"-B${WindowsGccRoot}/lib/gcc/${WindowsGccTriple}/4.8.3",
+		"-L${WindowsGccRoot}/lib/gcc/${WindowsGccTriple}/4.8.3",
+		"-B${WindowsGccRoot}/${WindowsGccTriple}/lib64",
+	}...)
 
 	windowsAvailableLibraries = addPrefix([]string{
 		"gdi32",
@@ -101,11 +126,24 @@ func init() {
 	pctx.StaticVariable("WindowsCflags", strings.Join(windowsCflags, " "))
 	pctx.StaticVariable("WindowsLdflags", strings.Join(windowsLdflags, " "))
 
+	pctx.StaticVariable("WindowsClangCflags", strings.Join(windowsClangCflags, " "))
+	pctx.StaticVariable("WindowsClangLdflags", strings.Join(windowsClangLdflags, " "))
+	pctx.StaticVariable("WindowsClangCppflags", strings.Join(windowsClangCppflags, " "))
+
 	pctx.StaticVariable("WindowsX86Cflags", strings.Join(windowsX86Cflags, " "))
 	pctx.StaticVariable("WindowsX8664Cflags", strings.Join(windowsX8664Cflags, " "))
 	pctx.StaticVariable("WindowsX86Ldflags", strings.Join(windowsX86Ldflags, " "))
 	pctx.StaticVariable("WindowsX8664Ldflags", strings.Join(windowsX8664Ldflags, " "))
 
+	pctx.StaticVariable("WindowsX86ClangCflags",
+		strings.Join(ClangFilterUnknownCflags(windowsX86Cflags), " "))
+	pctx.StaticVariable("WindowsX8664ClangCflags",
+		strings.Join(ClangFilterUnknownCflags(windowsX8664Cflags), " "))
+	pctx.StaticVariable("WindowsX86ClangLdflags", strings.Join(windowsX86ClangLdflags, " "))
+	pctx.StaticVariable("WindowsX8664ClangLdflags", strings.Join(windowsX8664ClangLdflags, " "))
+	pctx.StaticVariable("WindowsX86ClangCppflags", strings.Join(windowsX86ClangCppflags, " "))
+	pctx.StaticVariable("WindowsX8664ClangCppflags", strings.Join(windowsX8664ClangCppflags, " "))
+
 	pctx.StaticVariable("WindowsIncludeFlags", strings.Join(windowsIncludeFlags, " "))
 }
 
@@ -179,20 +217,36 @@ func (t *toolchainWindows) ClangSupported() bool {
 	return false
 }
 
-func (t *toolchainWindows) ClangTriple() string {
-	panic("Clang is not supported under mingw")
+func (t *toolchainWindowsX86) ClangTriple() string {
+	return "i686-windows-gnu"
+}
+
+func (t *toolchainWindowsX8664) ClangTriple() string {
+	return "x86_64-pc-windows-gnu"
+}
+
+func (t *toolchainWindowsX86) ClangCflags() string {
+	return "${config.WindowsClangCflags} ${config.WindowsX86ClangCflags}"
+}
+
+func (t *toolchainWindowsX8664) ClangCflags() string {
+	return "${config.WindowsClangCflags} ${config.WindowsX8664ClangCflags}"
+}
+
+func (t *toolchainWindowsX86) ClangCppflags() string {
+	return "${config.WindowsClangCppflags} ${config.WindowsX86ClangCppflags}"
 }
 
-func (t *toolchainWindows) ClangCflags() string {
-	panic("Clang is not supported under mingw")
+func (t *toolchainWindowsX8664) ClangCppflags() string {
+	return "${config.WindowsClangCppflags} ${config.WindowsX8664ClangCppflags}"
 }
 
-func (t *toolchainWindows) ClangCppflags() string {
-	panic("Clang is not supported under mingw")
+func (t *toolchainWindowsX86) ClangLdflags() string {
+	return "${config.WindowsClangLdflags} ${config.WindowsX86ClangLdflags}"
 }
 
-func (t *toolchainWindows) ClangLdflags() string {
-	panic("Clang is not supported under mingw")
+func (t *toolchainWindowsX8664) ClangLdflags() string {
+	return "${config.WindowsClangLdflags} ${config.WindowsX8664ClangLdflags}"
 }
 
 func (t *toolchainWindows) ShlibSuffix() string {