[dev.cc] runtime: generate GOOS- and GOARCH-specific files with go generate

Eventually I'd like almost everything cmd/dist generates
to be done with 'go generate' and checked in, to simplify
the bootstrap process. The only thing cmd/dist really needs
to do is write things like the current experiment info and
the current version.

This is a first step toward that. It replaces the _NaCl etc
constants with generated ones goos_nacl, goos_darwin,
goarch_386, and so on.

LGTM=dave, austin
R=austin, dave, bradfitz
CC=golang-codereviews, iant, r
https://codereview.appspot.com/174290043

2 files changed, 3 insertions, 64 deletions

diff --git a/src/cmd/dist/build.c b/src/cmd/dist/build.c
index e4f307bee..bfb3d15b8 100644
--- a/src/cmd/dist/build.c
+++ b/src/cmd/dist/build.c
@@ -615,8 +615,6 @@ static struct {
 	{"anames9.c", mkanames},
 	{"zdefaultcc.go", mkzdefaultcc},
 	{"zsys_", mkzsys},
-	{"zgoarch_", mkzgoarch},
-	{"zgoos_", mkzgoos},
 	{"zversion.go", mkzversion},
 	{"zaexperiment.h", mkzexperiment},
 
@@ -1419,12 +1417,13 @@ clean(void)
 			xremove(bpathf(&b, "%s/%s", bstr(&path), cleantab[i]+4));
 	}
 
-	// remove src/runtime/z* unconditionally
+	// remove src/runtime/z* unconditionally,
+	// except leave zgoos and zgoarch, now maintained with go generate.
 	vreset(&dir);
 	bpathf(&path, "%s/src/runtime", goroot);
 	xreaddir(&dir, bstr(&path));
 	for(j=0; j<dir.len; j++) {
-		if(hasprefix(dir.p[j], "z"))
+		if(hasprefix(dir.p[j], "z") && !hasprefix(dir.p[j], "zg"))
 			xremove(bpathf(&b, "%s/%s", bstr(&path), dir.p[j]));
 	}
 
diff --git a/src/cmd/dist/buildruntime.c b/src/cmd/dist/buildruntime.c
index e561937fb..38e99e116 100644
--- a/src/cmd/dist/buildruntime.c
+++ b/src/cmd/dist/buildruntime.c
@@ -67,66 +67,6 @@ mkzexperiment(char *dir, char *file)
 	bfree(&exp);
 }
 
-// mkzgoarch writes zgoarch_$GOARCH.go:
-//
-//	package runtime
-//	const theGoarch = <goarch>
-//
-void
-mkzgoarch(char *dir, char *file)
-{
-	Buf b, out;
-
-	USED(dir);
-	
-	binit(&b);
-	binit(&out);
-	
-	bwritestr(&out, bprintf(&b,
-		"// auto generated by go tool dist\n"
-		"\n"
-		"package runtime\n"
-		"\n"
-		"const theGoarch = `%s`\n", goarch));
-
-	writefile(&out, file, 0);
-	
-	bfree(&b);
-	bfree(&out);
-}
-
-// mkzgoos writes zgoos_$GOOS.go:
-//
-//	package runtime
-//	const theGoos = <goos>
-//
-void
-mkzgoos(char *dir, char *file)
-{
-	Buf b, out;
-
-	USED(dir);
-	
-	binit(&b);
-	binit(&out);
-
-	bwritestr(&out, "// auto generated by go tool dist\n\n");
-
-	if(streq(goos, "linux")) {
-		bwritestr(&out, "// +build !android\n\n");
-	}
-	
-	bwritestr(&out, bprintf(&b,
-		"package runtime\n"
-		"\n"
-		"const theGoos = `%s`\n", goos));
-
-	writefile(&out, file, 0);
-	
-	bfree(&b);
-	bfree(&out);
-}
-
 #define MAXWINCB 2000 /* maximum number of windows callbacks allowed */
 
 // mkzsys writes zsys_$GOOS_$GOARCH.s,