src/cmd/dist/buildruntime.c

// Copyright 2012 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "a.h"

/*
 * Helpers for building runtime.
 */

// mkzversion writes zversion.go:
//
//	package runtime
//	const defaultGoroot = <goroot>
//	const theVersion = <version>
//
void
mkzversion(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 defaultGoroot = `%s`\n"
		"const theVersion = `%s`\n"
		"var buildVersion = theVersion\n", goroot_final, goversion));

	writefile(&out, file, 0);
	
	bfree(&b);
	bfree(&out);
}

// mkzexperiment writes zaexperiment.h (sic):
//
//	#define GOEXPERIMENT "experiment string"
//
void
mkzexperiment(char *dir, char *file)
{
	Buf b, out, exp;
	
	USED(dir);

	binit(&b);
	binit(&out);
	binit(&exp);
	
	xgetenv(&exp, "GOEXPERIMENT");
	bwritestr(&out, bprintf(&b,
		"// auto generated by go tool dist\n"
		"\n"
		"#define GOEXPERIMENT \"%s\"\n", bstr(&exp)));

	writefile(&out, file, 0);
	
	bfree(&b);
	bfree(&out);
	bfree(&exp);
}

#define MAXWINCB 2000 /* maximum number of windows callbacks allowed */

// mkzsys writes zsys_$GOOS_$GOARCH.s,
// which contains arch or os specific asm code.
// 
void
mkzsys(char *dir, char *file)
{
	int i;
	Buf out;

	USED(dir);
	
	binit(&out);
	
	bwritestr(&out, "// auto generated by go tool dist\n\n");
	if(streq(goos, "linux")) {
		bwritestr(&out, "// +build !android\n\n");
	}
	
	if(streq(goos, "windows")) {
		bwritef(&out,
			"// runtime·callbackasm is called by external code to\n"
			"// execute Go implemented callback function. It is not\n"
			"// called from the start, instead runtime·compilecallback\n"
			"// always returns address into runtime·callbackasm offset\n"
			"// appropriately so different callbacks start with different\n"
			"// CALL instruction in runtime·callbackasm. This determines\n"
			"// which Go callback function is executed later on.\n"
			"TEXT runtime·callbackasm(SB),7,$0\n");
		for(i=0; i<MAXWINCB; i++) {
			bwritef(&out, "\tCALL\truntime·callbackasm1(SB)\n");
		}
		bwritef(&out, "\tRET\n");
	}

	writefile(&out, file, 0);
	
	bfree(&out);
}