runtime/pprof: support OS X CPU profiling

Work around profiling kernel bug with signal masks.
Still broken on 64-bit Snow Leopard kernel,
but I think we can ignore that one and let people
upgrade to Lion.

Add new trivial tools addr2line and objdump to take
the place of the GNU tools of the same name, since
those are not installed on OS X.

Adapt pprof to invoke 'go tool addr2line' and
'go tool objdump' if the system tools do not exist.

Clean up disassembly of base register on amd64.

Fixes issue 2008.

R=golang-dev, bradfitz, mikioh.mikioh, r, iant
CC=golang-dev
http://codereview.appspot.com/5697066

3 files changed, 188 insertions, 48 deletions

diff --git a/src/cmd/addr2line/main.c b/src/cmd/addr2line/main.c
new file mode 100644
index 000000000..6b2fe5dfe
--- /dev/null
+++ b/src/cmd/addr2line/main.c
@@ -0,0 +1,68 @@
+// 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.
+
+/*
+ * addr2line simulation - only enough to make pprof work on Macs
+ */
+
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <mach.h>
+
+void
+usage(void)
+{
+	fprint(2, "usage: addr2line binary\n");
+	fprint(2, "reads addresses from standard input and writes two lines for each:\n");
+	fprint(2, "\tfunction name\n");
+	fprint(2, "\tfile:line\n");
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int fd;
+	char *p;
+	uvlong pc;
+	Symbol s;
+	Fhdr fhdr;
+	Biobuf bin, bout;
+	char file[1024];
+
+	ARGBEGIN{
+	default:
+		usage();
+	}ARGEND
+
+	if(argc != 1)
+		usage();
+
+	fd = open(argv[0], OREAD);
+	if(fd < 0)
+		sysfatal("open %s: %r", argv[0]);
+	if(crackhdr(fd, &fhdr) <= 0)
+		sysfatal("crackhdr: %r");
+	machbytype(fhdr.type);
+	if(syminit(fd, &fhdr) <= 0)
+		sysfatal("syminit: %r");
+
+	Binit(&bin, 0, OREAD);
+	Binit(&bout, 1, OWRITE);
+	for(;;) {
+		p = Brdline(&bin, '\n');
+		if(p == nil)
+			break;
+		p[Blinelen(&bin)-1] = '\0';
+		pc = strtoull(p, 0, 16);
+		if(!findsym(pc, CTEXT, &s))
+			s.name = "??";
+		if(!fileline(file, sizeof file, pc))
+			strcpy(file, "??:0");
+		Bprint(&bout, "%s\n%s\n", s.name, file);
+	}
+	Bflush(&bout);
+	exits(0);
+}
diff --git a/src/cmd/dist/build.c b/src/cmd/dist/build.c
index 5664c1890..66b5c1f18 100644
--- a/src/cmd/dist/build.c
+++ b/src/cmd/dist/build.c
@@ -59,7 +59,7 @@ int
 find(char *p, char **l, int n)
 {
 	int i;
-	
+
 	for(i=0; i<n; i++)
 		if(streq(p, l[i]))
 			return i;
@@ -73,7 +73,7 @@ init(void)
 	char *p;
 	int i;
 	Buf b;
-	
+
 	binit(&b);
 
 	xgetenv(&b, "GOROOT");
@@ -126,7 +126,7 @@ init(void)
 	xsetenv("GOROOT", goroot);
 	xsetenv("GOARCH", goarch);
 	xsetenv("GOOS", goos);
-	
+
 	// Make the environment more predictable.
 	xsetenv("LANG", "C");
 	xsetenv("LANGUAGE", "en_US.UTF8");
@@ -170,13 +170,13 @@ findgoversion(void)
 	int i, nrev;
 	Buf b, path, bmore, branch;
 	Vec tags;
-	
+
 	binit(&b);
 	binit(&path);
 	binit(&bmore);
 	binit(&branch);
 	vinit(&tags);
-	
+
 	// The $GOROOT/VERSION file takes priority, for distributions
 	// without the Mercurial repo.
 	bpathf(&path, "%s/VERSION", goroot);
@@ -232,14 +232,14 @@ findgoversion(void)
 		bprintf(&b, "branch.%s", bstr(&branch));
 		tag = btake(&b);
 	}
-	
+
 	if(rev[0]) {
 		// Tag is before the revision we're building.
 		// Add extra information.
 		run(&bmore, goroot, CheckExit, "hg", "log", "--template", " +{node|short}", "-r", rev, nil);
 		chomp(&bmore);
 	}
-	
+
 	bprintf(&b, "%s", tag);
 	if(bmore.len > 0)
 		bwriteb(&b, &bmore);
@@ -249,14 +249,14 @@ findgoversion(void)
 
 done:
 	p = btake(&b);
-	
-	
+
+
 	bfree(&b);
 	bfree(&path);
 	bfree(&bmore);
 	bfree(&branch);
 	vfree(&tags);
-	
+
 	return p;
 }
 
@@ -325,7 +325,7 @@ setup(void)
 			xremoveall(p);
 		xmkdirall(p);
 	}
-	
+
 	// Create object directory.
 	// We keep it in pkg/ so that all the generated binaries
 	// are in one tree.  If pkg/obj/libgc.a exists, it is a dreg from
@@ -393,7 +393,7 @@ static char *proto_gccargs[] = {
 static Vec gccargs;
 
 // deptab lists changes to the default dependencies for a given prefix.
-// deps ending in /* read the whole directory; deps beginning with - 
+// deps ending in /* read the whole directory; deps beginning with -
 // exclude files with that prefix.
 static struct {
 	char *prefix;  // prefix of target
@@ -559,7 +559,7 @@ install(char *dir)
 	vinit(&clean);
 	vinit(&lib);
 	vinit(&extra);
-	
+
 	// path = full path to dir.
 	bpathf(&path, "%s/src/%s", goroot, dir);
 	name = lastelem(dir);
@@ -599,7 +599,7 @@ install(char *dir)
 	exe = "";
 	if(streq(gohostos, "windows"))
 		exe = ".exe";
-	
+
 	// Start final link command line.
 	// Note: code below knows that link.p[targ] is the target.
 	if(islib) {
@@ -696,13 +696,13 @@ install(char *dir)
 					}
 					files.len = n;
 					continue;
-				}				
+				}
 				vadd(&files, p);
 			}
 		}
 	}
 	vuniq(&files);
-	
+
 	// Convert to absolute paths.
 	for(i=0; i<files.len; i++) {
 		if(!isabs(files.p[i])) {
@@ -740,11 +740,11 @@ install(char *dir)
 		files.p[n++] = files.p[i];
 	}
 	files.len = n;
-	
+
 	for(i=0; i<lib.len && !stale; i++)
 		if(mtime(lib.p[i]) > ttarg)
 			stale = 1;
-		
+
 	if(!stale)
 		goto out;
 
@@ -792,9 +792,9 @@ install(char *dir)
 		copy(bpathf(&b, "%s/zasm_GOOS_GOARCH.h", workdir),
 			bpathf(&b1, "%s/zasm_%s_%s.h", bstr(&path), goos, goarch), 0);
 	}
-	
+
 	// Generate .c files from .goc files.
-	if(streq(dir, "pkg/runtime")) {		
+	if(streq(dir, "pkg/runtime")) {
 		for(i=0; i<files.len; i++) {
 			p = files.p[i];
 			if(!hassuffix(p, ".goc"))
@@ -808,7 +808,7 @@ install(char *dir)
 		}
 		vuniq(&files);
 	}
-	
+
 	if((!streq(goos, gohostos) || !streq(goarch, gohostarch)) && isgo) {
 		// We've generated the right files; the go command can do the build.
 		if(vflag > 1)
@@ -833,13 +833,13 @@ install(char *dir)
 				vadd(&compile, "-m32");
 			if(streq(dir, "lib9"))
 				vadd(&compile, "-DPLAN9PORT");
-	
+
 			vadd(&compile, "-I");
 			vadd(&compile, bpathf(&b, "%s/include", goroot));
-			
+
 			vadd(&compile, "-I");
 			vadd(&compile, bstr(&path));
-	
+
 			// lib9/goos.c gets the default constants hard-coded.
 			if(streq(name, "goos.c")) {
 				vadd(&compile, bprintf(&b, "-DGOOS=\"%s\"", goos));
@@ -849,7 +849,7 @@ install(char *dir)
 				vadd(&compile, bprintf(&b, "-DGOROOT=\"%s\"", bstr(&b1)));
 				vadd(&compile, bprintf(&b, "-DGOVERSION=\"%s\"", goversion));
 			}
-	
+
 			// gc/lex.c records the GOEXPERIMENT setting used during the build.
 			if(streq(name, "lex.c")) {
 				xgetenv(&b, "GOEXPERIMENT");
@@ -867,7 +867,7 @@ install(char *dir)
 			vadd(&compile, workdir);
 			vadd(&compile, bprintf(&b, "-DGOOS_%s", goos));
 			vadd(&compile, bprintf(&b, "-DGOARCH_%s", goarch));
-		}	
+		}
 
 		bpathf(&b, "%s/%s", workdir, lastelem(files.p[i]));
 		doclean = 1;
@@ -893,7 +893,7 @@ install(char *dir)
 			vadd(&clean, bstr(&b));
 	}
 	bgwait();
-	
+
 	if(isgo) {
 		// The last loop was compiling individual files.
 		// Hand the Go files to the compiler en masse.
@@ -905,16 +905,16 @@ install(char *dir)
 		vadd(&compile, bstr(&b));
 		vadd(&clean, bstr(&b));
 		vadd(&link, bstr(&b));
-		
+
 		vadd(&compile, "-p");
 		if(hasprefix(dir, "pkg/"))
 			vadd(&compile, dir+4);
 		else
 			vadd(&compile, "main");
-		
+
 		if(streq(dir, "pkg/runtime"))
 			vadd(&compile, "-+");
-		
+
 		vcopy(&compile, go.p, go.len);
 
 		runv(nil, bstr(&path), CheckExit, &compile);
@@ -980,7 +980,7 @@ shouldbuild(char *file, char *dir)
 	int i, j, ret;
 	Buf b;
 	Vec lines, fields;
-	
+
 	// Check file name for GOOS or GOARCH.
 	name = lastelem(file);
 	for(i=0; i<nelem(okgoos); i++)
@@ -989,11 +989,11 @@ shouldbuild(char *file, char *dir)
 	for(i=0; i<nelem(okgoarch); i++)
 		if(contains(name, okgoarch[i]) && !streq(okgoarch[i], goarch))
 			return 0;
-	
+
 	// Omit test files.
 	if(contains(name, "_test"))
 		return 0;
-	
+
 	// cmd/go/doc.go has a giant /* */ comment before
 	// it gets to the important detail that it is not part of
 	// package main.  We don't parse those comments,
@@ -1046,7 +1046,7 @@ out:
 	bfree(&b);
 	vfree(&lines);
 	vfree(&fields);
-	
+
 	return ret;
 }
 
@@ -1055,7 +1055,7 @@ static void
 copy(char *dst, char *src, int exec)
 {
 	Buf b;
-	
+
 	if(vflag > 1)
 		xprintf("cp %s %s\n", src, dst);
 
@@ -1070,11 +1070,13 @@ static char *buildorder[] = {
 	"lib9",
 	"libbio",
 	"libmach",
-	
+
 	"misc/pprof",
 
+	"cmd/addr2line",
 	"cmd/cov",
 	"cmd/nm",
+	"cmd/objdump",
 	"cmd/pack",
 	"cmd/prof",
 
@@ -1122,12 +1124,12 @@ static char *buildorder[] = {
 	"pkg/go/scanner",
 	"pkg/go/ast",
 	"pkg/go/parser",
-	"pkg/go/build",
 	"pkg/os/exec",
 	"pkg/net/url",
 	"pkg/text/template/parse",
 	"pkg/text/template",
 	"pkg/go/doc",
+	"pkg/go/build",
 	"cmd/go",
 };
 
@@ -1147,11 +1149,13 @@ static char *cleantab[] = {
 	"cmd/8c",
 	"cmd/8g",
 	"cmd/8l",
+	"cmd/addr2line",
 	"cmd/cc",
 	"cmd/cov",
 	"cmd/gc",
 	"cmd/go",
 	"cmd/nm",
+	"cmd/objdump",
 	"cmd/pack",
 	"cmd/prof",
 	"lib9",
@@ -1204,11 +1208,11 @@ clean(void)
 	int i, j, k;
 	Buf b, path;
 	Vec dir;
-	
+
 	binit(&b);
 	binit(&path);
 	vinit(&dir);
-	
+
 	for(i=0; i<nelem(cleantab); i++) {
 		bpathf(&path, "%s/src/%s", goroot, cleantab[i]);
 		xreaddir(&dir, bstr(&path));
@@ -1227,7 +1231,7 @@ clean(void)
 	if(rebuildall) {
 		// Remove object tree.
 		xremoveall(bpathf(&b, "%s/pkg/obj/%s_%s", goroot, gohostos, gohostarch));
-	
+
 		// Remove installed packages and tools.
 		xremoveall(bpathf(&b, "%s/pkg/%s_%s", goroot, gohostos, gohostarch));
 		xremoveall(bpathf(&b, "%s/pkg/%s_%s", goroot, goos, goarch));
@@ -1294,7 +1298,7 @@ cmdenv(int argc, char **argv)
 
 	if(argc > 0)
 		usage();
-	
+
 	xprintf(format, "GOROOT", goroot);
 	xprintf(format, "GOBIN", gobin);
 	xprintf(format, "GOARCH", goarch);
@@ -1346,7 +1350,7 @@ cmdbootstrap(int argc, char **argv)
 		clean();
 	goversion = findgoversion();
 	setup();
-	
+
 	// For the main bootstrap, building for host os/arch.
 	oldgoos = goos;
 	oldgoarch = goarch;
@@ -1356,7 +1360,7 @@ cmdbootstrap(int argc, char **argv)
 	gochar = gohostchar;
 	xsetenv("GOARCH", goarch);
 	xsetenv("GOOS", goos);
-	
+
 	for(i=0; i<nelem(buildorder); i++) {
 		install(bprintf(&b, buildorder[i], gohostchar));
 		if(!streq(oldgochar, gohostchar) && xstrstr(buildorder[i], "%s"))
@@ -1381,7 +1385,7 @@ defaulttarg(void)
 {
 	char *p;
 	Buf pwd, src, real_src;
-	
+
 	binit(&pwd);
 	binit(&src);
 	binit(&real_src);
@@ -1404,7 +1408,7 @@ defaulttarg(void)
 	bfree(&pwd);
 	bfree(&src);
 	bfree(&real_src);
-	
+
 	return p;
 }
 
@@ -1421,7 +1425,7 @@ cmdinstall(int argc, char **argv)
 	default:
 		usage();
 	}ARGEND
-	
+
 	if(argc == 0)
 		install(defaulttarg());
 
@@ -1469,7 +1473,7 @@ cmdbanner(int argc, char **argv)
 	binit(&b);
 	binit(&b1);
 	binit(&search);
-	
+
 	xprintf("\n");
 	xprintf("---\n");
 	xprintf("Installed Go for %s/%s in %s\n", goos, goarch, goroot);
@@ -1490,7 +1494,7 @@ cmdbanner(int argc, char **argv)
 			"On OS X the debuggers must be installed setgrp procmod.\n"
 			"Read and run ./sudo.bash to install the debuggers.\n");
 	}
-	
+
 	if(!streq(goroot_final, goroot)) {
 		xprintf("\n"
 			"The binaries expect %s to be copied or moved to %s\n",
diff --git a/src/cmd/objdump/main.c b/src/cmd/objdump/main.c
new file mode 100644
index 000000000..b684be7fb
--- /dev/null
+++ b/src/cmd/objdump/main.c
@@ -0,0 +1,68 @@
+// 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.
+
+/*
+ * objdump simulation - only enough to make pprof work on Macs
+ */
+
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <mach.h>
+
+void
+usage(void)
+{
+	fprint(2, "usage: objdump binary start stop\n");
+	fprint(2, "Disassembles binary from PC start up to stop.\n");
+	exits("usage");
+}
+
+void
+main(int argc, char **argv)
+{
+	int fd, n;
+	uvlong pc, start, stop;
+	Fhdr fhdr;
+	Biobuf bout;
+	char buf[1024];
+	Map *text;
+
+	ARGBEGIN{
+	default:
+		usage();
+	}ARGEND
+
+	if(argc != 3)
+		usage();
+	start = strtoull(argv[1], 0, 16);
+	stop = strtoull(argv[2], 0, 16);
+
+	fd = open(argv[0], OREAD);
+	if(fd < 0)
+		sysfatal("open %s: %r", argv[0]);
+	if(crackhdr(fd, &fhdr) <= 0)
+		sysfatal("crackhdr: %r");
+	machbytype(fhdr.type);
+	if(syminit(fd, &fhdr) <= 0)
+		sysfatal("syminit: %r");
+	text = loadmap(nil, fd, &fhdr);
+	if(text == nil)
+		sysfatal("loadmap: %r");
+
+	Binit(&bout, 1, OWRITE);
+	for(pc=start; pc<stop; ) {
+		if(fileline(buf, sizeof buf, pc))
+			Bprint(&bout, "%s\n", buf);
+		buf[0] = '\0';
+		machdata->das(text, pc, 0, buf, sizeof buf);
+		Bprint(&bout, " %llx: %s\n", pc, buf);
+		n = machdata->instsize(text, pc);
+		if(n <= 0)
+			break;
+		pc += n;
+	}
+	Bflush(&bout);
+	exits(0);
+}