debug/gosym: use "go build" instead of hand-running asm and link

Currently, TestPCLine manually invokes asm and link on its test data.
Once we introduce symbol ABIs this is going to become problematic
because the test program defines main.main and main.init in assembly
so they use ABI0, but the runtime expects to find them with the
internal ABI.

There are various ways we could solve this. This CL moves main.main
and main.init into Go code and switches to using "go build" to compile
and link the test binary. This has the added advantage of simplifying
this test.

For #27539.

Change-Id: I4c0cf6467f7a39e6b1500eca6ad2620b5ef2b73c
Reviewed-on: https://go-review.googlesource.com/c/146857
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/debug/gosym/pclntab_test.go b/src/debug/gosym/pclntab_test.go
index 7e7cee6793474583751dac688d668ad380a5dbb8..d21f0e24a8324030d4297d3b7a6697807bb20468 100644 (file)
--- a/src/debug/gosym/pclntab_test.go
+++ b/src/debug/gosym/pclntab_test.go
@@ -5,7 +5,6 @@
 package gosym
 
 import (
-       "bytes"
        "debug/elf"
        "internal/testenv"
        "io/ioutil"
@@ -33,33 +32,10 @@ func dotest(t *testing.T) {
        if err != nil {
                t.Fatal(err)
        }
-       // This command builds pclinetest from pclinetest.asm;
-       // the resulting binary looks like it was built from pclinetest.s,
-       // but we have renamed it to keep it away from the go tool.
        pclinetestBinary = filepath.Join(pclineTempDir, "pclinetest")
-       cmd := exec.Command(testenv.GoToolPath(t), "tool", "asm", "-o", pclinetestBinary+".o", "pclinetest.asm")
-       cmd.Stdout = os.Stdout
-       cmd.Stderr = os.Stderr
-       if err := cmd.Run(); err != nil {
-               t.Fatal(err)
-       }
-
-       // stamp .o file as being 'package main' so that go tool link will accept it
-       data, err := ioutil.ReadFile(pclinetestBinary + ".o")
-       if err != nil {
-               t.Fatal(err)
-       }
-       i := bytes.IndexByte(data, '\n')
-       if i < 0 {
-               t.Fatal("bad binary")
-       }
-       data = append(append(data[:i:i], "\nmain"...), data[i:]...)
-       if err := ioutil.WriteFile(pclinetestBinary+".o", data, 0666); err != nil {
-               t.Fatal(err)
-       }
-
-       cmd = exec.Command(testenv.GoToolPath(t), "tool", "link", "-H", "linux",
-               "-o", pclinetestBinary, pclinetestBinary+".o")
+       cmd := exec.Command(testenv.GoToolPath(t), "build", "-o", pclinetestBinary)
+       cmd.Dir = "testdata"
+       cmd.Env = append(os.Environ(), "GOOS=linux")
        cmd.Stdout = os.Stdout
        cmd.Stderr = os.Stderr
        if err := cmd.Run(); err != nil {
@@ -232,7 +208,7 @@ func TestPCLine(t *testing.T) {
        }
 
        // Test PCToLine
-       sym := tab.LookupFunc("linefrompc")
+       sym := tab.LookupFunc("main.linefrompc")
        wantLine := 0
        for pc := sym.Entry; pc < sym.End; pc++ {
                off := pc - text.Addr // TODO(rsc): should not need off; bug in 8g
@@ -244,13 +220,13 @@ func TestPCLine(t *testing.T) {
                file, line, fn := tab.PCToLine(pc)
                if fn == nil {
                        t.Errorf("failed to get line of PC %#x", pc)
-               } else if !strings.HasSuffix(file, "pclinetest.asm") || line != wantLine || fn != sym {
-                       t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.asm", wantLine, sym.Name)
+               } else if !strings.HasSuffix(file, "pclinetest.s") || line != wantLine || fn != sym {
+                       t.Errorf("PCToLine(%#x) = %s:%d (%s), want %s:%d (%s)", pc, file, line, fn.Name, "pclinetest.s", wantLine, sym.Name)
                }
        }
 
        // Test LineToPC
-       sym = tab.LookupFunc("pcfromline")
+       sym = tab.LookupFunc("main.pcfromline")
        lookupline := -1
        wantLine = 0
        off := uint64(0) // TODO(rsc): should not need off; bug in 8g

diff --git a/src/debug/gosym/testdata/main.go b/src/debug/gosym/testdata/main.go
new file mode 100644 (file)
index 0000000..b770218
--- /dev/null
+++ b/src/debug/gosym/testdata/main.go
@@ -0,0 +1,10 @@
+package main
+
+func linefrompc()
+func pcfromline()
+
+func main() {
+       // Prevent GC of our test symbols
+       linefrompc()
+       pcfromline()
+}

diff --git a/src/debug/gosym/pclinetest.h b/src/debug/gosym/testdata/pclinetest.h
similarity index 100%
rename from src/debug/gosym/pclinetest.h
rename to src/debug/gosym/testdata/pclinetest.h

diff --git a/src/debug/gosym/pclinetest.asm b/src/debug/gosym/testdata/pclinetest.s
similarity index 96%
rename from src/debug/gosym/pclinetest.asm
rename to src/debug/gosym/testdata/pclinetest.s
index b9ee9c0a50413f60bfa0aad8e758a09449d7ad71..53461cdfc1a1ee1033ba18945e7bbf95a6fc24d2 100644 (file)
--- a/src/debug/gosym/pclinetest.asm
+++ b/src/debug/gosym/testdata/pclinetest.s
@@ -1,4 +1,4 @@
-TEXT linefrompc(SB),4,$0       // Each byte stores its line delta
+TEXT ·linefrompc(SB),4,$0     // Each byte stores its line delta
 BYTE $2;
 BYTE $1;
 BYTE $1; BYTE $0;
@@ -28,7 +28,7 @@ BYTE $2;
 BYTE $2;
 BYTE $255;
 
-TEXT pcfromline(SB),4,$0       // Each record stores its line delta, then n, then n more bytes
+TEXT ·pcfromline(SB),4,$0     // Each record stores its line delta, then n, then n more bytes
 BYTE $32; BYTE $0;
 BYTE $1; BYTE $1; BYTE $0;
 BYTE $1; BYTE $0;
@@ -46,13 +46,3 @@ BYTE $3; BYTE $3; BYTE $0; BYTE $0; BYTE $0;
 
 BYTE $4; BYTE $3; BYTE $0; BYTE $0; BYTE $0;
 BYTE $255;
-
-// Keep the linker happy
-TEXT main·main(SB),4,$0
-       RET
-
-TEXT main·init(SB),4,$0
-       // Prevent GC of our test symbols
-       CALL linefrompc(SB)
-       CALL pcfromline(SB)
-       RET