cmd/compile: set LocalPkg.Path to -p flag

Since CL 391014, cmd/compile now requires the -p flag to be set the
build system. This CL changes it to initialize LocalPkg.Path to the
provided path, rather than relying on writing out `"".` into object
files and expecting cmd/link to substitute them.

However, this actually involved a rather long tail of fixes. Many have
already been submitted, but a few notable ones that have to land
simultaneously with changing LocalPkg:

1. When compiling package runtime, there are really two "runtime"
packages: types.LocalPkg (the source package itself) and
ir.Pkgs.Runtime (the compiler's internal representation, for synthetic
references). Previously, these ended up creating separate link
symbols (`"".xxx` and `runtime.xxx`, respectively), but now they both
end up as `runtime.xxx`, which causes lsym collisions (notably
inittask and funcsyms).

2. test/codegen tests need to be updated to expect symbols to be named
`command-line-arguments.xxx` rather than `"".foo`.

3. The issue20014 test case is sensitive to the sort order of field
tracking symbols. In particular, the local package now sorts to its
natural place in the list, rather than to the front.

Thanks to David Chase for helping track down all of the fixes needed
for this CL.

Updates #51734.

Change-Id: Iba3041cf7ad967d18c6e17922fa06ba11798b565
Reviewed-on: https://go-review.googlesource.com/c/go/+/393715
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>

6 files changed, 23 insertions, 23 deletions

diff --git a/test/codegen/clobberdead.go b/test/codegen/clobberdead.go
index c490790bb6..732be5f73b 100644
--- a/test/codegen/clobberdead.go
+++ b/test/codegen/clobberdead.go
@@ -15,16 +15,16 @@ var p1, p2, p3 T
 func F() {
 	// 3735936685 is 0xdeaddead. On ARM64 R27 is REGTMP.
 	// clobber x, y at entry. not clobber z (stack object).
-	// amd64:`MOVL\t\$3735936685, ""\.x`, `MOVL\t\$3735936685, ""\.y`, -`MOVL\t\$3735936685, ""\.z`
-	// arm64:`MOVW\tR27, ""\.x`, `MOVW\tR27, ""\.y`, -`MOVW\tR27, ""\.z`
+	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, `MOVL\t\$3735936685, command-line-arguments\.y`, -`MOVL\t\$3735936685, command-line-arguments\.z`
+	// arm64:`MOVW\tR27, command-line-arguments\.x`, `MOVW\tR27, command-line-arguments\.y`, -`MOVW\tR27, command-line-arguments\.z`
 	x, y, z := p1, p2, p3
 	addrTaken(&z)
 	// x is dead at the call (the value of x is loaded before the CALL), y is not
-	// amd64:`MOVL\t\$3735936685, ""\.x`, -`MOVL\t\$3735936685, ""\.y`
-	// arm64:`MOVW\tR27, ""\.x`, -`MOVW\tR27, ""\.y`
+	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, -`MOVL\t\$3735936685, command-line-arguments\.y`
+	// arm64:`MOVW\tR27, command-line-arguments\.x`, -`MOVW\tR27, command-line-arguments\.y`
 	use(x)
-	// amd64:`MOVL\t\$3735936685, ""\.x`, `MOVL\t\$3735936685, ""\.y`
-	// arm64:`MOVW\tR27, ""\.x`, `MOVW\tR27, ""\.y`
+	// amd64:`MOVL\t\$3735936685, command-line-arguments\.x`, `MOVL\t\$3735936685, command-line-arguments\.y`
+	// arm64:`MOVW\tR27, command-line-arguments\.x`, `MOVW\tR27, command-line-arguments\.y`
 	use(y)
 }
 
diff --git a/test/codegen/comparisons.go b/test/codegen/comparisons.go
index 181bb93496..7e9d4745f1 100644
--- a/test/codegen/comparisons.go
+++ b/test/codegen/comparisons.go
@@ -45,7 +45,7 @@ func CompareString3(s string) bool {
 // Check that arrays compare use 2/4/8 byte compares
 
 func CompareArray1(a, b [2]byte) bool {
-	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPW\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
 	// arm64:-`MOVBU\t`
 	// ppc64le:-`MOVBZ\t`
 	// s390x:-`MOVBZ\t`
@@ -53,25 +53,25 @@ func CompareArray1(a, b [2]byte) bool {
 }
 
 func CompareArray2(a, b [3]uint16) bool {
-	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
-	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPL\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPW\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
 	return a == b
 }
 
 func CompareArray3(a, b [3]int16) bool {
-	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
-	// amd64:`CMPW\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPL\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPW\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
 	return a == b
 }
 
 func CompareArray4(a, b [12]int8) bool {
-	// amd64:`CMPQ\t""[.+_a-z0-9]+\(SP\), [A-Z]`
-	// amd64:`CMPL\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPQ\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPL\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
 	return a == b
 }
 
 func CompareArray5(a, b [15]byte) bool {
-	// amd64:`CMPQ\t""[.+_a-z0-9]+\(SP\), [A-Z]`
+	// amd64:`CMPQ\tcommand-line-arguments[.+_a-z0-9]+\(SP\), [A-Z]`
 	return a == b
 }
 
diff --git a/test/codegen/memcombine.go b/test/codegen/memcombine.go
index 0292d7f0f3..1427f7a7d5 100644
--- a/test/codegen/memcombine.go
+++ b/test/codegen/memcombine.go
@@ -335,7 +335,7 @@ func load_op_no_merge(p, q *int) {
 
 // Make sure offsets are folded into loads and stores.
 func offsets_fold(_, a [20]byte) (b [20]byte) {
-	// arm64:`MOVD\t""\.a\+[0-9]+\(FP\), R[0-9]+`,`MOVD\tR[0-9]+, ""\.b\+[0-9]+\(FP\)`
+	// arm64:`MOVD\tcommand-line-arguments\.a\+[0-9]+\(FP\), R[0-9]+`,`MOVD\tR[0-9]+, command-line-arguments\.b\+[0-9]+\(FP\)`
 	b = a
 	return
 }
diff --git a/test/codegen/memops.go b/test/codegen/memops.go
index fb8208f984..7e59d88560 100644
--- a/test/codegen/memops.go
+++ b/test/codegen/memops.go
@@ -13,23 +13,23 @@ var x32 [2]uint32
 var x64 [2]uint64
 
 func compMem1() int {
-	// amd64:`CMPB\t"".x\+1\(SB\), [$]0`
+	// amd64:`CMPB\tcommand-line-arguments.x\+1\(SB\), [$]0`
 	if x[1] {
 		return 1
 	}
-	// amd64:`CMPB\t"".x8\+1\(SB\), [$]7`
+	// amd64:`CMPB\tcommand-line-arguments.x8\+1\(SB\), [$]7`
 	if x8[1] == 7 {
 		return 1
 	}
-	// amd64:`CMPW\t"".x16\+2\(SB\), [$]7`
+	// amd64:`CMPW\tcommand-line-arguments.x16\+2\(SB\), [$]7`
 	if x16[1] == 7 {
 		return 1
 	}
-	// amd64:`CMPL\t"".x32\+4\(SB\), [$]7`
+	// amd64:`CMPL\tcommand-line-arguments.x32\+4\(SB\), [$]7`
 	if x32[1] == 7 {
 		return 1
 	}
-	// amd64:`CMPQ\t"".x64\+8\(SB\), [$]7`
+	// amd64:`CMPQ\tcommand-line-arguments.x64\+8\(SB\), [$]7`
 	if x64[1] == 7 {
 		return 1
 	}
diff --git a/test/codegen/select.go b/test/codegen/select.go
index 4426924b36..82f6d1c7ef 100644
--- a/test/codegen/select.go
+++ b/test/codegen/select.go
@@ -10,7 +10,7 @@ func f() {
 	ch1 := make(chan int)
 	ch2 := make(chan int)
 	for {
-		// amd64:-`MOVQ\t[$]0, ""..autotmp_3`
+		// amd64:-`MOVQ\t[$]0, command-line-arguments..autotmp_3`
 		select {
 		case <-ch1:
 		case <-ch2:
diff --git a/test/codegen/zerosize.go b/test/codegen/zerosize.go
index 292c5a018b..ecf3305461 100644
--- a/test/codegen/zerosize.go
+++ b/test/codegen/zerosize.go
@@ -12,12 +12,12 @@ package codegen
 
 func zeroSize() {
 	c := make(chan struct{})
-	// amd64:`MOVQ\t\$0, ""\.s\+56\(SP\)`
+	// amd64:`MOVQ\t\$0, command-line-arguments\.s\+56\(SP\)`
 	var s *int
 	// force s to be a stack object, also use some (fixed) stack space
 	g(&s, 1, 2, 3, 4, 5)
 
-	// amd64:`LEAQ\t""\..*\+55\(SP\)`
+	// amd64:`LEAQ\tcommand-line-arguments\..*\+55\(SP\)`
 	c <- struct{}{}
 }