pkg/cover: add test for report generation

Test various combinations of no debug info,
no coverage instrumentation, no PCs, bad PCs, good PCs,
and what errors we produce for these.
Also implement support for cross-arch reports:
prefix objdump with cross-compile prefix
(e.g. aarch64-linux-gnu-objdump instead of objdump).

1 files changed, 8 insertions, 0 deletions

diff --git a/sys/targets/targets.go b/sys/targets/targets.go
index ee42ea3ad..22333048b 100644
--- a/sys/targets/targets.go
+++ b/sys/targets/targets.go
@@ -67,6 +67,8 @@ type osCommon struct {
 	CPP string
 	// Common CFLAGS for this OS.
 	cflags []string
+	// If set, this OS uses $SOURCEDIR to locate the toolchain.
+	NeedsSourceDir bool
 }
 
 func Get(OS, arch string) *Target {
@@ -356,6 +358,7 @@ var oses = map[string]osCommon{
 		ExecutorUsesShmem:      true,
 		ExecutorUsesForkServer: true,
 		KernelObject:           "netbsd.gdb",
+		NeedsSourceDir:         true,
 	},
 	"openbsd": {
 		SyscallNumbers:         true,
@@ -373,6 +376,7 @@ var oses = map[string]osCommon{
 		HostFuzzer:             true,
 		SyzExecutorCmd:         "syz-executor",
 		KernelObject:           "zircon.elf",
+		NeedsSourceDir:         true,
 	},
 	"windows": {
 		SyscallNumbers:         false,
@@ -389,6 +393,7 @@ var oses = map[string]osCommon{
 		ExecutorUsesForkServer: true,
 		HostFuzzer:             true,
 		KernelObject:           "akaros-kernel-64b",
+		NeedsSourceDir:         true,
 	},
 	"trusty": {
 		SyscallNumbers:   true,
@@ -501,6 +506,9 @@ func (target *Target) lazyInit() {
 		// On CI we want to fail loudly if cross-compilation breaks.
 		if _, err := exec.LookPath(target.CCompiler); err != nil {
 			target.BrokenCompiler = fmt.Sprintf("%v is missing", target.CCompiler)
+			if target.NeedsSourceDir && os.Getenv("SOURCEDIR") == "" {
+				target.BrokenCompiler = "SOURCEDIR is not set"
+			}
 			return
 		}
 	}