Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

2 files changed, 1 insertions, 44 deletions

diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index ccc42d3cf..551705208 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -85,22 +85,6 @@ Regular users do not need to execute it.
 `,
 		},
 		{
-			Action: gpuinfo,
-			Name:   "gpuinfo",
-			Usage:  "gpuinfo",
-			Description: `
-Prints OpenCL device info for all found GPUs.
-`,
-		},
-		{
-			Action: gpubench,
-			Name:   "gpubench",
-			Usage:  "benchmark GPU",
-			Description: `
-Runs quick benchmark on first GPU found.
-`,
-		},
-		{
 			Action: version,
 			Name:   "version",
 			Usage:  "print ethereum version numbers",
@@ -147,7 +131,6 @@ participating.
 		utils.OpposeDAOFork,
 		utils.MinerThreadsFlag,
 		utils.MiningEnabledFlag,
-		utils.MiningGPUFlag,
 		utils.AutoDAGFlag,
 		utils.TargetGasLimitFlag,
 		utils.NATFlag,
@@ -312,7 +295,7 @@ func startNode(ctx *cli.Context, stack *node.Node) {
 		if err := stack.Service(&ethereum); err != nil {
 			utils.Fatalf("ethereum service not running: %v", err)
 		}
-		if err := ethereum.StartMining(ctx.GlobalInt(utils.MinerThreadsFlag.Name), ctx.GlobalString(utils.MiningGPUFlag.Name)); err != nil {
+		if err := ethereum.StartMining(ctx.GlobalInt(utils.MinerThreadsFlag.Name)); err != nil {
 			utils.Fatalf("Failed to start mining: %v", err)
 		}
 	}
@@ -348,31 +331,6 @@ func makedag(ctx *cli.Context) error {
 	return nil
 }
 
-func gpuinfo(ctx *cli.Context) error {
-	eth.PrintOpenCLDevices()
-	return nil
-}
-
-func gpubench(ctx *cli.Context) error {
-	args := ctx.Args()
-	wrongArgs := func() {
-		utils.Fatalf(`Usage: geth gpubench <gpu number>`)
-	}
-	switch {
-	case len(args) == 1:
-		n, err := strconv.ParseUint(args[0], 0, 64)
-		if err != nil {
-			wrongArgs()
-		}
-		eth.GPUBench(n)
-	case len(args) == 0:
-		eth.GPUBench(0)
-	default:
-		wrongArgs()
-	}
-	return nil
-}
-
 func version(c *cli.Context) error {
 	fmt.Println(strings.Title(clientIdentifier))
 	fmt.Println("Version:", utils.Version)
diff --git a/cmd/geth/usage.go b/cmd/geth/usage.go
index 2cb6e77e8..4c4e27630 100644
--- a/cmd/geth/usage.go
+++ b/cmd/geth/usage.go
@@ -128,7 +128,6 @@ var AppHelpFlagGroups = []flagGroup{
 		Flags: []cli.Flag{
 			utils.MiningEnabledFlag,
 			utils.MinerThreadsFlag,
-			utils.MiningGPUFlag,
 			utils.AutoDAGFlag,
 			utils.EtherbaseFlag,
 			utils.TargetGasLimitFlag,