[Fix] DCG: name the assumed shell in blocks and enable Windows packs

src/core/prompts/sections/__tests__/system-info.spec.ts

@@ -10,6 +10,7 @@ vi.mock("../../../../utils/shell", () => ({
 }))
 
 import { getSystemInfoSection } from "../system-info"
+import { getShell } from "../../../../utils/shell"
 import osName from "os-name"
 
 const mockOsName = osName as unknown as ReturnType<typeof vi.fn>
@@ -101,4 +102,27 @@ describe("getSystemInfoSection", () => {
 		// sentinel string) breaks this exact join.
 		expect(result).toContain("default directory for all tool operations. When the user initially gives you a task")
 	})
+
+	describe("shell syntax", () => {
+		const cmdPath = "C:\\Windows\\System32\\cmd.exe"
+
+		it("states the dialect for cmd.exe when execute_command is available", () => {
+			vi.mocked(getShell).mockReturnValueOnce(cmdPath)
+
+			const result = getSystemInfoSection(mockCwd, policyFor())
+
+			expect(result).toContain(`Default Shell: ${cmdPath}
+Shell Syntax: Commands run through Windows cmd.exe`)
+		})
+
+		it("omits the dialect without execute_command", () => {
+			vi.mocked(getShell).mockReturnValueOnce(cmdPath)
+
+			expect(getSystemInfoSection(mockCwd, policyFor(false))).not.toContain("Shell Syntax")
+		})
+
+		it("omits the dialect for POSIX shells", () => {
+			expect(getSystemInfoSection(mockCwd, policyFor())).not.toContain("Shell Syntax")
+		})
+	})
 })

src/core/prompts/sections/system-info.ts

@@ -2,6 +2,7 @@
 import osName from "os-name"
 
 import { getShell } from "../../../utils/shell"
+import { describeShellDialect } from "../../../utils/shellDialect"
 
 import type { EffectiveToolPolicy } from "../tools/effective-tool-policy"
 
@@ -33,12 +34,19 @@
 		? " New terminals will be created in the current workspace directory, however if you change directories in a terminal it will then have a different working directory; changing directories in a terminal does not modify the workspace directory, because you do not have access to change the workspace directory."
 		: ""
 
+	const shell = getShell()
+	const shellDialect = executeCommandAvailable ? describeShellDialect(shell) : undefined
+	const shellDialectLine = shellDialect
+		? `
+Shell Syntax: ${shellDialect}`
+		: ""
+
 	const details = `====
 
 SYSTEM INFORMATION
 
 Operating System: ${osInfo}
-Default Shell: ${getShell()}
+Default Shell: ${shell}${shellDialectLine}
 Home Directory: ${os.homedir().toPosix()}
 Current Workspace Directory: ${cwd.toPosix()}
 

src/core/tools/ExecuteCommandTool.ts

@@ -31,6 +31,8 @@
 import { Package } from "../../shared/package"
 import { t } from "../../i18n"
 import { getTaskDirectoryPath } from "../../utils/storage"
+import { getShell } from "../../utils/shell"
+import { describeShellDialect, getShellName } from "../../utils/shellDialect"
 import { BaseTool, ToolCallbacks } from "./BaseTool"
 
 export { ShellIntegrationError } from "../../integrations/terminal/types"
@@ -55,20 +57,35 @@
 	timeout?: number | null
 }
 
-export function formatDcgBlockedMessage(reason?: string, ruleId?: string): string {
-	if (reason && ruleId) {
-		return t("tools:executeCommand.destructiveCommandGuard.blockedWithReasonAndRule", { reason, ruleId })
-	}
+/**
+ * @param shellPath The shell the command will run in. DCG parses every command as POSIX,
+ * so for cmd.exe/PowerShell the message says so, letting the user tell "dangerous" from "unreadable".
+ */
+export function formatDcgBlockedMessage(reason?: string, ruleId?: string, shellPath?: string): string {
+	const message = (() => {
+		if (reason && ruleId) {
+			return t("tools:executeCommand.destructiveCommandGuard.blockedWithReasonAndRule", { reason, ruleId })
+		}
 
-	if (reason) {
-		return t("tools:executeCommand.destructiveCommandGuard.blockedWithReason", { reason })
-	}
+		if (reason) {
+			return t("tools:executeCommand.destructiveCommandGuard.blockedWithReason", { reason })
+		}
+
+		if (ruleId) {
+			return t("tools:executeCommand.destructiveCommandGuard.blockedWithRule", { ruleId })
+		}
 
-	if (ruleId) {
-		return t("tools:executeCommand.destructiveCommandGuard.blockedWithRule", { ruleId })
+		return t("tools:executeCommand.destructiveCommandGuard.blocked")
+	})()
+
+	if (shellPath && describeShellDialect(shellPath)) {
+		const note = t("tools:executeCommand.destructiveCommandGuard.assumedPosixNote", {
+			shell: getShellName(shellPath),
+		})
+		return `${message} ${note}`
 	}
 
-	return t("tools:executeCommand.destructiveCommandGuard.blocked")
+	return message
 }
 
 export function resolveAgentTimeoutMs(timeoutSeconds: number | null | undefined): number {
@@ -182,7 +199,7 @@
 				// retryable tool_error via the outer catch — never as a policy denial.
 				dcgDecision = await runDcg(binaryPath, canonicalCommand, workingDirectory)
 				if (dcgDecision.decision === "deny") {
-					await task.say("error", formatDcgBlockedMessage(dcgDecision.reason, dcgDecision.ruleId))
+					await task.say("error", formatDcgBlockedMessage(dcgDecision.reason, dcgDecision.ruleId, getShell()))
 				}
 			}
 

src/core/tools/__tests__/executeCommandTool.spec.ts

@@ -71,6 +71,9 @@ vitest.mock("../../../services/destructive-command-guard", () => ({
 
 // Import the module
 import * as executeCommandModule from "../ExecuteCommandTool"
+
+// The DCG block message names the executing shell; pin it so tests do not depend on the host.
+vi.mock("../../../utils/shell", () => ({ getShell: vi.fn(() => "/bin/bash") }))
 const { executeCommandTool } = executeCommandModule
 
 // Spies installed on the auto-approval module are not restored between tests,
@@ -316,6 +319,17 @@ describe("executeCommandTool", () => {
 			expect(executeCommandModule.formatDcgBlockedMessage(reason, ruleId)).toBe(expected)
 		})
 
+		it.each([
+			["C:\\Windows\\System32\\cmd.exe", true],
+			["C:\\Program Files\\PowerShell\\7\\pwsh.exe", true],
+			["/bin/bash", false],
+			[undefined, false],
+		])("appends the POSIX-assumption note only for non-POSIX shell %s", (shellPath, expectNote) => {
+			const message = executeCommandModule.formatDcgBlockedMessage(undefined, undefined, shellPath)
+
+			expect(message.includes("executeCommand.destructiveCommandGuard.assumedPosixNote")).toBe(expectNote)
+		})
+
 		it("shows a DCG block message as an error before requesting explicit approval", async () => {
 			const provider = await mockCline.providerRef.deref()
 			provider.context = { globalStorageUri: { fsPath: "/test/storage" } }

src/i18n/locales/en/tools.json

@@ -19,7 +19,8 @@
 			"blocked": "Destructive Command Guard blocked this command.",
 			"blockedWithReason": "Destructive Command Guard blocked this command. Message from DCG: {{reason}}",
 			"blockedWithRule": "Destructive Command Guard blocked this command. (Rule: {{ruleId}})",
-			"blockedWithReasonAndRule": "Destructive Command Guard blocked this command. Message from DCG: {{reason}} (Rule: {{ruleId}})"
+			"blockedWithReasonAndRule": "Destructive Command Guard blocked this command. Message from DCG: {{reason}} (Rule: {{ruleId}})",
+			"assumedPosixNote": "Note: DCG analyzes commands as POSIX shell syntax, but this command runs in {{shell}}, so a block may mean DCG could not read the command rather than that it is destructive."
 		}
 	},
 	"newTask": {