Support SteppingGranularity & instruction stepping

src/GDBDebugSession.ts

@@ -335,6 +335,7 @@ export class GDBDebugSession extends LoggingDebugSession {
         response.body.supportsDisassembleRequest = true;
         response.body.supportsReadMemoryRequest = true;
         response.body.supportsWriteMemoryRequest = true;
+        response.body.supportsSteppingGranularity = true;
         this.sendResponse(response);
     }
 
@@ -1003,7 +1004,9 @@ export class GDBDebugSession extends LoggingDebugSession {
         args: DebugProtocol.NextArguments
     ): Promise<void> {
         try {
-            await mi.sendExecNext(this.gdb, args.threadId);
+            await (args.granularity === 'instruction'
+                ? mi.sendExecNextInstruction(this.gdb, args.threadId)
+                : mi.sendExecNext(this.gdb, args.threadId));
             this.sendResponse(response);
         } catch (err) {
             this.sendErrorResponse(
@@ -1019,7 +1022,9 @@ export class GDBDebugSession extends LoggingDebugSession {
         args: DebugProtocol.StepInArguments
     ): Promise<void> {
         try {
-            await mi.sendExecStep(this.gdb, args.threadId);
+            await (args.granularity === 'instruction'
+                ? mi.sendExecStepInstruction(this.gdb, args.threadId)
+                : mi.sendExecStep(this.gdb, args.threadId));
             this.sendResponse(response);
         } catch (err) {
             this.sendErrorResponse(

src/integration-tests/stepping-granularity.spec.ts

@@ -0,0 +1,200 @@
+/*********************************************************************
+ * Copyright (c) 2023 Ericsson and others
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *********************************************************************/
+
+import * as path from 'path';
+import { expect } from 'chai';
+import { CdtDebugClient } from './debugClient';
+import {
+    standardBeforeEach,
+    testProgramsDir,
+    fillDefaults,
+    resolveLineTagLocations,
+} from './utils';
+import { DebugProtocol } from '@vscode/debugprotocol';
+
+interface StackState {
+    main: DebugProtocol.StackFrame | undefined;
+    elsewhere: DebugProtocol.StackFrame | undefined;
+}
+
+interface StackStateCheck {
+    elsewhereDefined: boolean;
+    line: number;
+}
+
+describe('Stepping', async function () {
+    let dc: CdtDebugClient;
+    const steppingProgram = path.join(testProgramsDir, 'stepping');
+    const steppingSource = path.join(testProgramsDir, 'stepping.c');
+    const lineTags = {
+        'main for': 0,
+        'main getFromElsewhere call': 0,
+        'main printf call': 0,
+        'getFromElsewhere entry': 0,
+        'getFromElsewhere for': 0,
+    };
+
+    before(function () {
+        resolveLineTagLocations(steppingSource, lineTags);
+    });
+
+    beforeEach(async function () {
+        dc = await standardBeforeEach();
+
+        await dc.hitBreakpoint(
+            fillDefaults(this.currentTest, { program: steppingProgram }),
+            {
+                path: steppingSource,
+                line: lineTags['main getFromElsewhere call'],
+            }
+        );
+    });
+
+    afterEach(async () => {
+        await dc.stop();
+    });
+
+    async function getFrameState(threadId: number) {
+        const stack = await dc.stackTraceRequest({ threadId });
+        const main = stack.body.stackFrames.find(
+            (frame) => frame.name === 'main'
+        );
+        const elsewhere = stack.body.stackFrames.find(
+            (frame) => frame.name === 'getFromElsewhere'
+        );
+        return { main, elsewhere };
+    }
+
+    function expectStackState(state: StackState, check: StackStateCheck) {
+        if (check.elsewhereDefined) {
+            expect(state.elsewhere).not.to.be.undefined;
+        } else {
+            expect(state.elsewhere).to.be.undefined;
+        }
+        const target = check.elsewhereDefined ? 'elsewhere' : 'main';
+        expect(state[target]).not.to.be.undefined;
+        expect(state[target]?.line).equal(
+            check.line,
+            `It should have stopped at line ${check.line}`
+        );
+    }
+
+    it('steps in by line', async () => {
+        const threads = await dc.threadsRequest();
+        const threadId = threads.body.threads[0].id;
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: false,
+            line: lineTags['main getFromElsewhere call'],
+        });
+        await Promise.all([
+            dc.stepInRequest({ threadId, granularity: 'statement' }),
+            dc.waitForEvent('stopped'),
+        ]);
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: true,
+            line: lineTags['getFromElsewhere entry'],
+        });
+        await Promise.all([
+            dc.stepInRequest({ threadId, granularity: 'statement' }),
+            dc.waitForEvent('stopped'),
+        ]);
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: true,
+            line: lineTags['getFromElsewhere for'],
+        });
+    });
+
+    it('steps in by instruction', async () => {
+        const threads = await dc.threadsRequest();
+        const threadId = threads.body.threads[0].id;
+        let state = await getFrameState(threadId);
+        expectStackState(state, {
+            elsewhereDefined: false,
+            line: lineTags['main getFromElsewhere call'],
+        });
+        await Promise.all([
+            dc.stepInRequest({ threadId, granularity: 'instruction' }),
+            dc.waitForEvent('stopped'),
+        ]);
+        // First step should not take us straight to the function.
+        expectStackState((state = await getFrameState(threadId)), {
+            elsewhereDefined: false,
+            line: lineTags['main getFromElsewhere call'],
+        });
+        // Step until we leave that line.
+        while (
+            state.main?.line === lineTags['main getFromElsewhere call'] &&
+            !state.elsewhere
+        ) {
+            await Promise.all([
+                dc.stepInRequest({ threadId, granularity: 'instruction' }),
+                dc.waitForEvent('stopped'),
+            ]);
+            state = await getFrameState(threadId);
+        }
+        // First line we see should be inside `getFromElsewhere`
+        expectStackState(state, {
+            elsewhereDefined: true,
+            line: lineTags['getFromElsewhere entry'],
+        });
+    });
+
+    it('steps next by line and skips a function', async () => {
+        const threads = await dc.threadsRequest();
+        const threadId = threads.body.threads[0].id;
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: false,
+            line: lineTags['main getFromElsewhere call'],
+        });
+        await Promise.all([
+            dc.nextRequest({ threadId, granularity: 'statement' }),
+            dc.waitForEvent('stopped'),
+        ]);
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: false,
+            line: lineTags['main printf call'],
+        });
+        await Promise.all([
+            dc.nextRequest({ threadId, granularity: 'statement' }),
+            dc.waitForEvent('stopped'),
+        ]);
+        expectStackState(await getFrameState(threadId), {
+            elsewhereDefined: false,
+            line: lineTags['main for'],
+        });
+    });
+
+    it('steps next by instruction and skips a function', async () => {
+        const threads = await dc.threadsRequest();
+        const threadId = threads.body.threads[0].id;
+        let state = await getFrameState(threadId);
+        expectStackState(state, {
+            elsewhereDefined: false,
+            line: lineTags['main getFromElsewhere call'],
+        });
+        // Step until we get off line 'main getFromElsewhere call'.
+        while (
+            state.main?.line === lineTags['main getFromElsewhere call'] &&
+            !state.elsewhere
+        ) {
+            await Promise.all([
+                dc.nextRequest({ threadId, granularity: 'instruction' }),
+                dc.waitForEvent('stopped'),
+            ]);
+            state = await getFrameState(threadId);
+        }
+        // The first line we should see after 'main getFromElsewhere call'
+        // is 'main printf call', not something in `getFromElsewhere`.
+        expectStackState(state, {
+            elsewhereDefined: false,
+            line: lineTags['main printf call'],
+        });
+    });
+});

src/integration-tests/test-programs/.gitignore

@@ -21,3 +21,4 @@ MultiThreadRunControl
 /log
 stderr
 bug275-测试
+stepping

src/integration-tests/test-programs/Makefile

@@ -1,4 +1,4 @@
-BINS = empty empty\ space evaluate vars vars_cpp vars_env mem segv count disassemble functions loopforever MultiThread MultiThreadRunControl stderr bug275-测试 cwd.exe
+BINS = empty empty\ space evaluate vars vars_cpp vars_env mem segv count disassemble functions loopforever MultiThread MultiThreadRunControl stderr bug275-测试 cwd.exe stepping
 
 .PHONY: all
 all: $(BINS)
@@ -86,6 +86,9 @@ MultiThreadRunControl: MultiThreadRunControl.o
 stderr: stderr.o
 	$(LINK)
 
+stepping: stepping.o
+	$(LINK)
+
 %.o: %.c
 	$(CC) -c $< -g3 -O0
 

src/integration-tests/test-programs/stepping.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+
+extern int getFromElsewhere(int start);
+
+int main (int argc, char *argv[]) 
+{   char knownLocally = 10;
+    int i;
+    for (i = 0; i < 3; i++) { // main for
+        knownLocally += 1;
+        int gottenFromElsewhere = getFromElsewhere(knownLocally); // main getFromElsewhere call
+        printf("Saw it here first: %d", knownLocally); // main printf call
+    }
+    return 0;
+}
+
+// make the line of code the same as opening brace to account for different gdb/gcc combinations
+int getFromElsewhere(int start)
+{   int result = start; int i; // getFromElsewhere entry
+    for (i = 1; i <= 5; i++) {  // getFromElsewhere for
+        result += i;
+        printf("Eventually, I'll return something like... %d", result);
+    }
+    return result;
+}

src/mi/exec.ts

@@ -39,6 +39,14 @@ export function sendExecNext(gdb: GDBBackend, threadId?: number) {
     return gdb.sendCommand(command);
 }
 
+export function sendExecNextInstruction(gdb: GDBBackend, threadId?: number) {
+    let command = '-exec-next-instruction';
+    if (threadId !== undefined) {
+        command += ` --thread ${threadId}`;
+    }
+    return gdb.sendCommand(command);
+}
+
 export function sendExecStep(gdb: GDBBackend, threadId?: number) {
     let command = '-exec-step';
     if (threadId !== undefined) {
@@ -47,6 +55,14 @@ export function sendExecStep(gdb: GDBBackend, threadId?: number) {
     return gdb.sendCommand(command);
 }
 
+export function sendExecStepInstruction(gdb: GDBBackend, threadId?: number) {
+    let command = '-exec-step-instruction';
+    if (threadId !== undefined) {
+        command += ` --thread ${threadId}`;
+    }
+    return gdb.sendCommand(command);
+}
+
 export function sendExecFinish(gdb: GDBBackend, threadId?: number) {
     let command = '-exec-finish';
     if (threadId !== undefined) {