Fix in how lldb-mi integrates with the debugger detection logic (#1315)

* Tweak in the logic of detecting the CppTools lldb-mi debugger

* Updated test expectations. One more fix regarding how lldb-mi integrates with the debugger detection logic.

* Fix a mistake in the IF/ELSE changes

* Improve readability in the debugger detection code

src/debugger.ts

@@ -151,29 +151,34 @@ export async function getDebugConfigurationFromCache(cache: CMakeCache, target:
   }
 
   if (!debuggerPathOverride) {
-    const clang_compiler_regex = /(clang[\+]{0,2})+(?!-cl)/gi;
     // Look for a debugger, in the following order:
-    const cpptoolsExtension = vscode.extensions.getExtension('ms-vscode.cpptools');
-    const cpptoolsDebuggerPath = cpptoolsExtension ? path.join(cpptoolsExtension.extensionPath, "debugAdapters", "lldb-mi", "bin", "lldb-mi") : undefined;
-    let clang_debugger_path = compiler_path.replace(clang_compiler_regex, 'lldb-mi');
-    // 1. lldb-mi in the compiler path
-    if ((clang_debugger_path.search(new RegExp('lldb-mi')) != -1) && await checkDebugger(clang_debugger_path)) {
-      return createLLDBDebugConfiguration(clang_debugger_path, target);
-    } else if (cpptoolsDebuggerPath && await checkDebugger(cpptoolsDebuggerPath)) {
-      // 2. lldb-mi installed by CppTools
-      return createLLDBDebugConfiguration(cpptoolsDebuggerPath, target);
-    } else {
-      // 3. gdb in the compiler path
-      clang_debugger_path = compiler_path.replace(clang_compiler_regex, 'gdb');
-      if ((clang_debugger_path.search(new RegExp('gdb')) != -1) && await checkDebugger(clang_debugger_path)) {
-        return createGDBDebugConfiguration(clang_debugger_path, target);
-      } else {
-        // 4. lldb in the compiler path
-        clang_debugger_path = compiler_path.replace(clang_compiler_regex, 'lldb');
-        if ((clang_debugger_path.search(new RegExp('lldb')) != -1) && await checkDebugger(clang_debugger_path)) {
-          return createLLDBDebugConfiguration(clang_debugger_path, target);
-        }
+    // 1. LLDB-MI
+    const clang_compiler_regex = /(clang[\+]{0,2})+(?!-cl)/gi;
+    let mi_debugger_path = compiler_path.replace(clang_compiler_regex, 'lldb-mi');
+    if ((mi_debugger_path.search(new RegExp('lldb-mi')) != -1)) {
+      const cpptoolsExtension = vscode.extensions.getExtension('ms-vscode.cpptools');
+      const cpptoolsDebuggerPath = cpptoolsExtension ? path.join(cpptoolsExtension.extensionPath, "debugAdapters", "lldb-mi", "bin", "lldb-mi") : undefined;
+        // 1a. lldb-mi in the compiler path
+      if (await checkDebugger(mi_debugger_path)) {
+        return createLLDBDebugConfiguration(mi_debugger_path, target);
       }
+
+      // 1b. lldb-mi installed by CppTools
+      if (cpptoolsDebuggerPath && await checkDebugger(cpptoolsDebuggerPath)) {
+        return createLLDBDebugConfiguration(cpptoolsDebuggerPath, target);
+      }
+    }
+
+    // 2. gdb in the compiler path
+    mi_debugger_path = compiler_path.replace(clang_compiler_regex, 'gdb');
+    if ((mi_debugger_path.search(new RegExp('gdb')) != -1) && await checkDebugger(mi_debugger_path)) {
+      return createGDBDebugConfiguration(mi_debugger_path, target);
+    }
+
+    // 3. lldb in the compiler path
+    mi_debugger_path = compiler_path.replace(clang_compiler_regex, 'lldb');
+    if ((mi_debugger_path.search(new RegExp('lldb')) != -1) && await checkDebugger(mi_debugger_path)) {
+      return createLLDBDebugConfiguration(mi_debugger_path, target);
     }
   }
 

test/unit-tests/select-debugger.test.ts

@@ -1,6 +1,7 @@
 import * as chai from 'chai';
 import * as chaiAsPromised from 'chai-as-promised';
 import * as path from 'path';
+import * as vscode from 'vscode';
 
 chai.use(chaiAsPromised);
 
@@ -37,13 +38,24 @@ suite('Select debugger', async () => {
       throw new Error();
     }
     expect(config.name).to.be.eq('Debug Test');
-    expect(config['MIMode']).to.be.eq('gdb');
     expect(config.type).to.be.eq('cppdbg');
-    expect(config['miDebuggerPath']).to.be.eq('gdb');
     expect(stub.called).to.be.true;
 
+    // If CppTools extension is installed, the lldb-mi installed with that extension
+    // will represent the debugger fallback instead of gdb.
+    const cpptoolsExtension = vscode.extensions.getExtension('ms-vscode.cpptools');
+    const cpptoolsDebuggerPath = cpptoolsExtension ? path.join(cpptoolsExtension.extensionPath, "debugAdapters", "lldb-mi", "bin", "lldb-mi") : undefined;
+    if (cpptoolsDebuggerPath) {
+      expect(config['MIMode']).to.be.eq('lldb');
+      expect(config['miDebuggerPath']).to.be.eq(cpptoolsDebuggerPath);
+      expect(stub.calledWith('gdb')).to.be.false;
+    } else {
+      expect(config['MIMode']).to.be.eq('gdb');
+      expect(config['miDebuggerPath']).to.be.eq('gdb');
+      expect(stub.calledWith('gdb')).to.be.true;
+    }
+
     expect(stub.calledWith('lldb-mi')).to.be.true;
-    expect(stub.calledWith('gdb')).to.be.true;
   });
 
   test('Create debug config from cache - GCC', async () => {