Fix stale IntelliSense config after preset switches

CHANGELOG.md

@@ -49,6 +49,7 @@ Improvements:
 - Updated IntelliSense tooltips with changes from CMake 4.3.1. [#4872](https://github.com/microsoft/vscode-cmake-tools/pull/4872)
 
 Bug Fixes:
+- Fix stale C/C++ custom-configuration entries persisting after reconfigure/preset switches, which could cause Go to Definition/IntelliSense to surface symbols from inactive sources in the same folder. [#4472](https://github.com/microsoft/vscode-cmake-tools/issues/4472)
 - Fix `tasks.json` schema validation rejecting valid CMake task commands `package` and `workflow`. [#4167](https://github.com/microsoft/vscode-cmake-tools/issues/4167)
 - Import the `EXTERNAL_INCLUDE` environment variable from the VS developer environment so that MSVC's external-header diagnostic suppression works correctly. [#4217](https://github.com/microsoft/vscode-cmake-tools/issues/4217)
 - Fix test presets not automatically switching when the build preset changes in multi-config generator setups (e.g., Ninja Multi-Config). The extension now auto-selects a compatible test preset after a build preset change, and properly considers build type when guessing the test preset. [#4395](https://github.com/microsoft/vscode-cmake-tools/issues/4395)

src/cpptools.ts

@@ -430,6 +430,12 @@ export class CppConfigurationProvider implements cpptools.CustomConfigurationPro
      */
     private readonly fileIndex = new Map<string, Map<string, cpptools.SourceFileConfigurationItem>>();
 
+    /**
+     * Track indexed files per workspace folder so stale entries can be evicted
+     * when a folder is reconfigured (e.g. switching presets).
+     */
+    private readonly fileIndexByFolder = new Map<string, Set<string>>();
+
     /**
      * If a source file configuration exists for the active target, we will prefer that one when asked.
      */
@@ -438,6 +444,18 @@ export class CppConfigurationProvider implements cpptools.CustomConfigurationPro
     private activeBuildType: string | null = null;
     private buildTypesSeen = new Set<string>();
 
+    private clearConfigurationDataForFolder(folder: string) {
+        const normalizedFolder = util.platformNormalizePath(folder);
+        const indexedFiles = this.fileIndexByFolder.get(normalizedFolder);
+        if (indexedFiles) {
+            for (const filePath of indexedFiles) {
+                this.fileIndex.delete(filePath);
+            }
+            this.fileIndexByFolder.delete(normalizedFolder);
+        }
+        this.workspaceBrowseConfigurations.delete(normalizedFolder);
+    }
+
     /**
      * Create a source file configuration for the given file group.
      * @param fileGroup The file group from the code model to create config data for
@@ -552,9 +570,12 @@ export class CppConfigurationProvider implements cpptools.CustomConfigurationPro
      */
     private updateFileGroup(sourceDir: string, fileGroup: CodeModelFileGroup, options: CodeModelParams, target: TargetDefaults, sysroot?: string) {
         const configuration = this.buildConfigurationData(fileGroup, options, target, sysroot);
+        const normalizedFolder = util.platformNormalizePath(options.folder);
+        const indexedFiles = this.fileIndexByFolder.get(normalizedFolder);
         for (const src of fileGroup.sources) {
             const absolutePath = path.isAbsolute(src) ? src : path.join(sourceDir, src);
             const normalizedAbsolutePath = util.platformNormalizePath(absolutePath);
+            indexedFiles?.add(normalizedAbsolutePath);
             if (this.fileIndex.has(normalizedAbsolutePath)) {
                 this.fileIndex.get(normalizedAbsolutePath)!.set(target.name, {
                     uri: vscode.Uri.file(absolutePath).toString(),
@@ -593,6 +614,10 @@ export class CppConfigurationProvider implements cpptools.CustomConfigurationPro
         this.buildTypesSeen.clear();
         this.targets = [];
 
+        const normalizedFolder = util.platformNormalizePath(opts.folder);
+        this.clearConfigurationDataForFolder(normalizedFolder);
+        this.fileIndexByFolder.set(normalizedFolder, new Set<string>());
+
         let hadMissingCompilers = false;
         this.workspaceBrowseConfiguration = { browsePath: [] };
         this.activeTarget = opts.activeTarget;

test/unit-tests/cpptools.test.ts

@@ -406,4 +406,67 @@ suite('CppTools tests', () => {
         expect(browseConfig2?.browsePath.length).to.eq(1);
         expect(browseConfig2?.browsePath[0]).to.eq(util.platformNormalizePath(smokeFolder));
     });
+
+    test('Evicts stale file configurations after folder refresh', async () => {
+        const provider = new CppConfigurationProvider();
+        const cache = await CMakeCache.fromPath(getTestResourceFilePath('TestCMakeCache.txt'));
+        const folder = here;
+        const oldSourceFile = path.join(folder, 'stale_old.cpp');
+        const newSourceFile = path.join(folder, 'stale_new.cpp');
+
+        const oldCodeModel: codeModel.CodeModelContent = {
+            configurations: [{
+                name: 'Release',
+                projects: [{
+                    name: 'stale-config-test',
+                    sourceDirectory: folder,
+                    targets: [{
+                        name: 'oldTarget',
+                        type: 'EXECUTABLE',
+                        fileGroups: [{
+                            sources: [oldSourceFile],
+                            isGenerated: false,
+                            defines: ['OLD'],
+                            compileCommandFragments: ['-DOLD'],
+                            language: 'CXX'
+                        }]
+                    }]
+                }]
+            }],
+            toolchains: new Map<string, codeModel.CodeModelToolchain>()
+        };
+
+        provider.updateConfigurationData({ cache, codeModelContent: oldCodeModel, activeTarget: 'oldTarget', activeBuildTypeVariant: 'Release', folder });
+
+        const newCodeModel: codeModel.CodeModelContent = {
+            configurations: [{
+                name: 'Release',
+                projects: [{
+                    name: 'stale-config-test',
+                    sourceDirectory: folder,
+                    targets: [{
+                        name: 'newTarget',
+                        type: 'EXECUTABLE',
+                        fileGroups: [{
+                            sources: [newSourceFile],
+                            isGenerated: false,
+                            defines: ['NEW'],
+                            compileCommandFragments: ['-DNEW'],
+                            language: 'CXX'
+                        }]
+                    }]
+                }]
+            }],
+            toolchains: new Map<string, codeModel.CodeModelToolchain>()
+        };
+
+        provider.updateConfigurationData({ cache, codeModelContent: newCodeModel, activeTarget: 'newTarget', activeBuildTypeVariant: 'Release', folder });
+
+        const staleConfigurations = await provider.provideConfigurations([vscode.Uri.file(oldSourceFile)]);
+        expect(staleConfigurations.length).to.eq(0);
+
+        const activeConfigurations = await provider.provideConfigurations([vscode.Uri.file(newSourceFile)]);
+        expect(activeConfigurations.length).to.eq(1);
+        expect(activeConfigurations[0].configuration.defines).to.contain('NEW');
+    });
 });