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fix: linker fix for invalid symlink creation path in createSymlinkAnd…
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…PreserveContents
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@gregmagolan @alexeagle
gregmagolan authored and alexeagle committed Jan 26, 2021
1 parent 3eb4260 commit 14086a8
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Showing 2 changed files with 33 additions and 37 deletions.
23 changes: 13 additions & 10 deletions internal/linker/index.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -99,9 +99,6 @@ function deleteDirectory(p) {
function symlink(target, p) {
return __awaiter(this, void 0, void 0, function* () {
log_verbose(`symlink( ${p} -> ${target} )`);
if (!(yield exists(target))) {
return false;
}
try {
yield fs.promises.symlink(target, p, 'junction');
return true;
Expand Down Expand Up @@ -455,7 +452,7 @@ function main(args, runfiles) {
yield mkdirp(path.dirname(m.name));
if (m.link) {
const [root, modulePath] = m.link;
let target = '<package linking failed>';
let target;
switch (root) {
case 'execroot':
if (isExecroot) {
Expand Down Expand Up @@ -487,17 +484,23 @@ function main(args, runfiles) {
}
}
}
catch (_a) {
target = '<runfiles resolution failed>';
catch (err) {
target = undefined;
log_verbose(`runfiles resolve failed for module '${m.name}': ${err.message}`);
}
break;
}
const stats = yield gracefulLstat(m.name);
if (stats !== null && (yield isLeftoverDirectoryFromLinker(stats, m.name))) {
yield createSymlinkAndPreserveContents(stats, m.name, target);
if (target) {
const stats = yield gracefulLstat(m.name);
if (stats !== null && (yield isLeftoverDirectoryFromLinker(stats, m.name))) {
yield createSymlinkAndPreserveContents(stats, m.name, target);
}
else {
yield symlink(target, m.name);
}
}
else {
yield symlink(target, m.name);
log_verbose(`no symlink target found for module ${m.name}`);
}
}
if (m.children) {
Expand Down
47 changes: 20 additions & 27 deletions internal/linker/link_node_modules.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -108,18 +108,6 @@ async function deleteDirectory(p: string) {
async function symlink(target: string, p: string): Promise<boolean> {
log_verbose(`symlink( ${p} -> ${target} )`);

// Check if the target exists before creating the symlink.
// This is an extra filesystem access on top of the symlink but
// it is necessary for the time being.
if (!await exists(target)) {
// This can happen if a module mapping is propogated from a dependency
// but the target that generated the mapping in not in the deps. We don't
// want to create symlinks to non-existant targets as this will
// break any nested symlinks that may be created under the module name
// after this.
return false;
}

// Use junction on Windows since symlinks require elevated permissions.
// We only link to directories so junctions work for us.
try {
Expand Down Expand Up @@ -714,7 +702,7 @@ export async function main(args: string[], runfiles: Runfiles) {

if (m.link) {
const [root, modulePath] = m.link;
let target: string = '<package linking failed>';
let target: string|undefined;
switch (root) {
case 'execroot':
if (isExecroot) {
Expand Down Expand Up @@ -749,25 +737,30 @@ export async function main(args: string[], runfiles: Runfiles) {
throw e;
}
}
} catch {
target = '<runfiles resolution failed>';
} catch (err) {
target = undefined;
log_verbose(`runfiles resolve failed for module '${m.name}': ${err.message}`);
}
break;
}

const stats = await gracefulLstat(m.name);
// In environments where runfiles are not symlinked (e.g. Windows), existing linked
// modules are preserved. This could cause issues when a link is created at higher level
// as a conflicting directory is already on disk. e.g. consider in a previous run, we
// linked the modules `my-pkg/overlay`. Later on, in another run, we have a module mapping
// for `my-pkg` itself. The linker cannot create `my-pkg` because the directory `my-pkg`
// already exists. To ensure that the desired link is generated, we create the new desired
// link and move all previous nested links from the old module into the new link. Read more
// about this in the description of `createSymlinkAndPreserveContents`.
if (stats !== null && await isLeftoverDirectoryFromLinker(stats, m.name)) {
await createSymlinkAndPreserveContents(stats, m.name, target);
if (target) {
const stats = await gracefulLstat(m.name);
// In environments where runfiles are not symlinked (e.g. Windows), existing linked
// modules are preserved. This could cause issues when a link is created at higher level
// as a conflicting directory is already on disk. e.g. consider in a previous run, we
// linked the modules `my-pkg/overlay`. Later on, in another run, we have a module mapping
// for `my-pkg` itself. The linker cannot create `my-pkg` because the directory `my-pkg`
// already exists. To ensure that the desired link is generated, we create the new desired
// link and move all previous nested links from the old module into the new link. Read more
// about this in the description of `createSymlinkAndPreserveContents`.
if (stats !== null && await isLeftoverDirectoryFromLinker(stats, m.name)) {
await createSymlinkAndPreserveContents(stats, m.name, target);
} else {
await symlink(target, m.name);
}
} else {
await symlink(target, m.name);
log_verbose(`no symlink target found for module ${m.name}`);
}
}

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