Make -run to intercept not only ld but also ld.lld and ld.gold

README.md

@@ -85,9 +85,9 @@ command. It is sometimes very hard to pass an appropriate command line
 option to `cc` to specify an alternative linker.
 
 To deal with the situation, mold has a feature to intercept all
-invocations of `/usr/bin/ld` and redirect it to itself. To use the
-feature, run `make` (or other build command) as a subcommand of mold
-as follows:
+invocations of `/usr/bin/ld`, `/usr/bin/ld.lld` or `/usr/bin/ld.gold`
+ and redirect it to itself. To use the feature, run `make` (or other
+build command) as a subcommand of mold as follows:
 
 ```
 $ path/to/mold -run make <make-options-if-any>
@@ -96,7 +96,8 @@ $ path/to/mold -run make <make-options-if-any>
 Internally, mold invokes a given command with `LD_PRELOAD` environment
 variable set to its companion shared object file. The shared object
 file intercepts all function calls to exec-family functions to replace
-`argv[0]` with `mold` if it is `/usr/bin/ld`.
+`argv[0]` with `mold` if it is `/usr/bin/ld`, `/usr/bin/ld.gold` or
+`/usr/bin/ld.lld`.
 
 Alternatively, you can pass `-fuse-ld=<absolute-path-to-mold-executable>`
 to a linker command line. Since GCC doesn't support that option,

docs/mold.1

@@ -43,13 +43,13 @@ build\fR) as follows:
 .PP
 If you run a build command like above, the command runs under the
 influence of \fBmold\fR so that when the command tries to run
-\fB/usr/bin/ld\fR, \fBmold\fR is silently invoked instead.
+\fB/usr/bin/ld\fR, \fB/usr/bin/ld.gold\fR or \fB/usr/bin/ld.lld\fR,
+\fBmold\fR is silently invoked instead.
 .PP
 Internally, \fBmold\fR invokes a given command with the
 \fBLD_PRELOAD\fR environment variable set to its companion shared
 object file. The shared object file intercepts all \fBexec()\fR-family
-functions to run \fBmold\fR if \fB/usr/bin/ld\fR is attempted to be
-run.
+functions to run \fBmold\fR if other linker is attempted to be run.
 .PP
 If you don't want to use the \fB\-run\fR option, and if you are using
 \fBclang\fR, you can pass \fB\-fuse\-ld\fR=\fI/absolute/path/to/mold\fR to

mold-wrapper.c

@@ -3,6 +3,7 @@
 #include <dlfcn.h>
 #include <spawn.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -39,10 +40,16 @@ static void get_args(va_list ap, int argc, char **argv) {
   }
 }
 
+static bool is_ld(const char *path) {
+  return !strcmp(path, "/usr/bin/ld") ||
+         !strcmp(path, "/usr/bin/ld.lld") ||
+         !strcmp(path, "/usr/bin/ld.gold");
+}
+
 int execve(const char *path, char *const *argv, char *const *envp) {
   debug_print("execve %s\n", path);
 
-  if (!strcmp(path, "/usr/bin/ld")) {
+  if (is_ld(path)) {
     path = get_mold_path();
     ((const char **)argv)[0] = path;
   }
@@ -87,7 +94,7 @@ int execvp(const char *file, char *const *argv) {
 int execvpe(const char *file, char *const *argv, char *const *envp) {
   debug_print("execvpe %s\n", file);
 
-  if (!strcmp(file, "ld") || !strcmp(file, "/usr/bin/ld")) {
+  if (!strcmp(file, "ld") || is_ld(file)) {
     file = get_mold_path();
     ((const char **)argv)[0] = file;
   }
@@ -102,7 +109,7 @@ int posix_spawn(pid_t *pid, const char *path,
                 char *const *argv, char *const *envp) {
   debug_print("posix_spawn %s\n", path);
 
-  if (!strcmp(path, "/usr/bin/ld")) {
+  if (is_ld(path)) {
     path = get_mold_path();
     ((const char **)argv)[0] = path;
   }

subprocess.cc

@@ -264,8 +264,10 @@ void process_run_subcommand(Context<E> &ctx, int argc, char **argv) {
   putenv(strdup(("LD_PRELOAD=" + dso_path).c_str()));
   putenv(strdup(("MOLD_REAL_PATH=" + self).c_str()));
 
-  // If /usr/bin/ld is specified, run mold itself
-  if (std::string_view cmd = argv[2]; cmd == "ld" || cmd == "/usr/bin/ld") {
+  // If /usr/bin/ld{,lld,gold} is specified, run mold itself
+  if (std::string_view cmd = argv[2]; cmd == "ld" ||
+      cmd == "/usr/bin/ld" || cmd == "/usr/bin/ld.lld" ||
+      cmd == "/usr/bin/ld.gold") {
     execv(self.c_str(), argv + 2);
     Fatal(ctx) << "mold -run failed: " << self << ": " << strerror(errno);
   }

test/run.sh

@@ -35,5 +35,7 @@ grep -q mold $t/log
 ../mold -run env | grep -q '^MOLD_REAL_PATH=.*/mold$'
 
 ../mold -run /usr/bin/ld --version | grep -q mold
+../mold -run /usr/bin/ld.lld --version | grep -q mold
+../mold -run /usr/bin/ld.gold --version | grep -q mold
 
 echo OK