[OSS-Fuzz] Fix static library linking needed for OSS-Fuzz (#35523)

* getting transitive libraries for static linking

* Fixing commit

* integrating comments

build/config/linux/pkg-config.py

@@ -142,6 +142,8 @@ def main():
                       dest='dridriverdir')
     parser.add_option('--version-as-components', action='store_true',
                       dest='version_as_components')
+    parser.add_option('--static', action='store_true',
+                      dest='static')
     (options, args) = parser.parse_args()
 
     # Make a list of regular expressions to strip out.
@@ -203,7 +205,13 @@ def main():
         sys.stdout.write(dridriverdir.strip())
         return
 
-    cmd = [options.pkg_config, "--cflags", "--libs"] + args
+    cmd = [options.pkg_config, "--cflags", "--libs"]
+
+    if options.static:
+        cmd.append("--static")
+
+    cmd.extend(args)
+
     if options.debug:
         sys.stderr.write('Running: %s\n' % ' '.join(cmd))
 

build/config/linux/pkg_config.gni

@@ -137,10 +137,19 @@ template("pkg_config") {
 
       # Link libraries statically for OSS-Fuzz fuzzer build
       if (oss_fuzz) {
+        # Output libs needed for static linking (direct + transitive/non-direct libs), we will re-execute the script to get those libs
+        args += [ "--static" ]
+        pkgresult_static = exec_script(pkg_config_script, args, "value")
         libs = []
         ldflags = [ "-Wl,-Bstatic" ]
-        foreach(lib, pkgresult[3]) {
-          ldflags += [ "-l$lib" ]
+        foreach(lib, pkgresult_static[3]) {
+          # dl(dynamic loading) lib is not needed for linking statically and its presence triggers errors.
+          # example of errors:
+          #   ld.lld: error: undefined symbol: __dlsym
+          #   >>> referenced by dlsym.o:(dlsym) in archive /lib/x86_64-linux-gnu/libdl.a
+          if (lib != "dl") {
+            ldflags += [ "-l$lib" ]
+          }
         }
         ldflags += [ "-Wl,-Bdynamic" ]
         lib_dirs = pkgresult[4]