[lldb] Prefer executable files from sysroot over files from local filesystem

Summary:
In D49685 sysroot behaviour was partially fixed. But files from local filesystem with same path still has priority over files from sysroot.

This patch fixes it by removing fallback to local filesystem from RemoteAwarePlatform::GetModuleSpec(). It is not actually required because higher level code do such fallback itself. See, for example, resolver in Platform::GetSharedModule().

Reviewers: labath, clayborg, EugeneBi

Reviewed By: labath

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D77529

lldb/source/Target/RemoteAwarePlatform.cpp

@@ -21,7 +21,7 @@ bool RemoteAwarePlatform::GetModuleSpec(const FileSpec &module_file_spec,
     return m_remote_platform_sp->GetModuleSpec(module_file_spec, arch,
                                                module_spec);
 
-  return Platform::GetModuleSpec(module_file_spec, arch, module_spec);
+  return false;
 }
 
 Status RemoteAwarePlatform::RunShellCommand(

lldb/test/API/functionalities/postmortem/elf-core/TestLinuxCore.py

@@ -209,6 +209,44 @@ class LinuxCoreTestCase(TestBase):
 
         self.dbg.DeleteTarget(target)
 
+    @skipIf(triple='^mips')
+    @skipIfLLVMTargetMissing("X86")
+    @skipIfWindows
+    def test_x86_64_sysroot(self):
+        """Test that sysroot has more priority then local filesystem."""
+
+        # Copy wrong executable to the location outside of sysroot
+        exe_outside = os.path.join(self.getBuildDir(), "bin", "a.out")
+        lldbutil.mkdir_p(os.path.dirname(exe_outside))
+        shutil.copyfile("altmain.out", exe_outside)
+
+        # Copy correct executable to the location inside sysroot
+        tmp_sysroot = os.path.join(self.getBuildDir(), "mock_sysroot")
+        exe_inside = os.path.join(tmp_sysroot, os.path.relpath(exe_outside, "/"))
+        lldbutil.mkdir_p(os.path.dirname(exe_inside))
+        shutil.copyfile("linux-x86_64.out", exe_inside)
+
+        # Prepare patched core file
+        core_file = os.path.join(self.getBuildDir(), "patched.core")
+        with open("linux-x86_64.core", "rb") as f:
+            core = f.read()
+        core = replace_path(core, "/test" * 817 + "/a.out", exe_outside)
+        with open(core_file, "wb") as f:
+            f.write(core)
+
+        # Set sysroot and load core
+        self.runCmd("platform select remote-linux --sysroot '%s'" % tmp_sysroot)
+        target = self.dbg.CreateTarget(None)
+        self.assertTrue(target, VALID_TARGET)
+        process = target.LoadCore(core_file)
+
+        # Check that we found executable from the sysroot
+        mod_path = str(target.GetModuleAtIndex(0).GetFileSpec())
+        self.assertEqual(mod_path, exe_inside)
+        self.check_all(process, self._x86_64_pid, self._x86_64_regions, "a.out")
+
+        self.dbg.DeleteTarget(target)
+
     @skipIf(triple='^mips')
     @skipIfLLVMTargetMissing("ARM")
     def test_arm_core(self):
@@ -369,3 +407,9 @@ class LinuxCoreTestCase(TestBase):
         self.check_all(process, pid, region_count, thread_name)
 
         self.dbg.DeleteTarget(target)
+
+def replace_path(binary, replace_from, replace_to):
+    src = replace_from.encode()
+    dst = replace_to.encode()
+    dst += b"\0" * (len(src) - len(dst))
+    return binary.replace(src, dst)