[-gmodules] Let LLDB log a warning if the Clang module hash mismatches.

This feature is mostly there to aid debugging of Clang module issues,
since the only useful actual the end-user can to is to recompile their
program.

Differential Revision: https://reviews.llvm.org/D70272

4 files changed, 75 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/Makefile b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/Makefile
new file mode 100644
index 00000000000..59bf009f686
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/Makefile
@@ -0,0 +1,16 @@
+OBJC_SOURCES := main.m
+CFLAGS_EXTRAS = -I$(BUILDDIR)
+USE_PRIVATE_MODULE_CACHE = YES
+
+.PHONY: update-module
+
+all: $(EXE)
+	$(MAKE) -f $(SRCDIR)/Makefile update-module
+
+include Makefile.rules
+
+update-module:
+	echo "forcing an update of f.pcm"
+	echo "typedef int something_other;" > $(BUILDDIR)/f.h
+	$(CC) $(CFLAGS) $(MANDATORY_MODULE_BUILD_CFLAGS) \
+		-c $(SRCDIR)/other.m -o $(BUILDDIR)/other.o
diff --git a/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/TestClangModulesHashMismatch.py b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/TestClangModulesHashMismatch.py
new file mode 100644
index 00000000000..298e26ee400
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/TestClangModulesHashMismatch.py
@@ -0,0 +1,49 @@
+from __future__ import print_function
+
+import unittest2
+import os
+import shutil
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class TestClangModuleHashMismatch(TestBase):
+    mydir = TestBase.compute_mydir(__file__)
+
+    def setUp(self):
+        TestBase.setUp(self)
+
+    @skipUnlessDarwin
+    @skipIf(debug_info=no_match(["gmodules"]))
+    def test_expr(self):
+        with open(self.getBuildArtifact("module.modulemap"), "w") as f:
+            f.write("""
+                    module Foo { header "f.h" }
+                    """)
+        with open(self.getBuildArtifact("f.h"), "w") as f:
+            f.write("""
+                    typedef int my_int;
+                    void f() {}
+                    """)
+
+        mod_cache = self.getBuildArtifact("private-module-cache")
+        if os.path.isdir(mod_cache):
+          shutil.rmtree(mod_cache)
+        self.build()
+        self.assertTrue(os.path.isdir(mod_cache), "module cache exists")
+
+        logfile = self.getBuildArtifact("host.log")
+        self.runCmd("log enable -v -f %s lldb host" % logfile)
+        target, _, _, _ = lldbutil.run_to_source_breakpoint(
+            self, "break here", lldb.SBFileSpec("main.m"))
+        target.GetModuleAtIndex(0).FindTypes('my_int') 
+
+        found = False
+        with open(logfile, 'r') as f:
+            for line in f:
+                if "hash mismatch" in line and "Foo" in line:
+                    found = True
+        self.assertTrue(found)
diff --git a/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/main.m b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/main.m
new file mode 100644
index 00000000000..5065222731e
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/main.m
@@ -0,0 +1,6 @@
+#include "f.h"
+int main(int argc, char **argv) {
+  my_int i = argc;
+  f(); // break here
+  return 0;
+}
diff --git a/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/other.m b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/other.m
new file mode 100644
index 00000000000..0afd3eb078d
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/lang/objc/modules-hash-mismatch/other.m
@@ -0,0 +1,4 @@
+#include "f.h"
+something_other f() {
+  return 0;
+}