[IRInterpreter] Fix misevaluation of interpretation expressions with `urem`.

Scalar::MakeUnsigned was implemented incorrectly so it didn't
really change the sign of the type (leaving signed types signed).
This showed up as a misevaluation when IR-interpreting urem but
it's likely to arise in other contexts.

This commit fixes the definition, and adds a test to make
sure this won't regress in future (hopefully).

Fixes rdar://problem/42038760 and LLVM PR38076

Differential Revision:  https://reviews.llvm.org/D49155

llvm-svn: 336872

3 files changed, 26 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/Makefile b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/Makefile
new file mode 100644
index 00000000000..f5a47fcc46c
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/Makefile
@@ -0,0 +1,3 @@
+LEVEL = ../../make
+C_SOURCES := main.c
+include $(LEVEL)/Makefile.rules
diff --git a/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/TestScalarURem.py b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/TestScalarURem.py
new file mode 100644
index 00000000000..03424658f3e
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/TestScalarURem.py
@@ -0,0 +1,4 @@
+from lldbsuite.test import lldbinline
+from lldbsuite.test import decorators
+
+lldbinline.MakeInlineTest(__file__, globals(), None)
diff --git a/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/main.c b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/main.c
new file mode 100644
index 00000000000..98a957faf8b
--- /dev/null
+++ b/lldb/packages/Python/lldbsuite/test/expression_command/rdar42038760/main.c
@@ -0,0 +1,19 @@
+// Make sure we IR-interpret the expression correctly.
+
+typedef unsigned int uint32_t;
+struct S0 {
+  signed f2;
+};
+static g_463 = 0x1561983AL;
+void func_1(void)
+{
+  struct S0 l_19;
+  l_19.f2 = 419;
+  uint32_t l_4037 = 4294967295UL;
+  l_19.f2 = g_463; //%self.expect("expr ((l_4037 % (-(g_463))) | l_19.f2)", substrs=['(unsigned int) $0 = 358717883'])
+}
+int main()
+{
+  func_1();
+  return 0;
+}