change include test to only test our generated macro

Author: nickdesaulniers

libc/test/include/CMakeLists.txt

@@ -23,12 +23,10 @@ add_libc_test(
     stdbit_test.cpp
   DEPENDS
     libc.include.llvm-libc-macros.stdbit_macros
-    libc.src.__support.CPP.limits
-    libc.src.stdbit.stdc_leading_zeros_uc
-    libc.src.stdbit.stdc_leading_zeros_ui
-    libc.src.stdbit.stdc_leading_zeros_ul
-    libc.src.stdbit.stdc_leading_zeros_ull
-    libc.src.stdbit.stdc_leading_zeros_us
+    libc.include.stdbit
+    # Intentionally do not depend on libc.src.stdbit.*. The include test is
+    # simply testing the macros provided by stdbit.h, not the implementation of
+    # the underlying functions which the type generic macros may dispatch to.
   COMPILE_OPTIONS
     # stdbit is full of type generic macros implemented via C11 _Generic.
     -Wno-c11-extensions

libc/test/include/stdbit_test.cpp

@@ -8,15 +8,27 @@
 
 #include "test/UnitTest/Test.h"
 
-#include "llvm-libc-macros/stdbit-macros.h"
-#include "src/__support/CPP/limits.h" // UINT_WIDTH
-#include "src/stdbit/stdc_leading_zeros_uc.h"
-#include "src/stdbit/stdc_leading_zeros_ui.h"
-#include "src/stdbit/stdc_leading_zeros_ul.h"
-#include "src/stdbit/stdc_leading_zeros_ull.h"
-#include "src/stdbit/stdc_leading_zeros_us.h"
+#include <stdbit.h>
+
+/*
+ * The intent of this test is validate that:
+ * 1. We provide the definition of the various type generic macros of stdbit.h.
+ * 2. It dispatches to the correct underlying function.
+ * Because unit tests build without public packaging, the object files produced
+ * do not contain non-namespaced symbols.
+ */
+
+unsigned char stdc_leading_zeros_uc(unsigned char) { return 0xAA; }
+unsigned short stdc_leading_zeros_us(unsigned short) { return 0xAB; }
+unsigned stdc_leading_zeros_ui(unsigned) { return 0xAC; }
+unsigned long stdc_leading_zeros_ul(unsigned long) { return 0xAD; }
+unsigned long long stdc_leading_zeros_ull(unsigned long long) { return 0xAF; }
 
 TEST(LlvmLibcStdbitTest, TypeGenericMacro) {
-  using namespace LIBC_NAMESPACE;
-  EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(UINT_WIDTH));
+  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned char>(0U)), static_cast<unsigned char>(0xAA));
+  EXPECT_EQ(stdc_leading_zeros(static_cast<unsigned short>(0U)),
+            static_cast<unsigned short>(0xAB));
+  EXPECT_EQ(stdc_leading_zeros(0U), static_cast<unsigned>(0xAC));
+  EXPECT_EQ(stdc_leading_zeros(0UL), static_cast<unsigned long>(0xAD));
+  EXPECT_EQ(stdc_leading_zeros(0ULL), static_cast<unsigned long long>(0xAF));
 }