rename macro and set it for source/tests

Author: michaelrj-google

libc/cmake/modules/LLVMLibCCompileOptionRules.cmake

@@ -43,6 +43,7 @@ function(_get_common_compile_options output_var flags)
     list(APPEND compile_options "-fpie")
 
     if(LLVM_LIBC_FULL_BUILD)
+      list(APPEND compile_options "-DLIBC_FULL_BUILD")
       # Only add -ffreestanding flag in full build mode.
       list(APPEND compile_options "-ffreestanding")
     endif()
@@ -126,6 +127,7 @@ function(_get_common_test_compile_options output_var c_test flags)
     list(APPEND compile_options "-fpie")
 
     if(LLVM_LIBC_FULL_BUILD)
+      list(APPEND compile_options "-DLIBC_FULL_BUILD")
       # Only add -ffreestanding flag in full build mode.
       list(APPEND compile_options "-ffreestanding")
       list(APPEND compile_options "-fno-exceptions")
@@ -178,5 +180,10 @@ function(_get_hermetic_test_compile_options output_var flags)
          -Wno-multi-gpu --cuda-path=${LIBC_CUDA_ROOT}
          -nogpulib -march=${LIBC_GPU_TARGET_ARCHITECTURE} -fno-use-cxa-atexit)
   endif()
+
+  if(LLVM_LIBC_FULL_BUILD)
+    list(APPEND compile_options "-DLIBC_FULL_BUILD")
+  endif()
+  
   set(${output_var} ${compile_options} PARENT_SCOPE)
 endfunction()

libc/include/llvm-libc-macros/math-macros.h

@@ -10,7 +10,9 @@
 #define LLVM_LIBC_MACROS_MATH_MACROS_H
 
 // TODO: Remove this. This is a temporary fix for a downstream problem.
-#ifdef LLVM_LIBC_FULLBUILD
+// This cannot be left permanently since it would require downstream users to
+// define this macro.
+#ifdef LIBC_FULL_BUILD
 
 #include "limits-macros.h"
 
@@ -82,10 +84,10 @@ template <typename T> inline constexpr bool isnan(T x) {
 
 #endif
 
-#else
+#else // LIBC_FULL_BUILD
 
 #include <math.h>
 
-#endif // LLVM_LIBC_FULLBUILD
+#endif // LIBC_FULL_BUILD
 
 #endif // LLVM_LIBC_MACROS_MATH_MACROS_H