[libc] enable s(n)printf without fullbuild

To use the FILE data structure, LLVM-libc must be in fullbuild mode
since it expects its own implementation. This means that (f)printf can't
be used without fullbuild, but s(n)printf only uses strings. This patch
adjusts the CMake to allow for this.

Reviewed By: sivachandra, lntue

Differential Revision: https://reviews.llvm.org/D131913

Author: michaelrj-google

libc/config/linux/aarch64/entrypoints.txt

@@ -91,6 +91,10 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.realloc
     libc.src.stdlib.free
 
+    # stdio.h entrypoints
+    libc.src.stdio.sprintf
+    libc.src.stdio.snprintf
+
     # sys/stat.h entrypoints
     libc.src.sys.stat.mkdir
     libc.src.sys.stat.mkdirat
@@ -242,8 +246,6 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.funlockfile
     libc.src.stdio.fwrite
     libc.src.stdio.fwrite_unlocked
-    libc.src.stdio.sprintf
-    libc.src.stdio.snprintf
     libc.src.stdio.fprintf
     libc.src.stdio.printf
     libc.src.stdio.stderr

libc/config/linux/x86_64/entrypoints.txt

@@ -92,6 +92,10 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdlib.aligned_alloc
     libc.src.stdlib.free
 
+    # stdio.h entrypoints
+    libc.src.stdio.sprintf
+    libc.src.stdio.snprintf
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.mmap
     libc.src.sys.mman.munmap
@@ -298,8 +302,6 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.funlockfile
     libc.src.stdio.fwrite
     libc.src.stdio.fwrite_unlocked
-    libc.src.stdio.sprintf
-    libc.src.stdio.snprintf
     libc.src.stdio.fprintf
     libc.src.stdio.printf
     libc.src.stdio.stderr

libc/src/CMakeLists.txt

@@ -7,6 +7,7 @@ add_subdirectory(inttypes)
 add_subdirectory(math)
 add_subdirectory(string)
 add_subdirectory(stdlib)
+add_subdirectory(stdio)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(dirent)
@@ -24,6 +25,5 @@ endif()
 # since assert uses the signal API, we disable assert also.
 # add_subdirectory(assert)
 # add_subdirectory(signal)
-add_subdirectory(stdio)
 add_subdirectory(threads)
 add_subdirectory(time)

libc/test/src/CMakeLists.txt

@@ -34,6 +34,7 @@ add_subdirectory(inttypes)
 add_subdirectory(math)
 add_subdirectory(string)
 add_subdirectory(stdlib)
+add_subdirectory(stdio)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(fcntl)
@@ -50,7 +51,6 @@ add_subdirectory(dirent)
 # since assert uses the signal API, we disable assert also.
 # add_subdirectory(assert)
 # add_subdirectory(signal)
-add_subdirectory(stdio)
 add_subdirectory(time)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")

libc/utils/UnitTest/CMakeLists.txt

@@ -54,13 +54,6 @@ add_dependencies(
   libc.src.__support.CPP.array_ref
 )
 
-if(NOT LLVM_LIBC_FULL_BUILD) # TODO(michaelrj): make a more permanant solution.
-  return()
-endif()
-
-#currently stdio is fullbuild only, so this matcher that depends on a piece of
-#printf also has to be fullbuild only.
-
 add_library(
   LibcPrintfHelpers
     PrintfMatcher.h