[libc] Include (v)s(n)printf in baremetal configs

These are commonly used on baremetal targets. We disable float
support and other features to reduce the binary size. This would
ideally eventually be handled using the proposed config mechanism:
https://discourse.llvm.org/t/rfc-systematic-way-to-introduce-and-use-libc-config-options/72943
but for now we use a CMake conditional.

Differential Revision: https://reviews.llvm.org/D159067

Author: petrhosek

libc/config/baremetal/arm/entrypoints.txt

@@ -63,6 +63,12 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.inttypes.imaxdiv
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
+
+    # stdio.h entrypoints
+    libc.src.stdio.sprintf
+    libc.src.stdio.snprintf
+    libc.src.stdio.vsprintf
+    libc.src.stdio.vsnprintf
 
     # stdlib.h entrypoints
     libc.src.stdlib.abs

libc/config/baremetal/arm/headers.txt

@@ -4,6 +4,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.errno
     libc.include.inttypes
     libc.include.math
+    libc.include.stdio
     libc.include.stdlib
     libc.include.string
     libc.include.strings

libc/config/baremetal/riscv32/entrypoints.txt

@@ -64,6 +64,12 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.inttypes.strtoimax
     libc.src.inttypes.strtoumax
 
+    # stdio.h entrypoints
+    libc.src.stdio.sprintf
+    libc.src.stdio.snprintf
+    libc.src.stdio.vsprintf
+    libc.src.stdio.vsnprintf
+
     # stdlib.h entrypoints
     libc.src.stdlib.abs
     libc.src.stdlib.atoi

libc/config/baremetal/riscv32/headers.txt

@@ -4,6 +4,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.errno
     libc.include.inttypes
     libc.include.math
+    libc.include.stdio
     libc.include.stdlib
     libc.include.string
     libc.include.strings

libc/src/stdio/CMakeLists.txt

@@ -26,6 +26,14 @@ if(NOT LIBC_TARGET_ARCHITECTURE_IS_GPU)
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/generic)
 endif()
 
+if(${LIBC_TARGET_OS} STREQUAL "baremetal")
+  list(APPEND printf_copts
+      "-DLIBC_COPT_PRINTF_DISABLE_FLOAT"
+      "-DLIBC_COPT_PRINTF_DISABLE_INDEX_MODE"
+      "-DLIBC_COPT_PRINTF_DISABLE_WRITE_INT"
+    )
+endif()
+
 add_subdirectory(printf_core)
 add_subdirectory(scanf_core)
 
@@ -419,13 +427,13 @@ list(APPEND printf_deps
       libc.src.stdio.printf_core.vfprintf_internal
 )
 if(LLVM_LIBC_FULL_BUILD)
- list(APPEND printf_deps
+  list(APPEND printf_deps
       libc.src.__support.File.file
       libc.src.__support.File.platform_file
       libc.src.__support.File.platform_stdout
   )
 else()
- set(printf_copts "-DLIBC_COPT_PRINTF_USE_SYSTEM_FILE")
+  list(APPEND printf_copts "-DLIBC_COPT_PRINTF_USE_SYSTEM_FILE")
 endif()
 
 add_entrypoint_object(

libc/src/stdio/printf_core/CMakeLists.txt

@@ -93,6 +93,7 @@ add_object_library(
     libc.src.__support.float_to_string
   COMPILE_OPTIONS
     -DLIBC_COPT_FLOAT_TO_STR_USE_MEGA_LONG_DOUBLE_TABLE
+    ${printf_copts}
 )