From 36a66a7243126bc8f38d3c4bdea46bce18ff5a7a Mon Sep 17 00:00:00 2001
From: Ivan Grokhotkov <ivan@espressif.com>
Date: Thu, 2 Jan 2020 15:52:13 +0100
Subject: [PATCH] newlib: use --specs=nano.specs to enable "nano" version of C
 library

esp2020r1 toolchain includes a nano.specs file, which instructs GCC to
substitute libc.a with libc_nano.a.

In the build system, this simplifies handling of the nano formatting
option, eliminating LIBC and LIBM global variables.
---
 components/app_trace/CMakeLists.txt     | 2 +-
 components/newlib/CMakeLists.txt        | 6 +++++-
 components/newlib/project_include.cmake | 7 -------
 3 files changed, 6 insertions(+), 9 deletions(-)
 delete mode 100644 components/newlib/project_include.cmake

diff --git a/components/app_trace/CMakeLists.txt b/components/app_trace/CMakeLists.txt
index e982d1911..3ee0ff655 100644
--- a/components/app_trace/CMakeLists.txt
+++ b/components/app_trace/CMakeLists.txt
@@ -39,4 +39,4 @@ target_compile_options(${COMPONENT_LIB} PRIVATE "-fno-profile-arcs" "-fno-test-c
 
 # Force app_trace to also appear later than gcov in link line
 idf_component_get_property(app_trace app_trace COMPONENT_LIB)
-target_link_libraries(${COMPONENT_LIB} INTERFACE $<TARGET_FILE:${app_trace}> gcov $<TARGET_FILE:${app_trace}> ${LIBC})
+target_link_libraries(${COMPONENT_LIB} INTERFACE $<TARGET_FILE:${app_trace}> gcov $<TARGET_FILE:${app_trace}> c)
diff --git a/components/newlib/CMakeLists.txt b/components/newlib/CMakeLists.txt
index 2738e130d..1ffa52b6f 100644
--- a/components/newlib/CMakeLists.txt
+++ b/components/newlib/CMakeLists.txt
@@ -29,7 +29,7 @@ idf_component_register(SRCS "${srcs}"
 
 # Toolchain libraries require code defined in this component
 idf_component_get_property(newlib newlib COMPONENT_LIB)
-target_link_libraries(${COMPONENT_LIB} INTERFACE ${LIBC} ${LIBM} gcc "$<TARGET_FILE:${newlib}>")
+target_link_libraries(${COMPONENT_LIB} INTERFACE c m gcc "$<TARGET_FILE:${newlib}>")
 
 set_source_files_properties(heap.c PROPERTIES COMPILE_FLAGS -fno-builtin)
 
@@ -40,3 +40,7 @@ list(APPEND EXTRA_LINK_FLAGS "-u newlib_include_heap_impl")
 list(APPEND EXTRA_LINK_FLAGS "-u newlib_include_syscalls_impl")
 list(APPEND EXTRA_LINK_FLAGS "-u newlib_include_pthread_impl")
 target_link_libraries(${COMPONENT_LIB} INTERFACE "${EXTRA_LINK_FLAGS}")
+
+if(CONFIG_NEWLIB_NANO_FORMAT)
+    target_link_libraries(${COMPONENT_LIB} INTERFACE "--specs=nano.specs")
+endif()
diff --git a/components/newlib/project_include.cmake b/components/newlib/project_include.cmake
deleted file mode 100644
index 4a1784908..000000000
--- a/components/newlib/project_include.cmake
+++ /dev/null
@@ -1,7 +0,0 @@
-if(CONFIG_NEWLIB_NANO_FORMAT)
-    set(LIBC c_nano)
-else()
-    set(LIBC c)
-endif()
-
-set(LIBM m)