Weak symbols are not well supported by the PE format, so disable them.
We need to manually ensure that only one function is present in the source
code.
Add a Kconfig option to control this and enable it when building for
Windows.
Signed-off-by: Simon Glass <s...@chromium.org>
---
Kconfig | 15 +++++++++++++++
include/linux/compiler_attributes.h | 4 ++++
2 files changed, 19 insertions(+)
diff --git a/Kconfig b/Kconfig
index f24e4f0a331e..ca1402d09d10 100644
--- a/Kconfig
+++ b/Kconfig
@@ -72,6 +72,21 @@ config CLANG_VERSION
int
default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
+config CC_IS_MSYS
+ def_bool $(success,uname -o | grep -q Msys)
+
+config WEAK_SYMBOLS
+ bool "Enable use of weak symbols"
+ default y if !CC_IS_MSYS
+ help
+ The Portable Executable (PE) format used by Windows does not support
+ weak symbols very well. Even where it can be made to work, the __weak
+ function attribute cannot be made to work with PE. Supporting weak
+ symbols would involve changing the source code in undesirable ways.
+
+ This option controls whether weak symbols are used, or not. When
+ disabled, the __weak function attribute does nothing.
+
choice
prompt "Optimization level"
default CC_OPTIMIZE_FOR_SIZE
diff --git a/include/linux/compiler_attributes.h
b/include/linux/compiler_attributes.h
index 44c9a08d7346..c954109a065b 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -268,6 +268,10 @@
* gcc:
https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute
* gcc:
https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute
*/
+#ifdef CONFIG_WEAK_SYMBOLS
#define __weak __attribute__((__weak__))
+#else
+#define __weak
+#endif
#endif /* __LINUX_COMPILER_ATTRIBUTES_H */
--
2.40.0.634.g4ca3ef3211-goog
