[PATCH 1/2] StdLib/LibC: avoid LTO code for compiler intrinsics

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

The softfloat routines and some other routines supplied by LibC
will satisfy references to compiler intrinsics that are emitted
by the compiler backend, which under LTO means that the link-time
code generation may emit references to symbols that have been
optimized away already.

Work around this by building the ARM and AARCH64 versions of LibC
and the softfloat library without LTO.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 StdLib/LibC/LibC.inf                | 1 +
 StdLib/LibC/Softfloat/Softfloat.inf | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/StdLib/LibC/LibC.inf b/StdLib/LibC/LibC.inf
index f13630648555..6039bb81c7dd 100644
--- a/StdLib/LibC/LibC.inf
+++ b/StdLib/LibC/LibC.inf
@@ -120,3 +120,4 @@ [LibraryClasses]
 #
 [BuildOptions]
   MSFT:*_*_IA32_CC_FLAGS = /GL-
+  GCC:*_*_ARM_CC_FLAGS = -fno-lto
diff --git a/StdLib/LibC/Softfloat/Softfloat.inf b/StdLib/LibC/Softfloat/Softfloat.inf
index 99763bcb57ba..460406c38fa4 100644
--- a/StdLib/LibC/Softfloat/Softfloat.inf
+++ b/StdLib/LibC/Softfloat/Softfloat.inf
@@ -71,4 +71,4 @@ [Packages]
 # Nasty things could happen if you do.
 
 [BuildOptions]
-  GCC:*_*_*_CC_FLAGS  = -DSOFTFLOAT_FOR_GCC -Wno-enum-compare -fno-tree-vrp
+  GCC:*_*_*_CC_FLAGS  = -DSOFTFLOAT_FOR_GCC -Wno-enum-compare -fno-tree-vrp -fno-lto
-- 
2.7.4