From 02b1f91e93b4e26c8fc227f48878a66f342cb68f Mon Sep 17 00:00:00 2001
From: Cheng Shao <terrorjack@type.dance>
Date: Thu, 23 May 2024 13:39:22 +0000
Subject: [PATCH] driver: build C/C++ with -ffunction-sections -fdata-sections
when split sections is enabled
When -fsplit-sections is passed to GHC, pass -ffunction-sections
-fdata-sections to gcc/clang when building C/C++. Previously,
-fsplit-sections was only respected by the NCG/LLVM backends, but not
the unregisterised backend; the GHC driver did not pass
-fdata-sections and -ffunction-sections to the C compiler, which
resulted in excessive executable sizes.
Fixes #23381.
-------------------------
Metric Decrease:
size_hello_artifact
size_hello_unicode
-------------------------
---
compiler/GHC/Driver/Pipeline/Execute.hs | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/compiler/GHC/Driver/Pipeline/Execute.hs b/compiler/GHC/Driver/Pipeline/Execute.hs
index 8fc8e0d18ed..c0479f5735e 100644
--- a/compiler/GHC/Driver/Pipeline/Execute.hs
+++ b/compiler/GHC/Driver/Pipeline/Execute.hs
@@ -487,6 +487,13 @@ runCcPhase cc_phase pipe_env hsc_env location input_fn = do
, not $ target32Bit (targetPlatform dflags)
]
+ -- if -fsplit-sections is enabled, we should also
+ -- build with these flags.
+ ++ (if gopt Opt_SplitSections dflags &&
+ platformOS (targetPlatform dflags) /= OSDarwin
+ then ["-ffunction-sections", "-fdata-sections"]
+ else [])
+
-- Stub files generated for foreign exports references the runIO_closure
-- and runNonIO_closure symbols, which are defined in the base package.
-- These symbols are imported into the stub.c file via RtsAPI.h, and the
--
GitLab