Split linker flags in separate files

jcelerier · Aug 18, 2020 · 0679fc0 · 0679fc0
1 parent 33e8548
commit 0679fc0
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Showing 5 changed files with 45 additions and 29 deletions.
diff --git a/src/builtins/default.cmake b/src/builtins/default.cmake
@@ -3,12 +3,12 @@ cninja_require(compiler=clang)
 cninja_require(lld)
 # cninja_require(libcxx) - not useful as of now as linux distros default to libstdc++
 cninja_require(visibility)
+cninja_require(linker)
 cninja_require(linkerwarnings)
 
 # -pipe: Potentially makes the build faster
-# -ffunction-sections, etc... : Allows to discard unused code more easily with --gc-sections
-string(APPEND CMAKE_C_FLAGS_INIT " -pipe -ffunction-sections -fdata-sections")
-string(APPEND CMAKE_CXX_FLAGS_INIT " -pipe -ffunction-sections -fdata-sections")
+string(APPEND CMAKE_C_FLAGS_INIT " -pipe")
+string(APPEND CMAKE_CXX_FLAGS_INIT " -pipe")
 
 if(WIN32)
   # Remove obnoxious default <windows.h> features

diff --git a/src/builtins/earlybinding.cmake b/src/builtins/earlybinding.cmake
@@ -0,0 +1,11 @@
+# Force symbols in shared libraries to be loaded on startup instead of lazily loaded.
+cninja_require(pre)
+
+if(APPLE)
+  add_linker_flags(" -Wl,-z,now")
+elseif(MSVC)
+  # Nothing special to do here, it's the default
+else()
+  # For macOS this only works for executables
+  string(APPEND CMAKE_EXE_LINKER_FLAGS_INIT " -Wl,-bind_at_load")
+endif()
diff --git a/src/builtins/linker.cmake b/src/builtins/linker.cmake
@@ -0,0 +1,22 @@
+# Discard unused symbols & libraries
+cninja_require(pre)
+
+# -ffunction-sections, etc... : Allows to discard unused code more easily with --gc-sections
+string(APPEND CMAKE_C_FLAGS_INIT " -ffunction-sections -fdata-sections")
+string(APPEND CMAKE_CXX_FLAGS_INIT " -ffunction-sections -fdata-sections")
+
+if(NOT APPLE)
+  # In conjunction with ffunction-sections / fdata-sections, removes unused code
+  add_linker_flags(" -Wl,--gc-sections")
+
+  # Don't link against libraries of which no symbols are used
+  add_linker_flags(" -Wl,--as-needed")
+
+  # Make all platforms behave like Windows, which is in itself terrible but will
+  # spare you trying to debug why dynamic_cast of inline classes across DLLs
+  # doesn't work in MSW - simply don't write code assuming this works anywhere.
+  add_linker_flags(" -Bsymbolic -Bsymbolic-functions")
+else()
+  # Apple way to strip unneeded libs:
+  add_linker_flags(" -Wl,-dead_strip -Wl,-dead_strip_dylibs")
+endif()
diff --git a/src/builtins/linkerwarnings.cmake b/src/builtins/linkerwarnings.cmake
@@ -14,7 +14,6 @@ if(NOT "asan" IN_LIST CNINJA_FEATURES)
       if((CNINJA_LINKER STREQUAL "lld") OR (CNINJA_LINKER STREQUAL "gold"))
         set(temp_LINKER_WARNINGS
              "-Wl,-z,defs \
-    -Wl,-z,now \
     -Wl,--unresolved-symbols,report-all \
     -Wl,--no-undefined \
     -Wl,--no-allow-shlib-undefined \

diff --git a/src/builtins/lld.cmake b/src/builtins/lld.cmake
@@ -15,32 +15,16 @@ if(NOT APPLE)
     add_linker_flags(" -fuse-ld=gold")
     set(CNINJA_LINKER gold)
   endif()
+endif()
 
-  if(NOT APPLE)
-    # In conjunction with ffunction-sections / fdata-sections, removes unused code
-    add_linker_flags(" -Wl,--gc-sections")
-
-    # Don't link against libraries of which no symbols are used
-    add_linker_flags(" -Wl,--as-needed")
-
-    # Make all platforms behave like Windows, which is in itself terrible but will
-    # spare you trying to debug why dynamic_cast of inline classes across DLLs
-    # doesn't work in MSW - simply don't write code assuming this works anywhere.
-    add_linker_flags(" -Bsymbolic -Bsymbolic-functions")
-  else()
-    # Apple way to strip unneeded libs:
-    add_linker_flags(" -Wl,-dead_strip")
+if(NOT WIN32 AND NOT APPLE)
+  # Make linking faster
+  # Except that gold segfaults with -flto and --threads...
+  if((CNINJA_LINKER STREQUAL "lld") OR NOT ("lto" IN_LIST CNINJA_FEATURES))
+    add_linker_flags(" -Wl,--threads")
   endif()
 
-  if(NOT WIN32 AND NOT APPLE)
-    # Make linking faster
-    # Except that gold segfaults with -flto and --threads...
-    if((CNINJA_LINKER STREQUAL "lld") OR NOT ("lto" IN_LIST CNINJA_FEATURES))
-      add_linker_flags(" -Wl,--threads")
-    endif()
-
-    # Make debugging faster
-    # Pro tip (Thanks Milian !): also add "set index-cache on" to your .gdbinit
-    add_linker_flags(" -Wl,--gdb-index")
-  endif()
+  # Make debugging faster
+  # Pro tip (Thanks Milian !): also add "set index-cache on" to your .gdbinit
+  add_linker_flags(" -Wl,--gdb-index")
 endif()