SR-2280: swiftc -static-stdlib option fails on Linux (#5269)

- Link in static version of libicu if available in preference to
  the dynamic library when using the -static-stdlib option.

Author: spevans

lib/Driver/CMakeLists.txt

@@ -30,6 +30,9 @@ if(SWIFT_BUILD_STATIC_STDLIB)
         set(ICU_STATICLIB "TRUE")
       else()
         set(ICU_STATICLIB "FALSE")
+        find_package(ICU REQUIRED COMPONENTS uc i18n)
+        get_filename_component(ICU_UC_LIBDIR "${ICU_UC_LIBRARY}" DIRECTORY)
+        get_filename_component(ICU_I18N_LIBDIR "${ICU_I18N_LIBRARY}" DIRECTORY)
       endif()
       set(linkfile "${lowercase_sdk}/static-stdlib-args.lnk")
       add_custom_command_target(swift_static_stdlib_${sdk}_args
@@ -38,6 +41,8 @@ if(SWIFT_BUILD_STATIC_STDLIB)
           "${sdk}"
           "${SWIFTSTATICLIB_DIR}/${linkfile}"
           "${ICU_STATICLIB}"
+          "${ICU_UC_LIBDIR}"
+          "${ICU_I18N_LIBDIR}"
         OUTPUT
           "${SWIFTSTATICLIB_DIR}/${linkfile}")
 

utils/gen-static-stdlib-link-args

@@ -2,34 +2,62 @@
 
 #
 # Generate the static-stdlib-args.lnk used by the -static-stdlib option for
-# 'GenericUnix' (eg linux) plaforms. If libicu is built locally then include
-# libicudata
+# 'GenericUnix' (eg linux) plaforms. Tries to find static .a files for libs
+# not normally installed by default (currently libicu)
+# If libicu is built locally then include libicudata
 #
 
 # SDK=$1
 OUTPUTFILE=$2
 ICU_STATIC_LIB=$3
+# libdirs from pkg-config
+ICU_UC_LIBDIR=$4
+ICU_I18N_LIBDIR=$5
 
 
-if [ "${ICU_STATIC_LIB}" == "TRUE" ]; then
-    read -r -d '' ICU_LIBS <<EOF
+# Try and find the libicu .a library files to directly link in using the
+# fullpath to the files otherwise fullback to the default
+function find_static_iculibs {
+    if [ -n "${ICU_I18N_LIBDIR}" ]; then
+        LIBICU_I18N_A=${ICU_I18N_LIBDIR}/libicui18n.a
+    fi
+
+    if [ -n "${ICU_UC_LIBDIR}" ]; then
+        LIBICU_UC_A=${ICU_UC_LIBDIR}/libicuuc.a
+        LIBICU_DATA_A=${ICU_UC_LIBDIR}/libicudata.a
+    fi
+
+    if [ -f "${LIBICU_I18N_A}" ] && [ -f "${LIBICU_UC_A}" ] &&
+       [ -f "${LIBICU_DATA_A}" ]; then
+        read -d '' ICU_LIBS <<EOF
+$LIBICU_I18N_A
+$LIBICU_UC_A
+$LIBICU_DATA_A
+EOF
+    else
+        read -d '' ICU_LIBS <<EOF
 -licui18n
 -licuuc
--licudata
 EOF
-else
-    read -r -d '' ICU_LIBS <<EOF
+    fi
+}
+
+
+# If libicu was compiled as part of the swift build then link the libs as normal
+function use_local_iculibs {
+   read -d '' ICU_LIBS <<EOF
 -licui18n
 -licuuc
+-licudata
 EOF
-fi
-
+}
 
-if [ -z "${OUTPUTFILE}" ]; then
-    echo $0: No outputfile specified
-    exit 1
-fi
 
+function write_linkfile {
+    if [ -z "${OUTPUTFILE}" ]; then
+        echo $0: No outputfile specified
+        exit 1
+    fi
     cat >$OUTPUTFILE <<EOF
 -ldl
 -lpthread
@@ -43,3 +71,12 @@ $ICU_LIBS
 -Xlinker
 ALL
 EOF
+}
+
+
+if [ "${ICU_STATIC_LIB}" == "TRUE" ]; then
+    use_local_iculibs
+else
+    find_static_iculibs
+fi
+write_linkfile