4 files changed, 8 insertions, 10 deletions
diff --git a/tasks/toolchains/clang.rake b/tasks/toolchains/clang.rake
index c75fa030c..7d0fe6a45 100644
--- a/tasks/toolchains/clang.rake
+++ b/tasks/toolchains/clang.rake
@@ -3,7 +3,9 @@ MRuby::Toolchain.new(:clang) do |conf, _params|
 
   [conf.cc, conf.objc, conf.asm].each do |cc|
     cc.command = ENV['CC'] || 'clang'
+    cc.flags << '-Wzero-length-array' unless ENV['CFLAGS']
   end
   conf.cxx.command = ENV['CXX'] || 'clang++'
-  conf.linker.command = ENV['LD'] || 'clang'
+  conf.cxx.flags << '-Wzero-length-array' unless ENV['CXXFLAGS'] || ENV['CFLAGS']
+  conf.linker.command = ENV['LD'] || ENV['CXX'] || ENV['CC'] || 'clang'
 end
diff --git a/tasks/toolchains/gcc.rake b/tasks/toolchains/gcc.rake
index e0eb36f26..663fef9e6 100644
--- a/tasks/toolchains/gcc.rake
+++ b/tasks/toolchains/gcc.rake
@@ -1,8 +1,7 @@
 MRuby::Toolchain.new(:gcc) do |conf, _params|
   [conf.cc, conf.objc, conf.asm].each do |cc|
     cc.command = ENV['CC'] || 'gcc'
-    cc.flags = [ENV['CFLAGS'] || %w(-g -std=gnu99 -O3 -Wall -Werror-implicit-function-declaration -Wdeclaration-after-statement -Wwrite-strings)]
-    cc.defines = %w(DISABLE_GEMS)
+    cc.flags = [ENV['CFLAGS'] || %w(-g -std=gnu99 -O3 -Wall -Werror-implicit-function-declaration -Wdeclaration-after-statement -Wwrite-strings -Wundef)]
     cc.option_include_path = '-I%s'
     cc.option_define = '-D%s'
     cc.compile_options = '%{flags} -MMD -o %{outfile} -c %{infile}'
@@ -12,8 +11,7 @@ MRuby::Toolchain.new(:gcc) do |conf, _params|
 
   [conf.cxx].each do |cxx|
     cxx.command = ENV['CXX'] || 'g++'
-    cxx.flags = [ENV['CXXFLAGS'] || ENV['CFLAGS'] || %w(-g -O3 -Wall -Werror-implicit-function-declaration)]
-    cxx.defines = %w(DISABLE_GEMS)
+    cxx.flags = [ENV['CXXFLAGS'] || ENV['CFLAGS'] || %w(-g -O3 -Wall -Werror-implicit-function-declaration -Wundef)]
     cxx.option_include_path = '-I%s'
     cxx.option_define = '-D%s'
     cxx.compile_options = '%{flags} -MMD -o %{outfile} -c %{infile}'
@@ -22,7 +20,7 @@ MRuby::Toolchain.new(:gcc) do |conf, _params|
   end
 
   conf.linker do |linker|
-    linker.command = ENV['LD'] || 'gcc'
+    linker.command = ENV['LD'] || ENV['CXX'] || ENV['CC'] || 'gcc'
     linker.flags = [ENV['LDFLAGS'] || %w()]
     linker.libraries = %w(m)
     linker.library_paths = []
diff --git a/tasks/toolchains/openwrt.rake b/tasks/toolchains/openwrt.rake
index 1637f6d91..aeb6dbcbc 100644
--- a/tasks/toolchains/openwrt.rake
+++ b/tasks/toolchains/openwrt.rake
@@ -5,7 +5,6 @@ MRuby::Toolchain.new(:openwrt) do |conf|
     cc.command = ENV['TARGET_CC']
     cc.flags = ENV['TARGET_CFLAGS']
     cc.include_paths = ["#{MRUBY_ROOT}/include"]
-    cc.defines = %w(DISABLE_GEMS)
     cc.option_include_path = '-I%s'
     cc.option_define = '-D%s'
     cc.compile_options = '%{flags} -MMD -o %{outfile} -c %{infile}'
@@ -15,7 +14,6 @@ MRuby::Toolchain.new(:openwrt) do |conf|
     cxx.command = ENV['TARGET_CXX']
     cxx.flags = ENV['TARGET_CXXFLAGS']
     cxx.include_paths = ["#{MRUBY_ROOT}/include"]
-    cxx.defines = %w(DISABLE_GEMS)
     cxx.option_include_path = '-I%s'
     cxx.option_define = '-D%s'
     cxx.compile_options = '%{flags} -MMD -o %{outfile} -c %{infile}'
diff --git a/tasks/toolchains/visualcpp.rake b/tasks/toolchains/visualcpp.rake
index b008273a2..6275059bb 100644
--- a/tasks/toolchains/visualcpp.rake
+++ b/tasks/toolchains/visualcpp.rake
@@ -3,7 +3,7 @@ MRuby::Toolchain.new(:visualcpp) do |conf, _params|
     cc.command = ENV['CC'] || 'cl.exe'
     # C4013: implicit function declaration
     cc.flags = [ENV['CFLAGS'] || %w(/c /nologo /W3 /we4013 /Zi /MD /O2 /D_CRT_SECURE_NO_WARNINGS)]
-    cc.defines = %w(DISABLE_GEMS MRB_STACK_EXTEND_DOUBLING)
+    cc.defines = %w(MRB_STACK_EXTEND_DOUBLING)
     cc.option_include_path = '/I%s'
     cc.option_define = '/D%s'
     cc.compile_options = "%{flags} /Fo%{outfile} %{infile}"
@@ -14,7 +14,7 @@ MRuby::Toolchain.new(:visualcpp) do |conf, _params|
   conf.cxx do |cxx|
     cxx.command = ENV['CXX'] || 'cl.exe'
     cxx.flags = [ENV['CXXFLAGS'] || ENV['CFLAGS'] || %w(/c /nologo /W3 /Zi /MD /O2 /EHs /D_CRT_SECURE_NO_WARNINGS)]
-    cxx.defines = %w(DISABLE_GEMS MRB_STACK_EXTEND_DOUBLING)
+    cxx.defines = %w(MRB_STACK_EXTEND_DOUBLING)
     cxx.option_include_path = '/I%s'
     cxx.option_define = '/D%s'
     cxx.compile_options = "%{flags} /Fo%{outfile} %{infile}"