Implement stack probe for x86

src/compiler/crystal/codegen/fun.cr

@@ -412,6 +412,15 @@ class Crystal::CodeGenVisitor
       context.fun.add_attribute LLVM::Attribute::NoInline
       context.fun.linkage = LLVM::Linkage::External
     end
+
+    # TODO: crystal should support __chkstk/__chkstk_ms for windows.
+    if @program.has_flag?("unix")
+      if @program.has_flag?("i386") || @program.has_flag?("x86_64")
+        context.fun.add_target_dependent_attribute "probe-stack", "__crystal_probe_stack"
+      else
+        # currnetly LLVM does not support probe-stack for other architectures.
+      end
+    end
   end
 
   def setup_closure_vars(def_vars, closure_vars, context = self.context, closure_ptr = fun_literal_closure_ptr)

src/crystal/compiler_rt.cr

@@ -1,3 +1,4 @@
 {% skip_file if flag?(:skip_crystal_compiler_rt) %}
 
 require "./compiler_rt/mulodi4.cr"
+require "./compiler_rt/probestack.cr"

src/crystal/compiler_rt/probestack.cr

@@ -0,0 +1,47 @@
+{% skip_file unless flag?(:unix) %}
+
+{% if flag?(:x86_64) %}
+  # :nodoc:
+  @[Naked]
+  fun __crystal_probe_stack
+    asm("
+    mov %rax, %r11
+    cmp $$0x1000, %r11  // check %r11 first, otherwise segmentation fault occurs.
+    jna 2f
+  1:
+    sub $$0x1000, %rsp
+    test %rsp, 8(%rsp)
+    sub $$0x1000, %r11
+    cmp $$0x1000, %r11
+    ja 1b
+  2:
+    sub %r11, %rsp
+    test %rsp, 8(%rsp)
+    add %rax, %rsp
+    ret
+    ")
+  end
+{% elsif flag?(:i386) %}
+  # :nodoc:
+  @[Naked]
+  fun __crystal_probe_stack
+    asm("
+    push %ecx
+    mov %eax, %ecx
+    cmp $$0x1000, %ecx
+    jna 2f
+  1:
+    sub $$0x1000, %esp
+    test %esp, 8(%esp)
+    sub $$0x1000, %ecx
+    cmp $$0x1000, %ecx
+    ja 1b
+  2:
+    sub %ecx, %esp
+    test %esp, 8(%esp)
+    add %eax, %esp
+    pop %ecx
+    ret
+    ")
+  end
+{% end %}