AddressSanitizer support (#3560)

Makefile.common-jst

@@ -48,6 +48,8 @@ define dune_main_context
     (OCAMLLIB ("$(CURDIR)/_build/runtime_stdlib_install/lib/ocaml_runtime_stdlib")))
   (env (_
     (flags (:standard -warn-error +A -alert -unsafe_multidomain))
+    ; We never want to build the compiler itself with AddressSanitizer enabled.
+    (ocamlopt_flags (:standard -fno-asan))
     (env-vars ("OCAMLPARAM" "$(BUILD_OCAMLPARAM)"))))))
 endef
 

Makefile.config.in

@@ -199,6 +199,7 @@ INSTRUMENTED_RUNTIME_LIBS=@instrumented_runtime_libs@
 WITH_DEBUGGER=@with_debugger@
 ASM_CFI_SUPPORTED=@asm_cfi_supported@
 WITH_FRAME_POINTERS=@frame_pointers@
+WITH_ADDRESS_SANITIZER=@address_sanitizer@
 WITH_CPP_MANGLING=@cpp_mangling@
 WITH_PROFINFO=@profinfo@
 PROFINFO_WIDTH=@profinfo_width@

Makefile.upstream

@@ -1377,7 +1377,7 @@ SAK_CFLAGS ?= $(OC_CFLAGS) $(CFLAGS) $(OC_CPPFLAGS) $(CPPFLAGS)
 SAK_LINK ?= $(MKEXE_VIA_CC)
 
 $(SAK): $(RUNTIME_DIR)/sak.$(O)
-	$(V_MKEXE)$(call SAK_LINK,$@,$^)
+	$(V_MKEXE)$(call SAK_LINK,$@,$^ $(if $(filter true,$(WITH_ADDRESS_SANITIZER)),-fsanitize=address -fsanitize-recover=address))
 
 $(RUNTIME_DIR)/sak.$(O): $(RUNTIME_DIR)/sak.c $(RUNTIME_DIR)/caml/misc.h $(RUNTIME_DIR)/caml/config.h
 	$(V_CC)$(SAK_CC) -c $(SAK_CFLAGS) $(OUTPUTOBJ)$@ $<

backend/amd64/arch.ml

@@ -94,6 +94,8 @@ let trap_notes = ref true
 (* Emit extension symbols for CPUID startup check  *)
 let arch_check_symbols = ref true
 
+let is_asan_enabled = ref Config.with_address_sanitizer
+
 (* Machine-specific command-line options *)
 
 let command_line_options =
@@ -104,7 +106,11 @@ let command_line_options =
     "-ftrap-notes", Arg.Set trap_notes,
       " Emit .note.ocaml_eh section with trap handling information (default)";
     "-fno-trap-notes", Arg.Clear trap_notes,
-      " Do not emit .note.ocaml_eh section with trap handling information"
+      " Do not emit .note.ocaml_eh section with trap handling information";
+    "-fno-asan",
+      Arg.Clear is_asan_enabled,
+      " Disable AddressSanitizer. This is only meaningful if the compiler was \
+       built with AddressSanitizer support enabled."
   ] @ Extension.args
 
 (* Specific operations for the AMD64 processor *)

backend/amd64/arch.mli

@@ -39,6 +39,7 @@ end
 
 val trap_notes : bool ref
 val arch_check_symbols : bool ref
+val is_asan_enabled : bool ref
 val command_line_options : (string * Arg.spec * string) list
 
 (* Specific operations for the AMD64 processor *)