Add @(no_sanitize_memory) proc attribute with MSan additions to base:sanitizer

base/sanitizer/memory.odin

@@ -0,0 +1,74 @@
+#+no-instrumentation
+package sanitizer
+
+@(private="file")
+MSAN_ENABLED :: .Memory in ODIN_SANITIZER_FLAGS
+
+@(private="file")
+@(default_calling_convention="system")
+foreign {
+	__msan_unpoison :: proc(addr: rawptr, size: uint) ---
+}
+
+/*
+Marks a slice as fully initialized.
+
+Code instrumented with `-sanitize:memory` will be permitted to access any
+address within the slice as if it had already been initialized.
+
+When msan is not enabled this procedure does nothing.
+*/
+memory_unpoison_slice :: proc "contextless" (region: $T/[]$E) {
+	when MSAN_ENABLED {
+		__msan_unpoison(raw_data(region),  size_of(E) * len(region))
+	}
+}
+
+/*
+Marks a pointer as fully initialized.
+
+Code instrumented with `-sanitize:memory` will be permitted to access memory
+within the region the pointer points to as if it had already been initialized.
+
+When msan is not enabled this procedure does nothing.
+*/
+memory_unpoison_ptr :: proc "contextless" (ptr: ^$T) {
+	when MSAN_ENABLED {
+		__msan_unpoison(ptr, size_of(T))
+	}
+}
+
+/*
+Marks the region covering `[ptr, ptr+len)` as fully initialized.
+
+Code instrumented with `-sanitize:memory` will be permitted to access memory
+within this range as if it had already been initialized.
+
+When msan is not enabled this procedure does nothing.
+*/
+memory_unpoison_rawptr :: proc "contextless" (ptr: rawptr, len: int) {
+	when MSAN_ENABLED {
+		__msan_unpoison(ptr, uint(len))
+	}
+}
+
+/*
+Marks the region covering `[ptr, ptr+len)` as fully initialized.
+
+Code instrumented with `-sanitize:memory` will be permitted to access memory
+within this range as if it had already been initialized.
+
+When msan is not enabled this procedure does nothing.
+*/
+memory_unpoison_rawptr_uint :: proc "contextless" (ptr: rawptr, len: uint) {
+	when MSAN_ENABLED {
+		__msan_unpoison(ptr, len)
+	}
+}
+
+memory_unpoison :: proc {
+	memory_unpoison_slice,
+	memory_unpoison_ptr,
+	memory_unpoison_rawptr,
+	memory_unpoison_rawptr_uint,
+}

src/check_decl.cpp

@@ -1370,6 +1370,7 @@ gb_internal void check_proc_decl(CheckerContext *ctx, Entity *e, DeclInfo *d) {
 	e->Procedure.has_instrumentation = has_instrumentation;
 
 	e->Procedure.no_sanitize_address = ac.no_sanitize_address;
+	e->Procedure.no_sanitize_memory  = ac.no_sanitize_memory;
 
 	e->deprecated_message = ac.deprecated_message;
 	e->warning_message = ac.warning_message;

src/checker.cpp

@@ -3776,6 +3776,12 @@ gb_internal DECL_ATTRIBUTE_PROC(proc_decl_attribute) {
 		}
 		ac->no_sanitize_address = true;
 		return true;
+	} else if (name == "no_sanitize_memory") {
+		if (value != nullptr) {
+			error(value, "'%.*s' expects no parameter", LIT(name));
+		}
+		ac->no_sanitize_memory = true;
+		return true;
 	}
 	return false;
 }

src/checker.hpp

@@ -140,6 +140,7 @@ struct AttributeContext {
 	bool    instrumentation_enter : 1;
 	bool    instrumentation_exit  : 1;
 	bool    no_sanitize_address   : 1;
+	bool    no_sanitize_memory    : 1;
 	bool    rodata                : 1;
 	bool    ignore_duplicates     : 1;
 	u32 optimization_mode; // ProcedureOptimizationMode

src/entity.cpp

@@ -263,6 +263,7 @@ struct Entity {
 			bool    uses_branch_location       : 1;
 			bool    is_anonymous               : 1;
 			bool    no_sanitize_address        : 1;
+			bool    no_sanitize_memory         : 1;
 		} Procedure;
 		struct {
 			Array<Entity *> entities;

src/llvm_backend_proc.cpp

@@ -345,7 +345,7 @@ gb_internal lbProcedure *lb_create_procedure(lbModule *m, Entity *entity, bool i
 		if (build_context.sanitizer_flags & SanitizerFlag_Address && !entity->Procedure.no_sanitize_address) {
 			lb_add_attribute_to_proc(m, p->value, "sanitize_address");
 		}
-		if (build_context.sanitizer_flags & SanitizerFlag_Memory) {
+		if (build_context.sanitizer_flags & SanitizerFlag_Memory && !entity->Procedure.no_sanitize_memory) {
 			lb_add_attribute_to_proc(m, p->value, "sanitize_memory");
 		}
 		if (build_context.sanitizer_flags & SanitizerFlag_Thread) {