Move some utility functions to linker_utils
Also adds unit-tests for page_start, page_offset, and safe_add
Change-Id: Ia1325b4682d367328a01599a19848e4ffcd2c0ea
diff --git a/linker/linker_mapped_file_fragment.cpp b/linker/linker_mapped_file_fragment.cpp
index 6a500ef..27c1c69 100644
--- a/linker/linker_mapped_file_fragment.cpp
+++ b/linker/linker_mapped_file_fragment.cpp
@@ -16,32 +16,13 @@
#include "linker_mapped_file_fragment.h"
#include "linker_debug.h"
+#include "linker_utils.h"
#include <inttypes.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <unistd.h>
-constexpr off64_t kPageMask = ~static_cast<off64_t>(PAGE_SIZE-1);
-
-static off64_t page_start(off64_t offset) {
- return offset & kPageMask;
-}
-
-static bool safe_add(off64_t* out, off64_t a, size_t b) {
- CHECK(a >= 0);
- if (static_cast<uint64_t>(INT64_MAX - a) < b) {
- return false;
- }
-
- *out = a + b;
- return true;
-}
-
-static size_t page_offset(off64_t offset) {
- return static_cast<size_t>(offset & (PAGE_SIZE-1));
-}
-
MappedFileFragment::MappedFileFragment() : map_start_(nullptr), map_size_(0),
data_(nullptr), size_ (0)
{ }
diff --git a/linker/linker_utils.cpp b/linker/linker_utils.cpp
index f81b77b..db43d38 100644
--- a/linker/linker_utils.cpp
+++ b/linker/linker_utils.cpp
@@ -105,3 +105,23 @@
return true;
}
+constexpr off64_t kPageMask = ~static_cast<off64_t>(PAGE_SIZE-1);
+
+off64_t page_start(off64_t offset) {
+ return offset & kPageMask;
+}
+
+bool safe_add(off64_t* out, off64_t a, size_t b) {
+ CHECK(a >= 0);
+ if (static_cast<uint64_t>(INT64_MAX - a) < b) {
+ return false;
+ }
+
+ *out = a + b;
+ return true;
+}
+
+size_t page_offset(off64_t offset) {
+ return static_cast<size_t>(offset & (PAGE_SIZE-1));
+}
+
diff --git a/linker/linker_utils.h b/linker/linker_utils.h
index b998fb5..65ffbdc5 100644
--- a/linker/linker_utils.h
+++ b/linker/linker_utils.h
@@ -24,4 +24,8 @@
bool file_is_in_dir(const std::string& file, const std::string& dir);
bool parse_zip_path(const char* input_path, std::string* zip_path, std::string* entry_path);
+off64_t page_start(off64_t offset);
+size_t page_offset(off64_t offset);
+bool safe_add(off64_t* out, off64_t a, size_t b);
+
#endif
diff --git a/linker/tests/linker_utils_test.cpp b/linker/tests/linker_utils_test.cpp
index d9b290c..3be9b3f 100644
--- a/linker/tests/linker_utils_test.cpp
+++ b/linker/tests/linker_utils_test.cpp
@@ -69,3 +69,24 @@
ASSERT_EQ("", entry_path);
}
+TEST(linker_utils, page_start) {
+ ASSERT_EQ(0x0001000, page_start(0x0001000));
+ ASSERT_EQ(0x3002000, page_start(0x300222f));
+ ASSERT_EQ(0x6001000, page_start(0x6001fff));
+}
+
+TEST(linker_utils, page_offset) {
+ ASSERT_EQ(0x0U, page_offset(0x0001000));
+ ASSERT_EQ(0x22fU, page_offset(0x300222f));
+ ASSERT_EQ(0xfffU, page_offset(0x6001fff));
+}
+
+TEST(linker_utils, safe_add) {
+ int64_t val = 42;
+ ASSERT_FALSE(safe_add(&val, INT64_MAX-20, 21U));
+ ASSERT_EQ(42, val);
+ ASSERT_TRUE(safe_add(&val, INT64_MAX-42, 42U));
+ ASSERT_EQ(INT64_MAX, val);
+ ASSERT_TRUE(safe_add(&val, 2000, 42U));
+ ASSERT_EQ(2042, val);
+}