Begin marking unsafe libc functions as UNSAFE_BUFFERS().

Prepare for a time when the plugin will start enforcing these.
This is not an exhaustive list, but covers many of the most common
cases.

Change-Id: I36fdf195e7716e9f8ccfeda5164b5ba71ec70cd0
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/127271
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Thomas Sepez <tsepez@google.com>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/fpdfsdk/fpdf_signature_embeddertest.cpp b/fpdfsdk/fpdf_signature_embeddertest.cpp
index 1d36fa5..70f275e 100644
--- a/fpdfsdk/fpdf_signature_embeddertest.cpp
+++ b/fpdfsdk/fpdf_signature_embeddertest.cpp
@@ -54,7 +54,7 @@
   std::vector<char> contents(size);
   ASSERT_EQ(size,
             FPDFSignatureObj_GetContents(signature, contents.data(), size));
-  ASSERT_EQ(0, memcmp(kExpectedContents, contents.data(), size));
+  ASSERT_EQ(0, UNSAFE_TODO(memcmp(kExpectedContents, contents.data(), size)));
 
   // FPDFSignatureObj_GetContents() negative testing.
   ASSERT_EQ(0U, FPDFSignatureObj_GetContents(nullptr, nullptr, 0));
@@ -108,7 +108,8 @@
   std::vector<char> sub_filter(size);
   ASSERT_EQ(size,
             FPDFSignatureObj_GetSubFilter(signature, sub_filter.data(), size));
-  ASSERT_EQ(0, memcmp(kExpectedSubFilter, sub_filter.data(), size));
+  ASSERT_EQ(0,
+            UNSAFE_TODO(memcmp(kExpectedSubFilter, sub_filter.data(), size)));
 
   // FPDFSignatureObj_GetSubFilter() negative testing.
   ASSERT_EQ(0U, FPDFSignatureObj_GetSubFilter(nullptr, nullptr, 0));
@@ -174,7 +175,7 @@
   std::vector<char> time_buffer(size);
   ASSERT_EQ(size,
             FPDFSignatureObj_GetTime(signature, time_buffer.data(), size));
-  ASSERT_EQ(0, memcmp(kExpectedTime, time_buffer.data(), size));
+  ASSERT_EQ(0, UNSAFE_TODO(memcmp(kExpectedTime, time_buffer.data(), size)));
 
   // FPDFSignatureObj_GetTime() negative testing.
   ASSERT_EQ(0U, FPDFSignatureObj_GetTime(nullptr, nullptr, 0));