Fix GCC build

-Wno-sign-compare also for GCC.

-Wno-error=strict-overflow to ignore the following warning.

In file included from
../../third_party/pdfium/core/include/fpdfapi/cpdf_object.h:10:0,
                 from
../../third_party/pdfium/core/include/fpdfapi/cpdf_stream.h:10,
                 from
../../third_party/pdfium/core/include/fpdfapi/fpdf_resource.h:12,
                 from
../../third_party/pdfium/core/fpdfapi/fpdf_font/font_int.h:13,
                 from
../../third_party/pdfium/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp:7:
../../third_party/pdfium/core/include/fxcrt/fx_string.h: In function
'CFX_ByteString {anonymous}::CMap_GetString(const CFX_ByteStringC&)':
../../third_party/pdfium/core/include/fxcrt/fx_string.h:111:19: warning:
assuming signed overflow does not occur when assuming that (X - c) > X is always
false [-Wstrict-overflow]
     if (count < 0 || count > m_Length - index) {

BUG=589724
TEST=build with GCC
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1785943002 .

1 files changed, 5 insertions, 1 deletions

diff --git a/BUILD.gn b/BUILD.gn
index b18c76eaaa..9f3b27e9bc 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -65,10 +65,14 @@ config("pdfium_config") {
     ]
   }
 
-  if (is_clang) {
+  if (is_clang || is_posix) {
     # TODO(thestig): Fix all instances, remove this, pdfium:29
     cflags += [ "-Wno-sign-compare" ]
   }
+
+  if (is_posix && !is_clang) {  # When GCC.
+    cflags += [ "-Wno-error=strict-overflow" ]
+  }
 }
 
 static_library("pdfium") {