Fix TracingCategory::kNavigation GOLD linking problems.
Patch ae49e2975749409bc950fab17aadd01ffc4c2a92, "Add tracing to
ClassifyNavigation to make debugging easier." introduced the following
code:
struct TracingCategory {
static constexpr const char kNavigation[] = "navigation";
};
This looks fine at first glance, but has one subtle problem that the
author of the code might not have been aware of. In C++14 (which is
currently used by chomium) a static constexpr member variable (unlike
other global constexpr variables) has an external linkage. This is not
really intuitive and is probably why it was fixed in C++17, where such
static constexpr member is inline.
The interesting part is this subtle difference in linking semantics
breaks component builds when using GOLD linker instead of LLD.
obj/content/browser/browser/navigation_controller_impl.o(.debug_addr+0x858):
error: undefined reference to 'content::TracingCategory::kNavigation'
To fix this lets just convert TracingCategory from struct into a
namespace. This way it should be inlined no matter which version of the
C++ standard the compiler is instructed to adhere to.
Ref: https://en.cppreference.com/w/cpp/language/constexpr
Change-Id: Ibf0471eaf20805cc7af8236386aa7c5318d26f4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2436824
Commit-Queue: Nasko Oskov <[email protected]>
Reviewed-by: Nasko Oskov <[email protected]>
Reviewed-by: Alexander Timin <[email protected]>
Cr-Commit-Position: refs/heads/master@{#812257}
diff --git a/content/browser/renderer_host/navigation_controller_impl.cc b/content/browser/renderer_host/navigation_controller_impl.cc
index d50253c..bc3ec598 100644
--- a/content/browser/renderer_host/navigation_controller_impl.cc
+++ b/content/browser/renderer_host/navigation_controller_impl.cc
@@ -1248,7 +1248,7 @@
NavigationType NavigationControllerImpl::ClassifyNavigation(
RenderFrameHostImpl* rfh,
const FrameHostMsg_DidCommitProvisionalLoad_Params& params) {
- TraceReturnReason<TracingCategory::kNavigation> trace_return(
+ TraceReturnReason<tracing_category::kNavigation> trace_return(
"ClassifyNavigation");
if (params.did_create_new_entry) {
