[XRay][compiler-rt] FDRLogWriter Abstraction

Summary:
This change introduces an `FDRLogWriter` type which is responsible for
serialising metadata and function records to character buffers. This is
the first step in a refactoring of the implementation of the FDR runtime
to allow for more granular testing of the individual components of the
implementation.

The main contribution of this change is a means of hiding the details of
how specific records are written to a buffer, and for managing the
extents of these buffers. We make use of C++ features (templates and
some metaprogramming) to reduce repetition in the act of writing out
specific kinds of records to the buffer.

In this process, we make a number of changes across both LLVM and
compiler-rt to allow us to use the `Trace` abstraction defined in the
LLVM project in the testing of the runtime implementation. This gives us
a closer end-to-end test which version-locks the runtime implementation
with the loading implementation in LLVM.

We also allow using gmock in compiler-rt unit tests, by adding the
requisite definitions in the `AddCompilerRT.cmake` module. We also add
the terminfo library detection along with inclusion of the appropriate
compiler flags for header include lookup.

Finally, we've gone ahead and updated the FDR logging implementation to
use the FDRLogWriter for the lowest-level record-writing details.

Following patches will isolate the state machine transitions which
manage the set-up and tear-down of the buffers we're using in multiple
threads.

Reviewers: mboerger, eizan

Subscribers: mgorny, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D52220

llvm-svn: 342617

2 files changed, 14 insertions, 2 deletions

diff --git a/compiler-rt/cmake/Modules/AddCompilerRT.cmake b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
index cd4c704fc82..4efbd3a4a43 100644
--- a/compiler-rt/cmake/Modules/AddCompilerRT.cmake
+++ b/compiler-rt/cmake/Modules/AddCompilerRT.cmake
@@ -357,6 +357,16 @@ set(COMPILER_RT_GTEST_CFLAGS
   -I${COMPILER_RT_GTEST_PATH}
 )
 
+# Mocking support.
+set(COMPILER_RT_GMOCK_PATH ${LLVM_MAIN_SRC_DIR}/utils/unittest/googlemock)
+set(COMPILER_RT_GMOCK_SOURCE ${COMPILER_RT_GMOCK_PATH}/src/gmock-all.cc)
+set(COMPILER_RT_GMOCK_CFLAGS
+  -DGTEST_NO_LLVM_RAW_OSTREAM=1
+  -DGTEST_HAS_RTTI=0
+  -I${COMPILER_RT_GMOCK_PATH}/include
+  -I${COMPILER_RT_GMOCK_PATH}
+)
+
 append_list_if(COMPILER_RT_DEBUG -DSANITIZER_DEBUG=1 COMPILER_RT_UNITTEST_CFLAGS)
 append_list_if(COMPILER_RT_HAS_WCOVERED_SWITCH_DEFAULT_FLAG -Wno-covered-switch-default COMPILER_RT_UNITTEST_CFLAGS)
 
diff --git a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
index d8996a67571..e2884e23e37 100644
--- a/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
+++ b/compiler-rt/cmake/Modules/CompilerRTUtils.cmake
@@ -217,7 +217,7 @@ macro(load_llvm_config)
   endif()
   if (LLVM_CONFIG_PATH)
     execute_process(
-      COMMAND ${LLVM_CONFIG_PATH} "--obj-root" "--bindir" "--libdir" "--src-root"
+      COMMAND ${LLVM_CONFIG_PATH} "--obj-root" "--bindir" "--libdir" "--src-root" "--includedir"
       RESULT_VARIABLE HAD_ERROR
       OUTPUT_VARIABLE CONFIG_OUTPUT)
     if (HAD_ERROR)
@@ -228,11 +228,13 @@ macro(load_llvm_config)
     list(GET CONFIG_OUTPUT 1 TOOLS_BINARY_DIR)
     list(GET CONFIG_OUTPUT 2 LIBRARY_DIR)
     list(GET CONFIG_OUTPUT 3 MAIN_SRC_DIR)
+    list(GET CONFIG_OUTPUT 4 INCLUDE_DIR)
 
     set(LLVM_BINARY_DIR ${BINARY_DIR} CACHE PATH "Path to LLVM build tree")
-    set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
     set(LLVM_LIBRARY_DIR ${LIBRARY_DIR} CACHE PATH "Path to llvm/lib")
     set(LLVM_MAIN_SRC_DIR ${MAIN_SRC_DIR} CACHE PATH "Path to LLVM source tree")
+    set(LLVM_TOOLS_BINARY_DIR ${TOOLS_BINARY_DIR} CACHE PATH "Path to llvm/bin")
+    set(LLVM_INCLUDE_DIR ${INCLUDE_DIR} CACHE PATH "Paths to LLVM headers")
 
     # Make use of LLVM CMake modules.
     # --cmakedir is supported since llvm r291218 (4.0 release)