parser-gcc: fix incomplete file paths in UBSAN key events

UBSAN may only use the base name for the file path in its key event.
However, the top of the backtrace, if present, always contains the whole
path to this file.

Author: lzaoral

src/CMakeLists.txt

@@ -57,6 +57,7 @@ include_directories(lib)
 
 # link cslib.a and boost libraries
 link_libraries(cs
+    ${Boost_FILESYSTEM_LIBRARY}
     ${Boost_PROGRAM_OPTIONS_LIBRARY}
     ${Boost_REGEX_LIBRARY})
 
@@ -67,13 +68,11 @@ add_executable(cshtml       cshtml.cc)
 add_executable(cslinker     cslinker.cc)
 add_executable(cssort       cssort.cc)
 target_link_libraries(cshtml
-    ${Boost_FILESYSTEM_LIBRARY}
     ${Boost_SYSTEM_LIBRARY})
 
 # experimental
 add_executable(cstrans-df-run cstrans-df-run.cc)
 target_link_libraries(cstrans-df-run
-    ${Boost_FILESYSTEM_LIBRARY}
     ${Boost_SYSTEM_LIBRARY})
 
 # declare what 'make install' should install

src/lib/parser-gcc.cc

@@ -23,6 +23,7 @@
 #include "regex.hh"
 
 #include <algorithm>
+#include <boost/filesystem.hpp>
 
 namespace GccParserImpl {
 
@@ -639,8 +640,32 @@ void GccPostProcessor::Private::transUbsan(Defect *pDef) const
 
     // UBSAN always uses 'runtime error' for its key event
     DefEvent &keyEvt = pDef->events[pDef->keyEventIdx];
-    if (keyEvt.event == "runtime error")
-        pDef->checker = "UBSAN_WARNING";
+    if (keyEvt.event != "runtime error")
+        return;
+
+    pDef->checker = "UBSAN_WARNING";
+
+    // UBSAN may only use the base name for the file path in its key event.
+    // However, the top of the backtrace, if present, always contains the
+    // whole path to this file.
+    if (!keyEvt.fileName.empty() && keyEvt.fileName.front() == '/')
+        return;
+
+    using path = boost::filesystem::path;
+    const auto &keyFileName = path(keyEvt.fileName).filename();
+
+    for (const auto &evt : pDef->events) {
+        const auto &evtFileName = path(evt.fileName).filename();
+
+        // check that the basenames and line numbers match
+        if (&keyEvt != &evt
+                && keyFileName == evtFileName
+                && keyEvt.line == evt.line)
+        {
+            keyEvt.fileName = evt.fileName;
+            break;
+        }
+    }
 }
 
 void GccPostProcessor::Private::polishGccAnal(Defect *pDef) const

tests/csgrep/0112-gcc-parser-ubsan-bt-stdout.txt

@@ -1,5 +1,5 @@
 Error: UBSAN_WARNING:
-byteorder.h:83:9: runtime error: load of misaligned address 0x556e3e877805 for type 'const uint32_t', which requires 4 byte alignment
+/builddir/build/BUILD/rsync-3.2.3/byteorder.h:83:9: runtime error: load of misaligned address 0x556e3e877805 for type 'const uint32_t', which requires 4 byte alignment
 0x556e3e877805: note: pointer points here
 # b5 21 00 00 6c 00 00  07 ff 65 a0 b8 03 05 2f  74 65 78 74 0e 70 d6 f0  d2 4d 97 21 a4 81 00 00  a0
 #             ^
@@ -24,7 +24,7 @@ byteorder.h:83:9: runtime error: load of misaligned address 0x556e3e877805 for t
 /builddir/build/BUILD/rsync-3.2.3/rsync: note: _start() at 0x556e3dc0f324
 
 Error: UBSAN_WARNING:
-test.c:2:23: runtime error: load of null pointer of type 'char'
+/home/lukas/csdiff/tests/csgrep/test.c:2:23: runtime error: load of null pointer of type 'char'
 /home/lukas/csdiff/tests/csgrep/test.c:2: note: main() at 0x401147
 /lib64/libc.so.6: note: __libc_start_call_main() at 0x7f7851249b49
 /lib64/libc.so.6: note: __libc_start_main_alias_2() at 0x7f7851249c0a