Generalize breakpoint matching involving relative paths

Currently a breakpoint specified as relativefilepath:lineno will match only if the relative file path is a simple file name or if sandbox root + relative file path is an exact match. This is now generalized so that matching occurs if the relative file path is a suffix (path) of the absolute path of the execution location.

hphp/runtime/debugger/break_point.cpp

@@ -829,21 +829,28 @@ bool BreakPointInfo::MatchFile(const char *haystack, int haystack_len,
   return false;
 }
 
+// Returns true if file is a suffix path of fullPath
 bool BreakPointInfo::MatchFile(const std::string& file,
-                               const std::string& fullPath,
-                               const std::string& relPath) {
+                               const std::string& fullPath) {
   TRACE(2, "BreakPointInfo::MatchFile(const std::string&\n");
-  if (file == fullPath || file == relPath) {
+  if (file == fullPath) {
     return true;
   }
-  if (file.find('/') == std::string::npos &&
-      file == fullPath.substr(fullPath.rfind('/') + 1)) {
+  if (file.size() > 0 && file[0] != '/') {
+    auto pos = fullPath.rfind(file);
+    // check for match
+    if (pos == std::string::npos) return false;
+    // check if match is a suffix
+    if (pos + file.size() > fullPath.size()) return false;
+    // check if suffix is a sub path
+    if (pos == 0 || fullPath[pos-1] != '/') return false;
     return true;
   }
-  // file is possibly setup with a symlink in the path
-  if (StatCache::realpath(file.c_str()) ==
-      StatCache::realpath(fullPath.c_str())) {
-    return true;
+  // Perhaps file or fullPath is a symlink.
+  auto realFile = StatCache::realpath(file.c_str());
+  auto realFullPath = StatCache::realpath(fullPath.c_str());
+  if (realFile != file || realFullPath != fullPath) {
+    return MatchFile(realFile, realFullPath);
   }
   return false;
 }

hphp/runtime/debugger/break_point.h

@@ -134,8 +134,7 @@ public:
   static const char *GetInterruptName(InterruptType interrupt);
   static bool MatchFile(const char *haystack, int haystack_len,
                         const std::string &needle);
-  static bool MatchFile(const std::string& file, const std::string& fullPath,
-                        const std::string& relPath);
+  static bool MatchFile(const std::string& file, const std::string& fullPath);
 
 public:
   BreakPointInfo() : m_index(0) {} // for thrift

hphp/runtime/vm/debugger_hook.cpp

@@ -164,8 +164,7 @@ static void addBreakPointsInFile(Eval::DebuggerProxy* proxy,
   proxy->getBreakPoints(bps);
   for (unsigned int i = 0; i < bps.size(); i++) {
     Eval::BreakPointInfoPtr bp = bps[i];
-    if (Eval::BreakPointInfo::MatchFile(bp->m_file, efile->getFileName(),
-                                         efile->getRelPath())) {
+    if (Eval::BreakPointInfo::MatchFile(bp->m_file, efile->getFileName())) {
       addBreakPointInUnit(bp, efile->unit());
       break;
     }
@@ -326,8 +325,9 @@ void phpSetBreakPoints(Eval::DebuggerProxy* proxy) {
            g_vmContext->m_evaledFiles.begin();
            it != g_vmContext->m_evaledFiles.end(); ++it) {
         auto efile = it->second;
-        if (!Eval::BreakPointInfo::MatchFile(fileName, efile->getFileName(),
-                                             efile->getRelPath())) continue;
+        if (!Eval::BreakPointInfo::MatchFile(fileName, efile->getFileName())) {
+          continue;
+        }
         addBreakPointInUnit(bp, efile->unit());
         break;
       }

hphp/test/quick/debugger/break2.php.expectf

@@ -1,7 +1,7 @@
 Program %s/break2.php loaded. Type '[r]un' or '[c]ontinue' to go.
-break break2.php:7
-Breakpoint 1 set on line 7 of break2.php
-But wont break until file break2.php has been loaded.
+break quick/debugger/break2.php:7
+Breakpoint 1 set on line 7 of quick/debugger/break2.php
+But wont break until file quick/debugger/break2.php has been loaded.
 break foo2()
 Breakpoint 2 set upon entering foo2()
 But wont break until function foo2 has been loaded.
@@ -12,7 +12,7 @@ break cls2::pubCls()
 Breakpoint 4 set upon entering cls2::pubCls()
 But wont break until class cls2 has been loaded.
 break list
-  1	ALWAYS    on line 7 of break2.php (unbound)
+  1	ALWAYS    on line 7 of quick/debugger/break2.php (unbound)
   2	ALWAYS    upon entering foo2() (unbound)
   3	ALWAYS    upon entering cls2::pubObj() (unbound)
   4	ALWAYS    upon entering cls2::pubCls() (unbound)
@@ -26,12 +26,12 @@ Breakpoint 2 reached at foo2() on line 6 of %s/break2.php
    7   error_log($y);
 
 break list
-  1	ALWAYS    on line 7 of break2.php
+  1	ALWAYS    on line 7 of quick/debugger/break2.php
   2	ALWAYS    upon entering foo2()
   3	ALWAYS    upon entering cls2::pubObj()
   4	ALWAYS    upon entering cls2::pubCls()
 continue
-Breakpoint 1 reached at foo2() on line 7 of %s/break2.php
+Breakpoint 1 reached at foo2() on line 7 of %s/quick/debugger/break2.php
    6   $y = $x.'_suffix';
    7   error_log($y);
    8 }

hphp/test/quick/debugger/break2.php.in

@@ -1,4 +1,4 @@
-break break2.php:7
+break quick/debugger/break2.php:7
 break foo2()
 break cls2::pubObj()
 break cls2::pubCls()