Add c++ symbol support in xinfo. (#1028)

This change adds c++ symbol support in xinfo.

Currently, when using xinfo to get the symbol information in C++
programs, we might get incomplete data

This is because the gdb_get_location_from_symbol function could not
handle space in the symbol name.

This change updates the gdb_get_location_from_symbol, so we can handle
the space. It makes `xinfo` produces expected result.

gef.py

@@ -2010,11 +2010,13 @@ def gdb_get_location_from_symbol(address: int) -> Optional[Tuple[str, int]]:
     if sym.startswith("No symbol matches"):
         return None
 
+    # gdb outputs symbols with format: "<symbol_name> + <offset> in section <section_name> of <file>",
+    # here, we are only interested in symbol name and offset.
     i = sym.find(" in section ")
-    sym = sym[:i].split()
-    name, offset = sym[0], 0
-    if len(sym) == 3 and sym[2].isdigit():
-        offset = int(sym[2])
+    sym = sym[:i].split("+")
+    name, offset = sym[0].strip(), 0
+    if len(sym) == 2 and sym[1].isdigit():
+        offset = int(sym[1])
     return name, offset
 
 

tests/binaries/Makefile

@@ -2,7 +2,9 @@ CC              =       gcc
 DEBUG           =       1
 CFLAGS          +=      -Wall
 SOURCES         =       $(wildcard *.c)
+SOURCES         +=      $(wildcard *.cpp)
 LINKED          =       $(SOURCES:.c=.out)
+LINKED          :=      $(LINKED:.cpp=.out)
 LDFLAGS         =
 EXTRA_FLAGS     =
 TMPDIR          ?=      /tmp
@@ -27,6 +29,10 @@ all: $(LINKED)
 	@echo "[+] Building '$(TMPDIR)/$@'"
 	@$(CC) $(CFLAGS) $(EXTRA_FLAGS) -o $(TMPDIR)/$@ $? $(LDFLAGS)
 
+%.out : %.cpp
+	@echo "[+] Building '$(TMPDIR)/$@'"
+	@$(CC) $(CFLAGS) $(EXTRA_FLAGS) -o $(TMPDIR)/$@ $? $(LDFLAGS) -lstdc++
+
 clean :
 	@echo "[+] Cleaning stuff"
 	@cd $(TMPDIR) && rm -f $(LINKED)

tests/binaries/class.cpp

@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+class TraitA {};
+class TraitB {};
+
+class A {
+private:
+    int _a;
+
+public:
+    virtual ~A() {}
+    virtual void Run() { printf("I am A\n"); }
+};
+
+template <class TA, class TB>
+class B : public A {
+private:
+    int _b;
+
+public:
+    virtual void Run() { printf("I am B\n"); }
+};
+
+int main() {
+    A* a = new B<TraitA, TraitB>();
+    a->Run();
+    delete a;
+    return 0;
+}

tests/commands/xinfo.py

@@ -3,7 +3,7 @@
 """
 
 
-from tests.utils import GefUnitTestGeneric, gdb_run_cmd, gdb_start_silent_cmd
+from tests.utils import GefUnitTestGeneric, gdb_run_cmd, gdb_start_silent_cmd, gdb_run_silent_cmd, _target
 
 
 class XinfoCommand(GefUnitTestGeneric):
@@ -18,3 +18,10 @@ def test_cmd_xinfo(self):
         res = gdb_start_silent_cmd("xinfo $sp")
         self.assertNoException(res)
         self.assertTrue(len(res.splitlines()) >= 7)
+
+    def test_cmd_xinfo_on_class(self):
+        cmd = "xinfo $pc"
+        target = _target("class")
+        res = gdb_run_silent_cmd(cmd, target=target, before=["b B<TraitA, TraitB>::Run()"])
+        self.assertNoException(res)
+        self.assertIn("Symbol: B<TraitA, TraitB>::Run", res)