FWIW, we'll definitely get pushback about > Now you can't do in lldb anymore > (lldb) call _Zsomethingsomething(1,2,3)
There are clever users of lldb, often working at assembly language level without any symbolic information, who are able to correctly call a C++ mangled function by hand. It's not something I'd want to do personally, but I'd be mad at my debugger if it gave me an error message when I told it what to do. J > On Mar 12, 2018, at 6:40 PM, Davide Italiano via lldb-commits > <lldb-commits@lists.llvm.org> wrote: > > Author: davide > Date: Mon Mar 12 18:40:00 2018 > New Revision: 327356 > > URL: http://llvm.org/viewvc/llvm-project?rev=327356&view=rev > Log: > [ExpressionParser] Fix crash when evaluating invalid expresssions. > > Typical example, illformed comparisons (operator== where LHS and > RHS are not compatible). If a symbol matched `operator==` in any > of the object files lldb inserted a generic function declaration > in the ASTContext on which Sema operates. Maintaining the AST > context invariants is fairly tricky and sometimes resulted in > crashes inside clang (or assertions hit). > > The real reason why this feature exists in the first place is > that of allowing users to do something like: > (lldb) call printf("patatino") > > even if the debug informations for printf() is not available. > Eventually, we might reconsider this feature in its > entirety, but for now we can't remove it as it would break > a bunch of users. Instead, try to limit it to non-C++ symbols, > where getting the invariants right is hopefully easier. > > Now you can't do in lldb anymore > (lldb) call _Zsomethingsomething(1,2,3) > > but that doesn't seem to be such a big loss. > > <rdar://problem/35645893> > > Added: > lldb/trunk/lit/Expr/Inputs/basic.cpp > lldb/trunk/lit/Expr/TestCallCppSym.test > Modified: > lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp > > Added: lldb/trunk/lit/Expr/Inputs/basic.cpp > URL: > http://llvm.org/viewvc/llvm-project/lldb/trunk/lit/Expr/Inputs/basic.cpp?rev=327356&view=auto > ============================================================================== > --- lldb/trunk/lit/Expr/Inputs/basic.cpp (added) > +++ lldb/trunk/lit/Expr/Inputs/basic.cpp Mon Mar 12 18:40:00 2018 > @@ -0,0 +1,12 @@ > +class Patatino { > +private: > + long tinky; > + > +public: > + Patatino(long tinky) { this->tinky = tinky; } > +}; > + > +int main(void) { > + Patatino *a = new Patatino(26); > + return 0; > +} > > Added: lldb/trunk/lit/Expr/TestCallCppSym.test > URL: > http://llvm.org/viewvc/llvm-project/lldb/trunk/lit/Expr/TestCallCppSym.test?rev=327356&view=auto > ============================================================================== > --- lldb/trunk/lit/Expr/TestCallCppSym.test (added) > +++ lldb/trunk/lit/Expr/TestCallCppSym.test Mon Mar 12 18:40:00 2018 > @@ -0,0 +1,6 @@ > +# RUN: %cxx %p/Inputs/basic.cpp -g -o %t && %lldb -b -s %s -- %t 2>&1 | > FileCheck %s > + > +breakpoint set --file basic.cpp --line 12 > +run > +call (int)_Znwm(23) > +# CHECK: error: use of undeclared identifier '_Znwm' > > Modified: > lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp > URL: > http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp?rev=327356&r1=327355&r2=327356&view=diff > ============================================================================== > --- > lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp > (original) > +++ > lldb/trunk/source/Plugins/ExpressionParser/Clang/ClangExpressionDeclMap.cpp > Mon Mar 12 18:40:00 2018 > @@ -2072,6 +2072,15 @@ void ClangExpressionDeclMap::AddOneFunct > return; > } > } else if (symbol) { > + // Don't insert a generic function decl for C++ symbol names. > + // Creating a generic function decl is almost surely going to cause > troubles > + // as it breaks Clang/Sema invariants and causes crashes in clang while > + // we're trying to evaluate the expression. > + // This means users can't call C++ functions by mangled name when there > + // are no debug info (as it happens for C symbol, e.g. printf()). > + if (CPlusPlusLanguage::IsCPPMangledName( > + symbol->GetMangled().GetMangledName().GetCString())) > + return; > fun_address = symbol->GetAddress(); > function_decl = context.AddGenericFunDecl(); > is_indirect_function = symbol->IsIndirect(); > > > _______________________________________________ > lldb-commits mailing list > lldb-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
