Re: [csmith-dev] csmith and libc

[Yang Chen <chenyang@cs.utah.edu>]

Hi Timotej,

On 2015-07-28 13:55, Kapus, Timotej wrote:
>  Also how would I increase the number of times builtin functions are
> called? I am currently running with these flags: --builtins
> --builtin-function-prob 100 --no-unions --max-expr-complexity 3
> --no-arrays --max-funcs 50 --no-structs --no-pointers
> --no-comma-operators --no-embedded-assigns --no-compound-assignment,
> but I am still not happy with the density of bultin functions.

I think a small Csmith bug prevented us from producing more builtin 
functions. Can you apply the patch below and try again? Note that the 
crucial modification is adding "&& !CGOptions::builtins()". Roughly, it 
tells csmith to *not* keep choosing safe_math functions if we want to 
exercise builtins. The other changes are just for increasing the chance 
of generating function calls. For example, after I applied the patch, I 
got something below:

$ ./csmith --builtins --builtin-function-prob 100 --max-funcs 50 > 2.c
$ grep "__builtin" ./2.c | wc -l
319

- Yang

diff --git a/src/ExpressionFuncall.cpp b/src/ExpressionFuncall.cpp
index 2f3ae9f..a177ca2 100644
--- a/src/ExpressionFuncall.cpp
+++ b/src/ExpressionFuncall.cpp
@@ -55,10 +55,10 @@
 static bool
 ExpressionFunctionProbability(const CGContext &/*cg_context*/)
 {
-       if (Function::reach_max_functions_cnt()) {
+       if (Function::reach_max_functions_cnt() && 
!CGOptions::builtins()) {
                return true;
        }
-       return rnd_flipcoin(80);
+       return rnd_flipcoin(5);
 }

 /*
diff --git a/src/FunctionInvocation.cpp b/src/FunctionInvocation.cpp
index 229185a..54b9d2c 100644
--- a/src/FunctionInvocation.cpp
+++ b/src/FunctionInvocation.cpp
@@ -83,7 +83,7 @@ FunctionInvocation::make_random(bool is_std_func,
        // If we are looking for a program-defined function, try to find 
one.
        if (!is_std_func) {
                Function* callee = NULL;
-               if (pure_rnd_flipcoin(50)) {
+               if (pure_rnd_flipcoin(80)) {
                        callee = 
Function::choose_func(get_all_functions(), cg_context, type, qfer);
                }
                if (callee != NULL) {