Suppress [value] messages in the log of Frama-C's Value Analysis

Question

I want to use the result from the analysis of Value plugin in Frama-C (batch mode) for further evaluation of variables in functions. However, the output seems to be large with lots of [value] tags, what I need is only the part from [value] ====== VALUES COMPUTED ====== with computed values at the end of each function. Does Frama-C support the options that allow me to do that?

Answer 1

You may find that the command-line options frama-c -no-val-show-initial-state -no-val-show-progress … make the output more to your taste.

When using the latter option, you may appreciate -val-print-callstacks , which prints each time a message is emitted the call-stack the message corresponds to, since that context is no longer available from the previous lines in the log.

For illustration, the development version of Frama-C at the time of answering shows the messages below by default:

int x;

/*@ assigns x; */
void f(void);

void g(int y) {
  f();
  x += y;
}

int main(void) {
  g(1);
}

Analyzing with frama-c -val tc :

[value] Analyzing a complete application starting at main
[value] Computing initial state
[value] Initial state computed
[value] Values of globals at initialization
  x ∈ {0}
[value] computing for function g <- main.
        Called from t.c:12.
[value] computing for function f <- g <- main.
        Called from t.c:7.
[value] using specification for function f
t.c:3:[value] warning: no \from part for clause 'assigns x;' of function f
[value] Done for function f
t.c:8:[kernel] warning: signed overflow. assert x+y ≤ 2147483647;
[value] Recording results for g
[value] Done for function g
[value] Recording results for main
[value] done for function main
[value] ====== VALUES COMPUTED ======
[value] Values at end of function g:
  x ∈ [-2147483647..2147483647]
[value] Values at end of function main:
  x ∈ [-2147483647..2147483647]
  __retres ∈ {0}

Analyzing with frama-c -val tc -no-val-show-initial-state -no-val-show-progress :

[value] Analyzing a complete application starting at main
[value] Computing initial state
[value] Initial state computed
[value] using specification for function f
t.c:3:[value] warning: no \from part for clause 'assigns x;' of function f
t.c:8:[kernel] warning: signed overflow. assert x+y ≤ 2147483647;
[value] done for function main
[value] ====== VALUES COMPUTED ======
[value] Values at end of function g:
  x ∈ [-2147483647..2147483647]
[value] Values at end of function main:
  x ∈ [-2147483647..2147483647]
  __retres ∈ {0}

And adding the option -val-show-callstack means that for the alarm at line 8, the context is shown as below:

t.c:8:[kernel] warning: signed overflow. assert x+y ≤ 2147483647;
                  stack: g :: t.c:12 <- main