fix(callgrind/tests): prevent printf inlining with noinline wrapper

Wrap printf calls in a __attribute__((noinline)) function to prevent
glibc from inlining printf via stdio2.h. This ensures the inline tests
only capture the intended inline function calls.

The filter_inline script now skips my_printf wrapper function calls
to keep the test output focused on the functions being tested.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: art049

callgrind/tests/Makefile.am

@@ -34,8 +34,7 @@ AM_CFLAGS   += $(AM_FLAG_M3264_PRI)
 AM_CXXFLAGS += $(AM_FLAG_M3264_PRI)
 
 # Inline tests need -O2 to enable inlining and -g for debug info
-# Use -fno-builtin-printf to prevent compiler from inlining printf
-inline_samefile_CFLAGS = $(AM_CFLAGS) -O2 -g -fno-builtin-printf
-inline_crossfile_CFLAGS = $(AM_CFLAGS) -O2 -g -fno-builtin-printf
+inline_samefile_CFLAGS = $(AM_CFLAGS) -O2 -g
+inline_crossfile_CFLAGS = $(AM_CFLAGS) -O2 -g
 
 threads_LDADD = -lpthread

callgrind/tests/filter_inline

@@ -33,6 +33,10 @@ in_main {
         else if (/^cfn=0x/) {
             # Skip
         }
+        # Skip my_printf wrapper function calls
+        else if (/^cfn=my_printf/) {
+            # Skip
+        }
         else {
             print $0
         }

callgrind/tests/inline-crossfile.c

@@ -1,7 +1,17 @@
 #include <stdio.h>
+#include <stdarg.h>
 #include "inline-crossfile-helper1.h"
 #include "inline-crossfile-helper2.h"
 
+// Non-inlinable printf wrapper to prevent glibc from inlining printf
+__attribute__((noinline))
+static void my_printf(const char *fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+    vprintf(fmt, args);
+    va_end(args);
+}
+
 int main(int argc, char **argv) {
     int n = 5 + (argc - 1);  // n = 5 when argc = 1
 
@@ -11,7 +21,7 @@ int main(int argc, char **argv) {
     // Call second inline function from helper2.h
     int prod = compute_product(n);
 
-    printf("sum=%d, product=%d\n", sum, prod);
+    my_printf("sum=%d, product=%d\n", sum, prod);
 
     return 0;
 }

callgrind/tests/inline-samefile.c

@@ -1,4 +1,14 @@
 #include <stdio.h>
+#include <stdarg.h>
+
+// Non-inlinable printf wrapper to prevent glibc from inlining printf
+__attribute__((noinline))
+static void my_printf(const char *fmt, ...) {
+    va_list args;
+    va_start(args, fmt);
+    vprintf(fmt, args);
+    va_end(args);
+}
 
 // Function 1: Iterative fibonacci - WILL be inlined
 static inline int fibonacci_iterative(int n) {
@@ -34,7 +44,7 @@ int main(int argc, char **argv) {
     // Call the recursive fibonacci (should NOT be inlined)
     int fib_rec = fibonacci_recursive(10);
 
-    printf("Iterative fib(%d): %d, Recursive fib(10): %d\n", n, fib_iter, fib_rec);
+    my_printf("Iterative fib(%d): %d, Recursive fib(10): %d\n", n, fib_iter, fib_rec);
 
     return 0;
 }