Unify compiler flags example with locating right error message

lectures/debugging-strategies/slides.qmd

@@ -320,11 +320,11 @@ Also gcc compile time checks and options like
 
 
 
-## Look out for compiler warnings
+## Look out for compiler warnings {.leftalign auto-animate=true}
 
 ::::::::{.columns}
 
-:::{.column width=50%}
+:::{.column width=48%}
 
 ```c
 #include <stdlib.h>
@@ -336,33 +336,84 @@ int main() {
 
    free(ptr);
    // ERROR: Trying to free
-   //        memory from stack
+   // memory from stack
 
    return 0;
 }
 ```
 
+Compiling with
+
+`gcc inv_ptr.c           -o inv_ptr`
+
 :::
 
-:::{.column width=50% .fragment}
+:::{.column width=52% .fragment}
+
+Compiler output
 
-- Compilation only throws a warning
 ```
-$ gcc inv_pointer.c -o inv_pointer
-inv_pointer.c: In function ‘main’:
-inv_pointer.c:8:4: warning: ‘free’ called on unallocated object ‘number’ [-Wfree-nonheap-object]
+inv_ptr.c: In function ‘main’:
+inv_ptr.c:8:4: warning: ‘free’ called on unallocated object ‘number’ [-Wfree-nonheap-object]
     8 |    free(ptr);
       |    ^~~~~~~~~
-inv_pointer.c:4:8: note: declared here
+inv_ptr.c:4:8: note: declared here
     4 |    int number = 1;
       |        ^~~~~~
 ```
 
- - But running fails
- 
+Run output e.g.
+
+```
+Segmentation fault
+```
+
+:::
+
+::::::::
+
+
+## Look out for compiler warnings {.leftalign auto-animate=true}
+
+::::::::{.columns}
+
+:::{.column width=48%}
+
+```c
+#include <stdlib.h>
+
+int main() {
+   int number = 1;
+   int* ptr;
+   ptr = &number;
+
+   free(ptr);
+   // ERROR: Trying to free
+   // memory from stack
+
+   return 0;
+}
+```
+
+Compiling with
+
+`gcc inv_ptr.c -Werror -o inv_ptr`
+
+:::
+
+:::{.column width=52%}
+
+Compiler output
+
 ```
-munmap_chunk(): invalid pointer
-Aborted
+inv_ptr.c: In function ‘main’:
+inv_ptr.c:8:4: error: ‘free’ called on unallocated object ‘number’ [-Werror=free-nonheap-object]
+    8 |    free(ptr);
+      |    ^~~~~~~~~
+inv_ptr.c:4:8: note: declared here
+    4 |    int number = 1;
+      |        ^~~~~~
+cc1: all warnings being treated as errors
 ```
 
 :::
@@ -370,6 +421,7 @@ Aborted
 ::::::::
 
 
+
 ## Locating the right error message {.leftalign}
 
 ::::::::{.columns .smaller}
@@ -460,106 +512,6 @@ Try with more than just one compiler
 $\Rightarrow$ HPC systems usally provide native compiler plus gcc/gfortan. Try both variants.
 
 
-## Compiler flags example {.leftalign auto-animate=true}
-
-::::::::{.columns}
-
-:::{.column width=45%}
-
-```c
-#include <stdlib.h>
-
-int main() {
-   int number = 1;
-   int* ptr;
-   ptr = &number;
-
-   free(ptr);
-   // ERROR: Trying to free
-   // memory from stack
-
-   return 0;
-}
-```
-
-Compiling with
-
-`gcc inv_ptr.c -o inv_ptr`
-
-:::
-
-:::{.column width=55% .smaller}
-
-Compiler output
-
-```
-inv_ptr.c: In function ‘main’:
-inv_ptr.c:8:4: warning: ‘free’ called on unallocated object ‘number’ [-Wfree-nonheap-object]
-    8 |    free(ptr);
-      |    ^~~~~~~~~
-inv_ptr.c:4:8: note: declared here
-    4 |    int number = 1;
-      |        ^~~~~~
-```
-
-Run output
-
-```
-Segmentation fault
-```
-
-:::
-
-::::::::
-
-## Compiler flags example {.leftalign auto-animate=true}
-
-::::::::{.columns}
-
-:::{.column width=45%}
-
-```c
-#include <stdlib.h>
-
-int main() {
-   int number = 1;
-   int* ptr;
-   ptr = &number;
-
-   free(ptr);
-   // ERROR: Trying to free
-   // memory from stack
-
-   return 0;
-}
-```
-
-Compiling with
-
-`gcc inv_ptr.c -Werror -o inv_ptr`
-
-:::
-
-:::{.column width=55% .smaller}
-
-Compiler output
-
-```
-inv_ptr.c: In function ‘main’:
-inv_ptr.c:8:4: error: ‘free’ called on unallocated object ‘number’ [-Werror=free-nonheap-object]
-    8 |    free(ptr);
-      |    ^~~~~~~~~
-inv_ptr.c:4:8: note: declared here
-    4 |    int number = 1;
-      |        ^~~~~~
-cc1: all warnings being treated as errors
-```
-
-:::
-
-::::::::
-
-
 ## Fixing run-time errors
 
  - Produce sensible debug messages to determine code area with the issue