wikiheaders: Allow parts of the headers to be ignored.

The specific cases here were SDL_size_mul_overflow_builtin and
SDL_size_add_overflow_builtin, which are forced-inline symbols in
SDL_stdinc.h that have to exist, but aren't really part of the public API,
and thus shouldn't be exported as documentation.

build-scripts/wikiheaders.pl

@@ -594,6 +594,7 @@ while (my $d = readdir(DH)) {
     open(FH, '<', "$incpath/$dent") or die("Can't open '$incpath/$dent': $!\n");
 
     my @contents = ();
+    my $ignoring_lines = 0;
 
     while (<FH>) {
         chomp;
@@ -606,7 +607,18 @@ while (my $d = readdir(DH)) {
         # Since a lot of macros are just preprocessor logic spam and not all macros are worth documenting anyhow, we only pay attention to them when they have a Doxygen comment attached.
         # Functions and other things are a different story, though!
 
-        if (/\A\s*extern\s+(SDL_DEPRECATED\s+|)DECLSPEC/) {  # a function declaration without a doxygen comment?
+        if ($ignoring_lines && /\A\s*\#\s*endif\s*\Z/) {
+            $ignoring_lines = 0;
+            push @contents, $_;
+            next;
+        } elsif ($ignoring_lines) {
+            push @contents, $_;
+            next;
+        } elsif (/\A\s*\#\s*ifndef\s+SDL_WIKI_DOCUMENTATION_SECTION\s*\Z/) {
+            $ignoring_lines = 1;
+            push @contents, $_;
+            next;
+        } elsif (/\A\s*extern\s+(SDL_DEPRECATED\s+|)DECLSPEC/) {  # a function declaration without a doxygen comment?
             $symtype = 1;   # function declaration
             @templines = ();
             $decl = $_;

include/SDL3/SDL_endian.h

@@ -238,8 +238,7 @@ SDL_FORCE_INLINE Uint32 SDL_Swap32(Uint32 x)
 #pragma intrinsic(_byteswap_uint64)
 #define SDL_Swap64(x) _byteswap_uint64(x)
 #elif defined(__i386__) && !HAS_BROKEN_BSWAP
-SDL_FORCE_INLINE Uint64
-SDL_Swap64(Uint64 x)
+SDL_FORCE_INLINE Uint64 SDL_Swap64(Uint64 x)
 {
     union {
         struct {

include/SDL3/SDL_stdinc.h

@@ -2476,6 +2476,7 @@ SDL_FORCE_INLINE int SDL_size_mul_overflow (size_t a,
     return 0;
 }
 
+#ifndef SDL_WIKI_DOCUMENTATION_SECTION
 #if SDL_HAS_BUILTIN(__builtin_mul_overflow)
 /* This needs to be wrapped in an inline rather than being a direct #define,
  * because __builtin_mul_overflow() is type-generic, but we want to be
@@ -2488,6 +2489,7 @@ SDL_FORCE_INLINE int SDL_size_mul_overflow_builtin (size_t a,
 }
 #define SDL_size_mul_overflow(a, b, ret) (SDL_size_mul_overflow_builtin(a, b, ret))
 #endif
+#endif
 
 /**
  * If a + b would overflow, return -1.
@@ -2507,6 +2509,7 @@ SDL_FORCE_INLINE int SDL_size_add_overflow (size_t a,
     return 0;
 }
 
+#ifndef SDL_WIKI_DOCUMENTATION_SECTION
 #if SDL_HAS_BUILTIN(__builtin_add_overflow)
 /* This needs to be wrapped in an inline rather than being a direct #define,
  * the same as the call to __builtin_mul_overflow() above. */
@@ -2518,6 +2521,7 @@ SDL_FORCE_INLINE int SDL_size_add_overflow_builtin (size_t a,
 }
 #define SDL_size_add_overflow(a, b, ret) (SDL_size_add_overflow_builtin(a, b, ret))
 #endif
+#endif
 
 /* This is a generic function pointer which should be cast to the type you expect */
 #ifdef SDL_FUNCTION_POINTER_IS_VOID_POINTER