From dd4fc71bfae767bcb63d8e509333909e9a7860a7 Mon Sep 17 00:00:00 2001
From: Brett Jia <dev.bjia56@gmail.com>
Date: Mon, 21 Apr 2025 21:52:22 -0400
Subject: [PATCH] Prioritize extra loader and OSNAME targets

This change modifies the order of non-input platform loaders and generic
multi-OS loaders to prioritize non-input loaders, which allows us to add
loaders which match APE-supported architectures (arm64/amd64) but aren't
one of Linux/FreeBSD/NetBSD/OpenBSD. For example, this change enables us
to add a Blink binary compiled for SunOS, which only supports amd64. The
existing APE loaders passed as input will be matched last using existing
script logic if no specific OSNAME target is set.
---
 tool/build/apelink.c | 71 +++++++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 30 deletions(-)

diff --git a/tool/build/apelink.c b/tool/build/apelink.c
index f84b50ef2..221edab72 100644
--- a/tool/build/apelink.c
+++ b/tool/build/apelink.c
@@ -1088,7 +1088,12 @@ static void OpenLoader(struct Loader *ldr) {
   close(fd);
   if (IsElf64Binary((elf = ldr->map), ldr->size)) {
     ValidateElfImage(ldr->map, ldr->size, ldr->path, true);
-    ldr->os = _HOSTLINUX | _HOSTFREEBSD | _HOSTNETBSD | _HOSTOPENBSD;
+    if (ldr->kernel) {
+      // Don't make any assumptions about the loader's OS
+      ldr->os = 0;
+    } else {
+      ldr->os = _HOSTLINUX | _HOSTFREEBSD | _HOSTNETBSD | _HOSTOPENBSD;
+    }
     ldr->machine = elf->e_machine;
     if (ldr->machine == EM_NEXGEN32E && FindLoaderEmbeddedMachoHeader(ldr)) {
       ldr->os |= _HOSTXNU;
@@ -2212,11 +2217,45 @@ int main(int argc, char *argv[]) {
       macos_silicon_loader_source_path = 0;
     }
 
-    // extract the ape loader for open platforms
     bool gotsome = false;
     if (inputs.n && (support_vector & _HOSTXNU)) {
       p = stpcpy(p, "if [ ! -d /Applications ]; then\n");
     }
+
+    // extract the ape loader for non-input architectures
+    // if the user requested a host kernel check, get the host kernel
+    if (loader_kernel) {
+      p = stpcpy(p, "k=$(uname -s 2>/dev/null) || k=unknown\n");
+    }
+    for (i = 0; i < loaders.n; ++i) {
+      struct Loader *loader = loaders.p + i;
+      if (loader->used) {
+        continue;
+      }
+      if (loader->os) {
+        // if the os field is set, this is a multi-OS ape loader or a
+        // mach-o loader
+        continue;
+      }
+      loader->used = true;
+      p = GenerateScriptIfLoaderMachine(p, loader);
+      p = stpcpy(p, "mkdir -p \"${t%/*}\" ||exit\n"
+                    "dd if=\"$o\"");
+      p = stpcpy(p, " skip=");
+      loader->ddarg_skip2 = p;
+      p = GenerateDecimalOffsetRelocation(p);
+      p = stpcpy(p, " count=");
+      loader->ddarg_size2 = p;
+      p = GenerateDecimalOffsetRelocation(p);
+      p = stpcpy(p, " bs=1 2>/dev/null | gzip -dc >\"$t.$$\" ||exit\n"
+                    "chmod 755 \"$t.$$\" ||exit\n"
+                    "mv -f \"$t.$$\" \"$t\" ||exit\n");
+      p = stpcpy(p, "exec \"$t\" \"$o\" \"$@\"\n"
+                    "fi\n");
+      gotsome = true;
+    }
+
+    // extract the ape loader for open platforms
     for (i = 0; i < inputs.n; ++i) {
       struct Loader *loader;
       struct Input *in = inputs.p + i;
@@ -2240,34 +2279,6 @@ int main(int argc, char *argv[]) {
       }
     }
 
-    // extract the ape loader for non-input architectures
-    // if the user requested a host kernel check, get the host kernel
-    if (loader_kernel) {
-      p = stpcpy(p, "k=$(uname -s 2>/dev/null) || k=unknown\n");
-    }
-    for (i = 0; i < loaders.n; ++i) {
-      struct Loader *loader = loaders.p + i;
-      if (loader->used) {
-        continue;
-      }
-      loader->used = true;
-      p = GenerateScriptIfLoaderMachine(p, loader);
-      p = stpcpy(p, "mkdir -p \"${t%/*}\" ||exit\n"
-                    "dd if=\"$o\"");
-      p = stpcpy(p, " skip=");
-      loader->ddarg_skip2 = p;
-      p = GenerateDecimalOffsetRelocation(p);
-      p = stpcpy(p, " count=");
-      loader->ddarg_size2 = p;
-      p = GenerateDecimalOffsetRelocation(p);
-      p = stpcpy(p, " bs=1 2>/dev/null | gzip -dc >\"$t.$$\" ||exit\n"
-                    "chmod 755 \"$t.$$\" ||exit\n"
-                    "mv -f \"$t.$$\" \"$t\" ||exit\n");
-      p = stpcpy(p, "exec \"$t\" \"$o\" \"$@\"\n"
-                    "fi\n");
-      gotsome = true;
-    }
-
     // close if-statements
     if (inputs.n && (support_vector & _HOSTXNU)) {
       if (!gotsome) {