new file mode 100644
--- /dev/null
+++ b/js/src/jit-test/tests/baseline/bug1238815.js
@@ -0,0 +1,13 @@
+// This program crashes the ARM code generator because the machine code is
+// longer than the 32MB range of ARM branch instructions.
+//
+// Baseline should not attempt to compile the script.
+
+i = 1;
+function test(s) eval("line0 = Error.lineNumber\ndebugger\n" + s);
+function repeat(s) {
+        return Array(65 << 13).join(s)
+}
+long_expr = repeat(" + i")
+long_throw_stmt = long_expr;
+test(long_throw_stmt);

--- a/js/src/jit/BaselineJIT.h
+++ b/js/src/jit/BaselineJIT.h
@@ -105,17 +105,25 @@ struct DependentWasmModuleImport
       : module(module),
         importIndex(importIndex)
     { }
 };
 
 struct BaselineScript
 {
   public:
+    // Largest script that the baseline compiler will attempt to compile.
+#if defined(JS_CODEGEN_ARM)
+    // ARM branches can only reach 32MB, and the macroassembler doesn't mitigate
+    // that limitation. Use a stricter limit on the acceptable script size to
+    // avoid crashing when branches go out of range.
+    static const uint32_t MAX_JSSCRIPT_LENGTH = 1000000u;
+#else
     static const uint32_t MAX_JSSCRIPT_LENGTH = 0x0fffffffu;
+#endif
 
     // Limit the locals on a given script so that stack check on baseline frames
     // doesn't overflow a uint32_t value.
     // (MAX_JSSCRIPT_SLOTS * sizeof(Value)) must fit within a uint32_t.
     static const uint32_t MAX_JSSCRIPT_SLOTS = 0xffffu;
 
   private:
     // Code pointer containing the actual method.