Update gen_stub to avoid compile errors on duplicate function names

Closes GH-9406

Author: alcaeus

UPGRADING.INTERNALS

@@ -63,6 +63,11 @@ PHP 8.2 INTERNALS UPGRADE NOTES
 ========================
 
 * Unsupported libxml2 2.10.0 symbols are no longer exported on Windows.
+* Identifier names for namespaced functions generated from stub files through
+  gen_stub.php have been changed. This requires that namespaced functions
+  should be declared via the PHP_FUNCTION macro by using the fully qualified
+  function name (whereas each part is separated by "_") instead of just the
+  function name itself.
 
 ========================
 3. Module changes

build/gen_stub.php

@@ -1037,6 +1037,10 @@ public function getNonNamespacedName(): string {
     }
 
     public function getDeclarationName(): string {
+        return implode('_', $this->name->parts);
+    }
+
+    public function getFunctionName(): string {
         return $this->name->getLast();
     }
 
@@ -1380,39 +1384,42 @@ public function getFunctionEntry(): string {
             }
         } else if ($this->name instanceof FunctionName) {
             $namespace = $this->name->getNamespace();
-            $declarationName = $this->name->getDeclarationName();
+            $functionName = $this->name->getFunctionName();
+            $declarationName = $this->alias ? $this->alias->getNonNamespacedName() : $this->name->getDeclarationName();
+
+            if ($namespace) {
+                // Namespaced functions are always declared as aliases to avoid name conflicts when two functions with
+                // the same name exist in separate namespaces
+                $macro = $this->isDeprecated ? 'ZEND_NS_DEP_FALIAS' : 'ZEND_NS_FALIAS';
 
-            if ($this->alias && $this->isDeprecated) {
+                // Render A\B as "A\\B" in C strings for namespaces
                 return sprintf(
-                    "\tZEND_DEP_FALIAS(%s, %s, %s)\n",
-                    $declarationName, $this->alias->getNonNamespacedName(), $this->getArgInfoName()
+                    "\t%s(\"%s\", %s, %s, %s)\n",
+                    $macro, addslashes($namespace), $this->name->getFunctionName(), $declarationName, $this->getArgInfoName()
                 );
             }
 
             if ($this->alias) {
+                $macro = $this->isDeprecated ? 'ZEND_DEP_FALIAS' : 'ZEND_FALIAS';
+
                 return sprintf(
-                    "\tZEND_FALIAS(%s, %s, %s)\n",
-                    $declarationName, $this->alias->getNonNamespacedName(), $this->getArgInfoName()
+                    "\t%s(%s, %s, %s)\n",
+                    $macro, $functionName, $declarationName, $this->getArgInfoName()
                 );
             }
 
-            if ($this->isDeprecated) {
-                return sprintf(
-                    "\tZEND_DEP_FE(%s, %s)\n", $declarationName, $this->getArgInfoName());
+            switch (true) {
+                case $this->isDeprecated:
+                    $macro = 'ZEND_DEP_FE';
+                    break;
+                case $this->supportsCompileTimeEval:
+                    $macro = 'ZEND_SUPPORTS_COMPILE_TIME_EVAL_FE';
+                    break;
+                default:
+                    $macro = 'ZEND_FE';
             }
 
-            if ($namespace) {
-                // Render A\B as "A\\B" in C strings for namespaces
-                return sprintf(
-                    "\tZEND_NS_FE(\"%s\", %s, %s)\n",
-                    addslashes($namespace), $declarationName, $this->getArgInfoName());
-            } else {
-                if ($this->supportsCompileTimeEval) {
-                    return sprintf(
-                        "\tZEND_SUPPORTS_COMPILE_TIME_EVAL_FE(%s, %s)\n", $declarationName, $this->getArgInfoName());
-                }
-                return sprintf("\tZEND_FE(%s, %s)\n", $declarationName, $this->getArgInfoName());
-            }
+            return sprintf("\t%s(%s, %s)\n", $macro, $functionName, $this->getArgInfoName());
         } else {
             throw new Error("Cannot happen");
         }

ext/zend_test/test.c

@@ -95,6 +95,16 @@ static ZEND_FUNCTION(zend_test_deprecated)
 	zend_parse_parameters(ZEND_NUM_ARGS(), "|z", &arg1);
 }
 
+static ZEND_FUNCTION(zend_test_alias)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
+static ZEND_FUNCTION(zend_test_deprecated_alias)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
 /* Create a string without terminating null byte. Must be terminated with
  * zend_terminate_string() before destruction, otherwise a warning is issued
  * in debug builds. */
@@ -415,12 +425,38 @@ static ZEND_FUNCTION(zend_test_zend_ini_parse_uquantity)
 	}
 }
 
-static ZEND_FUNCTION(namespaced_func)
+static ZEND_FUNCTION(ZendTestNS2_namespaced_func)
 {
 	ZEND_PARSE_PARAMETERS_NONE();
 	RETURN_TRUE;
 }
 
+static ZEND_FUNCTION(ZendTestNS2_namespaced_deprecated_func)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
+static ZEND_FUNCTION(ZendTestNS2_ZendSubNS_namespaced_func)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+	RETURN_TRUE;
+}
+
+static ZEND_FUNCTION(ZendTestNS2_ZendSubNS_namespaced_deprecated_func)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
+static ZEND_FUNCTION(namespaced_alias_func)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
+static ZEND_FUNCTION(namespaced_deprecated_alias_func)
+{
+	ZEND_PARSE_PARAMETERS_NONE();
+}
+
 static ZEND_FUNCTION(zend_test_parameter_with_attribute)
 {
 	zend_string *parameter;

ext/zend_test/test.stub.php

@@ -109,6 +109,15 @@ function zend_test_compile_string(string $source_string, string $filename, int $
     /** @deprecated */
     function zend_test_deprecated(mixed $arg = null): void {}
 
+    /** @alias zend_test_alias */
+    function zend_test_aliased(): void {}
+
+    /**
+      * @deprecated
+      * @alias zend_test_deprecated_alias
+      */
+    function zend_test_deprecated_aliased(): void {}
+
     function zend_create_unterminated_string(string $str): string {}
 
     function zend_terminate_string(string &$str): void {}
@@ -168,6 +177,20 @@ class Foo {
         public function method(): void {}
     }
 
+    function namespaced_func(): bool {}
+
+    /** @deprecated */
+    function namespaced_deprecated_func(): void {}
+
+    /** @alias namespaced_alias_func */
+    function namespaced_aliased_func(): void {}
+
+    /**
+      * @deprecated
+      * @alias namespaced_deprecated_alias_func
+      */
+    function namespaced_deprecated_aliased_func(): void {}
+
 }
 
 namespace ZendTestNS2\ZendSubNS {
@@ -178,4 +201,16 @@ public function method(): void {}
 
     function namespaced_func(): bool {}
 
+    /** @deprecated */
+    function namespaced_deprecated_func(): void {}
+
+    /** @alias namespaced_alias_func */
+    function namespaced_aliased_func(): void {}
+
+    /**
+      * @deprecated
+      * @alias namespaced_deprecated_alias_func
+      */
+    function namespaced_deprecated_aliased_func(): void {}
+
 }