diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -190,6 +190,8 @@
     'PhutilInRequestKeyValueCache' => 'cache/PhutilInRequestKeyValueCache.php',
     'PhutilInteractiveEditor' => 'console/PhutilInteractiveEditor.php',
     'PhutilInvalidRuleParserGeneratorException' => 'parser/generator/exception/PhutilInvalidRuleParserGeneratorException.php',
+    'PhutilInvalidStateException' => 'exception/PhutilInvalidStateException.php',
+    'PhutilInvalidStateExceptionTestCase' => 'exception/__tests__/PhutilInvalidStateExceptionTestCase.php',
     'PhutilInvisibleSyntaxHighlighter' => 'markup/syntax/highlighter/PhutilInvisibleSyntaxHighlighter.php',
     'PhutilIrreducibleRuleParserGeneratorException' => 'parser/generator/exception/PhutilIrreducibleRuleParserGeneratorException.php',
     'PhutilJIRAAuthAdapter' => 'auth/PhutilJIRAAuthAdapter.php',
@@ -621,6 +623,8 @@
     'PhutilIPAddressTestCase' => 'PhutilTestCase',
     'PhutilInRequestKeyValueCache' => 'PhutilKeyValueCache',
     'PhutilInvalidRuleParserGeneratorException' => 'PhutilParserGeneratorException',
+    'PhutilInvalidStateException' => 'Exception',
+    'PhutilInvalidStateExceptionTestCase' => 'PhutilTestCase',
     'PhutilIrreducibleRuleParserGeneratorException' => 'PhutilParserGeneratorException',
     'PhutilJIRAAuthAdapter' => 'PhutilOAuth1AuthAdapter',
     'PhutilJSONParserException' => 'Exception',
diff --git a/src/auth/PhutilOAuthAuthAdapter.php b/src/auth/PhutilOAuthAuthAdapter.php
--- a/src/auth/PhutilOAuthAuthAdapter.php
+++ b/src/auth/PhutilOAuthAuthAdapter.php
@@ -151,8 +151,7 @@
   protected function loadAccessTokenData() {
     $code = $this->getCode();
     if (!$code) {
-      throw new Exception(
-        pht('Call %s before accessing adapter information.', 'setCode()'));
+      throw new PhutilInvalidStateException('setCode');
     }
 
     $params = array(
diff --git a/src/cache/PhutilDirectoryKeyValueCache.php b/src/cache/PhutilDirectoryKeyValueCache.php
--- a/src/cache/PhutilDirectoryKeyValueCache.php
+++ b/src/cache/PhutilDirectoryKeyValueCache.php
@@ -169,10 +169,7 @@
    */
   private function getCacheDirectory() {
     if (!$this->cacheDirectory) {
-      throw new Exception(
-        pht(
-          'Call %s before using a directory cache!',
-          'setCacheDirectory()'));
+      throw new PhutilInvalidStateException('setCacheDirectory');
     }
     return $this->cacheDirectory;
   }
@@ -237,11 +234,7 @@
    */
   private function unlockCache() {
     if (!$this->lock) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'lockCache()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('lockCache');
     }
 
     $this->lock->unlock();
diff --git a/src/cache/PhutilMemcacheKeyValueCache.php b/src/cache/PhutilMemcacheKeyValueCache.php
--- a/src/cache/PhutilMemcacheKeyValueCache.php
+++ b/src/cache/PhutilMemcacheKeyValueCache.php
@@ -114,10 +114,7 @@
     $n = count($this->servers);
 
     if (!$n) {
-      throw new Exception(
-        pht(
-          'Call %s before using Memcache!',
-          'setServers()'));
+      throw new PhutilInvalidStateException('setServers');
     }
 
     foreach ($keys as $key) {
diff --git a/src/cache/PhutilOnDiskKeyValueCache.php b/src/cache/PhutilOnDiskKeyValueCache.php
--- a/src/cache/PhutilOnDiskKeyValueCache.php
+++ b/src/cache/PhutilOnDiskKeyValueCache.php
@@ -177,11 +177,7 @@
    */
   private function saveCache() {
     if (!$this->lock) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'loadCache($hold_lock=true)',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('loadCache');
     }
 
     // We're holding a lock so we're safe to do a write to a well-known file.
@@ -201,10 +197,7 @@
    */
   private function getCacheFile() {
     if (!$this->cacheFile) {
-      throw new Exception(
-        pht(
-          'Call %s before using a disk cache!',
-          'setCacheFile()'));
+      throw new PhutilInvalidStateException('setCacheFile');
     }
     return $this->cacheFile;
   }
diff --git a/src/exception/PhutilInvalidStateException.php b/src/exception/PhutilInvalidStateException.php
new file mode 100644
--- /dev/null
+++ b/src/exception/PhutilInvalidStateException.php
@@ -0,0 +1,30 @@
+<?php
+
+final class PhutilInvalidStateException extends Exception {
+  private $callee;
+  private $function;
+
+  public function __construct($function, $callee = null) {
+    if ($callee === null) {
+      $callee = idx(debug_backtrace(), 1);
+      $callee = idx($callee, 'function');
+    }
+
+    $this->callee   = $callee;
+    $this->function = $function;
+
+    parent::__construct(
+      pht(
+        'Call %s before calling %s!',
+        $this->function.'()',
+        $this->callee.'()'));
+  }
+
+  public function getCallee() {
+    return $this->callee;
+  }
+
+  public function getFunction() {
+    return $this->function;
+  }
+}
diff --git a/src/exception/__tests__/PhutilInvalidStateExceptionTestCase.php b/src/exception/__tests__/PhutilInvalidStateExceptionTestCase.php
new file mode 100644
--- /dev/null
+++ b/src/exception/__tests__/PhutilInvalidStateExceptionTestCase.php
@@ -0,0 +1,17 @@
+<?php
+
+final class PhutilInvalidStateExceptionTestCase extends PhutilTestCase {
+
+  public function testException() {
+    try {
+      throw new PhutilInvalidStateException('someMethod');
+    } catch (PhutilInvalidStateException $ex) {
+      $this->assertEqual(
+        __FUNCTION__,
+        $ex->getCallee());
+      $this->assertEqual(
+        'someMethod',
+        $ex->getFunction());
+    }
+  }
+}
diff --git a/src/parser/PhutilParserGenerator.php b/src/parser/PhutilParserGenerator.php
--- a/src/parser/PhutilParserGenerator.php
+++ b/src/parser/PhutilParserGenerator.php
@@ -118,44 +118,28 @@
 
   public function getEOFSymbol() {
     if ($this->eofSymbol === null) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->eofSymbol;
   }
 
   public function getInitSymbol() {
     if ($this->initSymbol === null) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->initSymbol;
   }
 
   public function getEpsilonSymbol() {
     if ($this->epsilonSymbol === null) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->epsilonSymbol;
   }
 
   public function getEndSymbol() {
     if ($this->endSymbol === null) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->endSymbol;
   }
@@ -905,11 +889,7 @@
    */
   public function inspectRules() {
     if (!$this->rulesValidated) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->rules;
   }
@@ -920,11 +900,7 @@
    */
   public function inspectFirstTable() {
     if ($this->firstTable === null) {
-      throw new Exception(
-        pht(
-          'Call %s before %s!',
-          'processGrammar()',
-          __FUNCTION__.'()'));
+      throw new PhutilInvalidStateException('processGrammar');
     }
     return $this->firstTable;
   }
diff --git a/src/utils/PhutilEditDistanceMatrix.php b/src/utils/PhutilEditDistanceMatrix.php
--- a/src/utils/PhutilEditDistanceMatrix.php
+++ b/src/utils/PhutilEditDistanceMatrix.php
@@ -165,8 +165,7 @@
 
   private function requireSequences() {
     if ($this->x === null) {
-      throw new Exception(
-        pht('Call %s before performing useful work!', 'setSequences()'));
+      throw new PhutilInvalidStateException('setSequences');
     }
   }
 
@@ -292,8 +291,7 @@
 
   private function getTypeMatrix() {
     if (!$this->computeString) {
-      throw new Exception(
-        pht('Call %s before %s.', 'setComputeString()', 'getTypeMatrix()'));
+      throw new PhutilInvalidStateException('setComputeString');
     }
     if ($this->typeMatrix === null) {
       $this->computeMatrix($this->x, $this->y);