From 6a9411e784c58492e62a5dcb7d5d1aadfb2e1830 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Wed, 3 Oct 2018 09:31:01 -0400
Subject: manual: mention the "invalid parameter" case

This happens often enough and the error message is quite unhelpful.
Mention this error explicitly in the documentation.
---
 doc/manual.asciidoc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/doc/manual.asciidoc b/doc/manual.asciidoc
index 9e55c02..db164e7 100644
--- a/doc/manual.asciidoc
+++ b/doc/manual.asciidoc
@@ -880,7 +880,8 @@ quoting rules are deterimined by the called program, which on Windows
 are usually provided by the C library.  If you need shell
 interpretation of the command (such as the use of `&&` to chain
 multiple commands), make the command execute the Windows shell by
-prefixing the command with `cmd /c`.
+prefixing the command with `cmd /c`. Ninja may error with "invalid parameter"
+which usually indicates that the command line length has been exceeded.
 
 [[ref_outputs]]
 Build outputs
-- 
cgit v0.12


From e2aa04fdef84652492f7cd11ce9f4d971dd7a3c3 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Wed, 3 Oct 2018 09:31:02 -0400
Subject: Win32Fatal: support a "hint" for the error

The callsite might have extra context which is helpful for interpreting
the error message.
---
 src/util.cc | 8 ++++++--
 src/util.h  | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/util.cc b/src/util.cc
index 760bc23..8e67fd9 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -432,8 +432,12 @@ string GetLastErrorString() {
   return msg;
 }
 
-void Win32Fatal(const char* function) {
-  Fatal("%s: %s", function, GetLastErrorString().c_str());
+void Win32Fatal(const char* function, const char* hint) {
+  if (hint) {
+    Fatal("%s: %s (%s)", function, GetLastErrorString().c_str(), hint);
+  } else {
+    Fatal("%s: %s", function, GetLastErrorString().c_str());
+  }
 }
 #endif
 
diff --git a/src/util.h b/src/util.h
index 1b4227c..6a4a7a9 100644
--- a/src/util.h
+++ b/src/util.h
@@ -119,7 +119,7 @@ bool Truncate(const string& path, size_t size, string* err);
 string GetLastErrorString();
 
 /// Calls Fatal() with a function name and GetLastErrorString.
-NORETURN void Win32Fatal(const char* function);
+NORETURN void Win32Fatal(const char* function, const char* hint = NULL);
 #endif
 
 #endif  // NINJA_UTIL_H_
-- 
cgit v0.12


From 1463fdc0f73136aca4869be9ad577d08528b19c4 Mon Sep 17 00:00:00 2001
From: Ben Boeckel <ben.boeckel@kitware.com>
Date: Wed, 3 Oct 2018 09:31:02 -0400
Subject: subprocess-win32: add hint on ERROR_INVALID_PARAMETER

This is generally associated with the command line being too long. Give
a hint to this case in the error message.
---
 src/subprocess-win32.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/subprocess-win32.cc b/src/subprocess-win32.cc
index 5982b06..a4a7669 100644
--- a/src/subprocess-win32.cc
+++ b/src/subprocess-win32.cc
@@ -124,6 +124,10 @@ bool Subprocess::Start(SubprocessSet* set, const string& command) {
       buf_ = "CreateProcess failed: The system cannot find the file "
           "specified.\n";
       return true;
+    } else if (error == ERROR_INVALID_PARAMETER) {
+      // This generally means that the command line was too long. Give extra
+      // context for this case.
+      Win32Fatal("CreateProcess", "is the command line too long?");
     } else {
       Win32Fatal("CreateProcess");    // pass all other errors to Win32Fatal
     }
-- 
cgit v0.12