[gtk+] Revert "MSVC Introspection Builds: Remove GCC Requirement"

[Chun-wei Fan <fanchunwei src gnome org>]

commit 40a190520714a4cc91bf387a43f031fe3695bef5
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Aug 17 19:18:03 2015 +0800

    Revert "MSVC Introspection Builds: Remove GCC Requirement"
    
    This reverts commit aea7809f55ac520b9d2d5d9c1eea1345fabbd7a7.

 build/gtk-introspection-msvc.mak |  101 --------------------------------------
 build/introspection-msvc.mak     |   16 ++++++-
 2 files changed, 15 insertions(+), 102 deletions(-)
---
diff --git a/build/introspection-msvc.mak b/build/introspection-msvc.mak
index 55eec45..beff817 100644
--- a/build/introspection-msvc.mak
+++ b/build/introspection-msvc.mak
@@ -26,6 +26,7 @@ VALID_PKG_CONFIG_PATH = FALSE
 VALID_GCC_INSTPATH = FALSE
 
 MSG_INVALID_PKGCONFIG = You must set or specifiy a valid PKG_CONFIG_PATH
+MSG_INVALID_MINGWDIR = You must set or specifiy a valid MINGWDIR, where gcc.exe can be found in 
%MINGWDIR%\bin
 MSG_INVALID_CFG = You need to specify or set CFG to be release or debug to use this Makefile to build the 
Introspection Files
 
 ERROR_MSG =
@@ -46,7 +47,15 @@ VALID_PKG_CONFIG_PATH = TRUE
 VALID_PKG_CONFIG_PATH = FALSE
 !endif
 
-!if ![del $(ERRNUL) /q/f pkgconfig.chksize]
+!if ![IF EXIST %MINGWDIR%\bin\gcc.exe @echo VALID_GCC_INSTPATH=TRUE > gcccheck.x]
+!endif
+
+!if ![IF NOT EXIST %MINGWDIR%\bin\gcc.exe @echo VALID_GCC_INSTPATH=FALSE > gcccheck.x]
+!endif
+
+!include gcccheck.x
+
+!if ![del $(ERRNUL) /q/f pkgconfig.chksize gcccheck.x]
 !endif
 
 VALID_CFGSET = FALSE
@@ -54,6 +63,11 @@ VALID_CFGSET = FALSE
 VALID_CFGSET = TRUE
 !endif
 
+!if "$(VALID_GCC_INSTPATH)" != "TRUE"
+BUILD_INTROSPECTION = FALSE
+ERROR_MSG = $(MSG_INVALID_MINGWDIR)
+!endif
+
 !if "$(VALID_PKG_CONFIG_PATH)" != "TRUE"
 BUILD_INTROSPECTION = FALSE
 ERROR_MSG = $(MSG_INVALID_PKGCONFIG)