From 10fd7f926e9c7bf01862246e3cd866f4671758f7 Mon Sep 17 00:00:00 2001
From: Rafael Kitover <rkitover@gmail.com>
Date: Sun, 13 Nov 2016 14:31:34 -0800
Subject: [PATCH] enormous speedup for compiling Wx resources

Replace bin2c.cmake script with one written in C and compiled as an
intermediate target.

The C version is roughly 12000 times faster.

On msys2, the cmake version takes 7.5 minutes on this system, while the
C version takes 0.037 seconds.
---
 src/wx/CMakeLists.txt | 17 +++++++++------
 src/wx/bin2c.c        | 51 +++++++++++++++++++++++++++++++++++++++++++
 src/wx/bin2c.cmake    | 24 --------------------
 3 files changed, 61 insertions(+), 31 deletions(-)
 create mode 100644 src/wx/bin2c.c
 delete mode 100644 src/wx/bin2c.cmake

diff --git a/src/wx/CMakeLists.txt b/src/wx/CMakeLists.txt
index ded3c76c..571a1f2f 100644
--- a/src/wx/CMakeLists.txt
+++ b/src/wx/CMakeLists.txt
@@ -89,20 +89,24 @@ include_directories(${CMAKE_CURRENT_BINARY_DIR})
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
 # wxrc does not support xrs files in -c output (> 10x compression)
-# so do it manually using slow but portable bin2c.cmake script
+# we do it using the bin2.c utility
+
+ADD_EXECUTABLE(bin2c bin2c.c)
+# don't want SDL_main here
+SET_TARGET_PROPERTIES(bin2c PROPERTIES COMPILE_FLAGS "-Dmain=main")
+
 ADD_CUSTOM_COMMAND(OUTPUT wxvbam.xrs
                    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
                    COMMAND wxrc ${CMAKE_CURRENT_SOURCE_DIR}/xrc/*.xrc -o wxvbam.xrs
 		   DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/xrc/*.xrc)
 ADD_CUSTOM_COMMAND(OUTPUT builtin-xrc.h
-                   COMMAND ${CMAKE_COMMAND} -DINFILE=wxvbam.xrs -DOUTFILE=builtin-xrc.h -DVARNAME=builtin_xrs -P ${CMAKE_CURRENT_SOURCE_DIR}/bin2c.cmake
-		   DEPENDS wxvbam.xrs)
+                   COMMAND bin2c wxvbam.xrs builtin-xrc.h builtin_xrs
+		   DEPENDS bin2c wxvbam.xrs)
 
 # use a built-in vba-over.ini if no config file present
 ADD_CUSTOM_COMMAND(OUTPUT builtin-over.h
-                   COMMAND ${CMAKE_COMMAND} -DINFILE=${CMAKE_CURRENT_SOURCE_DIR}/../vba-over.ini -DOUTFILE=builtin-over.h -DVARNAME=builtin_over -P ${CMAKE_CURRENT_SOURCE_DIR}/bin2c.cmake
-		   DEPENDS ../vba-over.ini)
-
+                   COMMAND bin2c ${CMAKE_CURRENT_SOURCE_DIR}/../vba-over.ini builtin-over.h builtin_over
+                   DEPENDS bin2c ../vba-over.ini)
 
 # I don't like duplicating/triplicating code, so I only declare
 # event handlers once, and copy them in other places they are needed
@@ -179,7 +183,6 @@ SET( RES_WX
 )
 
 SET( CM_STUFF
-    bin2c.cmake
     copy-events.cmake
 )
 
diff --git a/src/wx/bin2c.c b/src/wx/bin2c.c
new file mode 100644
index 00000000..267efd24
--- /dev/null
+++ b/src/wx/bin2c.c
@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <stdio.h>
+
+int main(int argc, char** argv) {
+    char* in_file_name  = argv[1];
+    char* out_file_name = argv[2];
+    char* var_name      = argv[3];
+    FILE* in_file       = fopen(in_file_name,  "rb");
+    char* in_file_err   = !in_file ? strerror(errno) : NULL;
+    FILE* out_file      = fopen(out_file_name, "w");
+    char* out_file_err  = !out_file ? strerror(errno) : NULL;
+    unsigned char* buf  = (unsigned char*)malloc(4096);
+    size_t bytes_read;
+    int file_pos        = 0;
+
+    if (!buf) return 1;
+
+    if (!in_file) {
+        fprintf(stderr, "Can't open input file '%s': %s\n", in_file_name, in_file_err);
+        return 1;
+    }
+
+    if (!out_file) {
+        fprintf(stderr, "Can't open '%s' for writing: %s\n", out_file_name, out_file_err);
+        return 1;
+    }
+
+    fprintf(out_file, "/* generated from %s: do not edit */\n"
+                      "const unsigned char %s[] = {\n", in_file_name, var_name);
+
+    while ((bytes_read = fread(buf, 1, 4096, in_file))) {
+        int i = 0;
+        for (; i < bytes_read; i++) {
+            char* comma = feof(in_file) && i == bytes_read - 1 ? "" : ",";
+
+            fprintf(out_file, "0x%02x%s", buf[i], comma);
+
+            if (++file_pos % 16 == 0) fprintf(out_file, "\n");
+        }
+    }
+
+    fprintf(out_file, "};\n");
+
+    free(buf);
+    fclose(in_file);
+    fclose(out_file);
+
+    return 0;
+}
diff --git a/src/wx/bin2c.cmake b/src/wx/bin2c.cmake
deleted file mode 100644
index 6aaa17e2..00000000
--- a/src/wx/bin2c.cmake
+++ /dev/null
@@ -1,24 +0,0 @@
-# portably convert binary file to header
-FUNCTION(FILE2C INFILE VARNAME OUTFILE)
-  FILE(READ ${INFILE} HEXFILE HEX)
-  STRING(LENGTH ${HEXFILE} XRSLEN)
-  SET(HEXPOS 0)
-  FILE(WRITE ${OUTFILE}
-          "/* generated from ${INFILE}; do not edit */\n"
-          "const unsigned char ${VARNAME}[] = {")
-  WHILE(${HEXPOS} LESS ${XRSLEN})
-    MATH(EXPR LPOS "${HEXPOS} % 32")
-    IF(NOT ${LPOS})
-      FILE(APPEND ${OUTFILE} "\n")
-    ENDIF(NOT ${LPOS})
-    STRING(SUBSTRING ${HEXFILE} ${HEXPOS} 2 HEXBYTE)
-    FILE(APPEND ${OUTFILE} "0x${HEXBYTE}")
-    MATH(EXPR HEXPOS "${HEXPOS} + 2")
-    IF(${HEXPOS} LESS ${XRSLEN})
-      FILE(APPEND ${OUTFILE} ",")
-    ENDIF(${HEXPOS} LESS ${XRSLEN})
-  ENDWHILE(${HEXPOS} LESS ${XRSLEN})
-  FILE(APPEND ${OUTFILE} "};\n")
-ENDFUNCTION(FILE2C)
-
-FILE2C(${INFILE} ${VARNAME} ${OUTFILE})