Support ANSI escape code on Windows

In some cases (e.g. when a build system pipes stderr) the Windows console
API cannot be used to color output. For these, provide a way to switch to
ANSI escape codes. This is required for Clang's -fansi-escape-codes option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190460 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/Process.h

@@ -216,6 +216,12 @@ public:
   /// terminal, this function returns false.
   static bool StandardErrHasColors();
 
+  /// Enables or disables whether ANSI escape sequences are used to output
+  /// colors. This only has an effect on Windows.
+  /// Note: Setting this option is not thread-safe and should only be done
+  /// during initialization.
+  static void UseANSIEscapeCodes(bool enable);
+
   /// Whether changing colors requires the output to be flushed.
   /// This is needed on systems that don't support escape sequences for
   /// changing colors.

lib/Support/Process.cpp

@@ -80,6 +80,24 @@ TimeValue self_process::get_wall_time() const {
 #endif
 
 
+#define COLOR(FGBG, CODE, BOLD) "\033[0;" BOLD FGBG CODE "m"
+
+#define ALLCOLORS(FGBG,BOLD) {\
+    COLOR(FGBG, "0", BOLD),\
+    COLOR(FGBG, "1", BOLD),\
+    COLOR(FGBG, "2", BOLD),\
+    COLOR(FGBG, "3", BOLD),\
+    COLOR(FGBG, "4", BOLD),\
+    COLOR(FGBG, "5", BOLD),\
+    COLOR(FGBG, "6", BOLD),\
+    COLOR(FGBG, "7", BOLD)\
+  }
+
+static const char colorcodes[2][2][8][10] = {
+ { ALLCOLORS("3",""), ALLCOLORS("3","1;") },
+ { ALLCOLORS("4",""), ALLCOLORS("4","1;") }
+};
+
 // Include the platform-specific parts of this class.
 #ifdef LLVM_ON_UNIX
 #include "Unix/Process.inc"

lib/Support/Unix/Process.inc

@@ -310,29 +310,15 @@ bool Process::StandardErrHasColors() {
   return FileDescriptorHasColors(STDERR_FILENO);
 }
 
+void Process::UseANSIEscapeCodes(bool /*enable*/) {
+  // No effect.
+}
+
 bool Process::ColorNeedsFlush() {
   // No, we use ANSI escape sequences.
   return false;
 }
 
-#define COLOR(FGBG, CODE, BOLD) "\033[0;" BOLD FGBG CODE "m"
-
-#define ALLCOLORS(FGBG,BOLD) {\
-    COLOR(FGBG, "0", BOLD),\
-    COLOR(FGBG, "1", BOLD),\
-    COLOR(FGBG, "2", BOLD),\
-    COLOR(FGBG, "3", BOLD),\
-    COLOR(FGBG, "4", BOLD),\
-    COLOR(FGBG, "5", BOLD),\
-    COLOR(FGBG, "6", BOLD),\
-    COLOR(FGBG, "7", BOLD)\
-  }
-
-static const char colorcodes[2][2][8][10] = {
- { ALLCOLORS("3",""), ALLCOLORS("3","1;") },
- { ALLCOLORS("4",""), ALLCOLORS("4","1;") }
-};
-
 const char *Process::OutputColor(char code, bool bold, bool bg) {
   return colorcodes[bg?1:0][bold?1:0][code&7];
 }

lib/Support/Windows/Process.inc

@@ -216,6 +216,11 @@ bool Process::StandardErrHasColors() {
   return FileDescriptorHasColors(2);
 }
 
+static bool UseANSI = false;
+void Process::UseANSIEscapeCodes(bool enable) {
+  UseANSI = enable;
+}
+
 namespace {
 class DefaultColors
 {
@@ -237,10 +242,12 @@ DefaultColors defaultColors;
 }
 
 bool Process::ColorNeedsFlush() {
-  return true;
+  return !UseANSI;
 }
 
 const char *Process::OutputBold(bool bg) {
+  if (UseANSI) return "\033[1m";
+
   WORD colors = DefaultColors::GetCurrentColor();
   if (bg)
     colors |= BACKGROUND_INTENSITY;
@@ -251,6 +258,8 @@ const char *Process::OutputBold(bool bg) {
 }
 
 const char *Process::OutputColor(char code, bool bold, bool bg) {
+  if (UseANSI) return colorcodes[bg?1:0][bold?1:0][code&7];
+
   WORD colors;
   if (bg) {
     colors = ((code&1) ? BACKGROUND_RED : 0) |
@@ -276,6 +285,8 @@ static WORD GetConsoleTextAttribute(HANDLE hConsoleOutput) {
 }
 
 const char *Process::OutputReverse() {
+  if (UseANSI) return "\033[7m";
+
   const WORD attributes
    = GetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE));
 
@@ -302,6 +313,7 @@ const char *Process::OutputReverse() {
 }
 
 const char *Process::ResetColor() {
+  if (UseANSI) return "\033[0m";
   SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), defaultColors());
   return 0;
 }