cmOutputConverter: Adopt command line escaping code

Port code from the KWSys System_Shell APIs into cmOutputConverter.
Drop it from our copy of KWSys because upstream will drop it too,
and by doing it in this commit 'git blame' may have an easier time
connecting the history of the content.

1 files changed, 599 insertions, 16 deletions

diff --git a/Source/cmOutputConverter.cxx b/Source/cmOutputConverter.cxx
index 161a5b4..7cd6a47 100644
--- a/Source/cmOutputConverter.cxx
+++ b/Source/cmOutputConverter.cxx
@@ -14,10 +14,11 @@
 #include "cmAlgorithms.h"
 #include "cmake.h"
 
-#include <cmsys/System.h>
-
 #include <assert.h>
 
+#include <string.h> /* strlen */
+#include <ctype.h>  /* isalpha */
+
 cmOutputConverter::cmOutputConverter(cmState::Snapshot snapshot)
   : StateSnapshot(snapshot), LinkScriptShell(false)
 {
@@ -330,51 +331,51 @@ std::string cmOutputConverter::EscapeForShell(const std::string& str,
   int flags = 0;
   if(this->GetState()->UseWindowsVSIDE())
     {
-    flags |= cmsysSystem_Shell_Flag_VSIDE;
+    flags |= Shell_Flag_VSIDE;
     }
   else if(!this->LinkScriptShell)
     {
-    flags |= cmsysSystem_Shell_Flag_Make;
+    flags |= Shell_Flag_Make;
     }
   if(makeVars)
     {
-    flags |= cmsysSystem_Shell_Flag_AllowMakeVariables;
+    flags |= Shell_Flag_AllowMakeVariables;
     }
   if(forEcho)
     {
-    flags |= cmsysSystem_Shell_Flag_EchoWindows;
+    flags |= Shell_Flag_EchoWindows;
     }
   if(useWatcomQuote)
     {
-    flags |= cmsysSystem_Shell_Flag_WatcomQuote;
+    flags |= Shell_Flag_WatcomQuote;
     }
   if(this->GetState()->UseWatcomWMake())
     {
-    flags |= cmsysSystem_Shell_Flag_WatcomWMake;
+    flags |= Shell_Flag_WatcomWMake;
     }
   if(this->GetState()->UseMinGWMake())
     {
-    flags |= cmsysSystem_Shell_Flag_MinGWMake;
+    flags |= Shell_Flag_MinGWMake;
     }
   if(this->GetState()->UseNMake())
     {
-    flags |= cmsysSystem_Shell_Flag_NMake;
+    flags |= Shell_Flag_NMake;
     }
 
   // Compute the buffer size needed.
   int size = (this->GetState()->UseWindowsShell() ?
-              cmsysSystem_Shell_GetArgumentSizeForWindows(str.c_str(), flags) :
-              cmsysSystem_Shell_GetArgumentSizeForUnix(str.c_str(), flags));
+              Shell_GetArgumentSizeForWindows(str.c_str(), flags) :
+              Shell_GetArgumentSizeForUnix(str.c_str(), flags));
 
   // Compute the shell argument itself.
   std::vector<char> arg(size);
   if(this->GetState()->UseWindowsShell())
     {
-    cmsysSystem_Shell_GetArgumentForWindows(str.c_str(), &arg[0], flags);
+    Shell_GetArgumentForWindows(str.c_str(), &arg[0], flags);
     }
   else
     {
-    cmsysSystem_Shell_GetArgumentForUnix(str.c_str(), &arg[0], flags);
+    Shell_GetArgumentForUnix(str.c_str(), &arg[0], flags);
     }
   return std::string(&arg[0]);
 }
@@ -417,12 +418,12 @@ cmOutputConverter::EscapeWindowsShellArgument(const char* arg, int shell_flags)
 {
   char local_buffer[1024];
   char* buffer = local_buffer;
-  int size = cmsysSystem_Shell_GetArgumentSizeForWindows(arg, shell_flags);
+  int size = Shell_GetArgumentSizeForWindows(arg, shell_flags);
   if(size > 1024)
     {
     buffer = new char[size];
     }
-  cmsysSystem_Shell_GetArgumentForWindows(arg, buffer, shell_flags);
+  Shell_GetArgumentForWindows(arg, buffer, shell_flags);
   std::string result(buffer);
   if(buffer != local_buffer)
     {
@@ -465,3 +466,585 @@ cmState* cmOutputConverter::GetState() const
 {
   return this->StateSnapshot.GetState();
 }
+
+//----------------------------------------------------------------------------
+/*
+
+Notes:
+
+Make variable replacements open a can of worms.  Sometimes they should
+be quoted and sometimes not.  Sometimes their replacement values are
+already quoted.
+
+VS variables cause problems.  In order to pass the referenced value
+with spaces the reference must be quoted.  If the variable value ends
+in a backslash then it will escape the ending quote!  In order to make
+the ending backslash appear we need this:
+
+  "$(InputDir)\"
+
+However if there is not a trailing backslash then this will put a
+quote in the value so we need:
+
+  "$(InputDir)"
+
+Make variable references are platform specific so we should probably
+just NOT quote them and let the listfile author deal with it.
+
+*/
+
+/*
+TODO: For windows echo:
+
+To display a pipe (|) or redirection character (< or >) when using the
+echo command, use a caret character immediately before the pipe or
+redirection character (for example, ^>, ^<, or ^| ). If you need to
+use the caret character itself (^), use two in a row (^^).
+*/
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__CharIsWhitespace(char c)
+{
+  return ((c == ' ') || (c == '\t'));
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__CharNeedsQuotesOnUnix(char c)
+{
+  return ((c == '\'') || (c == '`') || (c == ';') || (c == '#') ||
+          (c == '&') || (c == '$') || (c == '(') || (c == ')') ||
+          (c == '~') || (c == '<') || (c == '>') || (c == '|') ||
+          (c == '*') || (c == '^') || (c == '\\'));
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__CharNeedsQuotesOnWindows(char c)
+{
+  return ((c == '\'') || (c == '#') || (c == '&') ||
+          (c == '<') || (c == '>') || (c == '|') || (c == '^'));
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__CharNeedsQuotes(char c, int isUnix, int flags)
+{
+  /* On Windows the built-in command shell echo never needs quotes.  */
+  if(!isUnix && (flags & Shell_Flag_EchoWindows))
+    {
+    return 0;
+    }
+
+  /* On all platforms quotes are needed to preserve whitespace.  */
+  if(Shell__CharIsWhitespace(c))
+    {
+    return 1;
+    }
+
+  if(isUnix)
+    {
+    /* On UNIX several special characters need quotes to preserve them.  */
+    if(Shell__CharNeedsQuotesOnUnix(c))
+      {
+      return 1;
+      }
+    }
+  else
+    {
+    /* On Windows several special characters need quotes to preserve them.  */
+    if(Shell__CharNeedsQuotesOnWindows(c))
+      {
+      return 1;
+      }
+    }
+  return 0;
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__CharIsMakeVariableName(char c)
+{
+  return c && (c == '_' || isalpha(((int)c)));
+}
+
+/*--------------------------------------------------------------------------*/
+const char* cmOutputConverter::Shell__SkipMakeVariables(const char* c)
+{
+  while(*c == '$' && *(c+1) == '(')
+    {
+    const char* skip = c+2;
+    while(Shell__CharIsMakeVariableName(*skip))
+      {
+      ++skip;
+      }
+    if(*skip == ')')
+      {
+      c = skip+1;
+      }
+    else
+      {
+      break;
+      }
+    }
+  return c;
+}
+
+/*
+Allowing make variable replacements opens a can of worms.  Sometimes
+they should be quoted and sometimes not.  Sometimes their replacement
+values are already quoted or contain escapes.
+
+Some Visual Studio variables cause problems.  In order to pass the
+referenced value with spaces the reference must be quoted.  If the
+variable value ends in a backslash then it will escape the ending
+quote!  In order to make the ending backslash appear we need this:
+
+  "$(InputDir)\"
+
+However if there is not a trailing backslash then this will put a
+quote in the value so we need:
+
+  "$(InputDir)"
+
+This macro decides whether we quote an argument just because it
+contains a make variable reference.  This should be replaced with a
+flag later when we understand applications of this better.
+*/
+#define KWSYS_SYSTEM_SHELL_QUOTE_MAKE_VARIABLES 0
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__ArgumentNeedsQuotes(const char* in,
+                                                  int isUnix, int flags)
+{
+  /* The empty string needs quotes.  */
+  if(!*in)
+    {
+    return 1;
+    }
+
+  /* Scan the string for characters that require quoting.  */
+  {
+  const char* c;
+  for(c=in; *c; ++c)
+    {
+    /* Look for $(MAKEVAR) syntax if requested.  */
+    if(flags & Shell_Flag_AllowMakeVariables)
+      {
+#if KWSYS_SYSTEM_SHELL_QUOTE_MAKE_VARIABLES
+      const char* skip = Shell__SkipMakeVariables(c);
+      if(skip != c)
+        {
+        /* We need to quote make variable references to preserve the
+           string with contents substituted in its place.  */
+        return 1;
+        }
+#else
+      /* Skip over the make variable references if any are present.  */
+      c = Shell__SkipMakeVariables(c);
+
+      /* Stop if we have reached the end of the string.  */
+      if(!*c)
+        {
+        break;
+        }
+#endif
+      }
+
+    /* Check whether this character needs quotes.  */
+    if(Shell__CharNeedsQuotes(*c, isUnix, flags))
+      {
+      return 1;
+      }
+    }
+  }
+
+  /* On Windows some single character arguments need quotes.  */
+  if(!isUnix && *in && !*(in+1))
+    {
+    char c = *in;
+    if((c == '?') || (c == '&') || (c == '^') || (c == '|') || (c == '#'))
+      {
+      return 1;
+      }
+    }
+
+  return 0;
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell__GetArgumentSize(const char* in,
+                                              int isUnix, int flags)
+{
+  /* Start with the length of the original argument, plus one for
+     either a terminating null or a separating space.  */
+  int size = (int)strlen(in) + 1;
+
+  /* String iterator.  */
+  const char* c;
+
+  /* Keep track of how many backslashes have been encountered in a row.  */
+  int windows_backslashes = 0;
+
+  /* Scan the string for characters that require escaping or quoting.  */
+  for(c=in; *c; ++c)
+    {
+    /* Look for $(MAKEVAR) syntax if requested.  */
+    if(flags & Shell_Flag_AllowMakeVariables)
+      {
+      /* Skip over the make variable references if any are present.  */
+      c = Shell__SkipMakeVariables(c);
+
+      /* Stop if we have reached the end of the string.  */
+      if(!*c)
+        {
+        break;
+        }
+      }
+
+    /* Check whether this character needs escaping for the shell.  */
+    if(isUnix)
+      {
+      /* On Unix a few special characters need escaping even inside a
+         quoted argument.  */
+      if(*c == '\\' || *c == '"' || *c == '`' || *c == '$')
+        {
+        /* This character needs a backslash to escape it.  */
+        ++size;
+        }
+      }
+    else if(flags & Shell_Flag_EchoWindows)
+      {
+      /* On Windows the built-in command shell echo never needs escaping.  */
+      }
+    else
+      {
+      /* On Windows only backslashes and double-quotes need escaping.  */
+      if(*c == '\\')
+        {
+        /* Found a backslash.  It may need to be escaped later.  */
+        ++windows_backslashes;
+        }
+      else if(*c == '"')
+        {
+        /* Found a double-quote.  We need to escape it and all
+           immediately preceding backslashes.  */
+        size += windows_backslashes + 1;
+        windows_backslashes = 0;
+        }
+      else
+        {
+        /* Found another character.  This eliminates the possibility
+           that any immediately preceding backslashes will be
+           escaped.  */
+        windows_backslashes = 0;
+        }
+      }
+
+    /* Check whether this character needs escaping for a make tool.  */
+    if(*c == '$')
+      {
+      if(flags & Shell_Flag_Make)
+        {
+        /* In Makefiles a dollar is written $$ so we need one extra
+           character.  */
+        ++size;
+        }
+      else if(flags & Shell_Flag_VSIDE)
+        {
+        /* In a VS IDE a dollar is written "$" so we need two extra
+           characters.  */
+        size += 2;
+        }
+      }
+    else if(*c == '#')
+      {
+      if((flags & Shell_Flag_Make) &&
+         (flags & Shell_Flag_WatcomWMake))
+        {
+        /* In Watcom WMake makefiles a pound is written $# so we need
+           one extra character.  */
+        ++size;
+        }
+      }
+    else if(*c == '%')
+      {
+      if((flags & Shell_Flag_VSIDE) ||
+         ((flags & Shell_Flag_Make) &&
+          ((flags & Shell_Flag_MinGWMake) ||
+           (flags & Shell_Flag_NMake))))
+        {
+        /* In the VS IDE, NMake, or MinGW make a percent is written %%
+           so we need one extra characters.  */
+        size += 1;
+        }
+      }
+    else if(*c == ';')
+      {
+      if(flags & Shell_Flag_VSIDE)
+        {
+        /* In a VS IDE a semicolon is written ";" so we need two extra
+           characters.  */
+        size += 2;
+        }
+      }
+    }
+
+  /* Check whether the argument needs surrounding quotes.  */
+  if(Shell__ArgumentNeedsQuotes(in, isUnix, flags))
+    {
+    /* Surrounding quotes are needed.  Allocate space for them.  */
+    if((flags & Shell_Flag_WatcomQuote) && (isUnix))
+      {
+        size += 2;
+      }
+    size += 2;
+
+    /* We must escape all ending backslashes when quoting on windows.  */
+    size += windows_backslashes;
+    }
+
+  return size;
+}
+
+/*--------------------------------------------------------------------------*/
+char* cmOutputConverter::Shell__GetArgument(const char* in, char* out,
+                                            int isUnix, int flags)
+{
+  /* String iterator.  */
+  const char* c;
+
+  /* Keep track of how many backslashes have been encountered in a row.  */
+  int windows_backslashes = 0;
+
+  /* Whether the argument must be quoted.  */
+  int needQuotes = Shell__ArgumentNeedsQuotes(in, isUnix, flags);
+  if(needQuotes)
+    {
+    /* Add the opening quote for this argument.  */
+    if(flags & Shell_Flag_WatcomQuote)
+      {
+      if(isUnix)
+        {
+        *out++ = '"';
+        }
+      *out++ = '\'';
+      }
+    else
+      {
+      *out++ = '"';
+      }
+    }
+
+  /* Scan the string for characters that require escaping or quoting.  */
+  for(c=in; *c; ++c)
+    {
+    /* Look for $(MAKEVAR) syntax if requested.  */
+    if(flags & Shell_Flag_AllowMakeVariables)
+      {
+      const char* skip = Shell__SkipMakeVariables(c);
+      if(skip != c)
+        {
+        /* Copy to the end of the make variable references.  */
+        while(c != skip)
+          {
+          *out++ = *c++;
+          }
+
+        /* The make variable reference eliminates any escaping needed
+           for preceding backslashes.  */
+        windows_backslashes = 0;
+
+        /* Stop if we have reached the end of the string.  */
+        if(!*c)
+          {
+          break;
+          }
+        }
+      }
+
+    /* Check whether this character needs escaping for the shell.  */
+    if(isUnix)
+      {
+      /* On Unix a few special characters need escaping even inside a
+         quoted argument.  */
+      if(*c == '\\' || *c == '"' || *c == '`' || *c == '$')
+        {
+        /* This character needs a backslash to escape it.  */
+        *out++ = '\\';
+        }
+      }
+    else if(flags & Shell_Flag_EchoWindows)
+      {
+      /* On Windows the built-in command shell echo never needs escaping.  */
+      }
+    else
+      {
+      /* On Windows only backslashes and double-quotes need escaping.  */
+      if(*c == '\\')
+        {
+        /* Found a backslash.  It may need to be escaped later.  */
+        ++windows_backslashes;
+        }
+      else if(*c == '"')
+        {
+        /* Found a double-quote.  Escape all immediately preceding
+           backslashes.  */
+        while(windows_backslashes > 0)
+          {
+          --windows_backslashes;
+          *out++ = '\\';
+          }
+
+        /* Add the backslash to escape the double-quote.  */
+        *out++ = '\\';
+        }
+      else
+        {
+        /* We encountered a normal character.  This eliminates any
+           escaping needed for preceding backslashes.  */
+        windows_backslashes = 0;
+        }
+      }
+
+    /* Check whether this character needs escaping for a make tool.  */
+    if(*c == '$')
+      {
+      if(flags & Shell_Flag_Make)
+        {
+        /* In Makefiles a dollar is written $$.  The make tool will
+           replace it with just $ before passing it to the shell.  */
+        *out++ = '$';
+        *out++ = '$';
+        }
+      else if(flags & Shell_Flag_VSIDE)
+        {
+        /* In a VS IDE a dollar is written "$".  If this is written in
+           an un-quoted argument it starts a quoted segment, inserts
+           the $ and ends the segment.  If it is written in a quoted
+           argument it ends quoting, inserts the $ and restarts
+           quoting.  Either way the $ is isolated from surrounding
+           text to avoid looking like a variable reference.  */
+        *out++ = '"';
+        *out++ = '$';
+        *out++ = '"';
+        }
+      else
+        {
+        /* Otherwise a dollar is written just $. */
+        *out++ = '$';
+        }
+      }
+    else if(*c == '#')
+      {
+      if((flags & Shell_Flag_Make) &&
+         (flags & Shell_Flag_WatcomWMake))
+        {
+        /* In Watcom WMake makefiles a pound is written $#.  The make
+           tool will replace it with just # before passing it to the
+           shell.  */
+        *out++ = '$';
+        *out++ = '#';
+        }
+      else
+        {
+        /* Otherwise a pound is written just #. */
+        *out++ = '#';
+        }
+      }
+    else if(*c == '%')
+      {
+      if((flags & Shell_Flag_VSIDE) ||
+         ((flags & Shell_Flag_Make) &&
+          ((flags & Shell_Flag_MinGWMake) ||
+           (flags & Shell_Flag_NMake))))
+        {
+        /* In the VS IDE, NMake, or MinGW make a percent is written %%.  */
+        *out++ = '%';
+        *out++ = '%';
+        }
+      else
+        {
+        /* Otherwise a percent is written just %. */
+        *out++ = '%';
+        }
+      }
+    else if(*c == ';')
+      {
+      if(flags & Shell_Flag_VSIDE)
+        {
+        /* In a VS IDE a semicolon is written ";".  If this is written
+           in an un-quoted argument it starts a quoted segment,
+           inserts the ; and ends the segment.  If it is written in a
+           quoted argument it ends quoting, inserts the ; and restarts
+           quoting.  Either way the ; is isolated.  */
+        *out++ = '"';
+        *out++ = ';';
+        *out++ = '"';
+        }
+      else
+        {
+        /* Otherwise a semicolon is written just ;. */
+        *out++ = ';';
+        }
+      }
+    else
+      {
+      /* Store this character.  */
+      *out++ = *c;
+      }
+    }
+
+  if(needQuotes)
+    {
+    /* Add enough backslashes to escape any trailing ones.  */
+    while(windows_backslashes > 0)
+      {
+      --windows_backslashes;
+      *out++ = '\\';
+      }
+
+    /* Add the closing quote for this argument.  */
+    if(flags & Shell_Flag_WatcomQuote)
+      {
+      *out++ = '\'';
+      if(isUnix)
+        {
+        *out++ = '"';
+        }
+      }
+    else
+      {
+      *out++ = '"';
+      }
+    }
+
+  /* Store a terminating null without incrementing.  */
+  *out = 0;
+
+  return out;
+}
+
+/*--------------------------------------------------------------------------*/
+char* cmOutputConverter::Shell_GetArgumentForWindows(const char* in,
+                                                     char* out, int flags)
+{
+  return Shell__GetArgument(in, out, 0, flags);
+}
+
+/*--------------------------------------------------------------------------*/
+char* cmOutputConverter::Shell_GetArgumentForUnix(const char* in,
+                                                  char* out, int flags)
+{
+  return Shell__GetArgument(in, out, 1, flags);
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell_GetArgumentSizeForWindows(const char* in,
+                                                       int flags)
+{
+  return Shell__GetArgumentSize(in, 0, flags);
+}
+
+/*--------------------------------------------------------------------------*/
+int cmOutputConverter::Shell_GetArgumentSizeForUnix(const char* in,
+                                                    int flags)
+{
+  return Shell__GetArgumentSize(in, 1, flags);
+}