math(): Add INCREMENT and DECREMENT modes

Help/command/math.rst

@@ -1,7 +1,10 @@
 math
 ----
 
-Evaluate a mathematical expression.
+Perform mathematical operations.
+
+Expression Evaluation
+^^^^^^^^^^^^^^^^^^^^^
 
 .. code-block:: cmake
 
@@ -37,3 +40,16 @@ For example
 
   math(EXPR value "100 * 0xA" OUTPUT_FORMAT DECIMAL)      # value is set to "1000"
   math(EXPR value "100 * 0xA" OUTPUT_FORMAT HEXADECIMAL)  # value is set to "0x3e8"
+
+Increment/Decrement
+^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+  math(INCREMENT <variable>)
+  math(DECREMENT <variable>)
+
+.. versionadded:: 4.5
+
+Take the value of ``<variable>``, increment/decrement it, and store the result back
+in ``<variable>``. The variable must be defined and be a valid base-10 integer.

Help/release/dev/math-increment-decrement.rst

@@ -0,0 +1,4 @@
+math-increment-decrement
+------------------------
+
+* The :command:`math` command gained new ``INCREMENT`` and ``DECREMENT`` modes.

Source/cmMathCommand.cxx

@@ -3,6 +3,11 @@
 #include "cmMathCommand.h"
 
 #include <cstdio>
+#include <limits>
+#include <stdexcept>
+
+#include <cm/string_view>
+#include <cmext/string_view>
 
 #include <cm3p/kwiml/int.h>
 
@@ -10,10 +15,16 @@
 #include "cmExecutionStatus.h"
 #include "cmExprParserHelper.h"
 #include "cmMakefile.h"
+#include "cmStringAlgorithms.h"
+#include "cmValue.h"
 
 namespace {
 bool HandleExprCommand(std::vector<std::string> const& args,
                        cmExecutionStatus& status);
+bool HandleIncDecCommand(std::vector<std::string> const& args,
+                         cmExecutionStatus& status, int amount,
+                         long long overflowFrom, long long overflowTo,
+                         cm::string_view verbing);
 }
 
 bool cmMathCommand(std::vector<std::string> const& args,
@@ -27,6 +38,16 @@ bool cmMathCommand(std::vector<std::string> const& args,
   if (subCommand == "EXPR") {
     return HandleExprCommand(args, status);
   }
+  if (subCommand == "INCREMENT") {
+    return HandleIncDecCommand(
+      args, status, 1, std::numeric_limits<long long>::max(),
+      std::numeric_limits<long long>::min(), "incrementing"_s);
+  }
+  if (subCommand == "DECREMENT") {
+    return HandleIncDecCommand(
+      args, status, -1, std::numeric_limits<long long>::min(),
+      std::numeric_limits<long long>::max(), "decrementing"_s);
+  }
   std::string e = "does not recognize sub-command " + subCommand;
   status.SetError(e);
   return false;
@@ -117,4 +138,50 @@ bool HandleExprCommand(std::vector<std::string> const& args,
   status.GetMakefile().AddDefinition(outputVariable, buffer);
   return true;
 }
+
+bool HandleIncDecCommand(std::vector<std::string> const& args,
+                         cmExecutionStatus& status, int amount,
+                         long long overflowFrom, long long overflowTo,
+                         cm::string_view verbing)
+{
+  std::string const messageHint = cmStrCat("sub-command ", args[0], " ");
+  if (args.size() != 2) {
+    status.SetError(cmStrCat(messageHint, "wrong number of arguments"));
+    return false;
+  }
+  auto value = status.GetMakefile().GetDefinition(args[1]);
+  if (!value) {
+    status.SetError(
+      cmStrCat(messageHint, "variable \"", args[1], "\" is not defined"));
+    return false;
+  }
+  if (value->empty()) {
+    status.SetError(
+      cmStrCat(messageHint, "value \"\" is not a valid integer"));
+    return false;
+  }
+  std::size_t pos = 0;
+  long long intValue = 0;
+  try {
+    intValue = std::stoll(*value, &pos, 10);
+  } catch (std::invalid_argument&) {
+    // Do nothing, leave pos as is, which will trigger the error
+  }
+  if (pos != value->length()) {
+    status.SetError(
+      cmStrCat(messageHint, "value \"", *value, "\" is not a valid integer"));
+    return false;
+  }
+  auto newValue = intValue + amount;
+  if (intValue == overflowFrom) {
+    status.GetMakefile().IssueDiagnostic(
+      cmDiagnosticCategory::CMD_AUTHOR,
+      cmStrCat("signed integer overflow while ", verbing, ":\n  ", intValue,
+               "\n"));
+    // Overflow is undefined behavior in C++, so define it manually
+    newValue = overflowTo;
+  }
+  status.GetMakefile().AddDefinition(args[1], std::to_string(newValue));
+  return true;
+}
 }

Tests/RunCMake/math/MATH-DECREMENT-Empty-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-Empty-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-Empty\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT value "" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-Empty.cmake

@@ -0,0 +1,2 @@
+set(value "")
+math(DECREMENT value)

Tests/RunCMake/math/MATH-DECREMENT-Extra-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-Extra-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-Extra\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT value "0a" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-Extra.cmake

@@ -0,0 +1,2 @@
+set(value 0a)
+math(DECREMENT value)

Tests/RunCMake/math/MATH-DECREMENT-Invalid-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-Invalid-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-Invalid\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT value "notanint" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-Invalid.cmake

@@ -0,0 +1,2 @@
+set(value notanint)
+math(DECREMENT value)

Tests/RunCMake/math/MATH-DECREMENT-NotEnoughArgs-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-NotEnoughArgs-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-NotEnoughArgs\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT wrong number of arguments
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-NotEnoughArgs.cmake

@@ -0,0 +1 @@
+math(DECREMENT)

Tests/RunCMake/math/MATH-DECREMENT-TooManyArgs-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-TooManyArgs-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-TooManyArgs\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT wrong number of arguments
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-TooManyArgs.cmake

@@ -0,0 +1 @@
+math(DECREMENT value 1)

Tests/RunCMake/math/MATH-DECREMENT-Undefined-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-DECREMENT-Undefined-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-DECREMENT-Undefined\.cmake:[0-9]+ \(math\):
+  math sub-command DECREMENT variable "value" is not defined
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-DECREMENT-Undefined.cmake

@@ -0,0 +1,2 @@
+set(value)
+math(DECREMENT value)

Tests/RunCMake/math/MATH-INCREMENT-Empty-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-Empty-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-Empty\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT value "" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-Empty.cmake

@@ -0,0 +1,2 @@
+set(value "")
+math(INCREMENT value)

Tests/RunCMake/math/MATH-INCREMENT-Extra-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-Extra-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-Extra\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT value "0a" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-Extra.cmake

@@ -0,0 +1,2 @@
+set(value 0a)
+math(INCREMENT value)

Tests/RunCMake/math/MATH-INCREMENT-Invalid-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-Invalid-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-Invalid\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT value "notanint" is not a valid integer
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-Invalid.cmake

@@ -0,0 +1,2 @@
+set(value notanint)
+math(INCREMENT value)

Tests/RunCMake/math/MATH-INCREMENT-NotEnoughArgs-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-NotEnoughArgs-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-NotEnoughArgs\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT wrong number of arguments
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-NotEnoughArgs.cmake

@@ -0,0 +1 @@
+math(INCREMENT)

Tests/RunCMake/math/MATH-INCREMENT-TooManyArgs-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-TooManyArgs-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-TooManyArgs\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT wrong number of arguments
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-TooManyArgs.cmake

@@ -0,0 +1 @@
+math(INCREMENT value 1)

Tests/RunCMake/math/MATH-INCREMENT-Undefined-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/math/MATH-INCREMENT-Undefined-stderr.txt

@@ -0,0 +1,4 @@
+^CMake Error at MATH-INCREMENT-Undefined\.cmake:[0-9]+ \(math\):
+  math sub-command INCREMENT variable "value" is not defined
+Call Stack \(most recent call first\):
+  CMakeLists\.txt:[0-9]+ \(include\)$

Tests/RunCMake/math/MATH-INCREMENT-Undefined.cmake

@@ -0,0 +1,2 @@
+set(value)
+math(INCREMENT value)

Tests/RunCMake/math/MATH.cmake

@@ -10,3 +10,21 @@ math_test("100 * 10" 1000)
 math_test("100 * 10" 1000 OUTPUT_FORMAT DECIMAL)
 math_test("100 * 0xA" 1000 OUTPUT_FORMAT DECIMAL)
 math_test("100 * 0xA" 0x3e8 OUTPUT_FORMAT HEXADECIMAL)
+
+function(inc_dec_test command initial_value expected)
+  set(value "${initial_value}")
+  math("${command}" value)
+  if(NOT value STREQUAL "${expected}")
+    message(FATAL_ERROR "wrong ${command} result: ${value} != ${expected}")
+  endif()
+endfunction()
+
+inc_dec_test(INCREMENT 0 1)
+inc_dec_test(INCREMENT 4 5)
+inc_dec_test(INCREMENT -04 -3)
+inc_dec_test(INCREMENT -9223372036854775808 -9223372036854775807)
+
+inc_dec_test(DECREMENT 0 -1)
+inc_dec_test(DECREMENT 4 3)
+inc_dec_test(DECREMENT -04 -5)
+inc_dec_test(DECREMENT 9223372036854775807 9223372036854775806)

Tests/RunCMake/math/Overflow-stderr.txt

@@ -68,4 +68,26 @@ CMake Warning \(author\) at [^
 
     -9223372036854775808
 
+This warning is for project developers\.  Use -Wno-author to suppress it\.
+
+CMake Warning \(author\) at [^
+]+/Tests/RunCMake/math/Overflow\.cmake:[0-9]+ \(math\):
+  signed integer overflow while incrementing:
+
+    9223372036854775807
+
+Call Stack \(most recent call first\):
+  [^
+]+/Tests/RunCMake/math/Overflow\.cmake:[0-9]+ \(inc_dec\)
+This warning is for project developers\.  Use -Wno-author to suppress it\.
+
+CMake Warning \(author\) at [^
+]+/Tests/RunCMake/math/Overflow\.cmake:[0-9]+ \(math\):
+  signed integer overflow while decrementing:
+
+    -9223372036854775808
+
+Call Stack \(most recent call first\):
+  [^
+]+/Tests/RunCMake/math/Overflow\.cmake:[0-9]+ \(inc_dec\)
 This warning is for project developers\.  Use -Wno-author to suppress it\.$

Tests/RunCMake/math/Overflow-stdout.txt

@@ -7,4 +7,6 @@
 --  0x7FFFFFFFFFFFFFFF \+ 1: -9223372036854775808
 -- -0x7FFFFFFFFFFFFFFF - 2: 9223372036854775807
 --  0x7FFFFFFFFFFFFFFF \* 2: -2
--- -~0x7FFFFFFFFFFFFFFF: -9223372036854775808$
+-- -~0x7FFFFFFFFFFFFFFF: -9223372036854775808
+-- INCREMENT 9223372036854775807: -9223372036854775808
+-- DECREMENT -9223372036854775808: 9223372036854775807$

Tests/RunCMake/math/Overflow.cmake

@@ -13,3 +13,12 @@ foreach(expr IN ITEMS
   math(EXPR result "${expr}")
   message(STATUS "${expr}: ${result}")
 endforeach()
+
+function(inc_dec command value)
+  set(new_value "${value}")
+  math("${command}" new_value)
+  message(STATUS "${command} ${value}: ${new_value}")
+endfunction()
+
+inc_dec(INCREMENT 9223372036854775807)
+inc_dec(DECREMENT -9223372036854775808)

Tests/RunCMake/math/RunCMakeTest.cmake

@@ -10,6 +10,18 @@ run_cmake(MATH-DivideByZero)
 run_cmake(MATH-ModByZero)
 run_cmake(MATH-DivideMinByMinusOne)
 run_cmake(MATH-ModMinByMinusOne)
+run_cmake(MATH-INCREMENT-NotEnoughArgs)
+run_cmake(MATH-INCREMENT-TooManyArgs)
+run_cmake(MATH-INCREMENT-Undefined)
+run_cmake(MATH-INCREMENT-Empty)
+run_cmake(MATH-INCREMENT-Invalid)
+run_cmake(MATH-INCREMENT-Extra)
+run_cmake(MATH-DECREMENT-NotEnoughArgs)
+run_cmake(MATH-DECREMENT-TooManyArgs)
+run_cmake(MATH-DECREMENT-Undefined)
+run_cmake(MATH-DECREMENT-Empty)
+run_cmake(MATH-DECREMENT-Invalid)
+run_cmake(MATH-DECREMENT-Extra)
 
 if(CMake_TEST_MATH_OVERFLOW)
   run_cmake_script(Overflow)