[libc][NFC] clean up printf_core and scanf_core

[michaelrj-google]

Add LIBC_INLINE annotations to functions and fix variable cases within
printf_core and scanf_core.

[llvmbot]

@llvm/pr-subscribers-libc

Author: None (michaelrj-google)

Changes

Add LIBC_INLINE annotations to functions and fix variable cases within
printf_core and scanf_core.

---

Full diff: https://github.com/llvm/llvm-project/pull/74535.diff

5 Files Affected:

• (modified) libc/src/stdio/printf_core/core_structs.h (+6-6)
• (modified) libc/src/stdio/printf_core/float_dec_converter.h (+16-15)
• (modified) libc/src/stdio/printf_core/writer.h (+1-1)
• (modified) libc/src/stdio/scanf_core/core_structs.h (+1-1)
• (modified) libc/src/stdio/scanf_core/reader.h (+5-4)

diff --git a/libc/src/stdio/printf_core/core_structs.h b/libc/src/stdio/printf_core/core_structs.h
index 88a13703fd947..ee0f2343fc6d2 100644
--- a/libc/src/stdio/printf_core/core_structs.h
+++ b/libc/src/stdio/printf_core/core_structs.h
@@ -53,7 +53,7 @@ struct FormatSection {
 
   // This operator is only used for testing and should be automatically
   // optimized out for release builds.
-  bool operator==(const FormatSection &other) const {
+  LIBC_INLINE bool operator==(const FormatSection &other) const {
     if (has_conv != other.has_conv)
       return false;
 
@@ -93,11 +93,11 @@ template <typename T> LIBC_INLINE constexpr TypeDesc type_desc_from_type() {
   if constexpr (cpp::is_same_v<T, void>) {
     return TypeDesc{0, PrimaryType::Unknown};
   } else {
-    constexpr bool isPointer = cpp::is_pointer_v<T>;
-    constexpr bool isFloat = cpp::is_floating_point_v<T>;
-    return TypeDesc{sizeof(T), isPointer ? PrimaryType::Pointer
-                               : isFloat ? PrimaryType::Float
-                                         : PrimaryType::Integer};
+    constexpr bool IS_POINTER = cpp::is_pointer_v<T>;
+    constexpr bool IS_FLOAT = cpp::is_floating_point_v<T>;
+    return TypeDesc{sizeof(T), IS_POINTER ? PrimaryType::Pointer
+                               : IS_FLOAT ? PrimaryType::Float
+                                          : PrimaryType::Integer};
   }
 }
 
diff --git a/libc/src/stdio/printf_core/float_dec_converter.h b/libc/src/stdio/printf_core/float_dec_converter.h
index ca52271004069..24d6120f4f151 100644
--- a/libc/src/stdio/printf_core/float_dec_converter.h
+++ b/libc/src/stdio/printf_core/float_dec_converter.h
@@ -103,14 +103,14 @@ class PaddingWriter {
   size_t min_width = 0;
 
 public:
-  PaddingWriter() {}
-  PaddingWriter(const FormatSection &to_conv, char init_sign_char)
+  LIBC_INLINE PaddingWriter() {}
+  LIBC_INLINE PaddingWriter(const FormatSection &to_conv, char init_sign_char)
       : left_justified((to_conv.flags & FormatFlags::LEFT_JUSTIFIED) > 0),
         leading_zeroes((to_conv.flags & FormatFlags::LEADING_ZEROES) > 0),
         sign_char(init_sign_char),
         min_width(to_conv.min_width > 0 ? to_conv.min_width : 0) {}
 
-  int write_left_padding(Writer *writer, size_t total_digits) {
+  LIBC_INLINE int write_left_padding(Writer *writer, size_t total_digits) {
     // The pattern is (spaces) (sign) (zeroes), but only one of spaces and
     // zeroes can be written, and only if the padding amount is positive.
     int padding_amount =
@@ -133,7 +133,7 @@ class PaddingWriter {
     return 0;
   }
 
-  int write_right_padding(Writer *writer, size_t total_digits) {
+  LIBC_INLINE int write_right_padding(Writer *writer, size_t total_digits) {
     // If and only if the conversion is left justified, there may be trailing
     // spaces.
     int padding_amount =
@@ -170,7 +170,7 @@ class FloatWriter {
   Writer *writer;                   // Writes to the final output.
   PaddingWriter padding_writer; // Handles prefixes/padding, uses total_digits.
 
-  int flush_buffer(bool round_up_max_blocks = false) {
+  LIBC_INLINE int flush_buffer(bool round_up_max_blocks = false) {
     const char MAX_BLOCK_DIGIT = (round_up_max_blocks ? '0' : '9');
 
     // Write the most recent buffered block, and mark has_written
@@ -249,17 +249,18 @@ class FloatWriter {
                 (sizeof(int) * 8));
 
 public:
-  FloatWriter(Writer *init_writer, bool init_has_decimal_point,
-              const PaddingWriter &init_padding_writer)
+  LIBC_INLINE FloatWriter(Writer *init_writer, bool init_has_decimal_point,
+                          const PaddingWriter &init_padding_writer)
       : has_decimal_point(init_has_decimal_point), writer(init_writer),
         padding_writer(init_padding_writer) {}
 
-  void init(size_t init_total_digits, size_t init_digits_before_decimal) {
+  LIBC_INLINE void init(size_t init_total_digits,
+                        size_t init_digits_before_decimal) {
     total_digits = init_total_digits;
     digits_before_decimal = init_digits_before_decimal;
   }
 
-  void write_first_block(BlockInt block, bool exp_format = false) {
+  LIBC_INLINE void write_first_block(BlockInt block, bool exp_format = false) {
     const DecimalString buf(block);
     const cpp::string_view int_to_str = buf.view();
     size_t digits_buffered = int_to_str.size();
@@ -280,7 +281,7 @@ class FloatWriter {
     }
   }
 
-  int write_middle_block(BlockInt block) {
+  LIBC_INLINE int write_middle_block(BlockInt block) {
     if (block == MAX_BLOCK) { // Buffer max blocks in case of rounding
       ++max_block_count;
     } else { // If a non-max block has been found
@@ -301,9 +302,9 @@ class FloatWriter {
     return 0;
   }
 
-  int write_last_block(BlockInt block, size_t block_digits,
-                       RoundDirection round, int exponent = 0,
-                       char exp_char = '\0') {
+  LIBC_INLINE int write_last_block(BlockInt block, size_t block_digits,
+                                   RoundDirection round, int exponent = 0,
+                                   char exp_char = '\0') {
     bool has_exp = (exp_char != '\0');
 
     char end_buff[BLOCK_SIZE];
@@ -458,13 +459,13 @@ class FloatWriter {
     return WRITE_OK;
   }
 
-  int write_zeroes(uint32_t num_zeroes) {
+  LIBC_INLINE int write_zeroes(uint32_t num_zeroes) {
     RET_IF_RESULT_NEGATIVE(flush_buffer());
     RET_IF_RESULT_NEGATIVE(writer->write('0', num_zeroes));
     return 0;
   }
 
-  int right_pad() {
+  LIBC_INLINE int right_pad() {
     return padding_writer.write_right_padding(writer, total_digits);
   }
 };
diff --git a/libc/src/stdio/printf_core/writer.h b/libc/src/stdio/printf_core/writer.h
index e4f503abc34c5..67513eca97288 100644
--- a/libc/src/stdio/printf_core/writer.h
+++ b/libc/src/stdio/printf_core/writer.h
@@ -45,7 +45,7 @@ struct WriteBuffer {
   // write as much of new_str to the buffer as it can. The current position in
   // the buffer will be reset iff stream_writer is called. Calling this with an
   // empty string will flush the buffer if relevant.
-  int overflow_write(cpp::string_view new_str) {
+  LIBC_INLINE int overflow_write(cpp::string_view new_str) {
     // If there is a stream_writer, write the contents of the buffer, then
     // new_str, then clear the buffer.
     if (stream_writer != nullptr) {
diff --git a/libc/src/stdio/scanf_core/core_structs.h b/libc/src/stdio/scanf_core/core_structs.h
index 246f770e0cabe..5f13287ec41dd 100644
--- a/libc/src/stdio/scanf_core/core_structs.h
+++ b/libc/src/stdio/scanf_core/core_structs.h
@@ -46,7 +46,7 @@ struct FormatSection {
 
   cpp::bitset<256> scan_set;
 
-  bool operator==(const FormatSection &other) {
+  LIBC_INLINE bool operator==(const FormatSection &other) {
     if (has_conv != other.has_conv)
       return false;
 
diff --git a/libc/src/stdio/scanf_core/reader.h b/libc/src/stdio/scanf_core/reader.h
index d8647fe2c4ec7..f750c4341a8d7 100644
--- a/libc/src/stdio/scanf_core/reader.h
+++ b/libc/src/stdio/scanf_core/reader.h
@@ -38,10 +38,11 @@ class Reader {
 
 public:
   // TODO: Set buff_len with a proper constant
-  Reader(ReadBuffer *string_buffer) : rb(string_buffer) {}
+  LIBC_INLINE Reader(ReadBuffer *string_buffer) : rb(string_buffer) {}
 
-  Reader(void *stream, StreamGetc stream_getc_in, StreamUngetc stream_ungetc_in,
-         ReadBuffer *stream_buffer = nullptr)
+  LIBC_INLINE Reader(void *stream, StreamGetc stream_getc_in,
+                     StreamUngetc stream_ungetc_in,
+                     ReadBuffer *stream_buffer = nullptr)
       : rb(stream_buffer), input_stream(stream), stream_getc(stream_getc_in),
         stream_ungetc(stream_ungetc_in) {}
 
@@ -63,7 +64,7 @@ class Reader {
   // this is a file reader, else c is ignored.
   void ungetc(char c);
 
-  size_t chars_read() { return cur_chars_read; }
+  LIBC_INLINE size_t chars_read() { return cur_chars_read; }
 };
 
 } // namespace scanf_core

[jhuber6]

Unrelated, but I'm wondering what the libc consensus is for things like int vs int32 in most cases.

[michaelrj-google]

I don't know if we have an official ruling in our style guide. My opinion is that int is good for situations where I don't really care how wide the integer is (e.g. a loop counter). I use int32_t when I actually care about the exact width. I also never use long if I don't have to, since it's sometimes the same as int and sometimes the same as long long.