From 652db433e11899d5a9b3a6507810f311d4d1e934 Mon Sep 17 00:00:00 2001
From: Francisco Casas <fcasas@codeweavers.com>
Date: Wed, 17 Jul 2024 11:22:44 -0400
Subject: [PATCH] vkd3d-shader/hlsl: Parse string escape sequences.

---
 libs/vkd3d-shader/hlsl.l | 118 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 117 insertions(+), 1 deletion(-)

diff --git a/libs/vkd3d-shader/hlsl.l b/libs/vkd3d-shader/hlsl.l
index 5552bbc4..b4db142f 100644
--- a/libs/vkd3d-shader/hlsl.l
+++ b/libs/vkd3d-shader/hlsl.l
@@ -29,6 +29,8 @@
 
 static void update_location(struct hlsl_ctx *ctx, YYLTYPE *loc);
 
+static void apply_escape_sequences(char *str);
+
 #define YY_USER_ACTION update_location(yyget_extra(yyscanner), yyget_lloc(yyscanner));
 
 %}
@@ -53,7 +55,7 @@ RESERVED4               typename|union|using|virtual
 
 WS                      [ \t]
 NEWLINE                 (\n)|(\r\n)
-STRING                  \"[^\"]*\"
+STRING                  \"([^\"\\]|\\.)*\"
 IDENTIFIER              [A-Za-z_][A-Za-z0-9_]*
 
 ANY                     (.)
@@ -213,6 +215,7 @@ while                   {return KW_WHILE;               }
                             char *string = hlsl_strdup(ctx, yytext + 1);
 
                             string[strlen(string) - 1] = 0;
+                            apply_escape_sequences(string);
                             yylval->name = string;
                             return STRING;
                         }
@@ -301,6 +304,7 @@ while                   {return KW_WHILE;               }
 
                             BEGIN(pp_ignore);
                             string[strlen(string) - 1] = 0;
+                            apply_escape_sequences(string);
                             yylval->name = string;
                             return STRING;
                         }
@@ -350,3 +354,115 @@ int hlsl_lexer_compile(struct hlsl_ctx *ctx, const struct vkd3d_shader_code *hls
     yylex_destroy(ctx->scanner);
     return ret;
 }
+
+static void apply_escape_sequences(char *str)
+{
+    unsigned int i = 0, k = 0, r;
+
+    while (str[i])
+    {
+        unsigned char v = 0;
+
+        if (str[i] != '\\')
+        {
+            str[k++] = str[i];
+            ++i;
+            continue;
+        }
+
+        ++i;
+        VKD3D_ASSERT(str[i]);
+
+        if ('0' <= str[i] && str[i] <= '7')
+        {
+            /* octal, up to 3 digits. */
+            for (r = 0; r < 3; ++r)
+            {
+                char c = str[i];
+
+                if ('0' <= c && c <= '7')
+                {
+                    v = v << 3;
+                    v += c - '0';
+                    ++i;
+                }
+                else
+                    break;
+            }
+            str[k++] = v;
+            continue;
+        }
+
+        if (str[i] == 'x')
+        {
+            bool number = false;
+
+            /* hexadecimal */
+            ++i;
+            while (1)
+            {
+                char c = str[i];
+
+                if ('0' <= c && c <= '9')
+                {
+                    v = v << 4;
+                    v += c - '0';
+                    number = true;
+                    ++i;
+                }
+                else if ('a' <= c && c <= 'f')
+                {
+                    v = v << 4;
+                    v += c - 'a' + 10;
+                    number = true;
+                    ++i;
+                }
+                else if ('A' <= c && c <= 'F')
+                {
+                    v = v << 4;
+                    v += c - 'A' + 10;
+                    number = true;
+                    ++i;
+                }
+                else
+                    break;
+            }
+            if (number)
+                str[k++] = v;
+            else
+                str[k++] = 'x';
+            continue;
+        }
+
+        switch (str[i])
+        {
+            case 'a':
+                str[k++] = '\a';
+                break;
+            case 'b':
+                str[k++] = '\b';
+                break;
+            case 'f':
+                str[k++] = '\f';
+                break;
+            case 'n':
+                str[k++] = '\n';
+                break;
+            case 'r':
+                str[k++] = '\r';
+                break;
+            case 't':
+                str[k++] = '\t';
+                break;
+            case 'v':
+                str[k++] = '\v';
+                break;
+
+            default:
+                str[k++] = str[i];
+                break;
+        }
+        ++i;
+    }
+    str[k++] = '\0';
+}